Statement of Financial Position [Abstract] Statement [Table] Statement [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Series D, E, F, G and I Preferred Stock Series D, E, F, G and I Preferred Stock [Member] Series D, E, F, G and I Preferred Stock [Member] Series J convertible perpetual preferred stock Series J Preferred Stock [Member] Series J Preferred Stock [Member] Statement [Line Items] Statement [Line Items] Liquidation Preference (in dollars per share) Preferred Stock, Liquidation Preference Per Share Common Stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common Stock, shares authorized Common Stock, Shares Authorized Common Stock, shares issued Common Stock, Shares, Issued Common Stock, shares outstanding Common Stock, Shares, Outstanding Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Asset Class [Axis] Asset Class [Axis] Asset Class [Domain] Asset Class [Domain] Encumbered Assets Encumbered Assets [Member] Encumbered Assets [Member] Unencumbered Assets Unencumbered Assets [Member] Unencumbered Assets [Member] Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] Loan Participations Payable Loan Participations Payable [Member] Loan Participations Payable [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Real estate, net Real Estate Investment Property, Held for Use, Net Real Estate Investment Property, Held for Use, Net Real estate available and held for sale Real Estate Available and Held for Sale Carrying amount as of the balance sheet date of investments in land and buildings held for sale, including real estate considered to be inventory of the entity. Land and development, net Inventory, Real Estate, Land and Land Development Costs Loans receivable and other lending investments, net Loans and Other Lending Investments Amount representing an agreement for an unconditional promise by the maker to pay the Entity (holder) a definite sum of money at a future date, net of any write-downs taken for collection uncertainty on the part of the holder. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among myriad other features and characteristics. In addition, amount also includes total debt and equity financial instruments including: securities held-to-maturity and securities available-for-sale. Other investments Other Investments Cash and other assets Cash and Other Assets Sum of all assets excluding the Company's Total Portfolio Assets. Total assets Assets General reserves for loan losses Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment Loans receivable, net Loans Receivable, Net Investments, All Other Investments [Abstract] Equity Method Investments, Summarized Financial Information [Table] Equity Method Investments, Summarized Financial Information [Table] Equity Method Investments, Summarized Financial Information [Table] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Marina Palms Marina Palms, LLC [Member] Marina Palms, LLC [Member] Net Lease Venture Equity investment 1 [Member] Equity investment 1 [Member] Equity Method Investments, Summarized Financial Information [Line Items] Equity Method Investments, Summarized Financial Information [Line Items] [Line Items] for Equity Method Investments, Summarized Financial Information [Table] Equity Method Investment, Summarized Financial Information, Revenue Equity Method Investment, Summarized Financial Information, Revenue Equity Method Investment, Summarized Financial Information, Cost of Sales Equity Method Investment, Summarized Financial Information, Cost of Sales Equity Method Investment, Summarized Financial Information, Net Income (Loss) Attributable to Parent Entities Equity Method Investment, Summarized Financial Information, Net Income (Loss) Land and development [Abstract] Land and development [Abstract] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Real Estate Property Ownership [Axis] Real Estate Property Ownership [Axis] Real Estate Properties [Domain] Real Estate Properties [Domain] Land & Development Land [Member] Redemption Status [Axis] Redemption Status [Axis] Redemption Status [Axis] Redemption Status [Domain] Redemption Status [Domain] [Domain] for Redemption Status [Axis] Not Currently Redeemable Not Currently Redeemable [Member] Not Currently Redeemable [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Land and land development Land and land development Land and land development Less: accumulated depreciation Real Estate Investment Property, Accumulated Depreciation and Amortization Real Estate Investment Property, Accumulated Depreciation and Amortization Land and development, net Noncontrolling interest, description Noncontrolling Interest, Description Noncontrolling interest, decrease from redemptions or purchase of interests Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Noncontrolling interest, ownership percentage by parent Noncontrolling Interest, Ownership Percentage by Parent Land development revenue Land Sales Land development cost of sales Costs of Land Sales Costs of Land Sales Redeemable noncontrolling interests Redeemable Noncontrolling Interest, Equity, Carrying Amount Redeemable noncontrolling interest, equity, fair value Redeemable Noncontrolling Interest, Equity, Fair Value Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosures [Table] Derivative Instruments and Hedging Activities Disclosures [Table] Derivative, by Nature [Axis] Derivative, by Nature [Axis] Derivative, Name [Domain] Derivative, Name [Domain] Foreign exchange contracts Foreign Exchange Forward [Member] Interest rate cap Interest Rate Cap [Member] Interest rate swap Interest Rate Swap One [Member] Forward based contracts first in which two parties agree to swap periodic payments that are fixed at the outset of the swap contract with variable payments based on a market interest rate (index rate) over a specified period. Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Designated as hedge Designated as Hedging Instrument [Member] Not designated as hedge Not Designated as Hedging Instrument [Member] Derivative Instruments and Hedging Activities Disclosures [Line Items] Derivative Instruments and Hedging Activities Disclosures [Line Items] Schedule of fair value of derivative financial instruments as well as their classification on Consolidated Balance Sheets Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Schedule of derivative financial instruments on Consolidated Statements of Operations Derivative Instruments, Gain (Loss) [Table Text Block] Schedule of notional amounts of outstanding derivative positions Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Derivatives Derivative Instruments and Hedging Activities Disclosure [Text Block] Real Estate [Abstract] Schedule of real estate assets Schedule of Real Estate Assets [Table Text Block] Schedule of Real Estate Assets [Table Text Block] Land and Development Land and Development [Text Block] Land and Development [Text Block] Schedule of other investments and its proportionate share of results for equity method investments Equity Method Investments [Table Text Block] Summarized investee financial information Equity Method Investments, Summarized Financial Information [Table Text Block] [Table Text Block] for Equity Method Investments, Summarized Financial Information [Table] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Gross contributions made by the Company Defined Contribution Plan, Cost Recognized Statement of Stockholders' Equity [Abstract] Net income (loss) attributable to redeemable noncontrolling interest Net Income (Loss) Attributable to Redeemable Noncontrolling Interest Organization, Consolidation and Presentation of Financial Statements [Abstract] Business and Organization Business and Organization [Text Block] This element represents nature of an entity's business, the major products or services it sells or provides and its principal markets. It also discloses background of the entity. Income Statement [Abstract] Revenues: Revenues [Abstract] Operating lease income Operating Leases, Income Statement, Lease Revenue Interest income Interest and Fee Income, Loans, Commercial Other income Other Income Total revenues Revenues Costs and expenses: Costs and Expenses [Abstract] Interest expense Interest Expense Real estate expense Cost of Real Estate Held-for-Sale and Other Real Estate Owned This element represents the aggregate of the holding and operating costs related to real estate held for investment and the net costs related to other real estate owned. Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction General and administrative General and Administrative Expense Provision for (recovery of) loan losses Provision for Loan Losses Expensed Other expense Other Expenses Total costs and expenses Costs and Expenses Income (loss) before earnings from equity method investments and other items Income (Loss) from Continuing Operations before Income (Loss) from Equity Method Investments and Other Items This element represents the income (loss) from continuing operations before income (loss) from equity method investments, gains (losses) on early extinguishment of debt, and other items. Loss on early extinguishment of debt, net Gains (Losses) on Extinguishment of Debt Earnings from equity method investments Income (Loss) from Equity Method Investments Income (loss) from continuing operations before income taxes Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest Income tax (expense) benefit Income Tax Expense (Benefit) Income (loss) from continuing operations Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest Income from sales of real estate Gain (Loss) on Sale of Properties Net income (loss) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net (income) loss attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Net income (loss) attributable to iStar Inc. Net Income (Loss) Attributable to Parent Preferred dividends Preferred Stock Dividends, Income Statement Impact Net (income) loss allocable to HPU holders and Participating Security holders Net Income (Loss) Available to HPU Holders and Participating Security Holders, Basic Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period) available to HPU holders and Participating Security holders. Net income (loss) allocable to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Per common share data: Earnings Per Share, Basic and Diluted [Abstract] Income (loss) attributable to iStar Inc. from continuing operations—Basic and diluted (in dollars per share) Income (Loss) from Continuing Operations, Per Basic and Diluted Share Net income (loss) attributable to iStar Inc.—Basic and diluted (in dollars per share) Earnings Per Share, Basic and Diluted Weighted average number of common shares, Basic and diluted (in shares) Weighted Average Number of Shares Outstanding, Basic and Diluted Per HPU share data: Net Income (Loss) Attributable to Parent [Abstract] Income (loss) attributable to iStar Inc. from continuing operations, Basic and diluted (in dollars per share) Income (Loss) From Continuing Operations, Per HPU Basic and Diluted Share Income (Loss) From Continuing Operations, Per HPU Basic and Diluted Share Net income (loss) attributable to iStar Inc., Basic and diluted (in dollars per share) Earnings Per HPU Share, Basic and Diluted Earnings Per HPU Share, Basic and Diluted Weighted average HPU shares, Basic and diluted (in shares) Weighted Average Number of HPU Shares Outstanding Basic and Diluted The average number of shares of High Performance common stock (a separate class of stock) issued and outstanding that are used in calculating basic and diluted EPS. Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk [Table] Derivative Instruments, Gain (Loss) [Table] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Interest Expense Interest Expense [Member] Earnings from equity method investments Earnings from Equity Method Investments [Member] Earnings from Equity Method Investments [Member] Other Expense Other Expense [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest rate swaps Interest Rate Swap [Member] Foreign exchange contracts Foreign Exchange Contract [Member] Derivative financial instruments on consolidated statements of operations Derivative Instruments, Gain (Loss) [Line Items] Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Effective Portion) Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income into Earnings (Effective Portion) Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Amount of Gain or (Loss) Recognized in Income Derivative, Gain (Loss) on Derivative, Net Receivables [Abstract] Loans sold, carrying value Loans, Sold Loans Carrying Value Represents the carrying value of loans sold during the period. Realized investment gains (losses) Realized Investment Gains (Losses) Segment Reporting [Abstract] Schedule of financial measures for each segment based on which performance is evaluated Schedule of Segment Reporting Information, by Segment [Table Text Block] Reconciliation of segment profit to income (loss) Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block] Loan Participations Payable [Abstract] Loan Participations Payable [Abstract] Loan Participations Payable, net [Table] Loan Participations Payable, net [Table] Loan Participations Payable, net [Table] Loan Participation Payable One Loan Participation Payable One [Member] Loan Participation Payable One [Member] Loan Participation Payable Two Loan Participation Payable Two [Member] Loan Participation Payable Two [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Loan Participations Payable, net [Line Items] Loan Participations Payable, net [Line Items] [Line Items] for Loan Participations Payable, net [Table] Loan participations payable, carrying amount Transfers Accounted for as Loan Participations Payable, Assets, Carrying Amount Transfers Accounted for as Loan Participations Payable, Assets, Carrying Amount Loans receivable, commitments Loans Receivable, Commitments Loans Receivable, Commitments Loans receivable, funded commitment Loans Receivable, Funded Commitment Loans Receivable, Funded Commitment Proceeds from loan participations payable Proceeds from Loan Participations Payable Proceeds from Loan Participations Payable Unfunded commitments Unfunded Commitments Represents certain off-balance sheet unfunded commitments of the entity. Loans receivable with fixed rates of interest Investment Fixed Interest Rate Investment Fixed Interest Rate Loans receivable, amount funded to borrower Loans Receivable, Amount Funded to Borrower Loans Receivable, Amount Funded to Borrower Description of variable rate basis Loan Participation Payable, Description of Variable Rate Basis Loan Participation Payable, Description of Variable Rate Basis Basis spread on variable rate Loan Participation Payable, Basis Spread on Variable Rate Loan Participation Payable, Basis Spread on Variable Rate Debt instrument, basis spread on variable rate Loan Participation Payable, Basis Spread on Variable Rate, During Period Loan Participation Payable, Basis Spread on Variable Rate, During Period Loan participations payable, net Loan Participations Payable, net Loan Participations Payable, net Schedule of Debt Securities [Table] Schedule of Available-for-sale Securities [Table] Debt Security [Axis] Debt Security [Axis] Major Types of Debt Securities [Domain] Major Types of Debt Securities [Domain] Municipal Debt Securities Municipal Bonds [Member] Corporate Debt Securities Corporate Debt Securities [Member] Schedule of Debt Securities [Line Items] Schedule of Available-for-sale Securities [Line Items] Available-for-Sale Securities Available-for-sale Securities, Fair Value to Amortized Cost Basis [Abstract] Face Value Available-for-sale Securities, Debt Security, Face Amount Available-for-sale Securities, Debt Security, Face Amount Amortized Cost Basis Available-for-sale Debt Securities, Amortized Cost Basis Net Unrealized Gain (Loss) Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax Estimated Fair Value Available-for-sale Securities, Debt Securities, Fair Value Available-for-sale Securities, Debt Securities, Fair Value Net Carrying Value Available-for-sale Securities, Debt Securities Held-to-Maturity Securities Held-to-maturity Securities, Debt Maturities [Abstract] Face Value Held-to-maturity Securities, Debt Security, Face Amount Held-to-maturity Securities, Debt Security, Face Amount Amortized Cost Basis Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment Estimated Fair Value Held-to-maturity Securities, Fair Value Net Carrying Value Held-to-maturity Securities Investments, Debt and Equity Securities [Abstract] Investments, Debt and Equity Securities [Abstract] Face Value Debt Securities, Face Amount Debt Securities, Face Amount Amortized Cost Basis Debt Securities, Amortized Cost Basis Debt Securities, Amortized Cost Basis Net Unrealized Gain (Loss) Debt Securities, Unrealized Holding Gains Debt Securities, Unrealized Holding Gains Estimated Fair Value Debt Securities, Fair Value Debt Securities, Fair Value Net Carrying Value Debt Securities, Net Carrying Amount Debt Securities, Net Carrying Amount Commitments and Contingencies Disclosure [Abstract] Percentage of capital committed to strategic investments that may be drawn down Percentage of Capital Committed that May be Drawn Down Represents the percentage of capital committed to strategic investments by the entity that may be drawn down. Other Commitments [Table] Other Commitments [Table] Unfunded Financial Commitments [Axis] Unfunded Financial Commitments [Axis] Information by arrangements in which the entity has committed to off-balance sheet financial commitments. Unfunded Financial Commitments [Domain] Unfunded Financial Commitments [Domain] This item is intended to be populated, by the entity, with Members identifying each off-balance sheet financial commitment. Loans and Other Lending Investments Loans Receivable [Member] Real Estate Real Estate [Member] Other Investments Other Investments [Member] Other Commitments [Line Items] Other Commitments [Line Items] Performance-Based Commitments Performance-Based Commitments Represents the off-balance sheet unfunded maximum amount of funds for construction and development loans and build-outs of space in net lease assets over a period of time if and when the borrowers and tenants meet established milestones and other performance criteria. Strategic Investments Other Commitments Represents the off-balance sheet maximum other commitments of the entity. Discretionary Fundings Discretionary Fundings Represents the off-balance sheet maximum amount of potential additional fundings which the entity will make available to a borrower or tenant for an expansion or addition to a project if it approves of the expansion or addition at its sole discretion. Total Transaction Type [Axis] Transaction Type [Axis] Transaction [Domain] Transaction [Domain] Real Estate Sales Real Estate Sales [Member] Real Estate Sales [Member] Acres of real estate property Area of Real Estate Property Unpaid purchase price Unpaid Purchase Price Unpaid Purchase Price Unpaid purchase price, interest rate Unpaid Purchase Price, Interest Rate Unpaid Purchase Price, Interest Rate Court settlement payment period Court Settlement Payment Period Court Settlement Payment Period Ownership percentage by noncontrolling owners Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] 3.875% senior notes Unsecured Notes 3 point 875 Percent Senior Notes Due July 2016 [Member] Unsecured Notes 3 point 875 Percent Senior Notes Due July 2016 [Member] Unsecured Debt Unsecured Debt [Member] Secured Debt Secured Debt [Member] Repayments of debt Repayments of Debt Maturities of Long-term Debt [Abstract] Maturities of Long-term Debt [Abstract] 2016 (remaining nine months) Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year 2017 Long-term Debt, Maturities, Repayments of Principal in Year Two 2018 Long-term Debt, Maturities, Repayments of Principal in Year Three 2019 Long-term Debt, Maturities, Repayments of Principal in Year Four 2020 Long-term Debt, Maturities, Repayments of Principal in Year Five Thereafter Long-term Debt, Maturities, Repayments of Principal after Year Five Total principal maturities Long-term Debt, Gross Unamortized discounts and deferred financing costs, net Debt Instrument, Unamortized Discount (Premium), Net Debt Instrument, Unamortized Discount (Premium) and Deferred Financing Costs, Net Debt Instrument, Unamortized Discount (Premium) and Deferred Financing Costs, Net Debt Instrument, Unamortized Discount (Premium) and Deferred Financing Costs, Net Total debt obligations, net Long-term Debt Income (loss) from continuing operations attributable to parent Income (Loss) from Continuing Operations Attributable to Parent Other Assets and Other Liabilities [Abstract] -- None. No documentation exists for this element. -- Schedule of Operating Leased Assets [Table] Schedule of Operating Leased Assets [Table] Land Parcel Landanddevelopment1 [Member] Landanddevelopment1 [Member] Net Lease Asset One Net Lease Asset One [Member] Net Lease Asset One [Member] Depreciation and Amortization Depreciation and Amortization [Member] Depreciation and Amortization [Member] Operating Leased Assets [Line Items] Operating Leased Assets [Line Items] Intangible assets, net Finite-Lived Intangible Assets, Net Restricted cash Restricted Cash and Cash Equivalents Other receivables Other Receivables Leasing costs, net Deferred Costs, Leasing, Net Furniture Fixtures, Leasehold Improvements and Software Costs, Net Furniture Fixtures, Leasehold Improvements and Software Costs, Net Furniture Fixtures, Leasehold Improvements and Software Costs, Net Corporate furniture, fixtures and equipment, net Furniture Fixtures and Leasehold Improvements, Net Net amount, at the balance sheet date, of long-lived, depreciable assets commonly used in offices that are additions or improvements to assets held under lease arrangement. Deferred expenses and other assets, net Deferred Expenses and Other Assets Net This element represents net amount of other deferred expenses and other assets capitalized at the end of the reporting period. Lease incentive asset Other Finite-Lived Intangible Assets, Gross Intangible assets, accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Amortization of above market lease Amortization of Above Market Lease and Lease Incentive Asset Amortization of Above Market Lease and Lease Incentive Asset Amortization of intangible assets Amortization of Intangible Assets Receivable related to the sale of land parcel Other Assets Accumulated amortization on leasing costs Deferred Costs, Leasing, Accumulated Amortization Accumulated depreciation on corporate furniture, fixtures and equipment Accumulated Depreciation Furniture Fixtures and Leasehold Improvements The cumulative amount of depreciation, related to leasehold improvements, corporate furniture, fixtures and equipment that has been recognized in the income statement. Earnings Per Share [Abstract] Reconciliation of income (loss) from continuing operations used in the basic and diluted EPS calculations Schedule of Income (Loss) from Continuing Operations Used in Basic and Diluted Earnings Per Share Calculations [Table Text Block] Tabular disclosure of the reconciliation of income (loss) from continuing operations used in the basic and diluted EPS calculations. Schedule of earnings per share allocable to common shares and HPU shares Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of anti-dilutive shares Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Accounting Policies [Abstract] New accounting pronouncements New Accounting Pronouncements, Policy [Policy Text Block] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] As Reported Scenario, Previously Reported [Member] Change Scenario, Adjustment [Member] As Adjusted Scenario, Actual [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Additional paid-in capital Additional Paid in Capital Common stock Common Stock, Value, Issued Treasury stock, at cost Treasury Stock, Value APIC_CommonStock_TreasuryStock APIC_CommonStock_TreasuryStock The sum of APIC, common stock and treasury stock. Total equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Equity [Abstract] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Series D Series D Preferred Stock [Member] Series E Series E Preferred Stock [Member] Series F Series F Preferred Stock [Member] Series G Series G Preferred Stock [Member] Series I Series I Preferred Stock [Member] Outstanding nonredeemable series I preferred stock or outstanding series I preferred stock. Classified within stockholders' equity if nonredeemable or redeemable solely at the option of the issuer. Classified within temporary equity if redemption is outside the control of the issuer. Series J Maximum Maximum [Member] Minimum Class of Stock [Line Items] Class of Stock [Line Items] Shares Issued and Outstanding Preferred Stock Shares Issued and Outstanding Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury) and held by stockholders. May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt and preferred shares that have been repurchased. Par Value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Rate per Annum Preferred Stock, Dividend Rate, Percentage Equivalent to Fixed Annual Rate (in dollars per share) Preferred Stock, Dividend Rate, Per-Dollar-Amount Number of days in year used in the computation of preferred stock dividends for any partial dividend period Preferred Stock, Dividends Computation of Dividends Payable for Any Partial Dividend Period, Number of Days in Year Represents the number of days in year used in the computation of preferred stock dividends for any partial dividend period. Number of months used in the computation of preferred stock dividends for any partial dividend period Preferred Stock, Dividends Computation of Dividends Payable for Any Partial Dividend Period, Number of Months Represents the number of months used in the computation of preferred stock dividends for any partial dividend period. Number of days in month, dividends computation of dividends payable for any partial dividend period Preferred Stock, Dividends Computation of Dividends Payable for Any Partial Dividend Period, Number of Days in Month Represents the number of days in month used in the computation of preferred stock dividends for any partial dividend period. Number of days prior to dividend payment date that Board of Directors may elect to designate as the payment date Preferred Stock Dividends, Number of Days Prior to Dividend Payment Date That Board of Directors May Elect to Designate as Payment Date Represents the number of days prior to dividend payment date that Board of Directors may elect to designate as the payment date. Dividends declared and paid Dividends declared and paid Aggregate dividends declared and paid during the period for each share of common stock outstanding. Amount of preferred dividends in arrears Preferred Stock, Amount of Preferred Dividends in Arrears Shares issued upon conversion Convertible Preferred Stock, Shares Issued upon Conversion Conversion price per share (in dollars per share) Convertible Preferred Stock, Conversion Price Per Share Convertible Preferred Stock, Conversion Price Per Share Redemption price as a percentage of liquidation preference Preferred Stock, Redemption Price as a Percentage of Liquidation Preference Preferred Stock, Redemption Price as a Percentage of Liquidation Preference Schedule of deferred expenses and other assets, net Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block] Schedule of accounts payable, accrued expenses and other liabilities Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] Schedule of deferred tax assets and liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Derivative [Table] Derivative [Table] Sells Indian rupee (INR)/Buys USD Forward Sells INR Buys USD Forward [Member] Sells INR Buys USD Forward [Member] Sells euro (EUR)/Buys USD Forward Sells EUR Buys USD Forward [Member] Represents the Sells EUR /Buy USD Forward Foreign currency contract member. Sells pound sterling (GBP)/Buys USD Forward Sells GBP Buys USD Forward [Member] Represents the Sells GBP/ Buy USD Forward Foreign currency contract member. Derivative [Line Items] Derivative [Line Items] Derivative, Notional Amount Derivative, Notional Amount Foreign currency transaction gain (loss) Foreign Currency Transaction Gain (Loss), before Tax Reconciliation of segment profit (loss) to income (loss) from continuing operations Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Abstract] Segment profit Segment Profit (Loss) Amount of profit or loss during the period recognized by the reportable segment. Less: (Provision for) loan losses Provision for Loan and Lease Losses Less: Stock-based compensation expense Allocated Share-based Compensation Expense Less: Depreciation and amortization Segment Depreciation and Amortization Segment Depreciation and Amortization Less: Income tax (expense) benefit Segment Income Tax (Benefit) Segment Income Tax (Benefit) Less: Loss on early extinguishment of debt, net Line of Credit Facility [Table] Line of Credit Facility [Table] 2015 Revolving Credit Facility Secured Credit Facility Revolver Due March 2018 [Member] Secured Credit Facility Revolver Due March 2018 [Member] 2012 Secured Credit Facilities Secured Credit Facilities, 2012 [Member] Represents the secured credit facility of the entity entered into in 2012. 2012 Tranche A-1 Facility Secured Credit Facilities Tranche A-1 Facility Due March, 2016 [Member] Represents the Secured Tranche A-1 Facility of the entity maturing in March 2016. 2012 Tranche A-2 Facility Secured Credit Facilities Tranche A-2 Facility Due March, 2017 [Member] Represents the Secured Tranche A-2 Facility of the entity maturing in March 2017. Maximum Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] London Interbank Offered Rate (LIBOR) London Interbank Offered Rate (LIBOR) [Member] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Line of credit facility, maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Commitment fee percentage Line of Credit Facility, Unused Capacity, Commitment Fee Percentage Line of Credit Facility, interest rate during period Line of Credit Facility, Interest Rate During Period Converted term loan, term Converted Term Loan, Term Converted Term Loan, Term Debt instrument, face amount Debt Instrument, Face Amount Number of tranches Number of Tranches under Term Loans Represents the number of tranches under term loans. Variable interest rate, basis Debt Instrument, Description of Variable Rate Basis Variable interest rate, spread Debt Instrument, Basis Spread on Variable Rate Percentage of par credit facilities were issued at Line of Credit Facility Issue Price as Percentage of Principal Amount Represents the percentage of principal amount used in the computation of issue price for the line of credit facility. Stated interest rates Debt Instrument, Interest Rate, Stated Percentage Term loans collateralized by net lease assets Secured Term Loans Collateralized by Loans Net Lease Assets Due Through 2026 [Member] Secured Term Loans Collateralized by net lease assets due through 2026 debt instrument of the entity. Total secured credit facilities and term loans Secured Credit Facilities [Member] Represents the secured credit facility of the entity. 5.875% senior notes Unsecured Notes 5 point 875 Percent Senior Notes Due March 2016 [Member] Unsecured Notes 5.875% due March 2016 senior notes debt instrument of the entity. 3.00% senior convertible notes Senior Convertible Three Point Zero Percent Notes Due November 2016 [Member] Senior Convertible Three Point Zero Percent Notes Due November 2016 [Member] 1.50% senior convertible notes Senior Convertible One Point 50 Percent Notes Due November 2016 [Member] Senior Convertible One Point 50 Percent Notes Due November 2016 [Member] 5.85% senior notes Unsecured Notes 5 point 85 Percent Senior Notes Due March 2017 [Member] Unsecured Notes 5.85% due March 2017 senior notes debt instrument of the entity. 9.00% senior notes Unsecured Notes Nine Percent Senior Notes Due June 2017 [Member] Unsecured Notes Nine Percent Senior Notes Due June 2017 [Member] 4.00% senior notes Unsecured Notes Four Percent Senior Notes Due November 2017 [Member] Unsecured Notes Four Percent Senior Notes Due November 2017 [Member] 7.125% senior notes Unsecured Notes Seven Point One Two Five Percent Senior Notes Due February 2018 [Member] Unsecured Notes Seven Point One Two Five Percent Senior Notes Due February 2018 [Member] 4.875% senior notes Unsecured Notes 4 point 875 Percent Senior Notes Due July 2018 [Member] Unsecured Notes 4 point 875 Percent Senior Notes Due July 2018 [Member] 5.00% senior notes Unsecured Notes Five Percent Senior Notes Due July 2019 [Member] Unsecured Notes Five Percent Senior Notes Due July 2019 [Member] 6.50% senior notes Unsecured Notes Six Point Five Percent Senior Notes Due July 2021 [Member] Unsecured Notes Six Point Five Percent Senior Notes Due July 2021 [Member] Unsecured Notes Unsecured Senior Notes [Member] Represents the unsecured senior notes of the entity. Other debt obligations Other Debt Securities, Due October 2035 [Member] Represents other debt obligations due in October, 2035. Federal Funds Effective Swap Rate Federal Funds Effective Swap Rate [Member] Debt Instrument, Interest Rate Category [Axis] Debt Instrument, Interest Rate Category [Axis] Debt Instrument, Interest Rate Category [Axis] Debt Instrument, Interest Rate Category [Domain] Debt Instrument, Interest Rate Category [Domain] [Domain] for Debt Instrument, Interest Rate Category [Axis] Interest Rate Category One Interest Rate Category One [Member] Interest Rate Category One [Member] Interest Rate Category Two Interest Rate Category Two [Member] Interest Rate Category Two [Member] Name of Property [Axis] Name of Property [Axis] Name of Property [Domain] Name of Property [Domain] Property One Property One [Member] Property One [Member] Total debt obligations Debt discounts and deferred financing costs, net Stated Interest Rates Stated interest rate, minimum Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum Stated interest rate, maximum Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum Debt instrument, margin Debt Instrument, Margin Debt Instrument, Margin Convertible debt conversion ratio Debt Instrument, Convertible, Conversion Ratio Weighted average interest rate Debt, Weighted Average Interest Rate Convertible debt conversion price Debt Instrument, Convertible, Conversion Price Interest costs capitalized Interest Costs Capitalized Debt Obligations, net Debt Disclosure [Text Block] Schedule of Financing Receivable, Allowance for Credit Losses [Table] Schedule of Financing Receivable, Allowance for Credit Losses [Table] Evaluation Type [Axis] Evaluation Type [Axis] Evaluation Type [Axis] Evaluation Type [Domain] Evaluation Type [Domain] [Domain] for Evaluation Type [Axis] Individually Evaluated for Impairment Individually Evaluated for Impairment [Member] Individually Evaluated for Impairment [Member] Collectively Evaluated for Impairment Collectively Evaluated for Impairment [Member] Collectively Evaluated for Impairment [Member] Financing Receivable, Allowance for Credit Losses [Line Items] Financing Receivable, Allowance for Credit Losses [Line Items] Loans Financing Receivable, Gross Less: Reserve for loan losses Financing Receivable, Allowance for Credit Losses Collectively Evaluated for Impairment Total Financing Receivable, Net Unamortized discounts, premiums, deferred fees and costs Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Preferred Stock Preferred Stock [Member] Series J Preferred Stock HPU's HPU [Member] This element represents HPU's (High Performance Units). Common Stock at Par Common Stock [Member] Additional Paid-In Capital Additional Paid-in Capital [Member] Retained Earnings (Deficit) Retained Earnings [Member] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Noncontrolling Interests Noncontrolling Interest [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning Balance Dividends declared—preferred Dividends, Preferred Stock, Cash Issuance of stock/restricted stock unit amortization, net Issuance of Stock and Restricted Stock Unit Amortization Net Value of stock related to restricted stocks awards issued during the period and the amortization of restricted stock units and other restricted stock activity. Net income (loss) for the period Profit (Loss) Adjusted for Income (Loss) Attributable to Redeemable Noncontrolling Interest The consolidated profit or loss for the period including the portion attributable to the noncontrolling interest, net of income taxes and income (loss) attributable to redeemable noncontrolling interest. Change in accumulated other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Repurchase of stock Stock Repurchased During Period, Value Change in additional paid in capital attributable to redeemable noncontrolling interest Adjustments to Additional Paid in Capital, Other Contributions from noncontrolling interests Noncontrolling Interest, Increase from Subsidiary Equity Issuance Distributions to noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Ending Balance ASSETS Assets [Abstract] Real estate, at cost Real Estate Investment Property, Held for Use, Gross Real Estate Investment Property, Held for Use, Gross Less: accumulated depreciation Real Estate Investment Property, Accumulated Depreciation Real estate, net Total real estate Real Estate Investment Property, Net Loans receivable and other lending investments, net Other investments Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Accrued interest and operating lease income receivable, net Accrued Interest and Operating Lease Income Receivable Net This element represents interest, rents, ancillary and operating lease income earned but not yet received by the entity on its loans and other lending investments and net lease assets. Deferred operating lease income receivable, net Deferred Rent Receivables, Net Deferred expenses and other assets, net LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Liabilities: Liabilities [Abstract] Accounts payable, accrued expenses and other liabilities Accounts Payable and Accrued Liabilities Loan participations payable, net Debt obligations, net Total liabilities Liabilities Commitments and contingencies Commitments and Contingencies Equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] iStar Inc. shareholders' equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred Stock Preferred Stock, Value, Issued Common Stock, $0.001 par value, 200,000 shares authorized, 75,441 and 81,109 shares issued and outstanding as of March 31, 2016 and December 31, 2015, respectively Retained earnings (deficit) Retained Earnings (Accumulated Deficit) Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Total iStar Inc. shareholders' equity Stockholders' Equity Attributable to Parent Noncontrolling interests Stockholders' Equity Attributable to Noncontrolling Interest Total liabilities and equity Liabilities and Equity Schedule of Operating Lease Allowance for Doubtful Accounts [Table] Schedule of Operating Lease Allowance for Doubtful Accounts [Table] Schedule of Operating Lease Allowance for Doubtful Accounts [Table] Receivable Type [Axis] Receivable Type [Axis] Receivable [Domain] Receivable [Domain] Real Estate Tenant Receivables Real Estate Tenant Receivables [Member] Real Estate Tenant Receivables [Member] Deferred Operating Lease Deferred Operating Lease [Member] Deferred Operating Lease [Member] Schedule of Operating Lease Allowance for Doubtful Accounts [Line Items] Schedule of Operating Lease Allowance for Doubtful Accounts [Line Items] [Line Items] for Schedule of Operating Lease Allowance for Doubtful Accounts [Table] Allowance for doubtful accounts receivable Allowance for Doubtful Accounts Receivable Schedule of Real Estate Properties [Table] Schedule of Real Estate Properties [Table] Operating Lease Income Operating Lease Income [Member] Operating Lease Income [Member] Real Estate Properties [Line Items] Real Estate Properties [Line Items] Tenant reimbursements Tenant Reimbursements Other Investments Other Investments [Text Block] This element represents the disclosures for equity method investments, cost method investments, and marketable securities. Loan Participations Payable, net Transfers and Servicing of Financial Assets [Text Block] Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] Variable Interest Entities by Classification of Entity [Axis] Variable Interest Entities [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] Consolidated VIEs Variable Interest Entity, Primary Beneficiary, Aggregated Disclosure [Member] Unconsolidated VIEs Variable Interest Entity, Not Primary Beneficiary [Member] Variable interest entities Variable Interest Entity [Line Items] Total revenues and total expenses related to consolidated VIEs Variable Interest Entity, Measure of Activity [Abstract] Variable interest entity, consolidated, carrying amount, assets Variable Interest Entity, Consolidated, Carrying Amount, Assets Variable interest entity, consolidated, carrying amount, liabilities Variable Interest Entity, Consolidated, Carrying Amount, Liabilities Carrying value of the investments Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net Variable interest entity unfunded commitment Variable Interest Entity Unfunded Commitment The amount of unfunded commitments that the entity has to the Variable Interest Entity. Dividends [Abstract] Dividends [Abstract] Minimum percentage of taxable income (excluding net capital gains) to be distributed in order to qualify as REIT Minimum Percentage of Taxable Income Excluding Capital Gains to be Distributed to Qualify as REIT Represents the minimum percentage of taxable income (excluding capital gains) to be distributed in order to qualify as REIT. Percentage of taxable income (including net capital gains) to be distributed in order to qualify as REIT Percentage of Taxable Income Including Capital Gains to be Distributed to Qualify as REIT Represents the percentage of taxable income (including capital gains) to be distributed in order to qualify as REIT. Operating loss carryforwards Operating Loss Carryforwards Other Assets and Other Liabilities Other Assets and Other Liabilities Disclosure [Text Block] This element may be used as a single block of text to encapsulate the entire disclosure for other assets and other liabilities including data and tables. Schedule of cumulative redeemable and convertible perpetual preferred stock outstanding by series Schedule of Stock by Class [Table Text Block] Accumulated other comprehensive income (loss) reflected in the Company's shareholders' equity Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments Operating Segments [Member] Corporate/Other Corporate, Non-Segment [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Real Estate Finance Real Estate Lending [Member] Represents the Real Estate Lending segment that includes all of the Company's activities related to senior and mezzanine real estate debt and corporate capital investments. Net Lease Net Leasing [Member] Represents the Net Leasing segment that includes all of the company's activities related to the ownership and leasing of corporate facilities. Operating Properties Operating Property [Member] Operating Property [Member] Corporate/Other Corporate and Other [Member] Segment Reporting Segment Reporting Information [Line Items] Number of reportable segments Number of Reportable Segments Earnings (loss) from equity method investments Total revenue and other earnings Revenue and Other Earnings The sum of the Company's total revenue and other earnings related to the Company's business segments. Real estate expense Land development cost of sales Other expense Allocated interest expense Interest Expense Including Discontinued Operations The cost of borrowed funds accounted for as interest that was charged against earnings during the period including amounts presented in discontinued operations. Allocated general and administrative General and Administrative Expense Excluding Stock-based Compensation Expense The aggregate total of expenses of managing and administering the affairs of the entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line, excluding stock-based compensation expense. Segment profit (loss) Depreciation and amortization Depreciation and Amortization Including Discontinued Operations The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production including amounts presented in discontinued operations. Capitalized expenditures Real Estate and Accumulated Depreciation Costs, Capitalized Subsequent to Acquisition Carrying amount as of the balance sheet date of costs that were capitalized after acquisition, including property improvements and carrying costs (for example, real estate taxes and insurance), but excluding the initial purchase price. Real estate available and held for sale Land and development Total portfolio assets Portfolio Assets The aggregate of Total real estate, loans receivable, net and Other investments. Cash and other assets Statement of Cash Flows [Abstract] Land Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income (loss) Adjustments to reconcile net income (loss) to cash flows from operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Provision for (recovery of) loan losses Payments for withholding taxes upon vesting of stock-based compensation Stock Based Compensation Shares Withheld For Employee Taxes Upon Vesting Shares withheld for employee taxes upon vesting of stock-based compensation arrangements. Non-cash expense for stock-based compensation Share-based Compensation Amortization of discounts/premiums and deferred financing costs on debt obligations, net Amortization of Financing Costs and Discounts Amortization of discounts/premiums and deferred interest on loans, net Amortization of Discounts or Premiums Deferred Interest and Costs on Lending Investments The component of interest income representing the noncash interest earned in the period on loans and other lending investments as well as the amortization of deferred costs or fees over the related loan investments. Earnings from equity method investments Distributions from operations of other investments Proceeds from Equity Method Investment, Dividends or Distributions Deferred operating lease income Straight Line Rent Income from sales of real estate Gain (Loss) on Sale of Properties, Cash Flow Impact Gain (Loss) on Sale of Properties, Cash Flow Impact Land development in excess of cost of sales Other operating activities, net Other Operating Activities, Cash Flow Statement Changes in assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Changes in accrued interest and operating lease income receivable, net Increase (Decrease) in Accrued Interest and Operating Lease and Income Receivable This element represents net change during the reporting period in accrued interest income and operating lease income receivable earned but not yet received. Changes in deferred expenses and other assets, net Increase (Decrease) in Prepaid Expense and Other Assets Changes in accounts payable, accrued expenses and other liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Cash flows used in operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Originations and fundings of loans receivable, net Payments to Acquire Notes Receivable Capital expenditures on real estate assets Payments for Capital Improvements Capital expenditures on land and development assets Payment for Capital Expenditures on Land and Development Assets Payment for Capital Expenditures on Land and Development Assets Repayments of and principal collections on loans receivable and other lending investments, net Proceeds from Principal Repayments on Portfolio of Assets Proceeds from Principal Repayments on Portfolio of Assets Net proceeds from sales of loans receivable Proceeds from Sale of Loans Held-for-investment Net proceeds from sales of real estate Proceeds from Sale of Real Estate Proceeds from Sale of Real Estate Held-for-investment Proceeds from Sale of Real Estate Held-for-investment Proceeds from Sale of Land Held-for-investment Proceeds from Sale of Land Held-for-investment Net proceeds from sales of land and development assets Proceeds from Sale of Equity Method Investments Distributions from other investments Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital Contributions to other investments Payments for Contributions to Unconsolidated Entities This element represents payments for contributions to unconsolidated entities. Changes in restricted cash held in connection with investing activities Increase (Decrease) in Restricted Cash Other investing activities, net Payments for (Proceeds from) Other Investing Activities Cash flows used in investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Borrowings from debt obligations Proceeds from Issuance of Debt Repayments of debt obligations Preferred dividends paid Payments of Ordinary Dividends, Preferred Stock and Preference Stock Repurchase of stock Payments for Repurchase of Common Stock Other financing activities, net Proceeds from (Payments for) Other Financing Activities Cash flows from (used in) financing activities Net Cash Provided by (Used in) Financing Activities Effect of exchange rate changes on cash Effect of Exchange Rate on Cash and Cash Equivalents Changes in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Earnings Per Share Earnings Per Share [Text Block] Segment Reporting Segment Reporting Disclosure [Text Block] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Schedule of changes in accounting principal Schedule of Error Corrections and Prior Period Adjustments [Table Text Block] Stock-Based Compensation Plans and Employee Benefits Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Statement of Comprehensive Income [Abstract] Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax [Abstract] Reclassification of (gains)/losses on available-for-sale securities into earnings upon realization Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Reclassification of (gains)/losses on cash flow hedges into earnings upon realization Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Unrealized gains/(losses) on available-for-sale securities Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Unrealized gains/(losses) on cash flow hedges Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Unrealized gains/(losses) on cumulative translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax Other comprehensive income (loss) Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive (income) loss attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive income (loss) attributable to iStar Inc. Comprehensive Income (Loss), Net of Tax, Attributable to Parent Schedule of the Company's loans and other lending investments by class Schedule of Loans and Other Lending Investments [Table Text Block] Tabular disclosure of loans and other lending investments by class. Includes the gross carrying value of a loan by class, reserve for loan losses, and the net carrying value as of the Balance Sheet date. Schedule of changes in the Company's reserve for loan losses Allowance for Credit Losses on Financing Receivables [Table Text Block] Schedule of recorded investment in loans and associated reserve for loan losses Schedule of Investment in Loans and Associated Reserve for Loan Losses [Table Text Block] Tabular disclosure of the Company's recorded investment in loans and the associated reserve for loan losses. Schedule of investment in performing loans, presented by class and by credit quality, as indicated by risk rating Financing Receivable Credit Quality Indicators [Table Text Block] Schedule of recorded investment in loans, aged by payment status and presented by class Past Due Financing Receivables [Table Text Block] Schedule of recorded investment in impaired loans, presented by class Impaired Financing Receivables [Table Text Block] Schedule of average recorded investment in impaired loans and interest income recognized, presented by class Impaired Financing Receivables Average Recorded Investment and Interest Income Recognized [Table Text Block] Tabular disclosure by class of the average recorded investment in impaired loans and the related interest income recognized. Schedule of other lending investments - securities Marketable Securities [Table Text Block] Deferred Expenses and Other Assets, Net Deferred Expenses and Other Assets, Net [Member] Deferred Expenses and Other Assets, Net [Member] Forward Contracts Forward Contracts [Member] Collateral Posted For Hedges Collateral Posted For Hedges Collateral Posted For Hedges Credit Derivative, Maximum Exposure, Undiscounted Derivative Liability, Fair Value, Amount Offset Against Collateral Income (loss) from continuing operations Net (income) loss attributable to noncontrolling interests Income (loss) from continuing operations attributable to iStar Inc. and allocable to common shareholders, HPU holders and Participating Security Holders for basic earnings per common share Income (Loss) from Continuing Operations Attributable to Parent and Available to Common Shareholders Hpu Holders and Participating Security Holders The income or loss from continuing operations during the period which is attributable to the parent and is available to common shareholders, HPU holders and Participating Security holders. Real Estate Real Estate Disclosure [Text Block] Accumulated other comprehensive income (loss) reflected in the Company's shareholders' equity Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Unrealized gains (losses) on available-for-sale securities Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Unrealized gains (losses) on cash flow hedges Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax Unrealized losses on cumulative translation adjustment Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax Accumulated other comprehensive income (loss) Interest Expense Reclassification of (gains)/losses on cash flow hedges into earnings upon realization Net Lease Net Lease Asset [Member] Represents details pertaining to net lease assets. Land and land improvements, at cost Land and Land Improvements Buildings and improvements, at cost Investment Building and Building Improvements Less: accumulated depreciation Document and Entity Information [Abstract] -- None. No documentation exists for this element. -- Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Held for Sale Reclassification [Axis] Held for Sale Reclassification [Axis] Held for Sale Reclassification [Axis] Held for Sale Reclassification [Domain] Held for Sale Reclassification [Domain] [Domain] for Held for Sale Reclassification [Axis] Executed Contract with Third Party Executed Contract with Third Party [Member] Executed Contract with Third Party [Member] Residential Operating Properties Residential Operating Properties [Member] Residential Operating Properties [Member] Number of real estate properties sold Number of Real Estate Properties Sold Number of Real Estate Properties Sold Property transferred to held for sale, carrying value Property Transferred to Held for Sale, Aggregate, Carrying Value Property Transferred to Held for Sale, Aggregate, Carrying Value Schedule of debt obligations Schedule of Debt [Table Text Block] Schedule of future scheduled maturities of outstanding long-term debt obligations, net Schedule of Maturities of Long-term Debt [Table Text Block] Schedule of carrying value of encumbered assets by asset type Schedule of Encumbered Assets [Table Text Block] Tabular disclosure of assets which were encumbered with mortgages or pledged as collateral for borrowings at the end of the reporting period(s). Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Other real estate equity investments Other Real Estate Equity Investments [Member] Other Real Estate Equity Investments [Member] Real Estate Equity Investment Real Estate Equity Investment Two [Member] Real Estate Equity Investment Two [Member] Net Lease Venture iStar Net Lease I LLC [Member] iStar Net Lease I LLC [Member] Operating Properties Loans Receivable and Other Lending Investments, Net Loans Receivable and Other Lending Investments, Net [Member] Loans Receivable and Other Lending Investments, Net [Member] Other Income Other Income [Member] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] iStar's ownership percentage Equity Method Investment, Ownership Percentage Equity method investments, carrying value Equity Method Investments Loans Commitments,Related Party Loans Commitments,Related Party Loans Commitments,Related Party Loans receivable, commitments, related party Loans Receivable, Commitments, Related Party Loans Receivable, Commitments, Related Party Loans receivable, related party Loans Receivable, Related Party Loans Receivable, Related Party Partners' capital account, contributions Partners' Capital Commitment Partners' Capital Commitment Equity method investment, related party ownership percentage Equity Method Investment, Related Party Ownership Percentage Equity Method Investment, Related Party Ownership Percentage Equity method investment, related party promote fee percentage Equity Method Investment, Related Party Promote Fee Percentage Equity Method Investment, Related Party Promote Fee Percentage Equity method investment, partner ownership percentage Equity Method Investment, Partner Ownership Percentage Equity Method Investment, Partner Ownership Percentage Total assets carrying value Equity Method Investment, Summarized Financial Information, Assets Management fees revenue Management Fees Revenue Cost method investments Cost Method Investments Proceeds from sale of available-for-sale securities, equity Proceeds from Sale of Available-for-sale Securities, Equity Available-for-sale securities, gross realized gains Available-for-sale Securities, Gross Realized Gain (Loss) Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangement by Title of Individual [Axis] Schedule of Share-based Compensation Arrangement by Title of Individual [Axis] Reflects the pertinent provisions pertaining to equity-based compensation arrangement, by individual. Schedule of Share-based Compensation Arrangement by Title of Individual with Relationship to Entity [Domain] Schedule of Share-based Compensation Arrangement by Title of Individual with Relationship to Entity [Domain] Title of the individual (or the nature of the entity's relationship with the individual) who is party to the equity-based compensation arrangement. Directors Director [Member] Award Type [Axis] Award Type [Axis] Award Type [Domain] Equity Award [Domain] CSE and Restricted Stock Units CSE and Restricted Stock Award [Member] CSE and Restricted Stock Award [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Non-vested, outstanding (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Aggregate intrinsic value for directors Share based Compensation Arrangement by Share based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value for Directors The aggregate intrinsic value of outstanding equity awards on equity-based plans excluding option plans for which the Company is contingently obligated to issue equity instruments or transfer assets to an director as calculated by applying the disclosed pricing methodology. Fair Value Disclosures [Abstract] Fair Values Fair Value Disclosures [Text Block] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Residential Condominiums Condominium Units [Member] Condominium Units [Member] Net Lease Asset Two Net Lease Asset Two [Member] Net Lease Asset Two [Member] Commercial Operating Properties Commercial Operating Properties [Member] Commercial Operating Properties [Member] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Proceeds from sale of other real estate Proceeds from Sale of Other Real Estate Proceeds from sale of property held-for-sale Proceeds from Sale of Property Held-for-sale Net proceeds from sales of real estate Initial term of ground lease Lessor Leasing Arrangements, Operating Leases, Term of Contract Deferred gain on sale of property Deferred Gain on Sale of Property Payments for repurchase of redeemable noncontrolling interest Payments for Repurchase of Redeemable Noncontrolling Interest Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Terminated interest rate swap Terminated Interest Rate Swap [Member] Terminated Interest Rate Swap [Member] Derivative, Variable Interest Rate Derivative, Basis Spread on Variable Rate Derivative, Fixed Rate Derivative, Fixed Interest Rate Cash flow hedge gain (loss) to be reclassified within twelve months Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months Schedule of Financing Receivables Past Due [Table] Schedule of Financing Receivables Past Due [Table] Senior mortgages First Mortgage [Member] Corporate/Partnership loans Corporate/Partnership Loan [Member] Corporate/Partnership Loan [Member] Subordinate mortgages Second Mortgage [Member] Recorded investment in loans, aged by payment status and presented by class Financing Receivable, Recorded Investment, Past Due [Line Items] Current Financing Receivable, Recorded Investment, Current Less Than and Equal to 90 Days Financing Receivable Recorded Investment Equal to Less than 90 Days Past Due Financing receivables that are equal to or less than 90 days past due. Greater Than 90 Days Financing Receivable Recorded Investment Greater than 90 Days Past Due Financing receivables that are greater than 90 days past due. Total Past Due Financing Receivable, Recorded Investment, Past Due Loans Financing receivable, number of loans greater than 90 days past due Financing Receivable, Number of Loans Greater than 90 Days Past Due Financing Receivable, Number of Loans Greater than 90 Days Past Due Financing receivables, past due time period Financing Receivables, Past Due Time Period Financing Receivables, Past Due Time Period Unsecured Credit Facilities Unsecured Credit Facilities [Member] Represents the unsecured credit facility of the entity. Minimum ratio of unencumbered assets to unsecured indebtedness Debt Instrument Covenant Ratio of Unencumbered Assets to Unsecured Indebtedness Represents the minimum ratio of encumbered assets to unsecured indebtedness required under the terms of the debt covenant. Debt instrument covenant multiple of minimum fixed charges on outstanding borrowings Debt Instrument Covenant Multiple of Minimum Fixed Charges on Outstanding Borrowings Debt Instrument Covenant Multiple of Minimum Fixed Charges on Outstanding Borrowings Multiple of the minimum collateral coverage on outstanding borrowings Debt Instrument Covenant Multiple of Minimum Collateral Coverage on Outstanding Borrowings Represents the multiple of the minimum collateral coverage on outstanding borrowings required under the terms of the debt covenant. Percentage of REIT taxable income permitted for distribution under debt covenants Debt Instrument Covenant Percentage of Taxable Income Permitted for Distribution if Reit classification is Maintained Represents the percentage of taxable income that is permitted for distribution, under the terms of the debt covenant, if the entity maintains its REIT qualification. Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, by Balance Sheet Grouping, Disclosure Item Amounts [Axis] Measurement Basis [Axis] Fair Value, Disclosure Item Amounts [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Fair Value Estimate of Fair Value Measurement [Member] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Recurring basis Fair Value, Measurements, Recurring [Member] Non-recurring basis Fair Value, Measurements, Nonrecurring [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Quoted market prices in active markets (Level 1) Fair Value, Inputs, Level 1 [Member] Significant other observable inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Significant unobservable inputs (Level 3) Fair Value, Inputs, Level 3 [Member] Valuation Technique [Axis] Valuation Technique [Axis] Valuation Technique [Domain] Valuation Technique [Domain] Appraisal Appraisal [Member] Appraisal [Member] Discounted Cash Flow Valuation Technique Discounted Cash Flow Valuation Technique [Member] Discounted cash flow valuation technique used to measure fair value. Loans Receivable One Loans Receivable One [Member] Loans Receivable One [Member] Loans Receivable Two Loans Receivable Two [Member] Loans Receivable Two [Member] Assets and liabilities recorded at fair value Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Derivative assets Derivative Asset Derivative liabilities Derivative Liability Available-for-sale securities Available-for-sale Securities Impaired loans Impaired Loans Receivable Fair Value Disclosure This element represents impaired loans as of the end of the reporting period that are valued by the entity at fair value on the balance sheet date. Payments to acquire available-for-sale securities Payments to Acquire Available-for-sale Securities Number of impaired loans Number of Impaired Loans Number of Impaired Loans Discount rate Fair Value Inputs, Discount Rate Allowance for Loan Losses [Roll Forward] Allowance for Loan Losses [Roll Forward] Reserve for loan losses at beginning of period Reserve for loan losses at end of period Recoveries of previously recorded loan loss reserves Allowance for Loan and Lease Loss, Recovery of Bad Debts Investment across a range of real estate sectors over the past two decades (more than) Real Estate Investment Represents the amount invested across a range of real estate sectors by the entity over a period of time. Stock Repurchase Program Stock Repurchase Program [Abstract] -- None. No documentation exists for this element. -- Repurchase of common stock, authorized amount Stock Repurchase Program, Authorized Amount Treasury stock, shares, acquired Stock Repurchased and Retired During Period, Shares Treasury stock value acquired including acquisition costs Common Stock Value Acquired Including Acquisition Costs Common Stock Value Acquired Including Acquisition Costs Treasury stock acquired, average cost per share (in dollars per share) Common Stock Acquired, Average Cost Per Share Common Stock Acquired, Average Cost Per Share Available repurchase of common stock, authorized amount (up to) Stock Repurchase Program, Remaining Authorized Repurchase Amount Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Joint venture shares Joint Venture Shares [Member] Incremental common shares attributable to joint venture shares that were not included in diluted earnings per share (EPS) because to do so would increase EPS amounts or decrease loss per share amounts during the period presented. 3.00% convertible senior unsecured notes Unsecured Notes 3 Percent Senior Convertible Notes Due October 2016 [Member] Unsecured Notes 3 Percent Senior Convertible Notes Due October 2016 1.50% convertible senior unsecured notes Unsecured Notes 1 point 50 Percent Senior Convertible Notes Due November 2016 [Member] [Member] Unsecured Notes 1 point 50 Percent Senior Convertible Notes Due November 2016 [Member] [Member] Anti-dilutive shares Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Anti-dilutive shares Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Schedule of deferred tax assets and liabilities [Table] Schedule of deferred tax assets and liabilities [Table] Schedule of deferred tax assets and liabilities [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Taxable REIT Subsidiaries Taxable REIT Subsidiaries [Member] Represents the taxable REIT subsidiaries ("TRSs") through which the entity is engaged in various real estate related opportunities, including but not limited to managing various investments in equity affiliates and managing activities related to certain foreclosed assets. Schedule of deferred tax assets and liabilities [Line Items] Schedule of deferred tax assets and liabilities [Line Items] [Line Items] for Schedule of deferred tax assets and liabilities [Table] Deferred tax assets Deferred Tax Assets, Gross Valuation allowance Deferred Tax Assets, Valuation Allowance Net deferred tax assets (liabilities) Deferred Tax Assets, Net Real estate basis differences Deferred Tax Assets, Investment in Subsidiaries Deferred expenses differences Deferred Tax Assets, Tax Deferred Expense, Other Land and land development assets land and land improvements [Table Text Block] [Table Text Block] for land and land improvements [Table] 2013-2014 Performance Incentive Plan 2013-2014 Performance Incentive Plan [Member] 2013-2014 Performance Incentive Plan [Member] 2015-2016 Performance Plan 2015-2016Performance Plan [Member] 2015-2016Performance Plan [Member] All Performance Incentive Plans All performance incentive plans [Member] All performance incentive plans [Member] Common Stock Subject to Sales Restriction Common Stock Subject to Sales Restriction [Member] Common Stock Subject to Sales Restriction [Member] Service Based Restricted Stock Units Vesting on December 31, 2018 Service Based Restricted Stock Units Vesting on December 31, 2018 [Member] Service Based Restricted Stock Units Vesting on December 31, 2018 [Member] Performance Based Restricted Stock Units Vesting on December 31, 2017 Performance Based Restricted Stock Units Vesting on December 31, 2017 [Member] Performance Based Restricted Stock Units Vesting on December 31, 2017 [Member] Service Based Restricted Stock Units Vesting on December 31, 2017 Service Based Restricted Stock Units Vesting on December 31, 2017 [Member] Service Based Restricted Stock Units Vesting on December 31, 2017 [Member] Performance Based Restricted Stock Units Vesting on December 31, 2016 Performance Based Restricted Stock Units Vesting on December 31, 2016 [Member] Performance Based Restricted Stock Units Vesting on December 31, 2016 [Member] Service Based Restricted Stock Units Vesting on December 31, 2016 Service Based Restricted Stock Units Vesting on December 31, 2016 [Member] Service Based Restricted Stock Units Vesting on December 31, 2016 [Member] Service Based Restricted Stock Units with specified vesting dates Service-based Restricted Stock Units with Specified Vesting Terms [Member] Represents details pertaining to service-based restricted stock units with specified original vesting terms. Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Long-term Incentive Plan 2009 Long-term Incentive Plan 2009 [Member] Represents information pertaining to 2009 Long-Term Incentive Plan of the entity. Employees Employees [Member] Represent employees of the entity. Stock-based compensation expense Unrecognized compensation cost Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Weighted-average period to recognize the unrecognized compensation cost Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Number of points issued (in shares) Number of Points Issued Number of Points Issued Accrued expenses Accrued Liabilities Other than Interest Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include property accounts payable, legal liabilities, loan costs, general and administrative liabilities, but exclude interest. Shares available for issuance Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Vested, number of shares Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period Restricted shares awarded Restricted Stock, Shares Issued Net of Shares for Tax Withholdings Sale restriction period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Sale Restriction Period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Sale Restriction Period Granted units Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Granted, Number Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Granted, Number Number of vesting installments Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vesting Installments, Number Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vesting Installments, Number Vesting percentage Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vesting Percentage Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vesting Percentage Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected stock price volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Vesting term Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Other real estate equity investments Real Estate Equity Investments [Member] Real Estate Equity Investments Oak Hill Funds Oak Hill Funds Group 2 [Member] Represents information pertaining to Oak Hill group two, which includes OHA Strategic Master Fund, L.P. Schedule of assets and liabilities recorded at fair value on a recurring and non-recurring basis by levels Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Accounts, Notes, Loans and Financing Receivable [Line Items] Total gross carrying value of loans Loans Receivable Net of Deferred Income Reflects the aggregate gross carrying amount of all categories of loans held in portfolio, after deducting deferred income, but before deducting the allowance for losses on loans. Reserves for loan losses Total loans receivable, net Other lending investments—securities Held-to-Maturity and Available-for-sale Securities This item represents investments in debt securities which are categorized as held-to-maturity and securities classified as available for sale. Total loans receivable and other lending investments, net Interest receivable Interest Receivable Common Stock Earnings allocable to common shares: Share-based Compensation, Allocation and Classification in Financial Statements [Abstract] Numerator for basic and diluted earnings per share: Net Income (Loss) Available to Common Stockholders, Basic [Abstract] Income (loss) from continuing operations attributable to iStar Inc. and allocable to common shareholders Income (Loss) from Continuing Operations, Attributable to Parent and Available to Common Shareholders The income or loss from continuing operations during the period which is attributable to the parent and is available to common shareholders. Denominator for basic and diluted earnings per share: Denominator for Basic and Diluted Earnings Per Share or Hpu Share [Abstract] -- None. No documentation exists for this element. -- Weighted average common shares outstanding for basic and diluted earnings per common share (in shares) Weighted Average Number of Shares Outstanding, Basic Basic and diluted earnings per common share: Net income (loss) attributable to iStar Inc. and allocable to common shareholders (in dollars per share) Earnings allocable to High Performance Units Earnings Allocable to High Performance Units [Abstract] Earnings Allocable to High Performance Units [Abstract] Numerator for basic and diluted earnings per HPU share: Numerator for Basic Earnings Per HPU Share [Abstract] Numerator for Basic Earnings Per HPU Share [Abstract] Net income (loss) attributable to iStar Inc. and allocable to HPU holders Net Income (Loss) Attributable to Parent and Available to HPU Holders Net Income (Loss) Attributable to Parent and Available to HPU Holders Denominator for basic and diluted earnings per HPU share: Denominator for Basic and Diluted Earnings Per HPU Share [Abstract] Denominator for Basic and Diluted Earnings Per HPU Share [Abstract] Weighted average High Performance Units outstanding for basic and diluted earnings per share (in shares) Basic and diluted earnings per HPU share: Basic Earnings Per HPU Share [Abstract] Basic Earnings Per HPU Share [Abstract] Net income (loss) attributable to iStar Inc. and allocable to HPU holders (in dollars per share) Earnings Per Share, Basic Basis of Presentation and Principles of Consolidation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Real Estate Asses Held-for-Sale Real Estate Asses Held-for-Sale [Member] Real Estate Asses Held-for-Sale [Member] Non Cash Member Non cash member [Member] Non cash member [Member] Landanddevelopment2 [Member] [Member] Landanddevelopment2 [Member] [Member] Landanddevelopment2 [Member] [Member] Real Estate, Type of Property [Axis] Real Estate, Type of Property [Axis] Real Estate [Domain] Real Estate [Domain] Residential Real Estate Residential Real Estate [Member] Residential Real Estate, Type of Property [Axis] Residential Real Estate, Type of Property [Axis] Residential Real Estate, Type of Property [Axis] Residential Real Estate, Type of Property [Domain] Residential Real Estate, Type of Property [Domain] Residential Real Estate, Type of Property [Domain] Master Planned Community Master Planned Community [Member] Master Planned Community [Member] Land and Development Asset Real Estate Available and Held for Sale Real Estate Available and Held for Sale [Member] Real Estate Available and Held for Sale [Member] Other Liabilities Other Liabilities Accrued interest payable Interest Payable Intangible liabilities, net Below Market Lease, Net Accounts payable, accrued expenses and other liabilities Profit sharing payable Profit Sharing Payable Profit Sharing Payable Special assessment bond Special Assessment Bond Number of properties Number of Properties Number of Properties Payable for common share repurchases Payable for common share repurchases Payable for common share repurchases Deferred revenue Deferred Revenue, Current Deferred finance costs, net Deferred Finance Costs, Net Below market lease, accumulated amortization Below Market Lease, Accumulated Amortization Amortization of below market lease Amortization of Below Market Lease Capital expenditures incurred but not yet paid Capital Expenditures Incurred but Not yet Paid Other assets Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] External Credit Rating by Grouping [Axis] External Credit Rating by Grouping [Axis] External Credit Rating by Grouping [Domain] External Credit Rating by Grouping [Domain] Real Estate Finance Performing Financial Instruments [Member] Recorded Investments in loans, presented by class and by credit quality, as indicated by risk rating Financing Receivable, Recorded Investment [Line Items] Risk rating Financing Receivable, Credit Quality, Additional Information Weighted Average Risk Ratings Weighted Average Risk Ratings Represents the weighted average risk rating of the instrument. Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Book and estimated fair values of financial instruments Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Obligations Obligations [Member] Deferred finance costs, current, net Deferred Finance Costs, Current, Net Equity Equity Related Disclosure [Text Block] This element includes disclosures of Equity related items, including common stock, preferred stock, dividend requirements, treasury stock and accumulated other comprehensive income. Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Other Assets Other Assets [Member] Other Liabilities Other Liabilities [Member] Derivative financial instruments on consolidated balance sheets Derivatives, Fair Value [Line Items] Derivative Assets, Fair Value Derivative Asset, Fair Value, Gross Asset Derivative Liabilities, Fair Value Derivative Liability, Fair Value, Gross Liability Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Impaired Loans Related Allowance [Axis] Impaired Loans Related Allowance [Axis] Attributes of impaired loans classified as impaired with or without specific allowance related to the loans, by class of financial receivable. Impaired Loans Related Allowance [Domain] Impaired Loans Related Allowance [Domain] Represents a subset of a class of impaired loans that have or do not have the specific allowances related to the impaired receivables. With no related allowance recorded Receivables Without Allowance [Member] Receivables Without Allowance [Member] With an allowance recorded Receivables With Allowance [Member] Receivables With Allowance [Member] Financing Receivable, Impaired [Line Items] Financing Receivable, Impaired [Line Items] Recorded Investment Impaired Financing Receivable, Recorded Investment Unpaid Principal Balance Impaired Financing Receivable, Unpaid Principal Balance Related Allowance Impaired Financing Receivable, Related Allowance Average Recorded Investment Impaired Financing Receivable, Average Recorded Investment Interest Income Recognized Impaired Financing Receivables Interest Income Cash or Accrual Method The interest income recognized on a cash-basis or accrual method of accounting during the time within that period that the financing receivables were impaired. Loans Receivable and Other Lending Investments, net Loans and Other Lending Investments Net [Text Block] This element represents a summarization of loans and other lending investments held by the company. Schedule of unfunded commitments Unfunded Financial Commitments [Table Text Block] Tabular disclosure of off-balance sheet unfunded financial commitments which includes performance-based commitments, discretionary funding arrangements and strategic investment commitments.