WEST VIII Series B 2025 term note payable at a fixed rate of interest of 6.07%, maturing in June 2050, secured by engines, airframes, and loan assets WEST VIII Series B Notes [Member] WEST VIII Series B Notes Common stock cash dividends paid (in dollars per share) Common Stock, Dividends, Per Share, Cash Paid Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Statistical Measurement [Domain] Statistical Measurement [Domain] Number of leased assets Number Of Leased Assets Number Of Leased Assets Award Timing Predetermined Award Timing Predetermined [Flag] Related Party Transaction [Axis] Related Party Transaction [Axis] Number of aircrafts in lease portfolio Equity Method Investment Number of Aircraft in Lease Portfolio Equity Method Investment Number of Aircraft in Lease Portfolio Entity File Number Entity File Number Paid in Capital in Excess of par Additional Paid-in Capital [Member] Willis Warehouse Facility LLC (“WWFL”) credit facility was terminated during the three months ended March 31, 2026 Willis Warehouse Facility LLC [Member] Willis Warehouse Facility LLC Income from investments Income from investments Income (Loss) from Equity Method Investments Tabular List, Table Tabular List [Table Text Block] Leases [Abstract] Leases [Abstract] Government grant income Government Assistance, Asset, Increase Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Share-based Payment Arrangement, Noncash Expense [Abstract] Share-Based Payment Arrangement, Noncash Expense [Abstract] Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Basic weighted average income per common share (in dollars per share) Basic weighted average income per common share (in dollars per share) Earnings Per Share, Basic Adjustment to Compensation: Adjustment to Compensation [Axis] Related Party Transactions Related Party Transactions Disclosure [Text Block] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Accounts payable and accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities The 2023 Stock Incentive Plan The 2023 Stock Incentive Plan [Member] 2021 Stock Incentive Plan [Member] Preferred stock dividends Payments of Ordinary Dividends, Preferred Stock and Preference Stock Schedule of Stock by Class [Table] Stock, Class of Stock [Table] Joint Venture Corporate Joint Venture [Member] Schedule of Reportable Segments Schedule of Segment Reporting Information, by Segment [Table Text Block] Shares issued (in shares) Stock Issued During Period, Shares, Employee Stock Purchase Plans Net finance costs: Interest and Debt Expense [Abstract] Adjustment to Compensation, Amount Adjustment to Compensation Amount Other assets Increase (Decrease) in Other Operating Assets Principles of Consolidation Consolidation, Policy [Policy Text Block] Stock-based compensation expense Share-Based Payment Arrangement, Noncash Expense Employee Stock Option Share-Based Payment Arrangement, Option [Member] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Category of Item Purchased [Axis] Category of Item Purchased [Axis] WEST V Series C 2020 term notes payable at a fixed rate of interest of 6.66%, maturing in March 2045, secured by engines WEST V Series C Notes [Member] WEST V Series C Notes [Member] Variable Interest Entity Variable Interest Entity, Primary Beneficiary [Member] Schedule of Operating Lease by Asset Class Lessor, Operating Lease, Carrying Value of Assets Subject to Leases [Table Text Block] Lessor, Operating Lease, Carrying Value of Assets Subject to Leases Accretion of deferred costs and note discounts Accretion of Deferred Costs and Discounts, Notes Accretion of Deferred Costs and Discounts, Notes Common stock cash dividends paid Dividends, Common Stock, Cash Shares issued under stock compensation plans Shares Issued, Value, Share-Based Payment Arrangement, before Forfeiture Total shareholders’ equity Balances, beginning of period Balances, end of period Equity, Attributable to Parent Measurement Frequency [Axis] Measurement Frequency [Axis] Effects of derivative instruments Derivative Instruments, Gain (Loss) [Line Items] Insider Trading Policies and Procedures [Line Items] Total Stock Compensation Expense Share-Based Payment Arrangement, Expense Common stock, shares authorized (in shares) Common Stock, Shares Authorized Hedging Designation [Domain] Hedging Designation [Domain] Maintenance reserves Increase (Decrease) in Maintenance Reserves A liability for future maintenance events that have a refundable aspect contingent on return conditions. Fair value of notes payable Notes Payable, Fair Value Disclosure Total liabilities, redeemable preferred stock and equity Liabilities and Equity Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Reclassification, Type [Domain] Reclassification, Type [Domain] Net realized gain from derivative instruments, net of tax expense of $155 Other Comprehensive Income (Loss), Cash Flow Hedge, Realized Gain (Loss), after Reclassification and Tax, Parent Other Comprehensive Income (Loss), Cash Flow Hedge, Realized Gain (Loss), after Reclassification and Tax, Parent LIABILITIES, REDEEMABLE PREFERRED STOCK AND SHAREHOLDERS’ EQUITY Liabilities and Equity [Abstract] Cover [Abstract] Cover [Abstract] Maximum Maximum [Member] Schedule of Equity Method Investments [Table] Equity Method Investment [Table] Fair value of investment in sales type leases Investment in Sales Type Leases, Fair Value Disclosure Investment in Sales Type Leases, Fair Value Disclosure Accounting Policies [Abstract] Accounting Policies [Abstract] Shares issued under stock compensation plans (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, before Forfeiture Restricted Stock Restricted Stock [Member] Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Long Term Debt [Line Items] Debt Instrument [Line Items] Transaction One Transaction One [Member] Transaction One Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Marine vessel Assets Leased To Others, Marine Vessels [Member] Assets Leased To Others, Marine Vessels Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Pay vs Performance Disclosure [Line Items] Net unrealized gain from currency translation adjustment, net of tax expense Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Liabilities: Liabilities [Abstract] Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Depreciation and amortization expense Depreciation, Depletion and Amortization, Nonproduction Risks and Uncertainties Risks And Uncertainties [Policy Text Block] Risks And Uncertainties Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company Investments in sales-type leases, allowance Sales-type Lease, Net Investment in Lease, Allowance for Credit Loss Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Operating Segments Operating Segments [Member] Transfers from Equipment held for operating lease to Spare parts inventory Transfers From Equipment Held For Operating Lease To Spare Parts Inventory Transfers From Equipment Held For Operating Lease To Spare Parts Inventory Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Company Selected Measure Amount Company Selected Measure Amount Reclassification [Line Items] Reclassification [Line Items] Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Total comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Security deposits Security Deposit Liability Name Measure Name Net gain (loss) recognized in other comprehensive income Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent Class of Stock [Line Items] Class of Stock [Line Items] Deferred income taxes Deferred Income Tax Liabilities, Net Document Fiscal Period Focus Document Fiscal Period Focus Intangible assets, net Intangible Assets, Net (Including Goodwill) Redeemable preferred stock, shares authorized (in shares) Temporary Equity, Shares Authorized Number of annual installments Share-Based Payment Arrangement, Number Of Annual Installments Share-Based Payment Arrangement, Number Of Annual Installments Award Timing Method Award Timing Method [Text Block] Cost of maintenance services Cost, Maintenance Award Type [Axis] Award Type [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Debt obligations Total debt obligations Long-Term Debt Total assets Assets Assets Purchase of equipment held for operating lease and for sale Payments to Acquire Equipment on Lease Investment, Name [Domain] Investment, Name [Domain] Schedule of Restricted Stock Activity Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] Trading Symbol Trading Symbol Management and advisory fees Management and Advisory Fees Management and Advisory Fees CASC Willis Engine Lease Company Limited CASC Willis Engine Lease Company Limited [Member] Represents information relating to CASC Willis Engine Lease Company Limited , a joint venture based in Shanghai, China formed for acquiring and leasing jet engines to Chinese airlines. Shares granted to date (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Gain on sale of asset Related Party Transaction, Gain (Loss) On Sale Of Asset Related Party Transaction, Gain (Loss) On Sale Of Asset Entity Address, City or Town Entity Address, City or Town Equity Method Investment Balances [Roll Forward] Equity Method Investment Balances [Roll Forward] Equity Method Investment Balances [Roll Forward] Cash flows from operating activities: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Receivable Type [Axis] Receivable Type [Axis] Willis Global Engine Testing Willis Global Engine Testing [Member] Willis Global Engine Testing Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Income Statement Location [Domain] Statement of Income Location, Balance [Domain] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Entity Emerging Growth Company Entity Emerging Growth Company 2029 Long-Term Debt, Maturity, Year Three Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Other sales and revenue Revenue from Contract with Customer, Including Assessed Tax Level 2 Fair Value, Inputs, Level 2 [Member] Less: unamortized debt issuance costs and note discounts Debt Issuance Costs, Net Redeemable preferred stock, par value (in dollars per share) Temporary Equity, Par or Stated Value Per Share Investment in joint ventures at beginning of the period Investment in joint ventures at end of the period Equity Method Investments Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] 2023 Incentive Stock Plan 2023 Stock Incentive Plan [Member] 2023 Stock Incentive Plan Plan Name [Axis] Plan Name [Axis] PEO PEO [Member] Supplemental disclosures of non-cash activities: Noncash Investing and Financing Items [Abstract] Changes in assets and liabilities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Unrecorded Unconditional Purchase Obligation [Line Items] Unrecorded Unconditional Purchase Obligation [Line Items] Gain on sale of financial assets Gain (Loss) on Sale of Financing Receivable Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Retained Earnings Retained Earnings [Member] Accounts payable and accrued expenses Accounts Payable and Accrued Liabilities Year Maturities of Long-Term Debt [Abstract] Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date Cash, cash equivalents and restricted cash at beginning of period Cash, cash equivalents and restricted cash at end of period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Consolidated Statements of Income Income Statement [Abstract] Derivative Assets Derivative Asset Income tax expense Income Tax Expense (Benefit) Variable rate (as a percent) Debt Instrument, Basis Spread on Variable Rate Preferred stock dividends (in dollars per share) Preferred Stock, Dividends, Per Share, Cash Paid Interest rate contracts Interest Expense [Member] Other assets Other Assets WEST III Series A 2017 term notes payable at a fixed rate of interest of 4.69%, maturing in August 2042, secured by engines WEST III Series A Notes [Member] WEST III Series A Notes Fair Value, Nonrecurring Fair Value, Nonrecurring [Member] Minimum quantity required under purchase obligation (in engines) Unrecorded Unconditional Purchase Obligation, Minimum Quantity Required Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Designated as Hedging Instrument Designated as Hedging Instrument [Member] Reclassification [Table] Reclassification [Table] Product and Service [Domain] Product and Service [Domain] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Hedging Relationship [Axis] Hedging Relationship [Axis] WEST VI Series B 2021 term notes payable at a fixed rate of interest of 5.44%, maturing in May 2046, secured by engines, airframes, and loan assets WEST VI Series B Notes [Member] WEST VI Series B Notes Gross Value Property, Plant and Equipment, Gross WWFL Credit Facility WWFL Credit Facility [Member] WWFL Credit Facility Payment for fleet management services Payment For Fleet Management Services Payment For Fleet Management Services Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Derivative, notional amount Notional amount Derivative, Notional Amount Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Other revenue Other Product and Service Revenue [Member] Other Product and Service Revenue Net unrealized gain (loss) from derivative instruments, tax benefit Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax, Parent City Area Code City Area Code Common stock dividends declared (in dollars per share) Dividends Payable, Amount Per Share Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] All Trading Arrangements All Trading Arrangements [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Balance of unvested shares at the beginning of the period (in shares) Balance of unvested shares at the end of the period (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Commitments and Contingencies Disclosure [Abstract] Net realized gain from derivative instruments, tax expense Other Comprehensive Income (Loss), Cash Flow Hedge, Realized Gain (Loss), after Reclassification, Tax, Parent Other Comprehensive Income (Loss), Cash Flow Hedge, Realized Gain (Loss), after Reclassification, Tax, Parent Cash flows from investing activities: Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] General and administrative General and administrative General and Administrative Expense Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Net cash provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Accretion of preferred shares issuance costs Preferred Stock, Accretion of Issuance Costs Preferred Stock, Accretion of Issuance Costs Management and advisory fee income Management and Advisory Fee Income Management and Advisory Fee Income Related Party Transactions [Abstract] Related Party Transactions [Abstract] Thereafter Long Term Debt, Maturity, After Year Four Long Term Debt, Maturity, After Year Four Number of secured engines Number Of Secured Engines Number Of Secured Engines Subsequent Event Subsequent Event [Member] Cash Flow Hedging Cash Flow Hedging [Member] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] PEO Total Compensation Amount PEO Total Compensation Amount Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Income from joint ventures Income (Loss) From Equity Method Investments Excluding Amortization On Deferred Gains Income (Loss) From Equity Method Investments Excluding Amortization On Deferred Gains Fair value of notes receivable Notes Receivable, Fair Value Disclosure Lessee, operating lease, number of engines subleased Lessee, Operating Lease, Number Of Engines Subleased Lessee, Operating Lease, Number Of Engines Subleased Equity Components [Axis] Equity Components [Axis] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Number of reportable segments Number of Reportable Segments Supplemental disclosures of cash flow information: Supplemental Cash Flow Information [Abstract] Other Performance Measure, Amount Other Performance Measure, Amount Debt issuance costs Payments of Debt Issuance Costs Entity Address, State or Province Entity Address, State or Province Equipment Held For Operating Lease Equipment Held For Operating Lease [Member] Equipment Held For Operating Lease Cancellation of restricted stock in satisfaction of withholding tax (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, Forfeited Long-Term Purchase Commitment, Category of Item Purchased [Domain] Long-Term Purchase Commitment, Category of Item Purchased [Domain] Derivative Instrument [Axis] Derivative Instrument [Axis] Individual: Individual [Axis] Vesting [Axis] Vesting [Axis] Restricted cash Restricted Cash Common stock cash dividends paid Payments of Ordinary Dividends, Common Stock Accumulated depreciation for equipment held for operating lease Accumulated Depreciation, Depletion and Amortization, Equipment Held for Operating Lease Accumulated Depreciation, Depletion and Amortization, Equipment Held for Operating Lease Investments [Abstract] Investments [Abstract] Net cash provided by investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Notes receivable, allowance Accounts and Financing Receivable, Allowance for Credit Loss Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Leasing and  Related Operations Leasing And Related Operations Segment [Member] Represents information pertaining to leasing and related operations which involves acquiring and leasing, primarily pursuant to operating leases, commercial aircraft, aircraft spare engines and other aircraft equipment and the selective purchase and resale of commercial aircraft engines and other aircraft equipment ,a segment of the entity. Interest Interest Paid, Excluding Capitalized Interest, Operating Activity WEST VI Series C 2021 term notes payable at a fixed rate of interest of 7.39%, maturing in May 2046, secured by engines, airframes, and loan assets WEST VI Series C Notes [Member] WEST VI Series C Notes Document Fiscal Year Focus Document Fiscal Year Focus Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Principal payments on debt obligations Repayments of Long-Term Debt Effective tax rate (as a percent) Effective Income Tax Rate Reconciliation, Percent Entity Interactive Data Current Entity Interactive Data Current Committed amount Investment Company, Committed Capital Plan Name [Domain] Plan Name [Domain] Currency translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax Purchase commitments Purchase Obligation Reportable Segments Segment Reporting Disclosure [Text Block] Property, Plant and Equipment, Type [Axis] Long-Lived Tangible Asset [Axis] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Net unrealized loss from derivative instruments, net of tax benefit Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Liquidation preference (in dollars per share) Temporary Equity, Liquidation Preference Per Share Number of assets impaired Number Of Assets Impaired Number Of Assets Impaired Depreciation and amortization expense Depreciation and amortization expense Depreciation, Depletion and Amortization Entity Central Index Key Entity Central Index Key PEO Name PEO Name Currency translation adjustment balance Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax Schedule of Debt Maturities Schedule of Maturities of Long-Term Debt [Table Text Block] Total revenue Revenues Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Payments received on notes receivable Proceeds from Collection of Notes Receivable Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Due from affiliates Increase (Decrease) Due from Affiliates Maintenance reserve revenue Maintenance reserve revenue Maintenance Reserve Revenue [Member] Maintenance Reserve Revenue [Member] Revolving credit facility Revolving Credit Facility [Member] Arrangement Duration Trading Arrangement Duration Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Investments in sales-type leases, net of allowances of $9 and $17 at March 31, 2026 and December 31, 2025, respectively Investments in sales-type leases Sales-Type Lease, Net Investment in Lease, after Allowance for Credit Loss Write-down of equipment Write-down of equipment Write-down of equipment Production Related Impairments or Charges Segments [Axis] Segments [Axis] Redeemable preferred stock ($0.01 par value, 5,000 shares authorized; 3,250 shares issued at March 31, 2026 and December 31, 2025, respectively) Balances, beginning of period, redeemable preferred stock Balances, end of period, redeemable preferred stock Temporary Equity, Carrying Amount, Attributable to Parent Due from affiliates Advances to Affiliate Exercise Price Award Exercise Price Entity Filer Category Entity Filer Category Class of Stock [Domain] Class of Stock [Domain] Local Phone Number Local Phone Number Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] WEST VII Series A 2023 term notes payable at a fixed rate of interest of 8.00%, maturing in October 2048, secured by engines, airframes, and loan assets WEST VII Series A Notes [Member] WEST VII Series A Notes Subsequent Event Type [Axis] Subsequent Event Type [Axis] Stock-Based Compensation Plans Share-Based Payment Arrangement [Text Block] Payments received on sales-type leases Proceeds from Lease Payment, Operating Activity Maximum loss exposure Variable Interest Entity, Nonconsolidated, Comparison of Carrying Amount of Assets and Liabilities to Maximum Loss Exposure ASSETS Assets [Abstract] Credit Facility [Axis] Credit Facility [Axis] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Vesting [Domain] Vesting [Domain] Debt Instrument [Axis] Debt Instrument [Axis] Blackstone Credit And Insurance Blackstone Credit And Insurance [Member] Blackstone Credit And Insurance Fair Value Measurements Fair Value Disclosures [Text Block] Loss on debt extinguishment Loss on debt extinguishment Gain (Loss) on Extinguishment of Debt Credit Facility [Domain] Credit Facility [Domain] Shareholders’ equity: Equity, Attributable to Parent [Abstract] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Service-Based Vesting Service-Based Vesting [Member] Service-Based Vesting Entity Address, Address Line One Entity Address, Address Line One Number of engines in lease portfolio Equity Method Investment Number of Engines in Lease Portfolio Represents the number of engines in lease portfolio of equity method investee. Accumulated Other Comprehensive Loss AOCI Attributable to Parent [Member] Fixed rate (as a percent) Debt Instrument, Interest Rate, Stated Percentage Investment, Name [Axis] Investment, Name [Axis] Equipment held for operating lease, less accumulated depreciation of $649,061 and $640,495 at March 31, 2026 and December 31, 2025, respectively Equipment Equipment held for operating lease Equipment Held For Operating Lease Equipment Held For Operating Lease Derivative Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Commitments, Contingencies, Guarantees and Indemnities Commitments Contingencies and Guarantees [Text Block] Fair Value as of Grant Date Award Grant Date Fair Value Receivables, net of allowances of $1,120 and $868 at March 31, 2026 and December 31, 2025, respectively Accounts Receivable, after Allowance for Credit Loss Entity Registrant Name Entity Registrant Name Net cash paid for (refunded): Net Cash Paid During the Period [Abstract] Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Other Fixed Rate Engine Notes Due July 2031 Through March 2034 Other Fixed Rate Engine Notes Due July 2031 Through March 2034 [Member] Other Fixed Rate Engine Notes Due July 2031 Through March 2034 Net unrealized gain (loss) from currency translation adjustments, tax expense (benefit) Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax, Portion Attributable to Parent Schedule of Notes Payable Schedule of Long-Term Debt Instruments [Table Text Block] Shares granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Aircraft and airframes Assets Leased To Others, Aircraft And Airframes [Member] Assets Leased To Others, Aircraft And Airframes Schedule of Cash Flow Hedging Instruments Schedule of Cash Flow Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block] Title and Position [Domain] Title and Position [Domain] Total expenses Costs and Expenses Shares forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Related Party Transaction [Line Items] Related Party Transaction [Line Items] Document Quarterly Report Document Quarterly Report Allowances and provisions Provision for Loan, Lease, and Other Losses Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Number of operating segments Number of Operating Segments Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Investments Investments Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Proceeds from sale of notes receivable (net of selling expenses) Proceeds from Sale of Notes Receivable Capital commitments is expected funded by certain executives and employees Capital Commitments Is Expected Funded By Certain Executives And Employees Capital Commitments Is Expected Funded By Certain Executives And Employees Unrecorded Unconditional Purchase Obligation [Table] Unrecorded Unconditional Purchase Obligation [Table] Total net finance costs Interest and Debt Expense WEST V Series B 2020 term notes payable at a fixed rate of interest of 4.21%, maturing in March 2045, secured by engines WEST V Series B Notes [Member] WEST V Series B Notes [Member] Restatement Determination Date: Restatement Determination Date [Axis] Non-PEO NEO Non-PEO NEO [Member] Maintenance rights Maintenance Rights Represents the carrying amount of maintenance rights as of balance sheet date. Dividend rate Preferred Stock, Dividend Rate, Percentage Name Trading Arrangement, Individual Name Award Type [Domain] Award Type [Domain] Payment for Debt Extinguishment or Debt Prepayment Cost Payment for Debt Extinguishment or Debt Prepayment Cost Equity Awards Adjustments Equity Awards Adjustments [Member] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Other Income Other Income Compensation Amount Outstanding Recovery Compensation Amount Debt instrument, face amount Debt Instrument, Face Amount Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Preferred Stock Preferred Stock [Member] Share Repurchase Program [Axis] Share Repurchase Program [Axis] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Name Awards Close in Time to MNPI Disclosures, Individual Name Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Spare parts inventory Airline Related Inventory, Aircraft Parts, Gross REVENUE Revenue: Revenues [Abstract] Maximum number of shares to be purchased by employee in one calendar year (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Maximum Number of Shares Per Employee Stock-based compensation expense, net of forfeitures APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Accumulated other comprehensive loss, net of income tax benefit of $224 and $395 at March 31, 2026 and December 31, 2025, respectively Accumulated Other Comprehensive Income (Loss), Net of Tax Adjustment to interest expense Adjustment to Interest Expense Adjustment to Interest Expense 2027 Long-Term Debt, Maturity, Year One Other Fixed Rate Engine Notes Due March 2032 and April 2034 Other Fixed Rate Engine Notes Due March 2032 and April 2034 [Member] Other Fixed Rate Engine Notes Due March 2032 and April 2034 Lessor, Lease, Description [Table] Lessor, Lease, Description [Table] Gain on sale of leased equipment Gain on sale of leased equipment Gain on sale of leased equipment Gain (Loss) on Sale of Leased Assets, Net, Operating Leases Segments [Domain] Segments [Domain] Schedule of Information About Financial Statement Effects Related to Cash Flow Hedges Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block] Maximum percentage of cash compensation allowed to be deducted for the purchase of common stock by eligible employees Share Based Compensation Arrangement by Share Based Payment Award Maximum Percentage of Cash Compensation Allowed to be Deducted for Purchase of Common Stock by Eligible Employees Represents the maximum percentage of cash compensation allowed to be deducted each pay period for the purchase of common stock by eligible employees. Income Statement Location [Axis] Statement of Income Location, Balance [Axis] Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Maximum amount of shares to be purchased by employee in one calendar year Share Based Compensation Arrangement by Share Based Payment Award Maximum Amount of Shares Per Employee The maximum amount of shares an employee can purchase under the plan per period. Number of transactions Number Of Transactions Number Of Transactions Schedule of Equipment Held for Lease and Held for Sale Schedule of Fair Value Assets and Gain (Losses) Measured on Nonrecurring Basis [Table Text Block] Tabular disclosure of the fair value hierarchy of the assets measured at fair value on a nonrecurring basis and the gains (losses) recorded during the period. Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Interest expense Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Number of interest rate swaps entered into Number of Interest Rate Derivatives Entered Into Number of Interest Rate Derivatives Entered Into Inventory Increase (Decrease) in Inventories Option to repurchase engine, amount Debt Instrument, Engine Purchase Option, Price Debt Instrument, Engine Purchase Option, Price Minimum Minimum [Member] 2021 Swap Arrangements 2021 Swap Arrangements [Member] 2021 Swap Arrangements Accumulated depreciation Accumulated Depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Number of leases renewed Number Of Leases Renewed Number Of Leases Renewed Company Selected Measure Name Company Selected Measure Name Debt Obligations Debt Disclosure [Text Block] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Government assistance, asset Government Assistance, Asset Cancellation of restricted stock in satisfaction of withholding tax Shares Issued, Value, Share-Based Payment Arrangement, Forfeited Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Net income attributable to common shareholders Net income attributable to common shareholders Net Income (Loss) Available to Common Stockholders, Diluted All Executive Categories All Executive Categories [Member] Stockholders' Equity Note [Abstract] Stockholders' Equity Note [Abstract] Notes receivable, net of allowances of $77 and $140 at March 31, 2026 and December 31, 2025, respectively Notes receivable Accounts and Financing Receivable, after Allowance for Credit Loss, Noncurrent Common stock ($0.01 par value, 20,000 shares authorized; 7,744 and 7,620 shares issued at March 31, 2026 and December 31, 2025, respectively) Common Stock, Value, Issued Title and Position [Axis] Title and Position [Axis] Diluted weighted average common shares outstanding (in shares) Diluted weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] WEST IX Series B 2025 term note payable at a fixed rate of interest of 5.70%, maturing in December 2050, secured by engines, airframes, and loan assets WEST XI Series B Notes [Member] WEST XI Series B Notes Derivative [Table] Derivative [Table] Entity Small Business Entity Small Business Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] 2024 Swap Agreements, Group 1 2024 Swap Agreements, Group 1 [Member] 2024 Swap Agreements, Group 1 Government assistance, liability Government Assistance, Liability Document Transition Report Document Transition Report Ownership interest Equity Method Investment, Ownership Percentage Underlying Securities Award Underlying Securities Amount Equity Component [Domain] Equity Component [Domain] Document Period End Date Document Period End Date PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Income Taxes Income Tax Disclosure [Text Block] Receivables, allowances Accounts Receivable, Allowance for Credit Loss Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Total Gain (Loss) on Sale of Assets and Asset Impairment Charges Hedging Designation [Axis] Hedging Designation [Axis] Willis Mitsui And Company Engine Support Limited Willis Mitsui And Company Engine Support Limited [Member] Represents the information pertaining to Willis Mitsui and Company Engine Support Limited, formed for the purpose of purchase of aircraft engines as part of joint venture interest. Document Type Document Type Earnings Per Share Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Paid-in capital in excess of par Additional Paid in Capital Product and Service [Axis] Product and Service [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Reclassification of gain on derivative instruments to interest expense Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax All Individuals All Individuals [Member] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Derivative [Line Items] Fair Value Disclosures [Abstract] Purchase of property, equipment and furnishings Payments to Acquire Property, Plant, and Equipment Name Forgone Recovery, Individual Name Statistical Measurement [Axis] Statistical Measurement [Axis] Lease rent revenue Lease rent revenue Lease Rent Revenue [Member] Lease Rent Revenue [Member] Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Proceeds from Lease Payment, Sales-Type and Direct Financing Leases, Investing Activity Proceeds from Lease Payment, Sales-Type and Direct Financing Leases, Investing Activity Preferred stock dividends Temporary Equity, Dividends, Adjustment Property, Equipment, and Furnishings Property, Equipment, And Furnishings, Excluding Equipment Held For Operating Lease [Member] Property, Equipment, And Furnishings, Excluding Equipment Held For Operating Lease Series Two Preferred Stock Series Two Preferred Stock [Member] Series A Two Preferred Stock [Member]A Repurchase of common stock authorized by board of directors Share Repurchase Program, Authorized, Amount WEST VIII Series A 2025 term notes payable at a fixed rate of interest of 5.58%, maturing in June 2050, secured by engines, airframes, and loan assets WEST VIII Series A Notes [Member] WEST VIII Series A Notes Term of purchase obligations Unrecorded Unconditional Purchase Obligation, Term Unfunded capital commitments Unfunded Capital Commitments Unfunded Capital Commitments Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Purchase price expressed as a percentage of the market price of the common stock on the purchase date or on the date of entry Share-Based Compensation Arrangement by Share-Based Payment Award, Purchase Price of Common Stock, Percent Engines and related equipment Assets Leased To Others, Engines And Related Equipment [Member] Assets Leased To Others, Engines And Related Equipment Spare Parts Sales Spare Parts Sales Segment [Member] Represents information pertaining to spare parts sales which involves the purchase and resale of after-market engine and airframe parts, whole engines, engine modules and routable aircraft components and leasing of engines destined for disassembly and sale of parts, a segment of the entity. Cancellation of restricted stock units in satisfaction of withholding tax Payment, Tax Withholding, Share-Based Payment Arrangement Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Net income attributable to common shareholders Net income attributable to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Share Repurchase Program [Domain] Share Repurchase Program [Domain] Equipment held for lease Gain Loss On Equipment Held For Lease Gain Loss On Equipment Held For Lease Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Transaction Type [Axis] Transaction Type [Axis] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Line of credit facility outstanding amount Long-Term Line of Credit Foreign currency translation adjustment Gain (Loss), Foreign Currency Transaction, before Tax Equipment Held for Operating Lease and Notes Receivable Lessor, Operating Leases [Text Block] Schedule of Related Party Transactions, by Related Party [Table] Related Party Transaction [Table] Diluted weighted average income per common share (in dollars per share) Diluted weighted average income per common share (in dollars per share) Earnings Per Share, Diluted Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Interest revenue Interest Income, Operating Title of 12(b) Security Title of 12(b) Security Spare parts and equipment sales Spare parts and equipment sales Spare Parts And Equipment Sales [Member] Represents the information pertaining to spare parts and equipment sales. Preferred stock dividends paid Dividends, Preferred Stock, Cash Amortization of contract asset Capitalized Contract Cost, Amortization Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Proceeds from sale of equipment (net of selling expenses) Proceeds from Sale of Machinery and Equipment Technical expense Technical expense Equipment Expense Earnings Per Share [Abstract] Earnings Per Share [Abstract] Consolidation Items [Domain] Consolidation Items [Domain] Investments Equity Method Investments and Joint Ventures Disclosure [Text Block] Unearned revenue Increase (Decrease) in Contract with Customer, Liability Ownership interest percentage Equity Method Investments, Ownership Percentage Equity Method Investments, Ownership Percentage Income Taxes Income Taxes Paid, Net Non Qualified Stock Options Non Qualified Stock Options [Member] Non Qualified Stock Options Number of assets sold Number Of Assets Sold Number Of Assets Sold Maintenance services revenue Maintenance Services Maintenance Services [Member] Maintenance Services Redeemable preferred stock, shares issued (in shares) Balances, beginning of period, redeemable preferred stock (in shares) Balances, end of period, redeemable preferred stock (in shares) Temporary Equity, Shares Issued Award Timing Disclosures [Line Items] Gross amount of debt Total Long-Term Debt, Gross Maintenance reserves Maintenance Reserves A liability for future maintenance events that have a refundable aspect contingent on return conditions. Note Receivable Notes Receivable [Member] Measurement Frequency [Domain] Measurement Frequency [Domain] Equity Equity [Text Block] Contributions Contribution Contribution Net income Net income Net Income (Loss) Attributable to Parent Subsequent Event [Table] Subsequent Event [Table] Performance-Based Vesting Performance-Based Vesting [Member] Performance-Based Vesting Eliminations Intersegment Eliminations [Member] Expiration Date Trading Arrangement Expiration Date Vesting period Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Schedule of Investments Equity Method Investments [Table Text Block] Property, equipment & furnishings, less accumulated depreciation of $29,421 and $27,869 at March 31, 2026 and December 31, 2025, respectively Net Book Value Fund value Property, Plant and Equipment, Net Reportable Segments Segment Reporting Information [Line Items] Adoption Date Trading Arrangement Adoption Date Proceeds from sale of assets Related Party Transaction, Proceeds From Sale Of Assets Related Party Transaction, Proceeds From Sale Of Assets Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Receivables Increase (Decrease) in Accounts Receivable Proceeds from shares issued under stock compensation plans Proceeds, Issuance of Shares, Share-Based Payment Arrangement, Excluding Option Exercised Series A Preferred Stock Series A Preferred Stock [Member] Entity Current Reporting Status Entity Current Reporting Status Derivative [Line Items] Derivative [Line Items] Liberty Mutual Investments Liberty Mutual Investments [Member] Liberty Mutual Investments Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Income from operations Income (loss) from operations Operating Income (Loss) Line of Credit Line of Credit [Member] Consolidated Entities [Domain] Consolidated Entities [Domain] WEST IX Series A 2025 term notes payable at a fixed rate of interest of 5.16%, maturing in December 2050, secured by engines, airframes, and loan assets WEST XI Series A Notes [Member] WEST XI Series A Notes Redeemable Preferred Stock Redeemable Preferred Stock [Member] Retained earnings Retained Earnings (Accumulated Deficit) Schedule of Components of Stock Compensation Expense Share-Based Payment Arrangement, Cost by Plan [Table Text Block] Gain on disposal of property, equipment and furnishings Gain (Loss) on Disposition of Property Plant Equipment WEST VI Series A 2021 term notes payable at a fixed rate of interest of 3.10%, maturing in May 2046, secured by engines, airframes, and loan assets WEST VI Series A Notes [Member] WEST VI Series A Notes Transaction [Domain] Transaction [Domain] Remaining maturity term Derivative, Remaining Maturity Consolidated Balance Sheets Statement of Financial Position [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Executive Category: Executive Category [Axis] Proceeds from debt obligations Proceeds from Issuance of Long-Term Debt Class of Stock [Axis] Class of Stock [Axis] Interest expense Interest expense Interest Expense, Operating and Nonoperating Current Fiscal Year End Date Current Fiscal Year End Date Equipment held for sale Equipment Held For Sale Equipment held for sale. Subsequent Event Type [Domain] Subsequent Event Type [Domain] Accumulated other comprehensive (loss) income, income tax (benefit) expense Accumulated Other Comprehensive Income (Loss) Tax Tax effect of accumulated other comprehensive income (loss) attributable to both parent entity and noncontrolling interest. Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] 2024 Swap Agreements, Group 2 2024 Swap Agreements, Group 2 [Member] 2024 Swap Agreements, Group 2 2024 Plan 2024 Plan [Member] 2024 Plan Number of shares available for future issuance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Statement [Table] Statement [Table] Derivative Liabilities Derivative Liability Series One Preferred Stock Series One Preferred Stock [Member] Series A One Preferred Stock [Member]. Adjustments to reconcile net income to net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Cash flows from financing activities: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Interest Rate Contract Interest Rate Contract [Member] Lessor, Lease, Description [Line Items] Lessor, Lease, Description [Line Items] Unearned revenue Contract with Customer, Liability Gain on sale of financial assets Gain (Loss) on Disposition of Assets for Financial Service Operations Accretion of preferred stock issuance costs Accretion of preferred shares issuance costs Accretion of preferred stock issuance costs Temporary Equity, Accretion to Redemption Value, Adjustment Shares not included in computation of diluted weighted average earnings per common (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount 2025 Swap Agreements 2025 Swap Agreements [Member] 2025 Swap Agreements All Adjustments to Compensation All Adjustments to Compensation [Member] Amendment Flag Amendment Flag Number of shares authorized (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized 2028 Long-Term Debt, Maturity, Year Two Equipment held for sale Gain (Loss) on Equipment Held For Sale Gain (Loss) on Equipment Held For Sale Willis Aviation Lending Warehouse I LLC Willis Aviation Lending Warehouse I LLC [Member] Willis Aviation Lending Warehouse I LLC Termination Date Trading Arrangement Termination Date Net cash used in financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Measure: Measure [Axis] Number of interest rate derivatives held Number of Interest Rate Derivatives Held Receivable [Domain] Receivable [Domain] Executive Chairman Executive Chairman [Member] Executive Chairman Gain on derivative instruments Derivative, Gain on Derivative Net fair value of swap asset (liability) Derivative, Fair Value, Net Government Grant Income Government Grant Income, Policy [Policy Text Block] Government Grant Income, Policy Basic weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Cost of spare parts and equipment sales Cost of spare parts and equipment sales Selling Expense Property, Plant and Equipment, Type [Domain] Long-Lived Tangible Asset [Domain] Stock repurchase program, remaining authorized repurchase amount Share Repurchase Program, Remaining Authorized, Amount Costs Not Expected To Exceed Costs Not Expected To Exceed [Member] Costs Not Expected To Exceed Schedule of Basic and Diluted EPS Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Austin C. Willis [Member] Austin C. Willis Related Party Transaction [Domain] Related Party Transaction [Domain] Subsequent Events [Abstract] Subsequent Events [Abstract] Segment Reporting [Abstract] Segment Reporting [Abstract] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Contributions Equity Method Investments, Contributions Equity Method Investments, Contributions Debt Disclosure [Abstract] Debt Disclosure [Abstract] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount WEST V Series A 2020 term notes payable at a fixed rate of interest of 3.23%, maturing in March 2045, secured by engines WEST V Series A Notes [Member] WEST V Series A Notes [Member] Entity Tax Identification Number Entity Tax Identification Number Number of assets purchased Number Of Assets Purchased Number Of Assets Purchased Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Stock-based compensation plans Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Consolidated Entities [Axis] Consolidated Entities [Axis] Unrealized gain (loss) on derivative instruments at joint venture Other comprehensive gain from joint ventures Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax, Joint Venture Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax, Joint Venture Common stock, shares issued (in shares) Balances, beginning of period, common stock (in shares) Balances, ending of period, common stock (in shares) Common Stock, Shares, Issued 2030 Long-Term Debt, Maturity, Year Four Stock options purchased (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross Transfers from Equipment held for operating lease to Equipment held for sale Loan and Lease, Transfer from Held-in-Portfolio to Held-for-Sale Tax expense (benefit) related to items of other comprehensive income Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent Trading Arrangement: Trading Arrangement [Axis] Total Shareholder Return Amount Total Shareholder Return Amount Unrealized gain (loss) on derivative instruments Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax, Parent Lease rent and maintenance reserve revenue Operating Lease, Lease Income Subsequent Events Subsequent Events [Text Block] Security deposits Increase (Decrease) in Deposit Assets Insider Trading Arrangements [Line Items] Security Exchange Name Security Exchange Name Note receivable, effective interest rate Receivable with Imputed Interest, Effective Yield (Interest Rate) 2026 Long-Term Debt, Maturity, Remainder of Fiscal Year Capital Addition Purchase Commitments Capital Addition Purchase Commitments [Member] Total liabilities Liabilities WEST III Series B 2017 term notes payable at a fixed rate of interest of 6.36%, maturing in August 2042, secured by engines WEST III Series B Notes [Member] WEST III Series B Notes Stock plan offering period Share-based Compensation Arrangement By Share-based Payment Award, Stock Plan Offering Period Share-based Compensation Arrangement By Share-based Payment Award, Stock Plan Offering Period Reclassification, Other Reclassification, Other [Member] Employee Stock Purchase Plan Employee Stock Purchase Plan [Member] Employee Stock Purchase Plan [Member] Credit facility at a floating rate of interest of one-month term Secured Overnight Financing Rate (“SOFR”) plus 2.35% at March 31, 2026, secured by engines, airframes, and loan assets. The credit facility has a committed amount of $1.75 billion at March 31, 2026, which revolves until the maturity date of April 2031. Secured Credit Facility Due April2021 [Member] Represents information pertaining to the secured credit facility, at a floating rate of interest of one-month LIBOR plus 2.0% due April 2021. Preferred stock dividends Dividends preferred stock accrued Dividends, Preferred Stock Total finance costs Finance Costs Net Finance Costs Net Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Shares repurchased (in shares) Stock Repurchased During Period, Shares EXPENSES Expenses: Operating Expenses [Abstract] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Purchase of investments and contributions to joint ventures Payments to Acquire Interest in Joint Venture Increase (Decrease) in Temporary Equity [Roll Forward] Increase (Decrease) in Temporary Equity [Roll Forward] Reclassification, Type [Axis] Reclassification, Type [Axis] Statement [Line Items] Statement [Line Items] Consolidation Items [Axis] Consolidation Items [Axis] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Cash and cash equivalents Cash and Cash Equivalent Borrowings at variable interest rates Long-Term Debt, Percentage Bearing Variable Interest, Amount Subsequent Event [Line Items] Subsequent Event [Line Items] Number of interest rate swaps terminated Number of Interest Rate Derivatives Terminated Number of Interest Rate Derivatives Terminated Deferred income taxes Increase (Decrease) in Deferred Income Taxes Common Stock Common Stock [Member] Shares vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Non-NEOs Non-NEOs [Member] (Decrease) increase in cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Management and Advisory Fees Management and Advisory Fees [Member] Management and Advisory Fees Potentially dilutive common shares (in shares) Weighted Average Number of Shares Outstanding, Diluted, Adjustment