Fair Value Measurement - Schedule of Level Three Assets and Liabilities Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Beneficial interest liabilities (derivatives)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning balance	$ 10,158	$ 10,532	$ 5,075	$ 10,089
Additions	0	0	0	0
Repayments and settlements / Payments on beneficial interests	(2,775)	(4,052)	(2,251)	(15,716)
Changes in fair value recorded in earnings	13,167	6,706	17,726	18,813
Fair value, ending balance	20,550	13,186	20,550	13,186
Beneficial Interests
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning balance	545,938	266,761	396,216	176,848
Acquisitions of beneficial interests	144,926	109,529	397,661	219,399
Repayments and settlements	(83,312)	(52,812)	(195,611)	(96,253)
Charge-offs and changes in fair value recorded in earnings	6,100	(7,279)	15,386	16,205
Fair value, ending balance	613,652	316,199	613,652	316,199
Fair Value, Inputs, Level 3 \| Payable to Securitization Note Holders
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning balance	32,122	65,152	46,542	87,321
Additions	0	0	0	0
Repayments and settlements / Payments on beneficial interests	(6,491)	(10,002)	(20,640)	(32,023)
Changes in fair value recorded in earnings	(126)	25	(397)	(123)
Fair value, ending balance	25,505	55,175	25,505	55,175
Fair Value, Inputs, Level 3 \| Line of Credit Receivable
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning balance	111,772	107,456	112,742	56,269
Issuances	2,297	9,453	7,976	59,292
Repayments and settlements	(3,719)	(2,375)	(10,046)	(2,375)
Charge-offs and changes in fair value recorded in earnings	(233)	236	(528)	1,299
Changes in accrued interest	(7)	76	(34)	361
Fair value, ending balance	110,110	114,846	110,110	114,846
Fair Value, Inputs, Level 3 \| Notes receivable and residual certificates (at fair value)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning balance	120,375	54,708	97,416	22,055
Acquisitions of beneficial interests	42,914	27,525	91,755	65,880
Repayments and settlements	(18,402)	(6,374)	(45,456)	(12,895)
Charge-offs and changes in fair value recorded in earnings	(274)	902	898	1,721
Fair value, ending balance	$ 144,613	$ 76,761	$ 144,613	$ 76,761

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Additions

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Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Changes In Accrued Interest

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

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Amount of issuances of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

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Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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