Fair Value - Assets and Liabilities Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Details) - Level 3 - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Loans held for investment
Assets
Beginning balance	$ 20,005,484	$ 19,190,065
Total gain (loss) included in earnings	450,670	382,169
Purchases and additions	857,672	810,325
Sales and settlements	(585,580)	(620,532)
Transfers in (out) between categories	(952,736)	(318,900)
Ending balance	19,775,510	19,443,127
Loans held for investment, subject to nonrecourse debt
Assets
Beginning balance	10,026,177	9,288,403
Total gain (loss) included in earnings	81,456	257,903
Purchases and additions	6,661	6,900
Sales and settlements	(298,082)	(242,557)
Transfers in (out) between categories	952,997	319,501
Ending balance	10,769,209	9,630,150
Loans held for sale
Assets
Beginning balance	36,123
Total gain (loss) included in earnings	3,984
Purchases and additions	43,760
Sales and settlements	0
Transfers in (out) between categories	0
Ending balance	83,867
Retained bonds
Assets
Beginning balance	38,685	40,407
Total gain (loss) included in earnings	(198)	988
Purchases and additions	0	0
Sales and settlements	(659)	(1,061)
Transfers in (out) between categories	(3,761)	0
Ending balance	34,067	40,334
HMBS related obligations
Liabilities
Beginning balance	(18,912,226)	(18,444,370)
Total gain (loss) included in earnings	(327,169)	(295,682)
Purchases and additions	(497,572)	(466,008)
Settlements	649,317	615,703
Transfers out between categories	0
Ending balance	(19,087,650)	(18,590,357)
Nonrecourse debt
Liabilities
Beginning balance	(9,736,493)	(8,954,068)
Total gain (loss) included in earnings	(68,864)	(152,909)
Purchases and additions	(1,694,792)	(780,901)
Settlements	1,045,554	724,479
Transfers out between categories	3,761
Ending balance	(10,450,834)	(9,163,399)
Deferred purchase price liabilities
Liabilities
Beginning balance	(12,547)	(16,684)
Total gain (loss) included in earnings	2,232	2,331
Purchases and additions	0	0
Settlements	5,791	2,206
Transfers out between categories	0
Ending balance	$ (4,524)	$ (12,147)

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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 transfer of financial instrument classified as an asset into (out of) level 3 of the fair value hierarchy.

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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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