Loan Sales and Servicing Activities - Summary of Cash Flows with Transferees (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Cash flows:
Sales proceeds	$ 19,676,917	$ 13,385,341
Servicing fees received	336,248	268,423
Allowance for losses rollforward
Balance at beginning of quarter	73,991	78,992
Provision (reversal of provision) for losses	(1,541)	(3,081)
Charge-offs, net	(5,123)	(733)
Balance at end of quarter	67,327	$ 75,178
Period end information:
Unpaid principal balance of loans outstanding	364,441,567		$ 352,790,614
30-89 days	12,128,892		13,775,493
90 days or more - Not in foreclosure	6,251,718		6,754,282
90 days or more - In foreclosure	647,459		618,694
90 days or more - Foreclosed	8,441		7,565
Bankruptcy	$ 1,479,461		$ 1,415,614