Loan Sales and Servicing Activities - Summary of Cash Flows with Transferees (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Cash flows:
Sales proceeds	$ 24,860,532	$ 25,024,768	$ 44,537,449	$ 38,410,109
Servicing fees received	348,730	282,315	684,978	550,738
Allowance for losses rollforward
Balance at beginning of period	67,327	75,178	73,991	78,992
Provision (reversal of provision) for losses	5,932	(1,968)	4,391	(5,049)
Charge-offs, net	(4,588)	(3,140)	(9,711)	(3,873)
Balance at end of period	68,671	$ 70,070	68,671	$ 70,070
Period end information:
Unpaid principal balance of loans outstanding	379,882,952		379,882,952		$ 352,790,614
30-89 days	14,965,096		14,965,096		13,775,493
90 days or more - Not in foreclosure	6,380,651		6,380,651		6,754,282
90 days or more - In foreclosure	576,397		576,397		618,694
90 days or more - Foreclosed	6,889		6,889		7,565
Bankruptcy	$ 1,615,265		$ 1,615,265		$ 1,415,614