Loan Sales and Servicing Activities - Summary of Cash Flows with Transferees (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Cash flows:
Sales proceeds	$ 34,656,042	$ 24,860,532	$ 62,243,471	$ 44,537,449
Servicing fees received	411,531	348,730	807,763	684,978
Allowance for losses rollforward
Balance at beginning of quarter	82,155	67,327	85,788	73,991
Provision for losses	7,786	5,932	11,970	4,391
Charge-offs, net	(7,916)	(4,588)	(15,733)	(9,711)
Balance at end of quarter	82,025	$ 68,671	82,025	$ 68,671
Period end information:
Unpaid principal balance of loans outstanding	448,312,667		448,312,667		$ 410,393,342
30-89 days	17,747,455		17,747,455		17,301,961
90 days or more - Not in foreclosure	6,819,040		6,819,040		8,104,348
90 days or more - In foreclosure	1,183,032		1,183,032		693,934
90 days or more - Foreclosed	3,254		3,254		2,928
Loans in bankruptcy	$ 1,936,703		$ 1,936,703		$ 1,762,324