Loan Sales and Servicing Activities - Summary of Cash Flows with Transferees (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Cash flows:
Sales proceeds	$ 13,385,341	$ 31,267,022
Servicing fees received	268,423	$ 204,928
Period end information:
Unpaid principal balance of loans outstanding	302,265,588		$ 295,032,674
30-89 days	9,485,878		11,019,194
90 days or more - Not in foreclosure	6,497,578		6,548,849
90 days or more - In foreclosure	793,231		834,155
90 days or more - Foreclosed	12,265		12,905
Bankruptcy	1,181,793		1,143,484
30-89 days delinquent under CARES Act	725,398		950,172
90 days or more delinquent not in foreclosure under CARES Act	2,464,057		2,934,718
Total delinquent loans in COVID-19 pandemic related forbearance	$ 3,189,455		$ 3,884,890