Loan Sales and Servicing Activities - Summary of Cash Flows with Transferees (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Cash flows:
Sales proceeds	$ 16,215,098	$ 39,040,868	$ 67,056,886	$ 118,048,768
Servicing fees received	242,622	$ 178,684	676,384	$ 576,332
Period end information:
Unpaid principal balance of loans outstanding	283,653,037		283,653,037		$ 254,524,015
30-89 days	9,359,346		9,359,346		6,129,597
90 days or more - Not in foreclosure	5,706,722		5,706,722		8,399,299
90 days or more - In foreclosure	726,438		726,438		715,016
90 days or more - Foreclosed	8,324		8,324		6,900
Bankruptcy	1,128,050		1,128,050		1,039,362
30-89 days delinquent under CARES Act	1,501,578		1,501,578		1,020,290
90 days or more delinquent not in foreclosure under CARES Act	2,708,785		2,708,785		2,550,703
Total delinquent loans in COVID-19 pandemic related forbearance	$ 4,210,363		$ 4,210,363		$ 3,570,993