Derivative Financial Instruments - Offsetting of Derivative Assets - Derivative Liabilities, Financial Liabilities, and Collateral Held by Counterparty (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Derivative liabilities:
Net amounts of liabilities presented in the consolidated balance sheet	$ 2,488,716	$ 7,319,966
Financial instruments	(2,446,014)	(7,297,360)
Net amount of liabilities in the consolidated balance sheet	42,702	22,606
Credit Suisse First Boston Mortgage Capital LLC
Derivative liabilities:
Net amounts of liabilities presented in the consolidated balance sheet	1,003,404	1,974,278
Financial instruments	(1,002,552)	(1,969,670)
Net amount of liabilities in the consolidated balance sheet	852	4,608
JP Morgan
Derivative liabilities:
Net amounts of liabilities presented in the consolidated balance sheet	111,571	300,912
Financial instruments	(107,675)	(300,912)
Net amount of liabilities in the consolidated balance sheet	3,896
Bank of America, N.A.
Derivative liabilities:
Net amounts of liabilities presented in the consolidated balance sheet	485,306	1,758,690
Financial instruments	(477,673)	(1,758,690)
Net amount of liabilities in the consolidated balance sheet	7,633
Barclays
Derivative liabilities:
Net amounts of liabilities presented in the consolidated balance sheet	60,082	677,419
Financial instruments	(59,891)	(676,685)
Net amount of liabilities in the consolidated balance sheet	191	734
Citibank, N.A.
Derivative liabilities:
Net amounts of liabilities presented in the consolidated balance sheet	228,578	403,003
Financial instruments	(225,646)	(402,806)
Net amount of liabilities in the consolidated balance sheet	2,932	197
Royal Bank of Canada
Derivative liabilities:
Net amounts of liabilities presented in the consolidated balance sheet	182,820	496,064
Financial instruments	(182,820)	(496,064)
BNP Paribas
Derivative liabilities:
Net amounts of liabilities presented in the consolidated balance sheet	37,554	349,172
Financial instruments	(37,554)	(349,172)
Morgan Stanley Bank, N.A.
Derivative liabilities:
Net amounts of liabilities presented in the consolidated balance sheet	88,467	299,580
Financial instruments	(86,760)	(292,105)
Net amount of liabilities in the consolidated balance sheet	1,707	7,475
Wells Fargo Bank, N.A.
Derivative liabilities:
Net amounts of liabilities presented in the consolidated balance sheet	83,803	203,779
Financial instruments	(79,082)	(200,338)
Net amount of liabilities in the consolidated balance sheet	4,721	3,441
Goldman Sachs
Derivative liabilities:
Net amounts of liabilities presented in the consolidated balance sheet	198,695	853,147
Financial instruments	(186,361)	(850,918)
Net amount of liabilities in the consolidated balance sheet	12,334	2,229
Other
Derivative liabilities:
Net amounts of liabilities presented in the consolidated balance sheet	2,902	2,642
Net amount of liabilities in the consolidated balance sheet	2,902	2,642
Interest rate lock commitments
Derivative liabilities:
Net amounts of liabilities presented in the consolidated balance sheet	5,534	1,280
Net amount of liabilities in the consolidated balance sheet	$ 5,534	$ 1,280