Loan Sales and Servicing Activities - Geographical Distribution of Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Loan Sales and Servicing Activities
Total loans serviced	$ 518,810,560	$ 509,708,281
California
Loan Sales and Servicing Activities
Total loans serviced	67,446,975	67,317,935
Florida
Loan Sales and Servicing Activities
Total loans serviced	42,991,482	42,064,686
Texas
Loan Sales and Servicing Activities
Total loans serviced	46,603,815	45,222,233
Virginia
Loan Sales and Servicing Activities
Total loans serviced	31,980,724	31,442,370
Maryland
Loan Sales and Servicing Activities
Total loans serviced	24,332,266	23,922,075
All other states
Loan Sales and Servicing Activities
Total loans serviced	$ 305,455,298	$ 299,738,982