Loan Sales and Servicing Activities - Geographical Distribution of Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Loan Sales and Servicing Activities
Total loans serviced	$ 589,392,888	$ 551,674,682
California
Loan Sales and Servicing Activities
Total loans serviced	70,097,836	68,542,279
Florida
Loan Sales and Servicing Activities
Total loans serviced	55,873,979	50,873,961
Texas
Loan Sales and Servicing Activities
Total loans serviced	54,118,039	47,911,696
Virginia
Loan Sales and Servicing Activities
Total loans serviced	34,798,867	33,478,151
Maryland
Loan Sales and Servicing Activities
Total loans serviced	26,367,206	25,473,417
All other states
Loan Sales and Servicing Activities
Total loans serviced	$ 348,136,961	$ 325,395,178