Loan Sales and Servicing Activities - Geographical Distribution of Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Loan Sales and Servicing Activities
Total loans serviced	$ 388,305,875	$ 368,684,232
California
Loan Sales and Servicing Activities
Total loans serviced	57,483,007	57,311,867
Florida
Loan Sales and Servicing Activities
Total loans serviced	31,896,387	28,940,696
Texas
Loan Sales and Servicing Activities
Total loans serviced	30,394,027	27,909,821
Virginia
Loan Sales and Servicing Activities
Total loans serviced	23,467,173	22,115,619
Maryland
Loan Sales and Servicing Activities
Total loans serviced	17,783,314	16,829,320
All other states
Loan Sales and Servicing Activities
Total loans serviced	$ 227,281,967	$ 215,576,909