Certain Transfers of Financial Assets Certain Transfers of Financial Assets (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Outstanding balance:
Beginning balance	$ 2,568,362	$ 1,949,785
Loans purchased and originated	8,963,499	7,288,823
Payments and loans sold	(10,889,549)	(6,571,942)
Ending balance	642,312	2,666,666
Fair value adjustment:
Fair value over (under) outstanding balance	8,772	19,689
Increase/(decrease) to fair value	(3,075)	(12,130)
Fair value over (under) outstanding balance	5,697	7,559
Loans held for sale	648,009	2,674,225	$ 2,577,134
Small Business Administration Loans [Member]
Fair value adjustment:
Fair value over (under) outstanding balance	5,800	299
Fair value over (under) outstanding balance	$ 9,000	$ 7,100