Guarantees - Changes from credit recourses agreements (Details) - Guarantee on loans sold or serviced with credit recourse - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Guarantor Obligations
Balance as of beginning of period	$ 20,244	$ 31,719	$ 22,484	$ 34,862
Impact of adopting CECL	0	0	0	(3,831)
Provision (reversal) for recourse liability	(1,568)	1,050	(751)	5,414
Net charge-offs	(3,014)	(1,464)	(6,071)	(5,140)
Balance as of end of period	$ 15,662	$ 31,305	$ 15,662	$ 31,305