Guarantees - Changes from credit recourses agreements (Details) - Guarantee on loans sold or serviced with credit recourse - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Guarantor Obligations
Balance as of beginning of period	$ 22,484	$ 34,862
Impact of adopting CECL	0	(3,831)
Provision for recourse liability	817	4,364
Net charge-offs	(3,057)	(3,676)
Balance as of end of period	$ 20,244	$ 31,719