FDIC Shared-Loss Payable (Changes in Receivable from FDIC) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
FDIC Indemnification Asset [Roll Forward]
Beginning balance	$ 112,395	$ 112,395	$ 105,618
Accretion		2,674	6,777
Payment made to the FDIC to settle shared-loss agreement	$ 99,500	(99,468)	0
Ending balance		$ 15,601	$ 112,395