FDIC Shared-Loss Receivable (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
FDIC Shared-Loss Receivable [Abstract]
Net payment to the FDIC for termination of shared-loss agreements	$ 0	$ 285
Termination of FDIC shared-loss agreements	0	240
Loss on termination of FDIC share-loss agreements	0	(45)
FDIC shared-loss payable	102,466	98,013	$ 101,342	$ 97,008
Net Impact from FDIC shared-loss termination	0	$ (45)
Loans and Leases Receivable, Gross, Carrying Amount, Covered	$ 65,500		$ 67,800