Covered Assets and FDIC Loss-sharing Asset (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Mar. 31, 2017
Covered Assets And FDIC Loss Sharing Asset [Line Items]
Payment from (to) FDIC to terminate loss-sharing agreements				$ 4,666	$ 0
FDIC indemnification asset settlement	$ 0	$ 3,123	$ 0		0
FDIC clawback liability removal upon termination of loss-sharing agreements		$ 5,400
FDIC loss-sharing agreement early termination, pretax charge				$ 2,409	$ 0
Non-Single Family Covered Assets						$ 74,000
Single Family Covered Assets						$ 26,400