Covered Assets and Indemnification Asset - FDIC Indemnification Asset (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Activity in the FDIC Indemnification Asset
Balance, beginning of period	$ 23,525	$ 40,304	$ 29,340	$ 71,313
FDIC Indemnification Asset accretion (amortization)	(694)	(5,348)	(6,509)	(13,533)
Transfers to due from FDIC and other		(1,813)		(24,637)
Balance, end of period	$ 22,831	$ 33,143	22,831	$ 33,143
FDIC, collections billed			147,800
FDIC, collections received			$ 145,800