Covered Assets and Indemnification Asset - Covered OREO (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Activity in covered OREO
Balance, beginning of period	$ 35,777	$ 45,374	$ 36,744	$ 51,642
Additions to covered OREO	2,351	3,404	4,846	5,127
Dispositions of covered OREO	(2,565)	(5,531)	(4,972)	(12,330)
Valuation adjustments in the period	(668)	(943)	(1,723)	(2,135)
Balance, end of period	$ 34,895	$ 42,304	$ 34,895	$ 42,304