Other Real Estate Owned and Repossessed Assets - Rollforward Tables (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Changes in other real estate owned
Balance at the beginning of the period	$ 16,812	$ 9,716
Additions due to acquisitions		13,227
Other additions	5,339	3,945
Net payments received	(582)	(171)
Disposals	(10,180)	(6,232)
Write-downs	(1,323)	(376)
Balance at the end of the period	10,066	20,109
Changes in repossessed assets
Balance at the beginning of the period	375	219
Additions due to acquisitions		313
Other additions	3,633	2,084
Net payments received	0	(764)
Disposals	(3,469)	(1,231)
Write-downs	0	0
Balance at the end of the period	$ 539	$ 621