Other Real Estate - Changes and Gains (Losses), Net on Other Real Estate (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Reconciliation Of Carrying Amount Of Real Estate Investments Roll Forward
Balance at beginning of period				$ 43,228	$ 62,051
Additions	[1]			7,084	4,498
Disposals				(9,680)	(14,430)
Write-downs				(965)	(2,161)
Balance at end of period		$ 39,667	$ 49,958	39,667	49,958
Gains (losses), net on the sale of other real estate included in other real estate expense		$ 588	$ 1,100	$ 1,002	$ 1,518

[1] Includes $475 thousand of other real estate acquired in the Reliance merger on April 7, 2017.