Other Real Estate - Changes and Gains (Losses), Net on Other Real Estate (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Reconciliation Of Carrying Amount Of Real Estate Investments Roll Forward
Balance at beginning of period				$ 43,228	$ 62,051
Additions	[1]			10,368	7,481
Disposals				(15,264)	(18,583)
Write-downs				(1,857)	(2,593)
Balance at end of period		$ 36,475	$ 48,356	36,475	48,356
Gains (losses), net on the sale of other real estate included in other real estate expense		$ 224	$ 200	$ 1,226	$ 1,722

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