Other Noninterest Income and Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other noninterest income:
Gain on sale of ORE, net	$ 659	$ 859	$ 3,084
Trust and investment management income	1,288	628	470
Other operating income	1,044	1,145	2,338
Total	2,991	2,632	5,892
Other noninterest expenses:
Communications	5,549	4,938	4,336
Lending expenses	5,656	7,222	6,390
ORE expenses, net	1,245	2,667	1,737
Employee expenses	3,508	3,722	3,204
Advertising and promotion	2,059	2,188	2,012
FDIC insurance premium	3,430	2,682	1,886
Other operating expenses	14,977	13,896	11,172
Total	$ 36,424	$ 37,315	$ 30,737