Accumulated Other Comprehensive Income - Reclassifications Out of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Securities gains, net	$ 0	$ 73	$ 590	$ 661
Income taxes	(2,205)	(1,654)	(5,726)	(5,172)
Net Income	4,787	3,963	13,129	12,179
Amount Reclassified from AOCI
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Net Income	0	48	383	430
Realized gain on sale of securities | Amount Reclassified from AOCI
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Securities gains, net	0	73	590	661
Income taxes	$ 0	$ (25)	$ (207)	$ (231)