Accumulated Other Comprehensive Income - Reclassifications Out of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Securities gains, net	$ 331	$ 222	$ 590	$ 588
Income taxes	(1,920)	(1,733)	(3,521)	(3,518)
Net Income	4,279	4,088	8,342	8,216
Amount Reclassified from AOCI
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Net Income	215	144	383	382
Realized gain on sale of securities | Amount Reclassified from AOCI
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Securities gains, net	331	222	590	588
Income taxes	$ (116)	$ (78)	$ (207)	$ (206)