Accumulated Other Comprehensive Income (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 (losses)	$ 18	$ (4)	$ 10	$ 64
Tax expense (benefit)	4,680	4,197	9,199	8,883
Net income	11,541	11,566	22,818	23,168
Unrealized Gains (Losses) on AFS Securities [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Securities gains (losses)	18	(4)	10	64
Tax expense (benefit)	6	(1)	4	23
Net income	$ 12	$ (3)	$ 6	$ 41