Accumulated Other Comprehensive Income - Significant Amounts Reclassified Out of Each Component of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Net gain on sale of available-for-sale securities	$ 0	$ 2
Provision for income taxes	(273)	(296)
Net income	$ 956	802
Amount Reclassified From Accumulated Other Comprehensive Income | Unrealized gains and losses on available-for-sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Net gain on sale of available-for-sale securities		2
Provision for income taxes		(1)
Net income		$ 1