Income Taxes - Components (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Components of income tax expense (benefit)
Federal income tax statutory rate (as a percent)	35.70%	36.30%	36.00%	36.50%
Income tax expense	$ 2,017	$ 2,357	$ 3,074	$ 5,048