Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal	$ 26,012	$ 25,479	$ 26,092
State	4,530	3,005	3,365
Total current	30,542	28,484	29,457
Deferred:
Federal	5,869	2,530	1,577
State	(488)	326	43
Deferred tax liability remeasurement	(2,614)	0	0
Total deferred	2,767	2,856	1,620
Total provision	$ 33,309	$ 31,340	$ 31,077