Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current
Federal									$ 31,679	$ 17,004	$ 16,474
State									2,131	995	540
Total									33,810	17,999	17,014
Deferred
Federal									10,480	12,625	8,649
State									557	1,126	642
Total									11,037	13,751	9,291
Total income tax expense	$ 11,461	$ 11,706	$ 11,154	$ 10,526	$ 10,149	$ 7,742	$ 6,842	$ 7,017	$ 44,847	$ 31,750	$ 26,305