Income Taxes - Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal	$ 3,953	$ 11,897	$ 16,664
State	1,736	988	1,866
Current income tax expense (benefit)	5,689	12,885	18,530
Deferred:
Federal	5,001	(17,264)	4,930
State	1,164	1,970	1,227
Deferred income tax expense (benefit)	6,165	(15,294)	6,157
Income Tax Expense (Benefit)	$ 11,854	$ (2,409)	$ 24,687