Income Taxes - Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current taxes:
Domestic	$ 4,944	$ 16,036	$ 8,424
Foreign	27	254
Current income tax expense	4,971	16,290	8,424
Deferred taxes:
Domestic	(1,830)	1,656	2,238
Foreign	1	(100)	(371)
Deferred income tax expense	(1,829)	1,556	1,867
Provision for income taxes	3,142	17,846	10,291
Income before income taxes
Domestic	7,437	50,692	27,984
Foreign	1,104	(1,585)	(1,721)
Income before income taxes	$ 8,541	$ 49,107	$ 26,263
Effective income tax rate (as a percent)	36.80%	36.30%	39.10%