Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income before income taxes:
Domestic	$ 28,327	$ 13,934	$ 31,748
Foreign	8,069	11,381	11,070
Income before income taxes	36,396	25,315	42,818
Current income tax expense:
Domestic	1,912	6,505	3,556
Foreign	2,777	2,080	2,736
Total current	4,689	8,585	6,292
Deferred income tax expense (benefit):
Domestic	19,935	(8,842)	4,565
Foreign	321	(168)	(197)
Total deferred	20,256	(9,010)	4,368
Total income tax (benefit) expense	$ 24,945	$ (425)	$ 10,660