Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 15,100	$ (15,587)	$ 15,587
Other comprehensive gain (loss), net of tax:
Foreign currency translation gain (loss)	1,766	(517)	(702)
Total other comprehensive income (loss)	1,766	(517)	(702)
Comprehensive income (loss)	$ 16,866	$ (16,104)	$ 14,885