UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Other Comprehensive Income (Loss), Tax [Abstract]
Net (loss) income	$ (3,438)	$ 28,927	$ (15,674)	$ 54,837
Other comprehensive (loss) income, net of tax:
Foreign currency translation (loss) gain	(482)	117	(233)	247
Net other comprehensive income (loss), net of ($11), ($26), ($70) and ($92) tax, respectively	78	594	(160)	638
Total other comprehensive (loss) income, net of tax	(404)	711	(393)	885
Total comprehensive (loss) income	$ (3,842)	$ 29,638	$ (16,067)	$ 55,722