Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 10,822	$ (5,525)	$ 41,704	$ (3,077)
Other comprehensive (loss) income, net of tax
Changes in cumulative translation adjustment	(61)	14	(55)	49
Comprehensive income (loss)	$ 10,761	$ (5,511)	$ 41,649	$ (3,028)