CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE 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)	$ 4,910	$ (14,064)	$ 15,202	$ (16,892)
Change in cumulative foreign currency translation adjustment	(236)	2,952	(2,987)	9,730
Total comprehensive income (loss)	$ 4,674	$ (11,112)	$ 12,215	$ (7,162)