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		$ 23,000	$ 491	$ 2,898
Other comprehensive income (loss), net of tax
Currency translation adjustment	[1]	2,263	220	17
Comprehensive income		25,263	711	2,915
Net income attributable to noncontrolling interest, net of tax		184	1,652	936
Total comprehensive income		$ 25,079	$ (941)	$ 1,979

[1] No other comprehensive income is attributable to noncontrolling interests.