Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 10,514	$ 42,151	$ 33,484
Other comprehensive income (loss):- Currency translation adjustment	(2,488)	(3,292)	(4,468)
Pension adjustment, net of tax of $624	(1,211)
Comprehensive income	$ 6,815	$ 38,859	$ 29,016