CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest [Abstract]
Net income	$ 20,132	$ 13,890	$ 48,429	$ 20,653
Translation adjustment	(8,788)	11,983	(8,933)	3,588
Unrealized loss on defined benefit plan, net of tax	(4,991)	(3,687)	(5,541)	(2,506)
Comprehensive income	6,353	22,186	33,955	21,735
Less: Comprehensive income attributable to noncontrolling interest	(705)	(271)	(1,415)	(325)
Total comprehensive income attributable to common stockholders	$ 5,648	$ 21,915	$ 32,540	$ 21,410