Employee Benefit Plans - Net Periodic Pension Costs (Details 5) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Components of net periodic pension cost (benefit) of the plans
Settlement	$ 800
U.S. Plans
Components of net periodic pension cost (benefit) of the plans
Service cost	1,136	$ 895	$ 1,165
Interest cost	4,499	4,815	4,423
Expected return on plan assets	(7,070)	(7,541)	(6,660)
Amortization of prior service cost	15	74	74
Net actuarial loss amortization	2,606	877	3,519
Settlement	607	1,025
Net periodic pension cost (benefit)	1,793	145	2,521
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss)
Current year actuarial (loss) gain	(3,348)	(19,756)	21,997
Amortization of actuarial loss	2,606	877	3,519
Amortization of prior service cost	15	74	74
Settlement	607	1,025
Total recognized in other comprehensive income (loss)	(120)	(17,780)	25,590
Total recognized in net periodic pension cost and other comprehensive income (loss)	(1,913)	(17,925)	23,069
Estimated amounts that will be amortized from accumulated other comprehensive income (loss) into net periodic pension cost
Net actuarial loss	3,136
Estimated amounts that will be amortized from accumulated other comprehensive income into net periodic pension cost	3,136
European Plans
Components of net periodic pension cost (benefit) of the plans
Service cost	288	342	314
Interest cost	1,250	1,653	1,511
Expected return on plan assets	(1,705)	(1,549)	(1,263)
Net actuarial loss amortization	219	245	203
Settlement	199		279
Net periodic pension cost (benefit)	251	691	1,044
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss)
Current year actuarial (loss) gain	(984)	(2,117)	(1,046)
Amortization of actuarial loss	219	245	203
Settlement	199		279
Foreign currency exchange	603	818	(292)
Total recognized in other comprehensive income (loss)	37	(1,054)	(856)
Total recognized in net periodic pension cost and other comprehensive income (loss)	(214)	$ (1,745)	$ (1,900)
Estimated amounts that will be amortized from accumulated other comprehensive income (loss) into net periodic pension cost
Net actuarial loss	235
Estimated amounts that will be amortized from accumulated other comprehensive income into net periodic pension cost	$ 235