Accrued Liabilities and Other Long Term Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accrued Liabilities, Current [Abstract]
Accrued expenses	$ 34,108	$ 27,384
Compensation and payroll taxes	23,867	19,423
Equipment purchases	13,060	8,563
Accrued pricing adjustments	3,767	2,328
Accrued professional services	2,082	1,978
Other	917	473
Accrued Liabilities, Current, Total	77,801	60,149
Liabilities, Noncurrent [Abstract]
Accrued defined benefit plan	30,406	37,618
Unrecognized tax benefits, net	20,933	15,425
Deferred grant and subsidy	20,361	9,538
Income tax contingencies	10,782	10,210
Deferred compensation	5,600	4,978
Other	2,071	1,163
Other long-term liabilities, Total	$ 90,153	$ 78,932