Accrued Liabilities and Other Current Liabilities, and Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accrued Liabilities, Current [Abstract]
Accrued expenses	$ 28,170	$ 29,764
Compensation and payroll taxes	33,632	34,359
Equipment purchases	12,568	20,637
Accrued pricing adjustments	3,591	11,410
Accrued professional services	3,242	2,088
Other	1,402	1,043
Accrued Liabilities, Current, Total	82,605	99,301
Liabilities, Noncurrent [Abstract]
Accrued defined benefit plan	26,349	34,428
Unrecognized tax benefits	27,711	24,211
Deferred grant and subsidy	15,359	17,173
Income tax contingencies	8,475	8,319
Deferred compensation	9,091	8,870
Other	3,794	1,924
Other long-term liabilities, Total	$ 90,779	$ 94,925