Pension and Other Postretirement Benefit Plans Schedule of Amounts Recognized in Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Deferred tax asset	$ 3,618	$ 5,396
Other long-term liabilities	37,216	45,964
Accumulated other comprehensive loss	(5,456)	(8,353)
Dutch Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Deferred tax asset	4,369	2,564
Other long-term liabilities	7,398	10,253
Accumulated other comprehensive loss	$ (5,650)	$ (8,162)