Pension (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
U.S. Plans
Defined Contribution Plan Disclosure [Line Items]
Total matching contribution to all Plans	$ 3.8	$ 3.6
NETHERLANDS | Non-U.S. Plans
Defined Contribution Plan Disclosure [Line Items]
Total matching contribution to all Plans	$ 2.0	$ 1.9
Salaried Employees
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution, percent of match	100.00%
Employer matching contribution, percent	6.00%
Hourly Employees
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution, percent of match	50.00%
Employer matching contribution, percent	6.00%