Pension (Net Pension Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Amortization of unrecognized:
Defined Contribution Plan, Cost Recognized	$ 3,400	$ 3,400	$ 3,100
Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost (benefits earned during the period)	4,943	7,330	5,928
Interest cost on projected benefit obligation	17,557	19,047	20,944
Expected return on plan assets	(23,027)	(25,108)	(24,834)
Amortization of unrecognized:
Prior service cost	56	173	1,223
Actuarial loss	5,054	8,890	5,069
Transition obligations	0	0	60
Settlement charge	168	21,587	774
Curtailment charge (credit)	0	(14)	0
Pension expense	4,751	31,905	9,164
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost (benefits earned during the period)	3,717	4,365	3,664
Interest cost on projected benefit obligation	14,963	14,715	15,378
Expected return on plan assets	(23,027)	(22,661)	(22,387)
Amortization of unrecognized:
Prior service cost	263	417	1,059
Actuarial loss	4,272	7,291	4,057
Transition obligations	0	0	0
Settlement charge	42	13	483
Curtailment charge (credit)	0	0	0
Pension expense	230	4,140	2,254
Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost (benefits earned during the period)	1,226	2,965	2,264
Interest cost on projected benefit obligation	2,594	4,332	5,566
Expected return on plan assets	0	(2,447)	(2,447)
Amortization of unrecognized:
Prior service cost	(207)	(244)	164
Actuarial loss	782	1,599	1,012
Transition obligations	0	0	60
Settlement charge	126	21,574	291
Curtailment charge (credit)	0	(14)	0
Pension expense	4,521	27,765	$ 6,910
NETHERLANDS
Amortization of unrecognized:
Defined Contribution Plan, Cost Recognized	$ 1,900
NETHERLANDS | Non-U.S. Plans
Amortization of unrecognized:
Settlement charge		$ 21,600