Pensions and Other Postretirement Benefit Plans (Schedule of Funded Status of Plans and Composition of Accrued Pension Cost) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Noncurrent asset	$ 7,800	$ 10,400
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	180,672	171,387	$ 183,199
Benefit obligation	210,856	199,856	213,110
Funded status	(30,184)	(28,469)
Noncurrent asset	7,794	10,423
Current liability	(2,057)	(2,110)
Noncurrent liability	(35,921)	(36,782)
Net amount recognized	(30,184)	(28,469)
Net actuarial loss	72,400	69,896
Prior service cost/(credit)	597	608
Net amount recognized	72,997	70,504
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Benefit obligation	57,488	59,970	$ 64,987
Funded status	(57,488)	(59,970)
Noncurrent asset
Current liability	(4,195)	(4,660)
Noncurrent liability	(53,293)	(55,310)
Net amount recognized	(57,488)	(59,970)
Net actuarial loss	34,782	37,997
Prior service cost/(credit)	(30,899)	(35,387)
Net amount recognized	3,883	$ 2,610
U.S. Pension Plans with Pension Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Net amount recognized	(5,197)
U.S. Pension Plans without Pension Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Net amount recognized	(7,761)
United States Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net amount recognized	(12,958)
Non-U.S. Pension Plans with Pension Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Net amount recognized	5,648
Non-U.S. Pension Plans without Pension Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Net amount recognized	(22,874)
Non-U.S. Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net amount recognized	17,226
Pension Plans with Pension Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Net amount recognized	451
Pension Plans without Pension Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Net amount recognized	$ (30,635)