Revenue Recognition (Schedule of Consolidated Statement of Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net income	$ 10,482	$ 10,974
Other comprehensive income/(loss), before tax:
Foreign currency translation adjustments	17,505	9,938
Amortization of pension liability adjustments:
Prior service credit	(1,114)	(1,113)
Net actuarial loss	1,297	1,347
Payments related to interest rate swaps included in earnings	180	600
Derivative valuation adjustment	5,715	416
Income taxes related to items of other comprehensive income/(loss):
Amortization of pension liability adjustment	(55)	(70)
Payments related to interest rate swaps included in earnings	(43)	(228)
Derivative valuation adjustment	(1,372)	(158)
Comprehensive income	32,595	21,706
Comprehensive income attributable to the noncontrolling interest	230	140
Comprehensive income attributable to the Company	32,365	$ 21,566
As reported [Member]
Net income	10,482
Other comprehensive income/(loss), before tax:
Foreign currency translation adjustments	17,505
Amortization of pension liability adjustments:
Prior service credit	(1,114)
Net actuarial loss	1,297
Payments related to interest rate swaps included in earnings	180
Derivative valuation adjustment	5,715
Income taxes related to items of other comprehensive income/(loss):
Pension/postretirement plan remeasurement
Amortization of pension liability adjustment	(55)
Payments related to interest rate swaps included in earnings	(43)
Derivative valuation adjustment	(1,372)
Comprehensive income	32,595
Comprehensive income attributable to the noncontrolling interest	230
Comprehensive income attributable to the Company	32,365
Adjustments to reverse effects of ASC 606 [Member]
Net income	(1,247)
Other comprehensive income/(loss), before tax:
Foreign currency translation adjustments	(308)
Amortization of pension liability adjustments:
Prior service credit
Net actuarial loss
Payments related to interest rate swaps included in earnings
Derivative valuation adjustment
Income taxes related to items of other comprehensive income/(loss):
Pension/postretirement plan remeasurement
Amortization of pension liability adjustment
Payments related to interest rate swaps included in earnings
Derivative valuation adjustment
Comprehensive income	(1,555)
Comprehensive income attributable to the noncontrolling interest	(57)
Comprehensive income attributable to the Company	(1,498)
As adjusted to exclude adoption of ASC 606 [Member]
Net income	9,235
Other comprehensive income/(loss), before tax:
Foreign currency translation adjustments	17,197
Amortization of pension liability adjustments:
Prior service credit	(1,114)
Net actuarial loss	1,297
Payments related to interest rate swaps included in earnings	180
Derivative valuation adjustment	5,715
Income taxes related to items of other comprehensive income/(loss):
Pension/postretirement plan remeasurement
Amortization of pension liability adjustment	(55)
Payments related to interest rate swaps included in earnings	(43)
Derivative valuation adjustment	(1,372)
Comprehensive income	31,040
Comprehensive income attributable to the noncontrolling interest	173
Comprehensive income attributable to the Company	$ 30,867