Retirement Benefits (Defined Benefit Pension Plans) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net periodic benefit cost:
Mark-to-market actuarial net loss (gain)	$ 13,300	$ (16,500)
Change in benefit obligation:
Actuarial loss (gain)				$ 17,900
Amounts recognized in the balance sheet:
Accrued expenses and other current liabilities	(73,759)	(52,867)	$ (73,759)	(52,867)
Postretirement and pension liabilities	(174,021)	(166,681)	(174,021)	(166,681)
United States [Member] | Pension Plan [Member]
Net periodic benefit cost:
Service cost			10	11	$ 11
Interest cost			11,787	11,308	14,594
Expected return on plan assets			(12,622)	(15,982)	(20,111)
Amortization of prior service cost					7
Mark-to-market actuarial net loss (gain)			1,228	16,633	(5,432)
Curtailment and settlement effects losses					2,581
Total net periodic benefit cost (credit)			403	11,970	(8,350)
Change in benefit obligation:
Benefit obligation at beginning of year			279,885	303,170
Service cost			10	11	11
Interest cost			11,787	11,308	14,594
Settlements				(25)
Benefits paid			(19,978)	(20,165)
Actuarial loss (gain)			24,477	(14,414)
Benefit obligation at end of year	296,181	279,885	296,181	279,885	303,170
Accumulated benefit obligation at end of year	296,181	279,885	296,181	279,885
Fair value of plan assets at beginning of year			204,425	239,260
Actual return on plan assets			35,871	(15,065)
Employer contributions			2,909	420
Benefits paid			(19,978)	(20,165)
Effect of settlements				(25)
Fair value of plan assets at end of year	223,227	204,425	223,227	204,425	$ 239,260
Amounts recognized in the balance sheet:
Accrued expenses and other current liabilities	(410)	(404)	(410)	(404)
Postretirement and pension liabilities	(72,544)	(75,056)	(72,544)	(75,056)
Funded status	$ (72,954)	$ (75,460)	$ (72,954)	$ (75,460)
Weighted-average assumptions as of December 31:
Discount rate			4.40%	3.80%	4.40%
Discount rate	3.35%	4.40%	3.35%	4.40%
Expected return on plan assets			7.70%	7.70%	8.20%
Pension plans with benefit obligations in excess of plan assets:
Benefit obligations	$ 296,181	$ 279,885	$ 296,181	$ 279,885
Plan assets	223,227	204,425	223,227	204,425
Pension plans with accumulated benefit obligations in excess of plan assets:
Projected benefit obligations	296,181	279,885	296,181	279,885
Accumulated benefit obligations	296,181	279,885	296,181	279,885
Plan assets	223,227	204,425	223,227	204,425
Prior service (cost):
Balance at beginning of year
Amounts recognized as net periodic benefit costs
Plan amendments
Exchange rate effects
Balance at end of year
Estimated amounts to be amortized in 2020
Non-U.S. Pension Plans [Member] | Pension Plan [Member]
Net periodic benefit cost:
Service cost			1,410	1,392	1,410
Interest cost			2,264	2,166	2,089
Expected return on plan assets			(758)	(755)	(773)
Amortization of prior service cost			7	6	8
Mark-to-market actuarial net loss (gain)			11,033	2,444	(1,792)
Curtailment and settlement effects losses			292	156	28
Special termination benefits				106	27
Total net periodic benefit cost (credit)			14,248	5,515	997
Change in benefit obligation:
Benefit obligation at beginning of year			106,098	109,450
Service cost			1,410	1,392	1,410
Interest cost			2,264	2,166	2,089
Curtailments			(45)
Amendments			23
Settlements			(734)	(517)
Special termination benefits				106
Plan participants' contributions			14	21
Benefits paid			(5,367)	(2,658)
Net transfer in				140
Actuarial loss (gain)			14,949	816
Exchange rate effect			(1,914)	(4,818)
Benefit obligation at end of year	116,698	106,098	116,698	106,098	109,450
Accumulated benefit obligation at end of year	107,332	97,406	107,332	97,406
Fair value of plan assets at beginning of year			32,979	36,314
Actual return on plan assets			4,336	(1,029)
Employer contributions			3,277	2,523
Plan participants' contributions			14	21
Benefits paid			(5,367)	(2,658)
Effect of settlements			(734)	(517)
Exchange rate effect			(607)	(1,675)
Fair value of plan assets at end of year	33,898	32,979	33,898	32,979	$ 36,314
Amounts recognized in the balance sheet:
Other non-current assets	44		44
Accrued expenses and other current liabilities	(2,589)	(2,912)	(2,589)	(2,912)
Postretirement and pension liabilities	(80,255)	(70,205)	(80,255)	(70,205)
Funded status	$ (82,800)	$ (73,117)	$ (82,800)	$ (73,117)
Weighted-average assumptions as of December 31:
Discount rate			2.61%	2.35%	2.24%
Discount rate	1.76%	2.61%	1.76%	2.61%
Rate of compensation increase			3.19%	3.18%	3.14%
Rate of compensation increase	3.11%	3.19%	3.11%	3.19%
Expected return on plan assets			2.74%	2.55%	2.54%
Pension plans with benefit obligations in excess of plan assets:
Benefit obligations	$ 84,791	$ 78,791	$ 84,791	$ 78,791
Plan assets	1,946	5,674	1,946	5,674
Pension plans with accumulated benefit obligations in excess of plan assets:
Projected benefit obligations	84,338	76,097	84,338	76,097
Accumulated benefit obligations	75,073	67,619	75,073	67,619
Plan assets	1,553	3,100	1,553	3,100
Prior service (cost):
Balance at beginning of year			(22)	2
Amounts recognized as net periodic benefit costs			(7)	(6)
Plan amendments			(14)
Exchange rate effects			(1)	(18)
Balance at end of year	(44)	$ (22)	(44)	$ (22)	$ 2
Estimated amounts to be amortized in 2020	$ (8)		$ (8)