Pensions and Other Benefit Programs (Components of Net Periodic Benefit Cost (Income)) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Defined Benefit Pension Plans | United States
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 9	$ 34	$ 46	$ 64
Interest cost	15,108	17,121	30,724	34,366
Expected return on plan assets	(25,119)	(24,369)	(50,543)	(48,917)
Amortization of transition credit	0	0	0	0
Amortization of prior service (credit) cost	(15)	(15)	(30)	(30)
Amortization of net actuarial loss	7,628	7,229	15,704	14,497
Net periodic benefit cost (income)	(2,389)	0	(4,099)	(20)
Contributions to benefit plans	1,906	1,046	3,194	2,594
Defined Benefit Pension Plans | Foreign
Defined Benefit Plan Disclosure [Line Items]
Service cost	575	559	1,164	1,101
Interest cost	4,591	4,640	9,287	9,184
Expected return on plan assets	(9,118)	(7,961)	(18,304)	(15,742)
Amortization of transition credit	(2)	(2)	(3)	(4)
Amortization of prior service (credit) cost	(18)	(17)	(37)	(35)
Amortization of net actuarial loss	1,870	1,892	3,783	3,926
Net periodic benefit cost (income)	(2,102)	(889)	(4,110)	(1,570)
Contributions to benefit plans	769	1,319	9,979	10,391
Nonpension Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	405	434	811	853
Interest cost	1,607	1,770	3,210	3,541
Expected return on plan assets	0	0	0	0
Amortization of transition credit	0	0	0	0
Amortization of prior service (credit) cost	88	74	176	148
Amortization of net actuarial loss	881	905	1,815	1,789
Net periodic benefit cost (income)	2,981	3,183	6,012	6,331
Contributions to benefit plans	$ 4,316	$ 4,426	$ 9,111	$ 9,124