Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.20%		4.20%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets			6.80%
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment	$ 200
Net periodic benefit cost [Abstract]
Total amount amortized out of accumulated other comprehensive income	1,407	$ 3,049	$ 7,765	$ 9,071
Defined contribution plan expense	8,649	7,521	27,500	25,632
U.S. Pension Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Service cost	1,861	3,021	7,148	9,063
Interest cost	5,236	5,429	15,491	16,288
Expected return on plan assets	(9,518)	(9,953)	(29,474)	(29,859)
Prior service cost (credit)	69	107	495	320
Recognized actuarial loss	150	1,396	2,951	4,187
Transition obligation	0	0	0	0
Net periodic (income)/expense	(2,202)	0	(3,389)	(1)
Foreign Pension Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Service cost	1,054	1,399	4,165	4,059
Interest cost	1,098	1,332	3,819	3,881
Expected return on plan assets	(1,710)	(1,885)	(5,838)	(5,522)
Prior service cost (credit)	(112)	(115)	(338)	(337)
Recognized actuarial loss	673	894	2,258	2,599
Transition obligation	0	1	2	3
Net periodic (income)/expense	1,003	1,626	4,068	4,683
Supplemental Employee Retirement Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Service cost	635	619	1,990	1,855
Interest cost	751	1,019	2,452	3,057
Prior service cost (credit)	931	1,103	3,245	3,308
Recognized actuarial loss	(298)	(298)	(834)	(894)
Net periodic (income)/expense	2,019	2,443	6,853	7,326
Post-Retirement Benefits [Member]
Net periodic benefit cost [Abstract]
Service cost	8	8	23	25
Interest cost	73	74	218	220
Prior service cost (credit)	3	2	10	6
Recognized actuarial loss	(8)	(41)	(23)	(121)
Net periodic (income)/expense	76	43	228	130
Discontinued Operations [Member] | U.S. Pension Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Net periodic (income)/expense	0	846	950	2,537
Discontinued Operations [Member] | Foreign Pension Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Net periodic (income)/expense	0	203	247	608
Discontinued Operations [Member] | Supplemental Employee Retirement Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Net periodic (income)/expense	0	307	351	920
Continuing Operations [Member] | U.S. Pension Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Net periodic (income)/expense	(2,202)	(846)	(4,339)	(2,538)
Continuing Operations [Member] | Foreign Pension Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Net periodic (income)/expense	1,003	1,423	3,821	4,075
Continuing Operations [Member] | Supplemental Employee Retirement Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Net periodic (income)/expense	$ 2,019	$ 2,136	$ 6,502	$ 6,406