Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Net periodic benefit cost [Abstract]
Total amount amortized out of accumulated other comprehensive income	$ 3,695	$ 5,753	$ 11,084	$ 17,316
Defined contribution plan expense	8,153	7,601	26,310	24,612
U.S. Pension Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Service cost	3,478	3,915	10,435	11,746
Interest cost	5,762	5,790	17,285	17,372
Expected return on plan assets	(9,698)	(10,392)	(29,095)	(31,178)
Prior service cost (income)	184	225	550	673
Recognized actuarial loss	1,610	3,155	4,828	9,465
Transition obligation	0	0	0	0
Other	0	0	0	810
Net periodic benefit cost	1,336	2,693	4,003	8,888
Foreign Pension Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Service cost	1,389	1,655	4,167	5,006
Interest cost	1,334	1,482	4,103	4,444
Expected return on plan assets	(1,899)	(2,012)	(5,821)	(6,042)
Prior service cost (income)	(100)	22	(299)	67
Recognized actuarial loss	670	665	2,010	2,001
Transition obligation	1	(15)	3	3
Other	0	2	0	5
Net periodic benefit cost	1,395	1,799	4,163	5,484
Supplemental Employee Retirement Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Service cost	740	934	2,219	2,804
Interest cost	1,317	1,266	3,951	3,797
Prior service cost (income)	1,567	1,731	4,700	5,195
Recognized actuarial loss	(141)	71	(421)	214
Net periodic benefit cost	3,483	4,002	10,449	12,010
Post-Retirement Benefits [Member]
Net periodic benefit cost [Abstract]
Service cost	13	41	39	122
Interest cost	105	128	314	384
Prior service cost (income)	(36)	(93)	(107)	(279)
Recognized actuarial loss	(59)	(8)	(177)	(23)
Net periodic benefit cost	$ 23	$ 68	$ 69	$ 204