Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net periodic benefit cost [Abstract]
Total amount amortized out of accumulated other comprehensive income	$ 766	$ 2,948	$ 1,718	$ 6,358
Defined contribution plan expense	13,247	11,144	26,153	24,014
Post-Retirement Benefits [Member]
Net periodic benefit cost [Abstract]
Service cost	5	7	10	15
Interest cost	78	72	156	145
Prior service cost (credit)	3	4	7	7
Recognized actuarial loss	(16)	(7)	(35)	(15)
Net periodic (income)/expense	70	76	138	152
Qualified Plan [Member] | Defined benefit pension plans | U.S. Pension Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Service cost	1,754	2,303	3,508	5,287
Interest cost	4,756	5,153	9,513	10,255
Expected return on plan assets	(8,534)	(9,745)	(17,068)	(19,956)
Prior service cost (credit)	76	339	151	426
Recognized actuarial loss	0	870	0	2,801
Transition obligation	0	0	0	0
Net periodic (income)/expense	(1,948)	(1,080)	(3,896)	(1,187)
Qualified Plan [Member] | Defined benefit pension plans | Foreign Pension Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Service cost	1,291	1,534	2,836	3,111
Interest cost	1,207	1,343	2,448	2,721
Expected return on plan assets	(1,608)	(2,037)	(3,126)	(4,128)
Prior service cost (credit)	(138)	(111)	(196)	(226)
Recognized actuarial loss	708	782	1,525	1,585
Transition obligation	0	1	0	2
Net periodic (income)/expense	1,460	1,512	3,487	3,065
Nonqualified Plan [Member] | Supplemental Employee Retirement Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Service cost	486	660	971	1,355
Interest cost	668	808	1,335	1,701
Prior service cost (credit)	703	1,351	1,406	2,314
Recognized actuarial loss	(570)	(281)	(1,140)	(536)
Net periodic (income)/expense	1,287	2,538	2,572	4,834
Discontinued Operations [Member] | Qualified Plan [Member] | Defined benefit pension plans | U.S. Pension Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Net periodic (income)/expense	0	273		950
Discontinued Operations [Member] | Qualified Plan [Member] | Defined benefit pension plans | Foreign Pension Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Net periodic (income)/expense	0	73	0	247
Discontinued Operations [Member] | Nonqualified Plan [Member] | Supplemental Employee Retirement Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Net periodic (income)/expense	0	97	0	351
Continuing Operations [Member] | Qualified Plan [Member] | Defined benefit pension plans | U.S. Pension Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Net periodic (income)/expense	(1,948)	(1,353)	(3,896)	(2,137)
Continuing Operations [Member] | Qualified Plan [Member] | Defined benefit pension plans | Foreign Pension Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Net periodic (income)/expense	1,460	1,439	3,487	2,818
Continuing Operations [Member] | Nonqualified Plan [Member] | Supplemental Employee Retirement Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Net periodic (income)/expense	$ 1,287	$ 2,441	$ 2,572	$ 4,483