Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Net periodic benefit cost [Abstract]
Total amount amortized out of accumulated other comprehensive income	$ 2,523	$ 952
Defined contribution plan expense	14,048	12,906
Post-Retirement Benefits [Member]
Net periodic benefit cost [Abstract]
Service cost	5	5
Interest cost	60	78
Prior service cost (credit)	3	3
Recognized actuarial loss	(4)	(18)
Net periodic (income)/expense	64	68
Qualified Plan [Member] | Defined benefit pension plans | United States
Net periodic benefit cost [Abstract]
Service cost	1,706	1,754
Interest cost	4,068	4,756
Expected return on plan assets	(7,869)	(8,534)
Prior service cost (credit)	57	76
Recognized actuarial loss	1,884	0
Net periodic (income)/expense	(154)	(1,948)
Qualified Plan [Member] | Defined benefit pension plans | Foreign Pension Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Service cost	1,293	1,545
Interest cost	825	1,241
Expected return on plan assets	(1,677)	(1,517)
Prior service cost (credit)	(119)	(58)
Recognized actuarial loss	742	816
Net periodic (income)/expense	1,064	2,027
Nonqualified Plan [Member] | Supplemental Employee Retirement Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Service cost	318	486
Interest cost	441	668
Prior service cost (credit)	424	703
Recognized actuarial loss	(464)	(570)
Net periodic (income)/expense	$ 719	$ 1,287