Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Amortization of:
one-time non-cash charge		$ 7,700
Pension and other postretirement benefit plans, accumulated other comprehensive income (loss), net Transition Assets (Obligations), before Tax		$ 12,800
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Reclassification Adjustments, Net of Tax			$ 500
Contribution to pension plans				$ 65,300
Estimated total contributions				80,000
Pension Benefits [Member]
Amortization of:
Net pension expense	$ 12,950		10,049	46,968	$ 30,863
Company Administered Plan [Member] | Pension Benefits [Member]
Components of net periodic benefit cost
Service cost	2,660		3,612	9,065	10,805
Interest cost	22,754		21,777	72,086	65,712
Expected return on plan assets	(22,601)		(24,697)	(68,353)	(74,618)
Amortization of:
Net actuarial loss	7,324		7,665	23,889	23,137
Prior service cost/(credit)	320		(80)	3,060	(230)
Net pension expense	10,457		8,277	39,747	24,806
Company Administered Plan [Member] | Pension Benefits U.S. [Member]
Amortization of:
Net pension expense	10,952		8,746	41,389	26,237
Company Administered Plan [Member] | Pension Benefits Non-U.S. [Member]
Amortization of:
Net pension expense	(495)		(469)	(1,642)	(1,431)
Union Administered Plan [Member] | Pension Benefits [Member]
Amortization of:
Net pension expense	$ 2,493		$ 1,772	$ 7,221	$ 6,057