Employee Benefits Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension expense from continuing operations
Pension lump sum settlement expense	$ 0	$ 97,231	$ 0
Amortization of:
Postretirement benefit (income) expense	41,704	138,656	48,118
Company-administered plans:
Pension expense from continuing operations
Service cost	13,820	13,023	15,991
Interest cost	88,013	100,909	89,682
Expected return on plan assets	(98,892)	(115,410)	(106,150)
Pension lump sum settlement expense	0	97,231	0
Census data adjustment	0	0	(3,905)
Amortization of:
Net actuarial gain	30,741	23,573	35,282
Prior service credit	(306)	(1,788)	(1,818)
Postretirement benefit (income) expense	33,376	117,538	36,892
Company-administered plans: | U.S.
Amortization of:
Postretirement benefit (income) expense	34,986	118,797	37,636
Company-administered plans: | Foreign
Amortization of:
Postretirement benefit (income) expense	(1,610)	(1,259)	(744)
Union-administered plans
Amortization of:
Postretirement benefit (income) expense	$ 8,328	$ 21,118	$ 11,226