Retirement Plans and Postretirement Medical Benefits (Other Changes in Plan Assets and Benefit Obligations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
United States
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)		$ 214,593	$ (111,232)
Amortization of net actuarial loss		(25,369)	(32,494)
Amortization of prior service (cost) credit		(9)	(380)
Net transition asset		0	0
Settlement / curtailment		(4,528)	(2,638)	48
Total recognized in other comprehensive income		184,687	(146,744)
Foreign
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)		61,525	(29,320)
Amortization of net actuarial loss		(8,268)	(14,445)
Amortization of prior service (cost) credit		57	(112)
Net transition asset		10	9
Settlement / curtailment	0	0	0	(444)
Total recognized in other comprehensive income		53,324	(43,868)
Nonpension postretirement benefit plans
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)		35,372	(34,890)
Amortization of net actuarial loss		(5,949)	(7,433)
Amortization of prior service cost		(159)	(128)
Curtailment		0	(2,920)
Other adjustments		412	481
Total recognized in other comprehensive income		$ 29,676	$ (44,890)