Commitments and Contingencies (Unaudited) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Environmental Matters
Low-end of the range of reasonably possible future costs for environmental remediation sites	$ 330
High-end of the range of reasonably possible future costs for environmental remediation sites	770
Accrual for Environmental Remediation Costs	352
Environmental liabilities recorded in other current liabilities	98
Environmental liabilities recorded in other non-current liabilities	254
Deferred inventoried costs	65
Deferred non-current assets	141
Financial Arrangements [Abstract]
Unused standby letters of credit	199
Bank guarantees	273
Surety bonds outstanding	165
Operating leases
Rental expense for operating leases, net of immaterial amounts of sublease rental income	$ 74	$ 84