Retirement Benefits Plans Retirement Benefits Plans - Employer Contributions to Retirement Benefits Plans (Details 9) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plans and Other Postretirement Benefit Plans
Funding postretirement Medicare Part D prescription drug benefits into VEBA trust				$ 154
VEBA target trust allocation in diversified global equities		50.00%
VEBA target trust allocation in fixed income securities		50.00%
United States pension plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans
Employer contributions to pension plans	254	196	311	264
Non-United States pension plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans
Employer contributions to pension plans	108	145	102	108
Total pension plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans
Employer contributions to pension plans	$ 362	$ 341	$ 413	$ 372