Other Financial Data - Schedule of Other Non-current Assets (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Other Financial Data [Abstract]
Prepaid pension	$ 933	[1]	$ 567	[1]
Deferred project costs	250		273
Taxes receivable	101		108
Other	233		282
Total Other Non-Current Assets	$ 1,517		$ 1,230

[1] Increase in prepaid pensions is primarily due to actuarial changes and cash contributions made to the U.K. pension plans.