Other Financial Data - Schedule of Other Non-current Assets (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Other Financial Data [Abstract]
Prepaid pension	$ 923	$ 933
Deferred project costs	220	250
Deferred tax assets	125	144
Investments	136	143
Taxes receivable	70	101
Other	199	233
Total	$ 1,673	$ 1,804