Equity Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (3,549)	$ (3,286)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(286)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(422)	(396)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	10
Other Comprehensive Income (Loss), Effect of Change in Accounting Principle, Net of Taxes	13
Other comprehensive income (loss), before cumulative effect of change in accounting principle	(276)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(35)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	9
Other Comprehensive Income (Loss), Effect of Change in Accounting Principle, Net of Taxes	0
Other comprehensive income (loss), before cumulative effect of change in accounting principle	(26)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	1
Other Comprehensive Income (Loss), Effect of Change in Accounting Principle, Net of Taxes	0
Other comprehensive income (loss), before cumulative effect of change in accounting principle	1
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(251)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0
Other Comprehensive Income (Loss), Effect of Change in Accounting Principle, Net of Taxes	13
Other comprehensive income (loss), before cumulative effect of change in accounting principle	$ (251)