Equity - AOCI Changes Net of Tax Table (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax Period Start	$ (143)
Net Other Comprehensive Income	9	9
Accumulated Other Comprehensive Income (Loss), Net of Tax Period End	(134)
Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax Period Start	(143)	(167)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(1)	3
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	10	11
Net Other Comprehensive Income	9	14
Accumulated Other Comprehensive Income (Loss), Net of Tax Period End	(134)	(153)
Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax Period Start	0	5
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	(5)
Net Other Comprehensive Income	0	(5)
Accumulated Other Comprehensive Income (Loss), Net of Tax Period End	0	0
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax Period Start	(143)	(162)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(1)	3
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	10	6
Net Other Comprehensive Income	9	9
Accumulated Other Comprehensive Income (Loss), Net of Tax Period End	$ (134)	$ (153)

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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