Equity - AOCI Changes Net of Tax Table (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax Period Start	$ (99)
Net Other Comprehensive Income	0	$ 9
Accumulated Other Comprehensive Income (Loss), Net of Tax Period End	(99)
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	(99)	(143)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(4)	(1)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	4	10
Net Other Comprehensive Income	0	9
Accumulated Other Comprehensive Income (Loss), Net of Tax Period End	(99)	(134)
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	(99)	(143)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(4)	(1)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	4	10
Net Other Comprehensive Income	0	9
Accumulated Other Comprehensive Income (Loss), Net of Tax Period End	$ (99)	$ (134)