Net Income Per Share (Reconciliation Of Earnings Attributable To Common Stockholders, Basic And Diluted) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Statement Operating Activities Segment [Line Items]
Basic income (loss) from continuing operations attributable to common stockholders	$ (78)	$ 122
Diluted income (loss) from continuing operations attributable to common stockholders	(78)	122
Continuing Operations [Member]
Statement Operating Activities Segment [Line Items]
Income (loss) from continuing operations attributable to parent	(74)	145
Participating Securities, Distributed and Undistributed Earnings, Basic	0	(1)
Basic income (loss) from continuing operations attributable to common stockholders	(74)	144
Diluted income (loss) from continuing operations attributable to common stockholders	(74)	144
Discontinued Operations [Member]
Statement Operating Activities Segment [Line Items]
Basic income (loss) from continuing operations attributable to common stockholders	(4)	(22)
Diluted income (loss) from continuing operations attributable to common stockholders	$ (4)	$ (22)