Stockholders' Equity (Narrative) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	1 Months Ended		3 Months Ended		9 Months Ended			1 Months Ended		3 Months Ended	1 Months Ended		3 Months Ended
	Jul. 30, 2013	Apr. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Series A Common Stock [Member]	Jul. 30, 2013 Quarterly [Member]	Apr. 30, 2013 Quarterly [Member]	Mar. 31, 2013 Quarterly [Member]	Jul. 30, 2013 Annual [Member]	Apr. 30, 2013 Annual [Member]	Mar. 31, 2013 Annual [Member]	Sep. 30, 2013 Equity Method Investments' Derivative [Member]
Class of Stock [Line Items]
Derivative, Gain (Loss) on Derivative, Net			$ (13)	$ (17)	$ (22)	$ (11)								$ 1
Common Stock, Dividends, Per Share, Declared								$ 0.18	$ 0.09	$ 0.075	$ 0.72	$ 0.36	$ 0.30
Common stock, par value							$ 0.0001
Common Stock, Dividends, Rate Increase, Percent	100.00%	20.00%