Subsequent Event (Details) (USD $) In Millions, except Share data, unless otherwise specified	9 Months Ended			3 Months Ended	0 Months Ended	9 Months Ended			0 Months Ended		0 Months Ended		0 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2014 Subsequent Event [Member]	Oct. 07, 2014 Subsequent Event [Member] Debt Remarketing Series E [Member]	Sep. 30, 2014 Senior Notes [Member]	May 05, 2014 Senior Notes [Member]	Apr. 07, 2014 Senior Notes [Member]	Oct. 07, 2014 Senior Notes [Member] Subsequent Event [Member] Debt Remarketing Series E Tranche One [Member]	Oct. 07, 2014 Senior Notes [Member] Subsequent Event [Member] Debt Remarketing Series E Tranche One [Member]	Oct. 07, 2014 Senior Notes [Member] Subsequent Event [Member] Debt Remarketing Series E Tranche Two [Member]	Oct. 07, 2014 Senior Notes [Member] Subsequent Event [Member] Debt Remarketing Series E Tranche Two [Member]	Oct. 07, 2014 Common Class A [Member] Subsequent Event [Member]	Oct. 07, 2014 Common Class A [Member] Subsequent Event [Member]
Subsequent Event [Line Items]
Approved dividend, amount per share				$ 0.35
Estimated aggregate dividend payment				$ 399
Debt Disclosure [Abstract]
Debt Instrument, Interest Rate, Stated Percentage							5.875%	3.60%		1.903%		4.721%
Debt Instrument, Maturity Date						Apr. 10, 2024			Dec. 15, 2017		Dec. 15, 2044
Proceeds From Remarketing					0
Proceeds from Issuance of Common Stock	$ 0	$ 1,000											$ 1,000
Common Stock, Shares, Issued	1,130,449,364		1,125,224,024											22,907,960