Condensed Financial Information (Parent Company) (Long-term Debt Outstanding) (Details) (Parent Company [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Long-term Debt [Abstract]
Senior notes	$ 15,938	$ 15,669
Notes Payable, Related Parties	3,600	3,250
Long-term Debt	19,538	18,919
Senior Notes, Unaffiliated [Member]
Long-term Debt [Abstract]
Interest Rate Range Minimum	1.52%
Interest Rate Range Maximum	7.72%
Weighted Average Interest Rate	4.96%
Debt Instrument, Maturity Date Range, Start	Aug. 06, 2014
Debt Instrument, Maturity Date Range, End	Jun. 15, 2045
Senior notes	15,938	15,669
Senior Notes, Affiliated [Member]
Long-term Debt [Abstract]
Interest Rate Range Minimum	3.57%
Interest Rate Range Maximum	7.44%
Weighted Average Interest Rate	5.43%
Debt Instrument, Maturity Date Range, Start	Jun. 30, 2014
Debt Instrument, Maturity Date Range, End	Sep. 30, 2033
Notes Payable, Related Parties	3,100	2,750
Other Affiliated Debt [Member]
Long-term Debt [Abstract]
Interest Rate Range Minimum	0.95%
Interest Rate Range Maximum	1.01%
Weighted Average Interest Rate	0.98%
Debt Instrument, Maturity Date Range, Start	Dec. 30, 2015
Debt Instrument, Maturity Date Range, End	Mar. 31, 2016
Notes Payable, Related Parties	$ 500	$ 500