Long-Term Debt (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended			1 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	May 31, 2013 Senior Notes [Member]	May 31, 2013 June 2018 Maturity [Member] Senior Notes [Member] Five Year Term [Member]	May 31, 2013 August 2023 Maturity [Member] Senior Notes [Member] Ten Year Term [Member]	May 31, 2013 June 2043 Maturity [Member] Senior Notes [Member] Thirty Year Term [Member]	May 31, 2013 August 2014 Maturity [Member] Senior Notes [Member]	May 31, 2013 November 2015 Maturity [Member] Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount				$ 2,850	$ 850	$ 1,050	$ 950
Debt Instrument, Maturity Date					Jun. 01, 2018	Aug. 01, 2023	Jun. 01, 2043	Aug. 01, 2014	Nov. 15, 2015
Debt Instrument, Interest Rate, Stated Percentage					1.75%	3.25%	4.75%	3.70%	1.85%
Payments of long-term debt	877	0	768					350	500
Gains (Losses) on Extinguishment of Debt				$ (30)