Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended			3 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Mar. 31, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Jun. 30, 2014 Tax Basis Restoration [Member]	Jun. 30, 2014 2007-2008 Federal Tax Audit Settlement [Member]	Jun. 30, 2014 2009-2010 Federal Tax Audit Settlement [Member]
Income Tax Disclosure [Line Items]
Effective income tax rate	32.90%	32.80%		23.60%	30.10%
Tax Adjustments, Settlements, and Unusual Provisions			$ 145				$ 265	$ 116	$ 143
Unrecognized Tax Benefits	$ 1,526			$ 1,526		$ 1,141