Income Taxes - Additional Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Taxes Other Information [Line Items]
Income Tax Expense (Benefit)	$ 273	$ 773	$ 79
Deferred Tax Assets, Valuation Allowance	(102)	(56)
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	237
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	17	18
Unrecognized Tax Benefits, Interest on Income Taxes Expense	(1)	(3)
Summary of Income Tax Examinations [Table Text Block]	The Company files U.S. federal, state, and local income tax returns. The Company's federal income tax returns are no longer subject to examination by the IRS for taxable years prior to 2010. With limited exceptions, the Company is no longer subject to examination by state and local taxing authorities for taxable years prior to 2006.
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	$ 75