Income Taxes (Details Textuals) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Taxes (Textuals)
Unrecognized tax benefits as a result of potential resolutions of prior years' tax	$ 629		$ 629
Unrecognized tax benefits, amounts recorded to equity	517		517
Unrecognized tax benefits impact not possible to quantify	$ 112		$ 112
Actual tax rates	29.60%	28.70%	31.20%	28.90%
Internal Revenue Service (IRS) [Member] | Earliest Year [Member]
Income Tax Contingency [Line Items]
Open tax years by major tax jurisdiction			2008
Internal Revenue Service (IRS) [Member] | Latest Year [Member]
Income Tax Contingency [Line Items]
Open tax years by major tax jurisdiction			2011