Income Taxes (Details Textuals) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Taxes (Textuals)
Unrecognized tax benefits as a result of potential resolutions of prior years' tax	$ 431		$ 431
Unrecognized tax benefits, amounts recorded to equity	$ 288		$ 288
Actual tax rates	34.70%	34.20%	34.20%	34.40%
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