Income Taxes (Details Textuals) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Taxes (Textuals)
Unrecognized tax benefits as a result of potential resolutions of prior years' tax	$ 448		$ 448
Unrecognized tax benefits, amounts recorded to equity	$ 306		$ 306
Actual tax rates	33.90%	33.90%	34.00%	34.50%
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