Income Taxes (Details Textuals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Taxes (Textuals) [Abstract]
Decrease in Unrecognized tax benefits, amounts recorded to equity	$ 289
Unrecognized tax benefits income tax penalties and interest accrued	$ (42)
Effective tax rate	10.60%	10.50%
Tax Benefits Recognized in the period	$ 289
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	2014