Income Taxes (Details Textuals) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2013	Dec. 31, 2011
Income Taxes (Textuals) [Abstract]
Gross unrecognized tax benefits	$ 970		$ 970			$ 952
Unrecognized tax benefits which would affect our effective tax rate, if recognized	865		865			847
Incremental tax liability asserted by IRS	1,162		1,162
Interest Expense Related To Income Taxes	9	10	11	17
Accrued Interest And Penalties Gross	333		333			313
Potential reduction in unrecognized tax benefits over next 12 months as a result of concluding certain matters					$ 26