Income Taxes and Accounting for Uncertainty in Income Taxes (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended			12 Months Ended
	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Maximum	Dec. 31, 2012 Maximum
Accounting for uncertainty in income taxes
Unrecognized tax benefits if recognized, could favorably affect our effective tax rate		$ 149
Interest and penalty (benefit) expense	4			4	1
Accrued interest and penalties		$ 13	$ 17