Income Taxes (Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits, beginning balance	$ 4	$ 59	$ 18
Additions for tax positions of prior years	0	0	45
Reductions for tax positions of prior years	0	(3)	(5)
Additions for tax positions of current years	0	0	1
Settlements	0	(52)	0
Unrecognized Tax Benefits, ending balance	$ 4	$ 4	$ 59