Income Taxes (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]
Balance at January 1,	$ 117	$ 143	$ 199
Additions, based on tax positions related to current year	16	26	7
Additions for tax positions of prior years	35	35	39
Reductions for tax positions of prior years	(7)	(41)	(91)
Settlements	(3)	(6)	(6)
Lapses in statutes of limitation	(30)	(40)	(5)
Balance at December 31,	$ 128	$ 117	$ 143