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	$ 475	$ 464	$ 430
Additions for current year tax positions	7	12	6
Additions for tax positions of prior years	10	29	49
Reductions for tax positions of prior years	(3)	(29)	(18)
Effects of foreign currency translation	0	0	(1)
Settlements	(65)	0	0
Lapse of statute of limitations	(32)	(1)	(2)
Balance at December 31	$ 392	$ 475	$ 464