Schedule I - Condensed Financial Information of Parent (Statement of Comprehensive Income Parenthetical) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]
Change in fair value of available-for-sale securities, income tax	$ 0	$ 0	$ 0
Available-for-sale securities, reclassification to earnings, income tax	0	0	0
Foreign currency translation adjustments, income tax	10	0	18
Foreign currency, reclassification to earnings, income tax	0	0	0
Change in derivative fair value, income tax	31	(35)	(108)
Derivative reclassification to earnings, income tax	(41)	(56)	(22)
Pension, prior service cost for period, income tax	0	0	0
Pension, amortization of net actuarial loss, income tax	(26)	(15)	(6)
Parent Company
Condensed Financial Statements, Captions [Line Items]
Change in fair value of available-for-sale securities, income tax	0	0	0
Available-for-sale securities, reclassification to earnings, income tax	0	0	0
Foreign currency translation adjustments, income tax	10	0	(18)
Foreign currency, reclassification to earnings, income tax	0	0	0
Change in derivative fair value, income tax	31	(33)	(95)
Derivative reclassification to earnings, income tax	(32)	(51)	(21)
Pension, prior service cost for period, income tax	(42)	64	25
Pension, amortization of net actuarial loss, income tax	$ (5)	$ (5)	$ (1)