Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Consolidated Statements of Comprehensive Income
Gains (losses) on cash-flow hedges, income tax effect	$ (29)	$ 25	$ 19
Reclassification adjustment for losses (gains) on cash flow hedges included in net income, income tax effect	(19)	15	61
Actuarial gains (losses) on pension and other postretirement obligations, settlements and plan amendments, income tax effect	32	(27)	(4)
Losses (gains) related to pension and other postretirement obligations reclassified to earnings, income tax effect	$ (3)	$ (2)	$ 5