CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Comprehensive Income [Abstract]
Reclassification of previously deferred derivative losses to (gains) losses on derivatives, net, tax effect	$ (4)	$ (4)	$ (5)
Net gain (loss) incurred during period, tax effect	(152)	56	77
Prior service credit (cost) incurred during period, tax effect			(5)
Amortization of net actuarial (gain) loss to general and administrative expense, tax effect	$ (49)	$ (32)	$ (31)