Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Foreign currency translation adjustments, income tax	$ 1	$ (7)	$ 10
Foreign currency, reclassification to earnings, income tax	0	0	0
Change in derivative fair value, income tax	16	72	(31)
Derivative reclassification to earnings, income tax	(11)	(26)	(41)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit), Tax	0	0	0
Pension, net actuarial gain (loss) for the period, income tax	(29)	27	(198)
Pension, amortization of net actuarial loss, income tax	$ (9)	$ (7)	$ (26)