Off-Balance Sheet Risk and Guarantees, Concentrations of Credit Risk and Fair Value of Financial Instruments - Derivative Instruments, Gain (Loss) by Hedging Relationship (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments, net, pretax	$ (29)	$ (26)	$ 7
Designated as Hedging Instrument | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instrument, designated as hedging instrument, gain (loss) recognized in income, ineffective portion and amount excluded from effectiveness testing	6	(7)	1
Not Designated as Hedging Instrument | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments, not designated as hedging instruments, gain (loss), net	(24)	(11)	7
Not Designated as Hedging Instrument | Other costs
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments, not designated as hedging instruments, gain (loss), net	$ (11)	$ (8)	$ (1)