Restructuring - Reserve Activity (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Restructuring Reserve Activity
Accrued liability as of January 1, 2015			$ 0
Charges (benefit)	$ 4	$ 0	112	$ 0
Payments			(98)
Adjustments(1)			2
Accrued liability as of June 30, 2015	16		16
Employee Severance and Benefits
Restructuring Reserve Activity
Accrued liability as of January 1, 2015			0
Charges (benefit)	4	0	112	0
Payments			(98)
Adjustments(1)			2
Accrued liability as of June 30, 2015	16		16
Other Associated Costs
Restructuring Reserve Activity
Accrued liability as of January 1, 2015			0
Charges (benefit)	0	$ 0	0	$ 0
Payments			0
Adjustments(1)			0
Accrued liability as of June 30, 2015	$ 0		$ 0