Recent Accounting Changes (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Income tax expense (benefit)		$ 305	$ 323
Additional paid-in capital		2,874		$ 2,859
Other, net (operating)	[1]	5	17
Net cash provided by operating activities	[1]	894	737
Other, net (financing)	[1]	(51)	(70)
Net cash provided by financing activities	[1]	(146)	530
Accounting Standards Update 2016-09 [Member] | Restatement Adjustment [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Income tax expense (benefit)		(23)
Additional paid-in capital		(23)
Other, net (operating)		73	67
Net cash provided by operating activities		73	67
Other, net (financing)		(73)	(67)
Net cash provided by financing activities		$ (73)	$ (67)

[1] As required by the adoption of ASU 2016-09, the Company retrospectively reclassified $73 million of cash payments from operating to financing activities for the three months ended March 31, 2015. These payments were related to employee tax obligations associated with stock compensation. The comparable amount reported in financing activities for the three months ended March 31, 2016 was $67 million. See Note 2 for further discussion.