Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Cash and cash equivalents:
Cash	$ 703		$ 616
Money market funds	827		842
Commercial paper	48		13
U.S. Treasury securities	0		5
U.S. corporate obligations	10		4
Non-U.S. bank and other obligations	39		33
Short-term investments:
Commercial paper	96		11
U.S. Treasury securities	32		51
U.S. corporate obligations	140		51
U.S. non-governmental agency asset-backed securities	53		0
Non-qualified plan assets:
Money market funds	0		1
Domestic bond funds	3		3
Domestic equity funds	5		5
International equity funds	3		3
Blended equity funds	5		5
Common stock	2		2
Derivatives, net asset (liability):
Foreign currency contracts	(58)		(99)
Total	1,908		1,546
Fair value of the fixed-rate debt	2,900	$ 2,900
Face value of the fixed-rate debt	2,700	$ 2,700
Fair Value Based on Quoted Prices in Active Markets for Identical Assets (Level 1)
Cash and cash equivalents:
Cash	703		616
Money market funds	827		842
Commercial paper	0		0
U.S. Treasury securities	0		5
U.S. corporate obligations	10		4
Non-U.S. bank and other obligations	39		33
Short-term investments:
Commercial paper	0		0
U.S. Treasury securities	32		51
U.S. corporate obligations	140		51
U.S. non-governmental agency asset-backed securities	0		0
Non-qualified plan assets:
Money market funds	0		1
Domestic bond funds	3		3
Domestic equity funds	5		5
International equity funds	3		3
Blended equity funds	5		5
Common stock	2		2
Derivatives, net asset (liability):
Foreign currency contracts	0		0
Total	1,769		1,621
Fair Value Based on Significant Other Observable Inputs (Level 2)
Cash and cash equivalents:
Cash	0		0
Money market funds	0		0
Commercial paper	48		13
U.S. Treasury securities	0		0
U.S. corporate obligations	0		0
Non-U.S. bank and other obligations	0		0
Short-term investments:
Commercial paper	96		11
U.S. Treasury securities	0		0
U.S. corporate obligations	0		0
U.S. non-governmental agency asset-backed securities	53		0
Non-qualified plan assets:
Money market funds	0		0
Domestic bond funds	0		0
Domestic equity funds	0		0
International equity funds	0		0
Blended equity funds	0		0
Common stock	0		0
Derivatives, net asset (liability):
Foreign currency contracts	(58)		(99)
Total	$ 139		$ (75)