Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2017

Fair Value Measurements

Fair Value, Assets and Liabilities Measured on Recurring Basis

			Fair Value Measurements
Description	Fair Value at		Using Inputs Considered as
(Millions)	December 31, 2017		Level 1		Level 2		Level 3
Assets:
Available-for-sale:
Marketable securities:
Corporate debt securities	$	14	$	—	$	14	$	—
Commercial paper		899		—		899		—
Certificates of deposit/time deposits		76		—		76		—
Asset-backed securities:
Automobile loan related		16		—		16		—
Credit card related		68		—		68		—
U.S. municipal securities		30		—		—		30
Derivative instruments — assets:
Foreign currency forward/option contracts		57		—		57		—
Interest rate swap contracts		21		—		21		—
Liabilities:
Derivative instruments — liabilities:
Foreign currency forward/option contracts		190		—		190		—
Interest rate swap contracts		7		—		7		—

			Fair Value Measurements
Description	Fair Value at		Using Inputs Considered as
(Millions)	December 31, 2016		Level 1		Level 2		Level 3
Assets:
Available-for-sale:
Marketable securities:
Corporate debt securities	$	10	$	—	$	10	$	—
Commercial paper		14		—		14		—
Certificates of deposit/time deposits		197		—		197		—
Asset-backed securities:
Automobile loan related		31		—		31		—
Credit card related		18		—		18		—
Other		7		—		7		—
U.S. municipal securities		20		—		—		20
Derivative instruments — assets:
Foreign currency forward/option contracts		234		—		234		—
Interest rate swap contracts		25		—		25		—
Liabilities:
Derivative instruments — liabilities:
Foreign currency forward/option contracts		94		—		94		—
Interest rate swap contracts		1		—		1		—

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation

Marketable securities — certain U.S. municipal securities only
(Millions)	2017		2016		2015
Beginning balance	$	20	$	12	$	15
Total gains or losses:
Included in earnings		—		—		—
Included in other comprehensive income		—		—		—
Purchases and issuances		13		12		—
Sales and settlements		(3)		(4)		(3)
Transfers in and/or out of level 3		—		—		—
Ending balance		30		20		12
Change in unrealized gains or losses for the period included in earnings for securities held at the end of the reporting period		—		—		—

Fair Value of Financial Instruments by Balance Sheet Grouping

	December 31, 2017				December 31, 2016
	Carrying		Fair		Carrying		Fair
(Millions)	Value		Value		Value		Value
Long-term debt, excluding current portion	$	12,096	$	12,535	$	10,678	$	11,168