Fair Value Measurement (Tables)

3 Months Ended

Mar. 31, 2013

Fair Value Disclosures [Abstract]

Assets and Liabilities Reported at Fair Value on a Recurring Basis

Assets and liabilities reported at fair value on a recurring basis:

(Millions)

	Level 1		Level 2		Level 3		Total
At March 31, 2013
Short-term investments:
Commercial paper and restricted cash	$	—	$	55	$	—	$	55
Other current assets:
Marketable equity securities	5		—		—		5
Foreign currency contracts(1)	—		2		—		2
Equity forward arrangement(1)	—		129		—		129
Investments:
Marketable equity securities	66		—		—		66
Accounts payable and accrued liabilities:
Foreign currency contracts(1)	—		9		—		9
Other liabilities:
Cross currency swaps(1)	—		45		—		45
At December 31, 2012
Short-term investments:
Commercial paper and restricted cash	$	—	$	455	$	—	$	455
Other current assets:
Marketable equity securities	5		—		—		5
Foreign currency contracts(1)	—		3		—		3
Equity forward arrangement(1)	—		130		—		130
Investments:
Marketable equity securities	60		—		—		60
Accounts payable and accrued liabilities:
Foreign currency contracts(1)	—		1		—		1
Other liabilities:
Cross currency swaps(1)	—		95		—		95

 (1) This balance is designated as a hedging instrument under U.S. GAAP.