Fair Value Measurements (Tables)

12 Months Ended

Mar. 31, 2012

Fair Value Measurements [Abstract]

Assets and liabilities measured at fair value on a recurring basis

	AT MARCH 31, 2012							AT MARCH 31, 2011
	FAIR VALUE MEASUREMENT USING INPUT TYPES				ESTIMATED FAIR VALUE			FAIR VALUE MEASUREMENT USING INPUT TYPES				ESTIMATED FAIR VALUE
(in millions)	Level 1		Level 2		Total			LEVEL 1		LEVEL 2		TOTAL
Assets:
Money market funds	$	1,374	$	—	$	1,374	(1)	$	2,009	$	—	$	2,009	(2)
Marketable securities(3)		—		—		—			—		179		179
Foreign exchange derivatives(4)		—		2		2			—		7		7
Interest rate derivatives (4)		—		27		27			—		15		15
Total Assets	$	1,374	$	29	$	1,403		$	2,009	$	201	$	2,210
Liabilities:
Foreign exchange derivatives (4)		—		4		4			—		1		1
Total Liabilities	$	—	$	4	$	4		$	—	$	1	$	1

(1) At March 31, 2012, the Company had approximately $1,324 million and $50 million of investments in money market funds classified as “Cash and cash equivalents” and “Other noncurrent assets, net” for restricted cash amounts, respectively, in the Company’s Consolidated Balance Sheet.

(2) At March 31, 2011, the Company had approximately $1,959 million and $50 million of investments in money market funds classified as “Cash and cash equivalents” and “Other noncurrent assets, net” for restricted cash amounts, respectively, in the Company’s Consolidated Balance Sheet.

(3) See Note 5, “Marketable Securities” for additional information.

(4) See Note 10, “Derivatives” for additional information. Interest rate derivatives fair value excludes accrued interest.

Carrying amounts and estimated fair values of the Company's instruments that are not measured at fair value on a recurring basis

	AT MARCH 31, 2012				AT MARCH 31, 2011
(in millions)	CARRYING VALUE		ESTIMATED FAIR VALUE		CARRYING VALUE		ESTIMATED FAIR VALUE
Liabilities:
Total debt(1)	$	1,301	$	1,408	$	1,551	$	1,619
Facilities abandonment reserve(2)	$	42	$	48	$	52	$	59

(1) Estimated fair value of total debt is based on quoted prices for similar liabilities for which significant inputs are observable except for certain long-term lease obligations, for which fair value approximates carrying value (Level 2).

(2) Estimated fair value for the facilities abandonment reserve was determined using the Company’s incremental borrowing rate at each of March 31, 2012 and 2011. At March 31, 2012 and 2011, the facilities abandonment reserve included approximately $16 million and $15 million, respectively, in “Accrued expenses and other current liabilities” and approximately $26 million and $37 million, respectively, in “Other noncurrent liabilities” in the Company’s Consolidated Balance Sheets (Level 3).