Financial Instruments (Tables)

9 Months Ended

Dec. 31, 2011

Financial Instruments [Abstract]

Fair Value Of Short-Term Investments

		As of December 31, 2011								As of March 31, 2011
		Cost or								Cost or
		Amortized	Gross Unrealized					Fair		Amortized	Gross Unrealized					Fair
		Cost	Gains		Losses			Value		Cost	Gains		Losses			Value
Corporate bonds	$	150	$	1	$	-	$	151	$	252	$	1	$	-	$	253
U.S. Treasury securities		123		-		-		123		124		-		-		124
U.S. agency securities		120		-		-		120		102		-		-		102
Commercial paper		12		-		-		12		18		-		-		18
Short-term investments	$	405	$	1	$	-	$	406	$	496	$	1	$	-	$	497

Fair Value Of Short-Term Investments By Stated Maturity Date Schedule

	As of December 31, 2011				As of March 31, 2011
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Short-term investments
Due in 1 year or less	$	187	$	187	$	214	$	214
Due in 1-2 years		118		118		156		157
Due in 2-3 years		100		101		126		126
Short-term investments	$	405	$	406	$	496	$	497

Fair Value Of Marketable Equity Securities Schedule

	Adjusted Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
As of December 31, 2011	$	32	$	111	$	-	$	143
As of March 31, 2011	$	32	$	129	$	-	$	161

Carrying Value And Fair Value Of Convertible Senior Notes

	As of December 31, 2011
	Carrying Value		Fair Value
0.75% Convertible Senior Notes due 2016	$	534	$	615