Financial Instruments (Tables)

6 Months Ended

Sep. 30, 2011

Financial Instruments [Abstract]

Fair Value Of Short-Term Investments Schedules

	As of September 30, 2011											As of March 31, 2011
		Cost or Amortized Cost	Gains		Losses			Value		Cost or Amortized Cost		Gains	Losses			Fair Value
Corporate bonds	$	169	$	1	$	-	$	170	$	252	$	1	$	-	$	253
U.S. agency securities		86		-		-		86		102		-		-		102
U.S. Treasury securities		82		-		-		82		124		-		-		124
Commercial paper		17		-		-		17		18		-		-		18
Short-term investments	$	354	$	1	$	-	$	355	$	496	$	1	$	-	$	497

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

	As of September 30, 2011				As of March 31, 2011
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Short-term investments
Due in 1 year or less	$	128	$	128	$	214	$	214
Due in 1-2 years		143		144		156		157
Due in 2-3 years		83		83		126		126
Short-term investments	$	354	$	355	$	496	$	497

Fair Value Of Marketable Equity Securities Schedule

		Adjusted Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
As of September 30, 2011	$	32	$	182	$	-	$	214
As of March 31, 2011	$	32	$	129	$	-	$	161

Carrying Value And Fair Value Of Convertible Senior Notes

	As of September 30, 2011
	Carrying Value		Fair Value
0.75% Convertible Senior Notes due 2016	$	529	$	608