Financial Instruments (Tables)

3 Months Ended

Jun. 30, 2013

Financial Instruments [Abstract]

Fair Value Of Short-Term Investments

Short-term investments consisted of the following as of June 30, 2013 and March 31, 2013 (in millions):

	As of June 30, 2013								As of March 31, 2013
	Cost or Amortized Cost		Gross Unrealized				Fair Value		Cost or Amortized Cost		Gross Unrealized				Fair Value
			Gains		Losses						Gains		Losses
Corporate bonds	$	194	$	—	$	1	$	193	$	177	$	1	$	—	$	178
U.S. agency securities	69		—		—		69		76		—		—		76
U.S. Treasury securities	53		—		—		53		85		—		—		85
Commercial paper	40		—		—		40		49		—		—		49
Short-term investments	$	356	$	—	$	1	$	355	$	387	$	1	$	—	$	388

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

The following table summarizes the amortized cost and fair value of our short-term investments, classified by stated maturity as of June 30, 2013 and March 31, 2013 (in millions):

	As of June 30, 2013				As of March 31, 2013
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Short-term investments
Due in 1 year or less	$	147	$	146	$	160	$	160
Due in 1-2 years	96		96		126		127
Due in 2-3 years	113		113		101		101
Short-term investments	$	356	$	355	$	387	$	388

Carrying Value And Fair Value Of Convertible Senior Notes

The following table summarizes the carrying value and fair value of our 0.75% Convertible Senior Notes due 2016 as of June 30, 2013 and March 31, 2013 (in millions):

	As of June 30, 2013				As of March 31, 2013
	Carrying Value		Fair Value		Carrying Value		Fair Value
0.75% Convertible Senior Notes due 2016	$	564	$	659	$	559	$	614