Financial Instruments (Tables)

6 Months Ended

Sep. 30, 2014

Financial Instruments [Abstract]

Fair Value Of Short-Term Investments

Short-term investments consisted of the following as of September 30, 2014 and March 31, 2014 (in millions):

	As of September 30, 2014								As of March 31, 2014
	Cost or Amortized Cost		Gross Unrealized				Fair Value		Cost or Amortized Cost		Gross Unrealized				Fair Value
			Gains		Losses						Gains		Losses
Corporate bonds	$	389	$	—	$	—	$	389	$	279	$	—	$	—	$	279
U.S. Treasury securities	165		—		—		165		114		—		—		114
U.S. agency securities	141		—		—		141		80		—		—		80
Commercial paper	69		—		—		69		110		—		—		110
Short-term investments	$	764	$	—	$	—	$	764	$	583	$	—	$	—	$	583

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 September 30, 2014 and March 31, 2014 (in millions):

	As of September 30, 2014				As of March 31, 2014
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Short-term investments
Due in 1 year or less	$	345	$	345	$	318	$	318
Due in 1-2 years	203		203		156		156
Due in 2-3 years	209		209		104		104
Due in 3-4 years	7		7		5		5
Short-term investments	$	764	$	764	$	583	$	583

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 September 30, 2014 and March 31, 2014 (in millions):

	As of September 30, 2014				As of March 31, 2014
	Carrying Value		Fair Value		Carrying Value		Fair Value
0.75% Convertible Senior Notes due 2016	$	591	$	787	$	580	$	731