Financial Instruments (Tables)

12 Months Ended

Mar. 31, 2017

Financial Instruments [Abstract]

Fair Value Of Short-Term Investments

Short-term investments consisted of the following as of March 31, 2017 and 2016 (in millions):

	As of March 31, 2017									As of March 31, 2016
	Cost or Amortized Cost		Gross Unrealized					Fair Value		Cost or Amortized Cost		Gross Unrealized				Fair Value
			Gains		Losses							Gains		Losses
Corporate bonds	$	944	$	—	$	(1	)	$	943	$	620	$	1	$	—	$	621
U.S. Treasury securities	414		—		(1		)	413		389		1		—		390
U.S. agency securities	152		—		(1		)	151		167		—		—		167
Commercial paper	212		—		—			212		50		—		—		50
Foreign government securities	113		—		—			113		113		—		—		113
Asset-backed securities	135		—		—			135		—		—		—		—
Short-term investments	$	1,970	$	—	$	(3	)	$	1,967	$	1,339	$	2	$	—	$	1,341

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 March 31, 2017 and 2016 (in millions):

	As of March 31, 2017				As of March 31, 2016
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Short-term investments
Due within 1 year	$	1,237	$	1,236	$	571	$	571
Due 1 year through 5 years	721		719		768		770
Due after 5 years	12		12		—		—
Short-term investments	$	1,970	$	1,967	$	1,339	$	1,341