Financial Instruments (Tables)

9 Months Ended

Dec. 31, 2018

Financial Instruments [Abstract]

Fair Value Of Short-Term Investments

Short-term investments consisted of the following as of December 31, 2018 and March 31, 2018 (in millions):

	As of December 31, 2018									As of March 31, 2018
	Cost or Amortized Cost		Gross Unrealized					Fair Value		Cost or Amortized Cost		Gross Unrealized					Fair Value
			Gains		Losses							Gains		Losses
Corporate bonds	$	528	$	—	$	(3	)	$	525	$	629	$	—	$	(5	)	$	624
U.S. Treasury securities	206		—		(1		)	205		212		—		(2		)	210
U.S. agency securities	62		—		(1		)	61		79		—		(1		)	78
Commercial paper	291		—		—			291		109		—		—			109
Foreign government securities	71		—		—			71		53		—		(1		)	52
Asset-backed securities	100		—		—			100		—		—		—			—
Certificates of deposit	21		—		—			21		—		—		—			—
Short-term investments	$	1,279	$	—	$	(5	)	$	1,274	$	1,082	$	—	$	(9	)	$	1,073

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 December 31, 2018 and March 31, 2018 (in millions):

	As of December 31, 2018				As of March 31, 2018
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Short-term investments
Due within 1 year	$	876	$	874	$	521	$	520
Due 1 year through 5 years	401		398		561		553
Due after 5 years	2		2		—		—
Short-term investments	$	1,279	$	1,274	$	1,082	$	1,073