Financial Instruments

6 Months Ended

Sep. 30, 2018

Financial Instruments [Abstract]

Financial Instruments

(4) FINANCIAL INSTRUMENTS

Cash and Cash Equivalents

As of September 30, 2018 and March 31, 2018, our cash and cash equivalents were $2,881 million and $4,258 million, respectively. Cash equivalents were valued using quoted market prices or other readily available market information.

Short-Term Investments

Short-term investments consisted of the following as of September 30, 2018 and March 31, 2018 (in millions):

	As of September 30, 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	$	739	$	—	$	(3	)	$	736	$	629	$	—	$	(5	)	$	624
U.S. Treasury securities	279		—		(2		)	277		212		—		(2		)	210
U.S. agency securities	74		—		(1		)	73		79		—		(1		)	78
Commercial paper	357		—		—			357		109		—		—			109
Foreign government securities	80		—		(1		)	79		53		—		(1		)	52
Asset-backed securities	121		—		—			121		—		—		—			—
Certificates of deposit	21		—		—			21		—		—		—			—
Short-term investments	$	1,671	$	—	$	(7	)	$	1,664	$	1,082	$	—	$	(9	)	$	1,073

The following table summarizes the amortized cost and fair value of our short-term investments, classified by stated maturity as of September 30, 2018 and March 31, 2018 (in millions):

	As of September 30, 2018				As of March 31, 2018
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Short-term investments
Due within 1 year	$	1,218	$	1,216	$	521	$	520
Due 1 year through 5 years	451		446		561		553
Due after 5 years	2		2		—		—
Short-term investments	$	1,671	$	1,664	$	1,082	$	1,073