Cash and Cash Equivalents and Investments in Marketable Securities (Tables)

12 Months Ended

Mar. 31, 2022

Marketable Securities [Abstract]

Summary of Investments in Marketable Securities

Investments in marketable securities consisted of the following:

	March 31, 2022
	Amortized		Unrealized		Unrealized			Fair
	cost		gains		losses			value
Available-for-sale debt securities:
U.S. government and agency obligations	$	538	$	-	$	(29	)	$	509
Foreign government and agency obligations		26		-		(3	)		23
Municipal debt securities		9		1		-			10
Corporate debt securities		598		4		(34	)		568
Mortgage-backed securities:
U.S. government agency		20		-		-			20
Non-agency residential		11		-		(1	)		10
Non-agency commercial		88		1		(3	)		86
Asset-backed securities		82		-		(4	)		78
Total available-for-sale debt securities	$	1,372	$	6	$	(74	)	$	1,304
Equity investments									3,649
Total investments in marketable securities								$	4,953

	March 31, 2021
	Amortized		Unrealized		Unrealized			Fair
	cost		gains		losses			value
Available-for-sale debt securities:
U.S. government and agency obligations	$	217	$	4	$	(10	)	$	211
Municipal debt securities		8		2		-			10
Commercial paper		196		-		-			196
Corporate debt securities		177		12		(2	)		187
Mortgage-backed securities:
U.S. government agency		31		1		-			32
Non-agency residential		1		-		-			1
Non-agency commercial		47		2		(2	)		47
Asset-backed securities		49		3		-			52
Total available-for-sale debt securities	$	726	$	24	$	(14	)	$	736
Equity investments									4,084
Total investments in marketable securities								$	4,820

Schedule of Gains and Losses on Investments in Marketable Securities Presented in Our Consolidated Statement of Income

The following table represents gains and losses on our investments in marketable securities presented in our Consolidated Statements of Income:

	Years ended March 31,
	2022			2021		2020
Available-for-sale debt securities:
Unrealized losses on  securities for which the    fair value option was elected	$	(41	)
Realized (losses) gains on sales	$	(4	)	$	20	$	9
Other-than-temporary impairment						$	(8	)
Equity investments:
Unrealized (losses) gains	$	(158	)	$	114	$	41
Realized gains on sales	$	22		$	15	$	5

Summary of Contractual Maturities of Available-For-Sale Debt Securities

The amortized cost and fair value by contractual maturities of available-for-sale debt securities are summarized in the following table.  Actual maturities may differ from contractual maturities because certain borrowers have the right to call or prepay certain obligations.

	March 31, 2022
	Amortized cost		Fair value
Available-for-sale debt securities:
Due within 1 year	$	53	$	53
Due after 1 year through 5 years		378		367
Due after 5 years through 10 years		381		360
Due after 10 years		359		330
Mortgage-backed and asset-backed securities 1		201		194
Total	$	1,372	$	1,304

¹

Mortgage-backed and asset-backed securities are shown separately from other maturity groupings as these securities have multiple maturity dates.