Investments in Marketable Securities (Tables)

6 Months Ended

Sep. 30, 2021

Marketable Securities [Abstract]

Summary of Investments in Marketable Securities

Investments in marketable securities consisted of the following:

	September 30, 2021
	Amortized		Unrealized		Unrealized			Fair
	cost		gains		losses			value
Available-for-sale debt securities:
U.S. government and agency obligations	$	448	$	5	$	(8	)	$	445
Foreign government and agency obligations		33		-		-			33
Municipal debt securities		9		2		-			11
Commercial paper		8		-		-			8
Corporate debt securities		638		19		(1	)		656
Mortgage-backed securities:
U.S. government agency		24		1		-			25
Non-agency residential		12		-		-			12
Non-agency commercial		71		3		(1	)		73
Asset-backed securities		88		3		-			91
Total available-for-sale debt securities	$	1,331	$	33	$	(10	)	$	1,354
Equity investments									3,481
Total investments in marketable securities								$	4,835

	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:

	Three months ended					Six months ended
	September 30,					September 30,
	2021			2020		2021		2020
Available-for-sale debt securities:
Unrealized (losses) gains for securities for which the fair value option was elected	$	(2	)	$	-	$	7	$	-
Realized gains	$	-		$	3	$	-	$	17
Equity investments:
Unrealized (losses) gains	$	(26	)	$	39	$	58	$	139
Realized gains on sales	$	-		$	1	$	22	$	12

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.

	September 30, 2021
	Amortized cost		Fair value
Available-for-sale debt securities:
Due within 1 year	$	28	$	28
Due after 1 year through 5 years		471		477
Due after 5 years through 10 years		398		405
Due after 10 years		239		243
Mortgage-backed and asset-backed securities 1		195		201
Total	$	1,331	$	1,354

^{1 Mortgage-backed and asset-backed securities are shown separately from other maturity groupings as these securities have multiple maturity dates.}