Investments (Tables)

12 Months Ended

Apr. 30, 2020

Investments

Schedule of investments

	April 30,
	2020		2019
	(In thousands)
Short-term investments:
Held-to-maturity securities:
Municipal securities	$	—	$	5,332
U.S. government securities		—		63,205
Corporate bonds		—		81,950
Total held-to-maturity investments		—		150,487
Available-for-sale securities:
Municipal securities		5,244		—
U.S. government securities		33,771		—
Corporate bonds		8,492		—
Total available-for-sale investments		47,507		—
Total short-term investments	$	47,507	$	150,487
Long-term investments:
Held-to-maturity securities:
U.S. government securities	$	—	$	7,404
Corporate bonds		—		1,982
Total held-to-maturity investments		—		9,386
Available-for-sale securities:
Municipal securities		1,592		—
U.S. government securities		8,996		—
Total available-for-sale investments		10,588		—
Equity method investments
Investment in limited partnership fund		4,442		—
Total equity method investments		4,442		—
Total long-term investments	$	15,030	$	9,386

Schedule of activity related to available-for-sale investments recorded in short-term and long-term investments

	April 30, 2020
			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
Municipal securities	$	6,807	$	29	$	—	$	6,836
U.S. government securities		42,730		41		(4)		42,767
Corporate bonds		8,495		—		(3)		8,492
Total held-to-maturity investments	$	58,032	$	70	$	(7)	$	58,095

Schedule of amortized cost, gross unrealized gains, gross unrealized losses, and estimated fair value of available-for-sale investments

April 30, 2020, are as follows:

	Cost		Fair Value
Due within one year	$	47,457	$	47,507
Due after one year through five years		10,575		10,588
Total	$	58,032	$	58,095

Held to maturity securities

Investments

Schedule of amortized cost, gross unrealized gains, gross unrealized losses, and estimated fair value of held-to-maturity investments

			Net
	Carrying		Unrealized
	Amount		Gains
Municipal securities	$	23,706	$	34
U.S. government securities		41,465		38
Corporate bonds		85,679		73
Certificate of deposits		1,017		5
Total held-to-maturity investments	$	151,867	$	150

The Company held no held-to maturity securities at April 30, 2020. The amortized cost, gross unrealized losses, and estimated fair value of the held-to-maturity securities as of April 30, 2019 are as follows (in thousands):

			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
Municipal securities	$	5,332	$	2	$	(1)	$	5,333
U.S. government securities		70,609		78		(52)		70,635
Corporate bonds		83,932		20		(5)		83,947
Total held-to-maturity investments	$	159,873	$	100	$	(58)	$	159,915

Schedule of amortized cost and fair value by contractual maturity

			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
Municipal securities	$	5,332	$	2	$	(1)	$	5,333
U.S. government securities		70,609		78		(52)		70,635
Corporate bonds		83,932		20		(5)		83,947
Total held-to-maturity investments	$	159,873	$	100	$	(58)	$	159,915