Marketable Securities (Tables)

12 Months Ended

May 31, 2019

Investments Debt And Equity Securities [Abstract]

Summary of Available-for-Sale Marketable Securities by Asset Type

The following tables summarize marketable securities held at May 31, 2019 and 2018 by asset type:

	Available-For-Sale Securities
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value (Net Carrying Amount)
May 31, 2019
Fixed maturity:
U.S. treasury and other government	$	24,483	$	372	$	(308	)	$	24,547
Corporate bonds		422		43		(3	)		462
Total available-for-sale securities	$	24,905	$	415	$	(311	)	$	25,009

	Available-For-Sale Securities
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value (Net Carrying Amount)
May 31, 2018
Equity securities:
Mutual funds - foreign	$	46,123	$	1,839	$	(1,197	)	$	46,765
Mutual funds - domestic		99,833		727		(2,770	)		97,790
Total equity securities		145,956		2,566		(3,967	)		144,555
Fixed maturity:
U.S. treasury and other government		23,562		39		(552	)		23,049
Corporate bonds		432		43		(8	)		467
Total fixed maturity securities		23,994		82		(560	)		23,516
Total	$	169,950	$	2,648	$	(4,527	)	$	168,071

Summary of Available-for-Sale Securities in Unrealized Loss Position and Included in Accumulated Other Comprehensive (Loss), Aggregated by Length of Time Investments

Summarized below are the available-for-sale securities we held at May 31, 2019 and 2018 that were in an unrealized loss position and that were included in accumulated other comprehensive income (loss), aggregated by the length of time the investments had been in that position:

	May 31, 2019					May 31, 2018
(In thousands)	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Total investments with unrealized losses	$	11,508	$	(311	)	$	106,253	$	(4,527	)
Unrealized losses with a loss position for less than 12 months		806		(2	)		68,376		(1,570	)
Unrealized losses with a loss position for more than 12 months		10,702		(309	)		37,877		(2,957	)

Net Carrying Values of Debt Securities by Contractual Maturity

The net carrying values of available-for-sale debt securities at May 31, 2019, by contractual maturity, are shown below. Expected maturities may differ from contractual maturities because the issuers of the securities may have the right to prepay obligations without prepayment penalties.

(In thousands)	Amortized Cost		Fair Value
Due:
Less than one year	$	8,594	$	8,563
One year through five years		10,886		10,836
Six years through ten years		4,468		4,582
After ten years		957		1,028
	$	24,905	$	25,009