Marketable Securities (Tables)

12 Months Ended

May 31, 2018

Investments Debt And Equity Securities [Abstract]

Summary of Marketable Securities by Asset Type

The following tables summarize marketable securities held at May 31, 2018 and 2017 by asset type:

	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

	Available-For-Sale Securities
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value (Net Carrying Amount)
May 31, 2017
Equity securities:
Stocks - domestic	$	2,391	$	76	$	-		$	2,467
Mutual funds - foreign		35,169		2,470		(204	)		37,435
Mutual funds - domestic		102,671		2,084		(3,118	)		101,637
Total equity securities		140,231		4,630		(3,322	)		141,539
Fixed maturity:
U.S. treasury and other government		22,176		120		(177	)		22,119
Corporate bonds		706		97		(6	)		797
Total fixed maturity securities		22,882		217		(183	)		22,916
Total	$	163,113	$	4,847	$	(3,505	)	$	164,455

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

Summarized below are the available-for-sale securities we held at May 31, 2018 and May 31, 2017 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, 2018					May 31, 2017
(In thousands)	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Total investments with unrealized losses	$	106,253	$	(4,527	)	$	59,987	$	(3,505	)
Unrealized losses with a loss position for less than 12 months		68,376		(1,570	)		40,854		(2,983	)
Unrealized losses with a loss position for more than 12 months		37,877		(2,957	)		19,133		(522	)

Net Carrying Values of Debt Securities by Contractual Maturity

The net carrying values of debt securities at May 31, 2018, 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	$	7,374	$	7,275
One year through five years		12,520		12,244
Six years through ten years		3,024		2,883
After ten years		1,076		1,114
	$	23,994	$	23,516