Investment (Income), Net - Net (Gain) on Marketable Securities (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2025	Nov. 30, 2024	Nov. 30, 2025	Nov. 30, 2024
Net Loss (Gain) on Marketable Securities
Unrealized (gains) on marketable equity securities	$ (3,092)	$ (4,727)	$ (11,678)	$ (10,505)
Realized (gains) on marketable equity securities	(2,457)	(70)	(2,554)	(265)
Realized losses on available-for-sale debt securities	0	84	10	86
Net (gain) on marketable securities	$ (5,549)	$ (4,713)	$ (14,222)	$ (10,684)