Investment in Nikola - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Aug. 31, 2021	Aug. 31, 2020
Marketable Securities [Line Items]
Proceeds from sale of Nikola shares	$ 0	$ 487,859
Gains on investment in Nikola	0	796,141
Charitable contribution of Nikola shares	$ 0	$ 20,653
Nikola Corporation
Marketable Securities [Line Items]
Marketable securities effective date	Jun. 03, 2020
Marketable securities number of shares owned	19,048,020
Proceeds from sale of Nikola shares	$ 796,141
Gains on investment in Nikola	$ 508,511
Number of shares sold	12,000,000
Marketable securities unrealized market to market gain	$ 287,630
Number of marketable securities unrealized market to market gain	7,048,000
Incremental expenses on gains from marketable securities	$ 49,511
Profit sharing and bonus expense on marketable securities gain	28,858
Charitable contribution of Nikola shares	$ 20,653
Number of shares contributed of marketable securities	500,000