Investment in Nikola - Additional Information (Detail) - USD ($)	3 Months Ended			6 Months Ended
	Nov. 30, 2021	Aug. 31, 2021	Nov. 30, 2020	Nov. 30, 2021	Nov. 30, 2020	Aug. 31, 2020
Marketable Securities [Line Items]
Proceeds from sale of Nikola shares	$ 0		$ 0	$ 0	$ 487,859,000
Gains on investment in Nikola	0		(143,780,000)	0	652,362,000
Charitable contribution of Nikola shares	$ 0		$ 0	$ 0	$ 20,653,000
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		$ 796,141,000
Gains on investment in Nikola		$ 508,511,000
Number of shares sold		12,000,000
Marketable securities unrealized market to market gain		$ 287,630,000
Number of marketable securities unrealized market to market gain		7,048,000
Incremental expenses on gains from marketable securities		$ 49,511,000		$ 4,570,000
Profit sharing and bonus expense on marketable securities gain		28,858,000
Charitable contribution of Nikola shares		$ 20,653,000
Number of shares contributed of marketable securities		500,000
Market price	$ 20.41			$ 20.41		$ 40.81
Marketable securities market price dropped per share				$ 20.41
Marketable securities unrealized market to market loss				$ 143,780,000
Number of shares of common stock marketable securities	7,048,000			7,048,000
Marketable securities realized pre-tax gain				$ 652,362,000