Financial Assets and Liabilities Measured on a Recurring Basis (Detail) - Recurring Basis $ in Thousands	May 31, 2020 USD ($)
Current trading investments:
Total value of investments	$ 15
Current Liabilities:
Margin balance	(3)
Total value of liabilities	(3)
Total	12
Stocks, options and ETF (long)
Current trading investments:
Current trading investments	15
Level 1 Assets and Liabilities
Current trading investments:
Total value of investments	15
Current Liabilities:
Margin balance	(3)
Total value of liabilities	(3)
Total	12
Level 1 Assets and Liabilities | Stocks, options and ETF (long)
Current trading investments:
Current trading investments	15
Level 2 Assets and Liabilities
Current trading investments:
Total value of investments	0
Current Liabilities:
Total	0
Level 3 Assets and Liabilities
Current trading investments:
Total value of investments	0
Current Liabilities:
Total	$ 0