Fair Value - Assets Measured at Fair Value on Non-Recurring Basis (Parenthetical) (Detail)	Nov. 01, 2019 USD ($)	Nov. 30, 2020 USD ($)		May 31, 2020 USD ($)		Feb. 29, 2020 USD ($)	Aug. 31, 2019 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair market value of assets				$ 2,800,000
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair market value of assets		$ 6,334,000		26,984,000
Fair Value, Measurements, Nonrecurring | WSP Joint Venture
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair market value of assets						$ 700,000
Oil And Gas Operations | Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair market value of assets						3,384,000
Noncontrolling Interests | Engineered Cabs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percent of ownership interest held in unconsolidated affiliates	20
Fair value of acquisition date	$ 13,623,000
Long Lived Assets Held And Used | Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair market value of assets		6,334,000	[1]	9,277,000	[2]
Long Lived Assets Held And Used | Engineered Cabs | Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair market value of assets							$ 12,860,000
Long Lived Assets Held And Used | Packing Solutions Business
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair market value of assets				$ 266,000
Long Lived Assets Held And Used | Oil & gas equipment | Oklahoma
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair market value of assets		5,934,000
Long Lived Assets Held And Used | Alternative Fuel Cylinders Manufacturing Line Facility | Jefferson
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair market value of assets		$ 400,000
Fixed Assets [Member] | Oil And Gas Operations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair market value of assets						$ 6,211,000

[1] Comprised of our oil & gas equipment assets in Tulsa, Oklahoma with an estimated fair value of $5,934,000, and our alternative fuel cylinders assets at the Jefferson, Ohio facility with an estimated fair market value of $400,000.  Refer to “NOTE E – Impairment of Long-Lived Assets” for additional information.   

[2] During the fourth quarter of 2020, in connection with the annual indefinite lived assets impairment test, certain European tradenames were written down to their estimated fair market value of $2,800,000.