Fair Value Measurements - Assets Measured at Fair Value on Non-Recurring Basis (Detail) - Fair Value, Measurements, Nonrecurring $ in Thousands	May 31, 2018 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset measured at fair value on non-recurring basis	$ 30,000
Long-lived Assets Held and Used
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset measured at fair value on non-recurring basis	30,000	[1]
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset measured at fair value on non-recurring basis	30,000
Significant Other Observable Inputs (Level 2) | Long-lived Assets Held and Used
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset measured at fair value on non-recurring basis	$ 30,000	[1]

[1] During the fourth quarter of fiscal 2018, management committed to a plan to sell the Company’s cryogenics business in Turkey, Worthington Aritas, and certain underperforming oil & gas equipment assets within Pressure Cylinders. In accordance with the applicable accounting guidance, the net assets were recorded at the lower of net book value or fair value less costs to sell. The book value of Worthington Aritas exceeded its estimated fair market value of $9,000,000, resulting in an impairment charge of $42,422,000. The book value of the oil & gas equipment asset group also exceeded its estimated fair market value of $21,000,000, resulting in an impairment charge of $10,497,000.