Derivatives and Hedging - Schedule of Derivatives Instruments for Gains or Losses Initially Recognized in AOCI in Consolidated Balance Sheet (Detail) - Derivatives Designated as Hedging Instruments - USD ($) $ in Thousands	12 Months Ended
	May 31, 2020	May 31, 2019	May 31, 2018
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Pretax gain/(loss) recognized in AOCI	$ (8,386)	$ 4,998	$ (769)
Pretax gain/(loss) reclassified from AOCI into income	(1,930)
Interest Rate Swap | Interest Expense | Cash Flow
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Pretax gain/(loss) recognized in AOCI	(7,998)
Pretax gain/(loss) reclassified from AOCI into income, cash flow	$ 170
Income Statement Location	Interest Expense
Cross Currency Swap | Interest Expense | Cash Flow
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Pretax gain/(loss) recognized in AOCI	$ (2,254)
Pretax gain/(loss) reclassified from AOCI into income, cash flow	$ 554
Income Statement Location	Interest Expense
Cross Currency Swap | Foreign Exchange Gain/Loss | Cash Flow
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Pretax gain/(loss) reclassified from AOCI into income, cash flow	$ (2,654)
Income Statement Location	Foreign Exchange Gain/(Loss)
Cross Currency Swap | Gain or (loss) on sale of subsidiary | Net Investment
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Pretax gain/(loss) recognized in AOCI	$ 1,866	$ 4,998	$ (769)
Income Statement Location	Gain or (loss) on sale of subsidiary