Derivative Instrument and Hedging Activity - Narrative (Details) - Designated as Hedging Instrument - Interest Rate Swap - USD ($)	May 31, 2021	May 31, 2020	May 31, 2019	May 31, 2018	May 31, 2017
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative interest rate					1.81%
Derivative, notional amount			$ 65,000,000.0	$ 65,000,000.0	$ 65,000,000.0
Forecast
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	$ 25,000,000.0	$ 25,000,000.0