Derivative Instrument and Hedging Activity (Details) - Designated as Hedging Instrument - Interest Rate Swap - USD ($)	May 31, 2021	May 31, 2020	May 31, 2019	May 31, 2018	Mar. 31, 2018	Dec. 31, 2017	May 31, 2017
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative rate							1.81%
Derivative, notional amount							$ 65,000,000
Interest rate swap derivative instrument					$ 1,200,000	$ 500,000
Scenario, Forecast
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	$ 25,000,000	$ 25,000,000	$ 65,000,000	$ 65,000,000