Contingencies and Accrued Losses - Additional Information (Detail) - USD ($)		3 Months Ended					9 Months Ended
	Dec. 22, 2020	Feb. 28, 2021	Feb. 29, 2020	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	Feb. 28, 2021	Feb. 29, 2020
Error Corrections And Prior Period Adjustments Restatement [Line Items]
Increase (decrease) in net income due to restatement effect		$ 38,242,000	$ 11,853,000				$ 346,496,000	$ 195,072,000
Penalty to be paid	$ 2,000,000.0
General Counsel
Error Corrections And Prior Period Adjustments Restatement [Line Items]
Penalty to be paid	$ 22,500
Restatements
Error Corrections And Prior Period Adjustments Restatement [Line Items]
Increase (decrease) in net income due to restatement effect				$ 18,000,000.0	$ (10,800,000)	$ (7,200,000)