Contingencies and Accrued Losses - Additional Information (Detail) - USD ($)		3 Months Ended					6 Months Ended
	Dec. 22, 2020	Nov. 30, 2020	Nov. 30, 2019	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	Nov. 30, 2020	Nov. 30, 2019
Error Corrections And Prior Period Adjustments Restatement [Line Items]
Increase (decrease) in net income due to restatement effect		$ 127,659,000	$ 77,030,000				$ 308,254,000	$ 183,218,000
Subsequent Event
Error Corrections And Prior Period Adjustments Restatement [Line Items]
Penalty to be paid	$ 2,000,000.0
Subsequent Event | 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)