Summary of Accounts Receivable Net of Allowances and Net Contract Assets (Liabilities) (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Nov. 30, 2019	Nov. 30, 2019	Aug. 31, 2019	May 31, 2019
Disaggregation Of Revenue [Line Items]
Accounts receivable, less allowance	$ 1,047,813	$ 1,047,813	$ 1,109,259	$ 1,232,350
Contract assets	18,959	18,959	26,434	21,628
Contract liabilities - short-term	(25,205)	(25,205)	(27,402)	(25,896)
Net Contract Liabilities	(6,246)	(6,246)	$ (968)	$ (4,268)
Change In Contract With Customer Asset And Liability [Abstract]
Change in accounts receivable, less allowance	(61,446)	(184,537)
Change in contract assets	(7,475)	(2,669)
Change in Net Contract Liabilities	$ (5,278)	$ (1,978)
Percentage of change in accounts receivable, less allowance	(5.50%)	(15.00%)
Percentage of change in contract assets	(28.30%)	(12.30%)
Percentage of change in Net Contract Liabilities	545.20%	46.30%
Short-term
Change In Contract With Customer Asset And Liability [Abstract]
Change in contract liabilities	$ 2,197	$ 691
Percentage of change in contract liabilities	(8.00%)	(2.70%)