Summary of Accounts Receivable Net of Allowances and Net Contract Assets (Liabilities) (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Feb. 29, 2020	Feb. 29, 2020	Nov. 30, 2019	May 31, 2019
Disaggregation Of Revenue [Line Items]
Accounts receivable, less allowance	$ 948,351	$ 948,351	$ 1,047,813	$ 1,232,350
Contract assets	16,143	16,143	18,959	21,628
Contract liabilities - short-term	(23,605)	(23,605)	(25,205)	(25,896)
Net Contract Liabilities	(7,462)	(7,462)	$ (6,246)	$ (4,268)
Change In Contract With Customer Asset And Liability [Abstract]
Change in accounts receivable, less allowance	(99,462)	(283,999)
Change in contract assets	(2,816)	(5,485)
Change in Net Contract Liabilities	$ (1,216)	$ (3,194)
Percentage of change in accounts receivable, less allowance	(9.50%)	(23.00%)
Percentage of change in contract assets	(14.90%)	(25.40%)
Percentage of change in Net Contract Liabilities	19.50%	74.80%
Short-term
Change In Contract With Customer Asset And Liability [Abstract]
Change in contract liabilities	$ 1,600	$ 2,291
Percentage of change in contract liabilities	(6.30%)	(8.80%)