Summary of Accounts Receivable Net of Allowances and Net Contract Assets (Liabilities) (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Feb. 28, 2019	Feb. 28, 2019	Nov. 30, 2018	May 31, 2018
Disaggregation Of Revenue [Line Items]
Accounts receivable, less allowance	$ 961,628	$ 961,628	$ 1,013,030	$ 1,113,818
Contract assets	11,204	11,204	15,955	18,212
Contract liabilities - short-term	(24,697)	(24,697)	(23,454)	(23,335)
Net Contract Liabilities	(13,493)	(13,493)	$ (7,499)	$ (5,123)
Change in Contract with Customer, Asset and Liability [Abstract]
Change in accounts receivable, less allowance	(51,402)	(152,190)
Change in contract assets	(4,751)	(7,008)
Change in Net Contract Liabilities	$ (5,994)	$ (8,370)
Percentage of change in accounts receivable, less allowance	(5.10%)	(13.70%)
Percentage of change in contract assets	(29.80%)	(38.50%)
Percentage of change in Net Contract Liabilities	79.90%	163.40%
Short-term
Change in Contract with Customer, Asset and Liability [Abstract]
Change in contract liabilities	$ (1,243)	$ (1,362)
Percentage of change in contract liabilities	5.30%	5.80%