Summary of Trade Accounts Receivable Net of Allowances and Net Contract Assets (Liabilities) (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Feb. 28, 2021	Feb. 28, 2021	Nov. 30, 2020	May 31, 2020
Disaggregation Of Revenue [Line Items]
Trade accounts receivable, less allowances	$ 998,783	$ 998,783	$ 1,081,841	$ 1,137,957
Contract assets	22,993	22,993	27,154	25,249
Contract liabilities - short-term	(31,918)	(31,918)	(28,310)	(25,288)
Net Contract (Liabilities)	(8,925)	(8,925)	$ (1,156)	$ (39)
Change in Contract with Customer, Asset and Liability [Abstract]
Change in trade accounts receivable, less allowance	(83,058)	(139,174)
Change in contract assets	(4,161)	(2,256)
Change in Net Contract Assets (Liabilities)	$ (7,769)	$ (8,886)
Percentage of change in trade accounts receivable, less allowance	(7.70%)	(12.20%)
Percentage of change in contract assets	(15.30%)	(8.90%)
Percentage of change in Net Contract (Liabilities)	672.10%
Short-term
Change in Contract with Customer, Asset and Liability [Abstract]
Change in contract liabilities	$ (3,608)	$ (6,630)
Percentage of change in contract liabilities	12.70%	26.20%