Summary of Trade Accounts Receivable Net of Allowances and Net Contract Assets (Liabilities) (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Nov. 30, 2020	Nov. 30, 2020	Aug. 31, 2020	May 31, 2020
Disaggregation Of Revenue [Line Items]
Trade accounts receivable, less allowances	$ 1,081,841	$ 1,081,841	$ 1,159,130	$ 1,137,957
Contract assets	27,154	27,154	36,292	25,249
Contract liabilities - short-term	(28,310)	(28,310)	(25,605)	(25,288)
Net Contract Assets (Liabilities)	(1,156)	(1,156)	$ 10,687	$ (39)
Change in Contract with Customer, Asset and Liability [Abstract]
Change in trade accounts receivable, less allowance	(77,289)	(56,116)
Change in contract assets	(9,138)	1,905
Change in Net Contract Assets (Liabilities)	$ (11,843)	$ (1,117)
Percentage of change in trade accounts receivable, less allowance	(6.70%)	(4.90%)
Percentage of change in contract assets	(25.20%)	7.50%
Short-term
Change in Contract with Customer, Asset and Liability [Abstract]
Change in contract liabilities	$ (2,705)	$ (3,022)
Percentage of change in contract liabilities	10.60%	12.00%