Summary of Accounts Receivable Net of Allowances and Net Contract Assets (Liabilities) (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Nov. 30, 2018	Nov. 30, 2018	Aug. 31, 2018	May 31, 2018
Disaggregation Of Revenue [Line Items]
Accounts receivable, less allowance	$ 1,013,030	$ 1,013,030	$ 1,070,626	$ 1,113,818
Contract assets	15,955	15,955	23,580	18,212
Contract liabilities - short-term	(23,454)	(23,454)	(26,702)	(23,335)
Net Contract Liabilities	(7,499)	(7,499)	$ (3,122)	$ (5,123)
Change in Contract with Customer, Asset and Liability [Abstract]
Change in accounts receivable, less allowance	(57,596)	(100,788)
Change in contract assets	(7,625)	(2,257)
Change in Net Contract Liabilities	$ (4,377)	$ (2,376)
Percentage of change in accounts receivable, less allowance	(5.40%)	(9.00%)
Percentage of change in contract assets	(32.30%)	(12.40%)
Percentage of change in Net Contract Liabilities	140.20%	46.40%
Short-term
Change in Contract with Customer, Asset and Liability [Abstract]
Change in contract liabilities	$ 3,248	$ (119)
Percentage of change in contract liabilities	(12.20%)	0.50%