Revenue - Additional Information (Detail) $ in Thousands	3 Months Ended								12 Months Ended
	May 31, 2020 USD ($)	Feb. 29, 2020 USD ($)	Nov. 30, 2019 USD ($)	Aug. 31, 2019 USD ($)	May 31, 2019 USD ($)	Feb. 28, 2019 USD ($)	Nov. 30, 2018 USD ($)	Aug. 31, 2018 USD ($)	May 31, 2020 USD ($) Segment		May 31, 2019 USD ($) Segment		May 31, 2018 USD ($)	[1]
Disaggregation Of Revenue [Line Items]
Number of reportable segments | Segment									4		3
Revenue performance obligation description of payment terms									Payment terms and conditions vary by contract type, although our customers’ payment terms generally include a requirement to pay within 30 to 60 days of fulfilling our performance obligations.
Revenue, Practical Expedient, Financing Component [true false]									false
Net contract assets (liabilities)									$ 4,229
Net Sales	$ 1,458,962	$ 1,173,976	$ 1,401,292	$ 1,472,764	$ 1,601,401	$ 1,140,630	$ 1,362,531	$ 1,459,989	5,506,994	[1]	$ 5,564,551	[1]	$ 5,321,643
Long-term deferred revenue	66,000				$ 66,500				$ 66,000		$ 66,500
General Contracting And Roofing Services
Disaggregation Of Revenue [Line Items]
Net Sales	$ 22,100

[1] It is not practicable to obtain the information needed to disclose revenues attributable to each of our product lines.