Revenue - Additional Information (Detail) $ in Thousands	3 Months Ended
	Aug. 31, 2020 USD ($) Segment	Aug. 31, 2019 USD ($)	May 31, 2020 USD ($)
Disaggregation Of Revenue [Line Items]
Number of reportable segments | Segment	4
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)	$ 10,726
Net Sales	1,606,670	$ 1,472,764
Long-term deferred revenue	66,400		$ 66,000
General Contracting And Roofing Services
Disaggregation Of Revenue [Line Items]
Net Sales	$ 25,100