Restructuring - Additional Information (Detail) - 2020 MAP to Growth - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Feb. 29, 2020	Feb. 28, 2019	Feb. 29, 2020	Feb. 28, 2019	May 31, 2019
Restructuring Cost And Reserve [Line Items]
Restructuring plan, expected to be formulated			During the quarter ended November 30, 2018
Increase in current total expected costs			$ 7,500,000
Consumer Group ("Consumer") Segment | Cost of Sales
Restructuring Cost And Reserve [Line Items]
Inventory-related charges	$ 200,000	$ 800,000	7,400,000	$ 2,100
Inventory-related charges, favorable adjustment					$ 200,000
Performance Coatings Group ("PCG") Segment | Cost of Sales
Restructuring Cost And Reserve [Line Items]
Inventory-related charges	100,000	900,000	3,200,000	7,500
Construction Products Group ("CPG") Segment | Cost of Sales
Restructuring Cost And Reserve [Line Items]
Inventory-related charges	100,000	$ 200,000	300,000	$ 700
Specialty Products Group ("SPG") Segment | Cost of Sales
Restructuring Cost And Reserve [Line Items]
Inventory-related charges	$ 100,000		100,000
Severance and Benefit Charges
Restructuring Cost And Reserve [Line Items]
Increase in current total expected costs			4,600,000
Facility Closure and Other Related Costs
Restructuring Cost And Reserve [Line Items]
Increase in current total expected costs			2,500,000
Other Asset Write-offs
Restructuring Cost And Reserve [Line Items]
Increase in current total expected costs			$ 400,000