Summary of Charges Recorded in Connection with Restructuring by Reportable Segment (Parenthetical) (Detail) - MAP to Growth - Severance and Benefit Costs - Position	3 Months Ended		6 Months Ended
	Nov. 30, 2020	Nov. 30, 2019	Nov. 30, 2020	Nov. 30, 2019
Construction Products Segment
Restructuring Cost And Reserve [Line Items]
Number of positions eliminated	12	25	21	46
Specialty Products Group ("SPG") Segment
Restructuring Cost And Reserve [Line Items]
Number of positions eliminated	1	49	24	59
Number of positions not eliminated	5
Performance Coatings Segment
Restructuring Cost And Reserve [Line Items]
Number of positions eliminated	11	18	50	69
Consumer Segment
Restructuring Cost And Reserve [Line Items]
Number of positions eliminated		9	3	11