Summary of Charges Recorded in Connection with Restructuring by Reportable Segment (Parenthetical) (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2019 USD ($) Position	Nov. 30, 2018 USD ($) Position	Nov. 30, 2019 USD ($) Position	Nov. 30, 2018 USD ($) Position Executive
Restructuring Cost And Reserve [Line Items]
Restructuring Charges	$ 4,801	$ 7,724	$ 11,423	$ 27,800
2020 MAP to Growth
Restructuring Cost And Reserve [Line Items]
Restructuring Charges	4,801	7,724	11,423	27,800
2020 MAP to Growth | Severance and Benefit Costs
Restructuring Cost And Reserve [Line Items]
Restructuring Charges	$ 2,729	$ 6,533	$ 6,515	$ 25,595
Construction Products Group ("CPG") Segment | 2020 MAP to Growth Related to Current Elimination | Severance and Benefit Costs
Restructuring Cost And Reserve [Line Items]
Number of positions eliminated | Position	25	37	46	68
Construction Products Group ("CPG") Segment | 2020 MAP to Growth Plan Related to Legal Function
Restructuring Cost And Reserve [Line Items]
Number of positions eliminated | Position				1
Restructuring Charges				$ 200
Construction Products Group ("CPG") Segment | 2020 MAP to Growth
Restructuring Cost And Reserve [Line Items]
Restructuring Charges	$ 1,596	$ 3,961	$ 2,444	6,758
Construction Products Group ("CPG") Segment | 2020 MAP to Growth | Severance and Benefit Costs
Restructuring Cost And Reserve [Line Items]
Restructuring Charges	$ 1,447	3,574	$ 1,607	$ 5,993
Construction Products Group ("CPG") Segment | 2020 MAP to Growth | Construction Segment Executives
Restructuring Cost And Reserve [Line Items]
Number of corporate executives | Executive				3
Performance Coatings Group ("PCG") Segment | 2020 MAP to Growth Related to Current Elimination | Severance and Benefit Costs
Restructuring Cost And Reserve [Line Items]
Number of positions eliminated | Position	18		69
Performance Coatings Group ("PCG") Segment | 2020 MAP to Growth
Restructuring Cost And Reserve [Line Items]
Restructuring Charges	$ 1,239	993	$ 3,848	$ 6,034
Performance Coatings Group ("PCG") Segment | 2020 MAP to Growth | Severance and Benefit Costs
Restructuring Cost And Reserve [Line Items]
Restructuring Charges	$ 431	364	$ 2,931	$ 4,769
Consumer Group ("Consumer") Segment | 2020 MAP to Growth Related to Current Elimination | Severance and Benefit Costs
Restructuring Cost And Reserve [Line Items]
Number of positions eliminated | Position	9		11
Consumer Group ("Consumer") Segment | 2020 MAP to Growth
Restructuring Cost And Reserve [Line Items]
Number of positions eliminated | Position				9
Restructuring Charges	$ 1,124	181	$ 2,407	$ 1,200
Consumer Group ("Consumer") Segment | 2020 MAP to Growth | Severance and Benefit Costs
Restructuring Cost And Reserve [Line Items]
Restructuring Charges	$ 780	$ 76	$ 1,547	$ 1,095
Specialty Segment | 2020 MAP to Growth Related to Current Elimination | Severance and Benefit Costs
Restructuring Cost And Reserve [Line Items]
Number of positions eliminated | Position	49		59
Specialty Segment | 2020 MAP to Growth
Restructuring Cost And Reserve [Line Items]
Number of positions eliminated | Position		95		120
Restructuring Charges	$ 819	$ 1,528	$ 2,708	$ 3,748
Specialty Segment | 2020 MAP to Growth | Severance and Benefit Costs
Restructuring Cost And Reserve [Line Items]
Restructuring Charges	48	$ 1,458	414	$ 3,678
Specialty Segment | 2020 MAP to Growth | Specialty Segment
Restructuring Cost And Reserve [Line Items]
Number of corporate executives | Executive				4
Performance Coatings Group ("PCG") Segment | 2020 MAP to Growth
Restructuring Cost And Reserve [Line Items]
Number of positions eliminated | Position		17		102
Corporate/Other Segment | 2020 MAP to Growth
Restructuring Cost And Reserve [Line Items]
Restructuring Charges	23	$ 1,061	16	$ 10,060
Corporate/Other Segment | 2020 MAP to Growth | Severance and Benefit Costs
Restructuring Cost And Reserve [Line Items]
Restructuring Charges	$ 23	$ 1,061	$ 16	$ 10,060
Number of corporate executives | Executive				2
Corporate/Other Segment | 2020 MAP to Growth | Vesting Equity Awards
Restructuring Cost And Reserve [Line Items]
Number of corporate executives | Executive				2