Summary of Charges Recorded in Connection with Restructuring by Reportable Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2019	Nov. 30, 2018	Nov. 30, 2019	Nov. 30, 2018
Restructuring Cost And Reserve [Line Items]
Current Year Charges	$ 4,801	$ 7,724	$ 11,423	$ 27,800
2020 MAP to Growth
Restructuring Cost And Reserve [Line Items]
Current Year Charges	4,801	7,724	11,423	27,800
Cumulative Costs to Date	71,247		71,247
Total Expected Costs	103,433		103,433
2020 MAP to Growth | Severance and Benefit Costs
Restructuring Cost And Reserve [Line Items]
Current Year Charges	2,729	6,533	6,515	25,595
Cumulative Costs to Date	48,991		48,991
Total Expected Costs	72,111		72,111
2020 MAP to Growth | Facility Closure and Other Related Costs
Restructuring Cost And Reserve [Line Items]
Current Year Charges	1,821	1,037	4,593	1,473
Cumulative Costs to Date	18,972		18,972
Total Expected Costs	27,284		27,284
2020 MAP to Growth | Other Asset Write-offs
Restructuring Cost And Reserve [Line Items]
Current Year Charges	251	154	315	732
Cumulative Costs to Date	3,284		3,284
Total Expected Costs	4,038		4,038
2020 MAP to Growth | Construction Products Group ("CPG") Segment
Restructuring Cost And Reserve [Line Items]
Current Year Charges	1,596	3,961	2,444	6,758
Cumulative Costs to Date	18,232		18,232
Total Expected Costs	28,894		28,894
2020 MAP to Growth | Construction Products Group ("CPG") Segment | Severance and Benefit Costs
Restructuring Cost And Reserve [Line Items]
Current Year Charges	1,447	3,574	1,607	5,993
Cumulative Costs to Date	12,836		12,836
Total Expected Costs	22,146		22,146
2020 MAP to Growth | Construction Products Group ("CPG") Segment | Facility Closure and Other Related Costs
Restructuring Cost And Reserve [Line Items]
Current Year Charges	110	384	798	397
Cumulative Costs to Date	3,767		3,767
Total Expected Costs	4,597		4,597
2020 MAP to Growth | Construction Products Group ("CPG") Segment | Other Asset Write-offs
Restructuring Cost And Reserve [Line Items]
Current Year Charges	39	3	39	368
Cumulative Costs to Date	1,629		1,629
Total Expected Costs	2,151		2,151
2020 MAP to Growth | Performance Coatings Group ("PCG") Segment
Restructuring Cost And Reserve [Line Items]
Current Year Charges	1,239	993	3,848	6,034
Cumulative Costs to Date	14,086		14,086
Total Expected Costs	21,931		21,931
2020 MAP to Growth | Performance Coatings Group ("PCG") Segment | Severance and Benefit Costs
Restructuring Cost And Reserve [Line Items]
Current Year Charges	431	364	2,931	4,769
Cumulative Costs to Date	9,344		9,344
Total Expected Costs	14,765		14,765
2020 MAP to Growth | Performance Coatings Group ("PCG") Segment | Facility Closure and Other Related Costs
Restructuring Cost And Reserve [Line Items]
Current Year Charges	636	483	745	906
Cumulative Costs to Date	4,219		4,219
Total Expected Costs	6,638		6,638
2020 MAP to Growth | Performance Coatings Group ("PCG") Segment | Other Asset Write-offs
Restructuring Cost And Reserve [Line Items]
Current Year Charges	172	146	172	359
Cumulative Costs to Date	523		523
Total Expected Costs	528		528
2020 MAP to Growth | Consumer Group ("Consumer") Segment
Restructuring Cost And Reserve [Line Items]
Current Year Charges	1,124	181	2,407	1,200
Cumulative Costs to Date	16,502		16,502
Total Expected Costs	21,801		21,801
2020 MAP to Growth | Consumer Group ("Consumer") Segment | Severance and Benefit Costs
Restructuring Cost And Reserve [Line Items]
Current Year Charges	780	76	1,547	1,095
Cumulative Costs to Date	8,925		8,925
Total Expected Costs	12,424		12,424
2020 MAP to Growth | Consumer Group ("Consumer") Segment | Facility Closure and Other Related Costs
Restructuring Cost And Reserve [Line Items]
Current Year Charges	344	105	860	105
Cumulative Costs to Date	7,552		7,552
Total Expected Costs	9,352		9,352
2020 MAP to Growth | Consumer Group ("Consumer") Segment | Other Asset Write-offs
Restructuring Cost And Reserve [Line Items]
Cumulative Costs to Date	25		25
Total Expected Costs	25		25
2020 MAP to Growth | Specialty Products Group ("Specialty") Segment
Restructuring Cost And Reserve [Line Items]
Current Year Charges	819	1,528	2,708	3,748
Cumulative Costs to Date	10,291		10,291
Total Expected Costs	18,671		18,671
2020 MAP to Growth | Specialty Products Group ("Specialty") Segment | Severance and Benefit Costs
Restructuring Cost And Reserve [Line Items]
Current Year Charges	48	1,458	414	3,678
Cumulative Costs to Date	5,750		5,750
Total Expected Costs	10,640		10,640
2020 MAP to Growth | Specialty Products Group ("Specialty") Segment | Facility Closure and Other Related Costs
Restructuring Cost And Reserve [Line Items]
Current Year Charges	731	65	2,190	65
Cumulative Costs to Date	3,434		3,434
Total Expected Costs	6,697		6,697
2020 MAP to Growth | Specialty Products Group ("Specialty") Segment | Other Asset Write-offs
Restructuring Cost And Reserve [Line Items]
Current Year Charges	40	5	104	5
Cumulative Costs to Date	1,107		1,107
Total Expected Costs	1,334		1,334
2020 MAP to Growth | Corporate/Other Segment
Restructuring Cost And Reserve [Line Items]
Current Year Charges	23	1,061	16	10,060
Cumulative Costs to Date	12,136		12,136
Total Expected Costs	12,136		12,136
2020 MAP to Growth | Corporate/Other Segment | Severance and Benefit Costs
Restructuring Cost And Reserve [Line Items]
Current Year Charges	23	$ 1,061	16	$ 10,060
Cumulative Costs to Date	12,136		12,136
Total Expected Costs	$ 12,136		$ 12,136