v3.26.1
Earnings Per Share - Reconciliation of Numerator and Denominator of Basic and Diluted Earnings Per Share (Detail) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 12 Months Ended
May 31, 2026
May 31, 2025
May 31, 2024
Numerator for earnings per share:      
Net Income (Loss) $ 661,392 $ 688,688 $ 588,397
Less: Allocation of earnings and dividends to participating securities (2,581) (2,625) (2,630)
Net income available to common shareholders - basic 658,811 686,063 585,767
Add: Undistributed earnings reallocated to unvested shareholders 6 9 8
Net income available to common shareholders - diluted $ 658,817 $ 686,072 $ 585,775
Denominator for basic and diluted earnings per share:      
Basic weighted average common shares 127,049 127,570 127,767
Average diluted options and awards 505 634 573
Total shares for diluted earnings per share 127,554 128,204 [1] 128,340 [1]
Earnings Per Share of Common Stock Attributable to RPM International Inc. Stockholders:      
Basic Earnings Per Share of Common Stock $ 5.19 $ 5.38 $ 4.58
Method used to calculate basic earnings per share Two-Class Two-Class Two-Class
Diluted Earnings Per Share of Common Stock $ 5.17 $ 5.35 $ 4.56
Method used to calculate diluted earnings per share Two-Class Two-Class Two-Class
[1] The dilutive effect of performance stock units is included when they have met minimum performance thresholds. The dilutive effect of SARs includes all outstanding awards except awards that are considered antidilutive. SARs are antidilutive when the exercise price exceeds the average market price of the Company’s common shares during the periods presented. For the years ended May 31, 2026, 2025 and 2024, approximately 450,000, 170,000 and 260,000 shares of stock, respectively, granted under stock-based compensation plans were excluded from the calculation of diluted EPS, as the effect would have been anti-dilutive.