Reconciliation of Numerator and Denominator of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended
		Aug. 31, 2017	Aug. 31, 2016
Numerator for earnings per share:
Net income attributable to RPM International Inc. stockholders		$ 116,416	$ 112,769
Less: Allocation of earnings and dividends to participating securities		(1,750)	(1,819)
Net income available to common shareholders - basic		114,666	110,950
Add: Undistributed earnings reallocated to unvested shareholders		5	7
Add: Income effect of contingently issuable shares		1,377	1,362
Net income available to common shareholders - diluted		$ 116,048	$ 112,319
Denominator for basic and diluted earnings per share:
Basic weighted average common shares		131,236	130,600
Average diluted options		574	749
Additional shares issuable assuming conversion of convertible securities	[1]	3,910	3,892
Total shares for diluted earnings per share	[2]	135,720	135,241
Earnings per Share of Common Stock Attributable to RPM International Inc. Stockholders:
Basic Earnings Per Share of Common Stock		$ 0.87	$ 0.85
Diluted Earnings Per Share of Common Stock		$ 0.86	$ 0.83

[1] Represents the number of shares that would be issued if our contingently convertible notes were converted. We include these shares in the calculation of diluted EPS as the conversion of the notes may be settled, at our election, in cash, shares of our common stock, or a combination of cash and shares of our common stock.

[2] Restricted shares totaling 43,380 for the three months ended August 31, 2017 were excluded from the calculation of diluted earnings per share because the grant price of the restricted shares exceeded the average market price of the shares during the period and their effect, accordingly, would have been anti-dilutive. There were no restricted shares identified as being anti-dilutive for the three months ended August 31, 2016. In addition, stock appreciation rights (“SARs”) totaling 600,000 for the three months ended August 31, 2017 and 1,170,000 for the three months ended August 31, 2016 were excluded from the calculation of diluted earnings per share as their effect would have been anti-dilutive.