Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Feb. 28, 2019	Feb. 28, 2018	Feb. 28, 2019	Feb. 28, 2018
Income Statement [Abstract]
Net Sales		$ 1,140,630	$ 1,102,677	$ 3,963,150	$ 3,763,487
Cost of Sales		694,490	663,184	2,384,999	2,200,971
Gross Profit		446,140	439,493	1,578,151	1,562,516
Selling, General and Administrative Expenses		410,871	382,972	1,300,693	1,196,980
Restructuring Charges		8,679		36,479
Interest Expense		26,525	27,459	74,058	80,628
Investment (Income), Net		(4,726)	(5,471)	(126)	(13,663)
Other Expense (Income), Net		327	(165)	4,052	(592)
Income Before Income Taxes		4,464	34,698	162,995	299,163
(Benefit) Provision for Income Taxes		(10,032)	(5,890)	29,140	45,814
Net Income		14,496	40,588	133,855	253,349
Less: Net Income Attributable to Noncontrolling Interests		306	361	677	1,243
Net Income Attributable to RPM International Inc. Stockholders		$ 14,190	$ 40,227	$ 133,178	$ 252,106
Average Number of Shares of Common Stock Outstanding:
Basic		130,105	131,178	131,019	131,195
Diluted	[1]	131,889	131,178	132,829	135,657
Earnings per Share of Common Stock Attributable to RPM International Inc. Stockholders:
Basic		$ 0.11	$ 0.30	$ 1.01	$ 1.90
Diluted		$ 0.11	$ 0.30	$ 1.00	$ 1.87

[1] Restricted shares totaling 429,750 and 323,000 for the three and nine months ended February 28, 2019, respectively, and restricted shares totaling 48,212 for the three and nine months ended February 28, 2018 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. In addition, stock appreciation rights (SARs) totaling 890,000 for the three and nine months ended February 28, 2019 and 600,000 for the three and nine months ended February 28, 2018, were excluded from the calculation of diluted earnings per share as their effect would have been anti-dilutive.