Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Nov. 30, 2020	Nov. 30, 2019	Nov. 30, 2020	Nov. 30, 2019
Income Statement [Abstract]
Net Sales		$ 1,485,915	$ 1,401,292	$ 3,092,586	$ 2,874,056
Cost of Sales		899,743	871,894	1,852,759	1,769,904
Gross Profit		586,172	529,398	1,239,827	1,104,152
Selling, General and Administrative Expenses		399,418	403,357	795,370	803,923
Restructuring Charges		4,918	4,801	9,151	11,423
Interest Expense		21,266	26,341	43,011	54,658
Investment (Income), Net		(9,519)	(8,805)	(22,281)	(14,190)
Other Expense, Net		3,133	1,951	6,251	3,736
Income Before Income Taxes		166,956	101,753	408,325	244,602
Provision for Income Taxes		39,072	24,431	99,655	60,784
Net Income		127,884	77,322	308,670	183,818
Less: Net Income Attributable to Noncontrolling Interests		225	292	416	600
Net Income Attributable to RPM International Inc. Stockholders		$ 127,659	$ 77,030	$ 308,254	$ 183,218
Average Number of Shares of Common Stock Outstanding:
Basic		128,500	128,393	128,459	128,639
Diluted	[1]	129,090	129,079	129,078	129,294
Earnings per Share of Common Stock Attributable to RPM International Inc. Stockholders:
Basic		$ 0.98	$ 0.60	$ 2.38	$ 1.42
Diluted		$ 0.98	$ 0.59	$ 2.37	$ 1.41

[1] Restricted shares totaling 225,500 and 339,550 for the three and six months ended November 30, 2020, respectively and 178,000 the six months ended November 30, 2019, were excluded from the calculation of diluted earnings per share as their effect would have been anti-dilutive. There were no shares of restricted stock identified as being anti-dilutive for the three months ended November 30, 2019.  In addition, stock appreciation rights (“SARs”) totaling 360,000 and for the three and six months ended November 30, 2020, respectively, and 790,000 for the six months ended November 30, 2019, were excluded from the calculation of diluted earnings per share as their effect would have been anti-dilutive.  There were no SARs identified as being anti-dilutive for the three months ended November 30, 2019.