Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Nov. 30, 2015	Nov. 30, 2014	Nov. 30, 2015	Nov. 30, 2014
Income Statement [Abstract]
Net Sales		$ 1,155,984	$ 1,071,128	$ 2,398,510	$ 2,275,024
Cost of Sales		662,050	617,185	1,371,618	1,312,688
Gross Profit		493,934	453,943	1,026,892	962,336
Selling, General and Administrative Expenses		352,594	334,889	725,448	681,414
Interest Expense		22,478	19,404	44,938	38,819
Investment (Income), Net		(1,100)	(5,058)	(5,168)	(8,861)
Other (Income), Net		(299)	(1,042)	(788)	(2,864)
Income (Expense) Before Income Taxes	[1]	120,261	105,750	262,462	253,828
Provision for Income Taxes		36,112	31,894	77,951	75,133
Net Income		84,149	73,856	184,511	178,695
Less: Net Income Attributable to Noncontrolling Interests		716	4,090	1,263	9,850
Net Income Attributable to RPM International Inc. Stockholders		$ 83,433	$ 69,766	$ 183,248	$ 168,845
Average Number of Shares of Common Stock Outstanding:
Basic		129,398	130,028	129,723	130,061
Diluted	[2],[3]	136,734	134,966	137,072	135,000
Earnings per Share of Common Stock Attributable to RPM International Inc. Stockholders:
Basic		$ 0.63	$ 0.52	$ 1.39	$ 1.27
Diluted		0.62	0.52	1.36	1.24
Cash Dividends Declared per Share of Common Stock		$ 0.275	$ 0.260	$ 0.535	$ 0.500

[1] The presentation includes a reconciliation of Income (Loss) Before Income Taxes, a measure defined by Generally Accepted Accounting Principles (GAAP) in the United States, to EBIT.

[2] For the six months ended November 30, 2014, approximately 3.0 million shares of stock granted under stock-based compensation plans were excluded from the calculation of diluted EPS, as the effect would have been anti-dilutive.

[3] For the three months ended November 30, 2014, approximately 3.2 million shares of stock granted under stock-based compensation plans were excluded from the calculation of diluted EPS, as the effect would have been anti-dilutive.