Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Paid-In Capital	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Total RPM International Inc. Equity	Noncontrolling Interests
Beginning Balance at May. 31, 2020	$ 1,264,663	$ 1,295	$ 1,014,428	$ (580,117)	$ (717,497)	$ 1,544,336	$ 1,262,445	$ 2,218
Beginning Balance (in shares) at May. 31, 2020		129,511,000
Net income	180,785					180,595	180,595	190
Other comprehensive (loss) income	49,904				49,835		49,835	69
Dividends declared and paid	(46,622)					(46,622)	(46,622)
Stock compensation expense and other deferred compensation, shares granted less shares returned for taxes	3,341	$ 5	10,451	(7,115)			3,341
Stock compensation expense and other deferred compensation, shares granted less shares returned for taxes (in shares)		464,000
Ending Balance at Aug. 31, 2020	1,452,071	$ 1,300	1,024,879	(587,232)	(667,662)	1,678,309	1,449,594	2,477
Ending Balance (in shares) at Aug. 31, 2020		129,975,000
Beginning Balance at May. 31, 2020	1,264,663	$ 1,295	1,014,428	(580,117)	(717,497)	1,544,336	1,262,445	2,218
Beginning Balance (in shares) at May. 31, 2020		129,511,000
Net income	308,670
Other comprehensive (loss) income	$ 67,747
Share repurchases under repurchase program (in shares)	0
Ending Balance at Nov. 30, 2020	$ 1,550,443	$ 1,301	1,035,539	(595,851)	(649,819)	1,756,571	1,547,741	2,702
Ending Balance (in shares) at Nov. 30, 2020		130,106,000
Beginning Balance at Aug. 31, 2020	1,452,071	$ 1,300	1,024,879	(587,232)	(667,662)	1,678,309	1,449,594	2,477
Beginning Balance (in shares) at Aug. 31, 2020		129,975,000
Net income	127,884					127,659	127,659	225
Other comprehensive (loss) income	17,843				17,843		17,843
Dividends declared and paid	$ (49,397)					(49,397)	(49,397)
Share repurchases under repurchase program (in shares)	0
Stock compensation expense and other deferred compensation, shares granted less shares returned for taxes	$ 2,042	$ 1	10,660	(8,619)			2,042
Stock compensation expense and other deferred compensation, shares granted less shares returned for taxes (in shares)		131,000
Ending Balance at Nov. 30, 2020	1,550,443	$ 1,301	1,035,539	(595,851)	(649,819)	1,756,571	1,547,741	2,702
Ending Balance (in shares) at Nov. 30, 2020		130,106,000
Beginning Balance at May. 31, 2021	1,743,025	$ 1,295	1,055,400	(653,006)	(514,884)	1,852,259	1,741,064	1,961
Beginning Balance (in shares) at May. 31, 2021		129,573,000
Net income	134,795					134,582	134,582	213
Other comprehensive (loss) income	(25,654)				(25,624)		(25,624)	(30)
Dividends declared and paid	(48,901)					(48,901)	(48,901)
Share repurchases under repurchase program	(12,500)	$ (1)	1	(12,500)			(12,500)
Share repurchases under repurchase program (in shares)		(133,000)
Stock compensation expense and other deferred compensation, shares granted less shares returned for taxes	(45)	$ 3	5,760	(5,808)			(45)
Stock compensation expense and other deferred compensation, shares granted less shares returned for taxes (in shares)		303,000
Ending Balance at Aug. 31, 2021	1,790,720	$ 1,297	1,061,161	(671,314)	(540,508)	1,937,940	1,788,576	2,144
Ending Balance (in shares) at Aug. 31, 2021		129,743,000
Beginning Balance at May. 31, 2021	1,743,025	$ 1,295	1,055,400	(653,006)	(514,884)	1,852,259	1,741,064	1,961
Beginning Balance (in shares) at May. 31, 2021		129,573,000
Net income	259,911
Other comprehensive (loss) income	(58,920)
Share repurchases under repurchase program	$ (12,500)
Share repurchases under repurchase program (in shares)	(133,388)
Ending Balance at Nov. 30, 2021	$ 1,837,756	$ 1,297	1,073,039	(675,471)	(573,745)	2,010,991	1,836,111	1,645
Ending Balance (in shares) at Nov. 30, 2021		129,677,000
Beginning Balance at Aug. 31, 2021	1,790,720	$ 1,297	1,061,161	(671,314)	(540,508)	1,937,940	1,788,576	2,144
Beginning Balance (in shares) at Aug. 31, 2021		129,743,000
Net income	125,116					124,875	124,875	241
Other comprehensive (loss) income	(33,266)				(33,237)		(33,237)	(29)
Dividends declared and paid	$ (52,535)					(51,824)	(51,824)	(711)
Share repurchases under repurchase program (in shares)	0
Stock compensation expense and other deferred compensation, shares granted less shares returned for taxes	$ 7,721		11,878	(4,157)			7,721
Stock compensation expense and other deferred compensation, shares granted less shares returned for taxes (in shares)		(66,000)
Ending Balance at Nov. 30, 2021	$ 1,837,756	$ 1,297	$ 1,073,039	$ (675,471)	$ (573,745)	$ 2,010,991	$ 1,836,111	$ 1,645
Ending Balance (in shares) at Nov. 30, 2021		129,677,000