Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021
Statement of Comprehensive Income [Abstract]
Net Income	$ 33,249	$ 38,466	$ 293,160	$ 347,136
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments (net of tax of $296; $273; $3,562 and $3,216, respectively)	16,124	25,718	(69,722)	102,880
Pension and other postretirement benefit liability adjustments (net of tax of $951; $1,356; $3,630 and $3,864, respectively)	3,057	4,719	11,086	13,623
Unrealized (loss) on securities and other (net of tax of $238; $330; $473 and $8, respectively)	(384)	(957)	(287)	(787)
Unrealized gain (loss) on derivatives (net of tax of $838; $763; $6,551 and $6,425, respectively)	2,648	(2,554)	21,448	(21,043)
Total other comprehensive income (loss)	21,445	26,926	(37,475)	94,673
Total Comprehensive Income	54,694	65,392	255,685	441,809
Less: Comprehensive Income Attributable to Noncontrolling Interests	238	268	633	752
Comprehensive Income Attributable to RPM International Inc. Stockholders	$ 54,456	$ 65,124	$ 255,052	$ 441,057