Changes in Equity - Summary of Changes in Equity by Component and in Total (Detail) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Feb. 28, 2025	Nov. 30, 2024	Aug. 31, 2024	Feb. 29, 2024	Nov. 30, 2023	Aug. 31, 2023	Feb. 28, 2025	Feb. 29, 2024
Balance	$ 912,958	$ 903,241	$ 891,012	$ 1,923,967	$ 1,901,916	$ 1,821,628	$ 891,012	$ 1,821,628
Net earnings (loss)	39,339	28,009	24,008	22,000	28,167	99,703	91,356	149,869
Other comprehensive income (loss)	(1,995)	(3,320)	484	6,323	14,446	(5,408)	(4,831)	15,361
Common shares issued, net of withholding tax	(22)	(3,893)	(3,158)	(1,023)	(9,207)	(5,130)
Common shares in non-qualified plans	33	56	32	53	195	130
Stock-based compensation	2,890	5,539	6,216	2,071	4,511	8,995
Separation of Worthington Steel				(1,033,245)
Purchases and retirement of common shares	(6,170)	(8,079)	(6,803)
Cash dividends declared	(8,512)	(8,595)	(8,550)	(8,050)	(16,061)	(16,081)
Dividends to noncontrolling interests						(1,921)
Balance	938,521	912,958	903,241	914,442	1,923,967	1,901,916	938,521	914,442
Halo
Acquisition of Halo				2,346
Additional Paid-in Capital
Balance	301,729	301,239	299,033	290,293	294,794	290,799	299,033	290,799
Common shares issued, net of withholding tax	(22)	(3,893)	(3,158)	(1,023)	(9,207)	(5,130)
Common shares in non-qualified plans	33	56	32	53	195	130
Stock-based compensation	2,890	5,539	6,216	2,071	4,511	8,995
Purchases and retirement of common shares	(920)	(1,212)	(884)
Balance	303,710	301,729	301,239	291,394	290,293	294,794	303,710	291,394
AOCI, Net of Tax
Balance	(2,382)	938	454	(14,141)	(28,587)	(23,179)	454	(23,179)
Other comprehensive income (loss)	(1,995)	(3,320)	484	6,323	14,446	(5,408)
Separation of Worthington Steel				(717)				(717)
Balance	(4,377)	(2,382)	938	(8,535)	(14,141)	(28,587)	(4,377)	(8,535)
Retained Earnings
Balance	611,974	599,176	589,392	1,516,657	1,508,416	1,428,391	589,392	1,428,391
Net earnings (loss)	39,663	28,260	24,253	22,000	24,302	96,106
Separation of Worthington Steel				(901,370)
Purchases and retirement of common shares	(5,250)	(6,867)	(5,919)
Cash dividends declared	(8,512)	(8,595)	(8,550)	(8,050)	(16,061)	(16,081)
Balance	637,875	611,974	599,176	629,237	1,516,657	1,508,416	637,875	629,237
Parent
Balance	911,321	901,353	888,879	1,792,809	1,774,623	1,696,011	888,879	1,696,011
Net earnings (loss)	39,663	28,260	24,253	22,000	24,302	96,106
Other comprehensive income (loss)	(1,995)	(3,320)	484	6,323	14,446	(5,408)
Common shares issued, net of withholding tax	(22)	(3,893)	(3,158)	(1,023)	(9,207)	(5,130)
Common shares in non-qualified plans	33	56	32	53	195	130
Stock-based compensation	2,890	5,539	6,216	2,071	4,511	8,995
Separation of Worthington Steel				(902,087)
Purchases and retirement of common shares	(6,170)	(8,079)	(6,803)
Cash dividends declared	(8,512)	(8,595)	(8,550)	(8,050)	(16,061)	(16,081)
Balance	937,208	911,321	901,353	912,096	1,792,809	1,774,623	937,208	912,096
Noncontrolling Interest
Balance	1,637	1,888	2,133	131,158	127,293	125,617	2,133	125,617
Net earnings (loss)	(324)	(251)	(245)		3,865	3,597
Separation of Worthington Steel				(131,158)
Dividends to noncontrolling interests						(1,921)
Balance	$ 1,313	$ 1,637	$ 1,888	2,346	$ 131,158	$ 127,293	$ 1,313	$ 2,346
Noncontrolling Interest | Halo
Acquisition of Halo				$ 2,346