Changes in Equity - Summary of Changes in Equity by Component and in Total (Detail) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Feb. 29, 2024	Nov. 30, 2023	Aug. 31, 2023	Feb. 28, 2023	Nov. 30, 2022	Aug. 31, 2022	Feb. 29, 2024	Feb. 28, 2023
Balance	$ 1,923,967	$ 1,901,916	$ 1,821,628	$ 1,639,292	$ 1,646,972	$ 1,613,962	$ 1,821,628	$ 1,613,962
Net earnings	22,000	28,167	99,703	50,258	19,505	65,244	149,869	135,007
Other comprehensive (loss) income	6,323	14,446	(5,408)	36,228	(3,224)	(20,462)	15,361	12,542
Common shares issued, net of withholding tax	(1,023)	(9,207)	(5,130)	704	(649)	(3,466)
Common shares in non-qualified plans	53	195	130	107	298	136
Stock-based compensation	2,071	4,511	8,995	3,818	3,620	6,976
Separation of Worthington Steel	(1,030,899)
Cash dividends declared	(8,050)	(16,061)	(16,081)	(15,149)	(15,470)	(15,418)
Dividends to noncontrolling interests			(1,921)		(11,760)
Balance	914,442	1,923,967	1,901,916	1,715,258	1,639,292	1,646,972	914,442	1,715,258
Additional Paid-in Capital
Balance	290,293	294,794	290,799	280,354	277,085	273,439	290,799	273,439
Common shares issued, net of withholding tax	(1,023)	(9,207)	(5,130)	704	(649)	(3,466)
Common shares in non-qualified plans	53	195	130	107	298	136
Stock-based compensation	2,071	4,511	8,995	3,818	3,620	6,976
Balance	291,394	290,293	294,794	284,983	280,354	277,085	291,394	284,983
AOCI, Net of Tax
Balance	(14,141)	(28,587)	(23,179)	(46,536)	(43,312)	(22,850)	(23,179)	(22,850)
Other comprehensive (loss) income	6,323	14,446	(5,408)	36,228	(3,224)	(20,462)
Separation of Worthington Steel	(717)						(717)
Balance	(8,535)	(14,141)	(28,587)	(10,308)	(46,536)	(43,312)	(8,535)	(10,308)
Retained Earnings
Balance	1,516,657	1,508,416	1,428,391	1,279,575	1,278,827	1,230,163	1,428,391	1,230,163
Net earnings	22,000	24,302	96,106	46,325	16,218	64,082
Separation of Worthington Steel	(901,370)
Cash dividends declared	(8,050)	(16,061)	(16,081)	(15,149)	(15,470)	(15,418)
Balance	629,237	1,516,657	1,508,416	1,310,751	1,279,575	1,278,827	629,237	1,310,751
Parent
Balance	1,792,809	1,774,623	1,696,011	1,513,393	1,512,600	1,480,752	1,696,011	1,480,752
Net earnings	22,000	24,302	96,106	46,325	16,218	64,082
Other comprehensive (loss) income	6,323	14,446	(5,408)	36,228	(3,224)	(20,462)
Common shares issued, net of withholding tax	(1,023)	(9,207)	(5,130)	704	(649)	(3,466)
Common shares in non-qualified plans	53	195	130	107	298	136
Stock-based compensation	2,071	4,511	8,995	3,818	3,620	6,976
Separation of Worthington Steel	(902,087)
Cash dividends declared	(8,050)	(16,061)	(16,081)	(15,149)	(15,470)	(15,418)
Balance	912,096	1,792,809	1,774,623	1,585,426	1,513,393	1,512,600	912,096	1,585,426
Noncontrolling Interest
Balance	131,158	127,293	125,617	125,899	134,372	133,210	125,617	133,210
Net earnings		3,865	3,597	3,933	3,287	1,162
Separation of Worthington Steel	(128,812)
Dividends to noncontrolling interests			(1,921)		(11,760)
Balance	$ 2,346	$ 131,158	$ 127,293	$ 129,832	$ 125,899	$ 134,372	$ 2,346	$ 129,832