Revenue Recognition - Schedule of Adjustments on Consolidated Financial Statements (Detail) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		May 31, 2020	Feb. 29, 2020	Nov. 30, 2019	Aug. 31, 2019	May 31, 2019	Feb. 28, 2019	Nov. 30, 2018	Aug. 31, 2018	May 31, 2020	May 31, 2019	May 31, 2018
Consolidated Statement of Earnings
Net sales		$ 611,627	$ 763,996	$ 827,637	$ 855,859	$ 938,842	$ 874,381	$ 958,226	$ 988,107	$ 3,059,119	$ 3,759,556	$ 3,581,620
Cost of goods sold										2,615,782	3,279,601	3,018,763
Income tax expense										26,342	43,183	8,220
Net earnings		11,089	18,888	56,922	(2,455)	38,975	29,548	37,792	56,958	84,444	163,273	200,850
Net earnings attributable to noncontrolling interests	[1]									5,648	9,818	6,056
Net earnings attributable to controlling interest		$ 16,175	$ 15,311	$ 52,086	$ (4,776)	$ 37,738	$ 26,773	$ 34,002	$ 54,942	$ 78,796	153,455	$ 194,794
Accounting Standards Update 2014-09
Consolidated Statement of Earnings
Net sales											3,759,556
Cost of goods sold											3,279,601
Income tax expense											43,183
Net earnings											163,273
Net earnings attributable to noncontrolling interests											9,818
Net earnings attributable to controlling interest											153,455
Accounting Standards Update 2014-09 | Cumulative Effect of Topic 606 Adoption
Consolidated Statement of Earnings
Net sales											(6,608)
Cost of goods sold											(5,253)
Income tax expense											(319)
Net earnings											(1,036)
Net earnings attributable to noncontrolling interests											16
Net earnings attributable to controlling interest											(1,052)
Accounting Standards Update 2014-09 | Calculated under Revenue Guidance in Effect before Topic 606
Consolidated Statement of Earnings
Net sales											3,752,948
Cost of goods sold											3,274,348
Income tax expense											42,864
Net earnings											162,237
Net earnings attributable to noncontrolling interests											9,834
Net earnings attributable to controlling interest											$ 152,403

[1] Net earnings attributable to noncontrolling interests are not taxable to Worthington.