Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Worthington Energy Innovations L L C	DHybrid Systems LLC	Worthington Artas Basncl Kaplar Sanayi	Common Shares	Additional Paid-in Capital	Additional Paid-in Capital DHybrid Systems LLC	Additional Paid-in Capital Worthington Artas Basncl Kaplar Sanayi	Accumulated Other Comprehensive Loss, Net of Tax	Retained Earnings	Total	Total DHybrid Systems LLC	Total Worthington Artas Basncl Kaplar Sanayi	Noncontrolling Interests	Noncontrolling Interests Worthington Energy Innovations L L C	Noncontrolling Interests DHybrid Systems LLC	Noncontrolling Interests Worthington Artas Basncl Kaplar Sanayi
Balance at May. 31, 2016	$ 919,846					$ 298,984			$ (28,565)	$ 522,952	$ 793,371			$ 126,475
Balance (in shares) at May. 31, 2016					61,533,668
Net earnings	217,937									204,515	204,515			13,422
Other comprehensive income (loss)	762								790		790			(28)
Common shares issued, net of withholding tax	(9,075)					(9,075)					(9,075)
Common shares issued, net of withholding tax (in shares)					1,268,788
Theoretical common shares in NQ plans	1,259					1,259					1,259
Stock-based compensation	13,158					13,158					13,158
Purchase of noncontrolling interest			$ (2,888)				$ (935)					$ (935)				$ (1,953)
Dividends to noncontrolling interests	(15,622)													(15,622)
Cash dividends declared ($0.80 per share in 2017, $0.84 per share in 2018 and $0.92 per share in 2019)	(51,448)									(51,448)	(51,448)
Balance at May. 31, 2017	1,073,929					303,391			(27,775)	676,019	951,635			122,294
Balance (in shares) at May. 31, 2017					62,802,456
Net earnings	200,850									194,794	194,794			6,056
Other comprehensive income (loss)	15,269								14,896		14,896			373
Common shares issued, net of withholding tax	(2,120)					(2,120)					(2,120)
Common shares issued, net of withholding tax (in shares)					449,465
Theoretical common shares in NQ plans	1,218					1,218					1,218
Stock-based compensation	13,460					13,460					13,460
Purchase of noncontrolling interest				$ (1,913)				$ 924					$ 924				$ (2,837)
Sale of controlling interest		$ (365)													$ (365)
Reclassification of stranded tax effects	(1,701)								(1,701)	1,701
Purchases and retirement of common shares	$ (204,267)					(21,281)				(182,986)	(204,267)
Purchases and retirement of common shares (in shares)	(4,375,000)				(4,375,000)
Dividends to noncontrolling interests	$ (7,915)													(7,915)
Cash dividends declared ($0.80 per share in 2017, $0.84 per share in 2018 and $0.92 per share in 2019)	(51,771)									(51,771)	(51,771)
Balance at May. 31, 2018	1,036,375					295,592			(14,580)	637,757	918,769			117,606
Balance (in shares) at May. 31, 2018					58,876,921
Net earnings	163,273									153,455	153,455			9,818
Other comprehensive income (loss)	(29,004)								(28,884)		(28,884)			(120)
Common shares issued, net of withholding tax	(6,371)					(6,371)					(6,371)
Common shares issued, net of withholding tax (in shares)					690,604
Theoretical common shares in NQ plans	680					680					680
Stock-based compensation	13,927					13,927					13,927
ASC 606 transition adjustment	1,744									1,174	1,174			570
Purchases and retirement of common shares	$ (168,113)					(20,651)				(147,462)	(168,113)
Purchases and retirement of common shares (in shares)	(4,100,000)				(4,100,000)
Dividends to noncontrolling interests	$ (10,726)													(10,726)
Cash dividends declared ($0.80 per share in 2017, $0.84 per share in 2018 and $0.92 per share in 2019)	(53,391)									(53,391)	(53,391)
Balance at May. 31, 2019	$ 948,394					$ 283,177			$ (43,464)	$ 591,533	$ 831,246			$ 117,148
Balance (in shares) at May. 31, 2019					55,467,525