Consolidated Statements of Earnings - Entity [Domain] - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		May. 31, 2015	May. 31, 2014	May. 31, 2013
Net sales		$ 3,384,234	$ 3,126,426	$ 2,612,244
Cost of goods sold		2,920,701	2,633,907	2,215,601
Gross margin		463,533	492,519	396,643
Selling, general and administrative expense		295,920	300,396	258,324
Impairment of goodwill and long-lived assets		100,129	58,246	6,488
Restructuring and other expense (income)		6,514	(2,912)	3,293
Joint venture transactions		413	1,036	(604)
Operating income		60,557	135,753	129,142
Other income (expense):
Miscellaneous income		795	16,963	1,452
Interest expense		(35,800)	(26,671)	(23,918)
Equity in net income of unconsolidated affiliates		87,476	91,456	94,624
Earnings before income taxes		113,028	217,501	201,300
Income tax expense		25,772	57,349	64,465
Net earnings		87,256	160,152	136,835
Net earnings attributable to noncontrolling interests	[1]	10,471	8,852	393
Net earnings attributable to controlling interest		$ 76,785	$ 151,300	$ 136,442
Basic
Average common shares outstanding		66,309	68,944	69,301
Earnings per share attributable to controlling interest		$ 1.16	$ 2.19	$ 1.97
Diluted
Average common shares outstanding		68,483	71,664	71,314
Earnings per share attributable to controlling interest		$ 1.12	$ 2.11	$ 1.91

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