Summary of Changes in Total Equity, Shareholders' Equity Attributable to Controlling Interest, and Equity Attributable to Noncontrolling Interest (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Feb. 28, 2014	Feb. 28, 2013
Beginning Balance			$ 872,237
Net earnings	44,211	37,331	128,904	104,818
Other comprehensive income (loss)	3,399	(866)	9,654	7,692
Common shares issued			5,246
Stock-based compensation			19,536
Purchases and retirement of common shares			(91,078)
Cash dividends declared			(31,549)
Dividends paid to noncontrolling interest			(39,150)
Ending Balance	957,913		957,913
Worthington Aritas
Acquisition			11,744
TWB
Acquisition			72,369
Additional Paid-in Capital
Beginning Balance			244,864
Common shares issued			5,246
Stock-based compensation			19,536
Purchases and retirement of common shares			(8,661)
Ending Balance	260,985		260,985
Accumulated Other Comprehensive (Loss), Net of Tax
Beginning Balance			(12,036)
Other comprehensive income (loss)			9,906
Ending Balance	(2,130)		(2,130)
Retained Earnings
Beginning Balance			597,994
Net earnings			118,137
Purchases and retirement of common shares			(82,417)
Cash dividends declared			(31,549)
Ending Balance	602,165		602,165
Parent
Beginning Balance			830,822
Net earnings			118,137
Other comprehensive income (loss)			9,906
Common shares issued			5,246
Stock-based compensation			19,536
Purchases and retirement of common shares			(91,078)
Cash dividends declared			(31,549)
Ending Balance	861,020		861,020
Noncontrolling Interest
Beginning Balance			41,415
Net earnings			10,767
Other comprehensive income (loss)			(252)
Dividends paid to noncontrolling interest			(39,150)
Ending Balance	96,893		96,893
Noncontrolling Interest | Worthington Aritas
Acquisition			11,744
Noncontrolling Interest | TWB
Acquisition			$ 72,369