Debt and Receivables Securitization - Additional Information (Detail) (USD $)				9 Months Ended			1 Months Ended
	Feb. 28, 2013 Unsecured Revolving Credit Facility	Feb. 28, 2013 Line of Credit	Feb. 28, 2013 Worthington Nitin Cylinders Limited	Feb. 28, 2013 Maximum Line of Credit	Feb. 28, 2013 Financial Stand-By Letters Of Credit	Feb. 28, 2013 Accounts Receivable Facilities D	Aug. 10, 2012 2024 Notes	Feb. 28, 2013 Revised Accounts Receivable Facilities	Feb. 28, 2013 Extended Term Accounts Receivable Facilities
Debt And Receivables Securitization [Line Items]
Principal amount							$ 150,000,000
Debt maturity date							Aug. 10, 2024
Debt, interest rate							4.60%
Maximum borrowing capacity	425,000,000		9,500,000			150,000,000		100,000,000
Maturity date	2017-05		2013-11						2015-01
Borrowings outstanding	24,280,000		6,308,000			0
Outstanding stand-by letters of credit amount for third-party beneficiaries					11,982,000
Remaining borrowing capacity		$ 388,738,000
Applicable variable rate	1.25%		2.25%
Debt maturity period				1 year
Number of days past due trade accounts receivables are ineligible for securitization						90