Debt and Receivables Securitization - Additional Information (Detail) (USD $)	9 Months Ended
	Feb. 28, 2014
Worthington Aritas
Debt And Receivables Securitization [Line Items]
Maximum borrowing capacity	$ 2,900,000
Maturity date	2014-04
Borrowings outstanding	554,000
Applicable fixed rate	5.75%
Worthington Nitin Cylinders Limited
Debt And Receivables Securitization [Line Items]
Maximum borrowing capacity	9,500,000
Maturity date	2014-11
Borrowings outstanding	5,072,000
Applicable variable rate	2.25%
Line of Credit | Maximum
Debt And Receivables Securitization [Line Items]
Debt maturity period	1 year
Unsecured Revolving Credit Facility
Debt And Receivables Securitization [Line Items]
Maximum borrowing capacity	425,000,000
Maturity date	2017-05
Borrowings outstanding	9,730,000
Remaining borrowing capacity	403,538,000
Applicable variable rate	1.21%
Accounts Receivable Facilities
Debt And Receivables Securitization [Line Items]
Maximum borrowing capacity	100,000,000
Maturity date	2015-01
Borrowings outstanding	20,000,000
Number of days past due trade accounts receivables are ineligible for securitization	90 days
Financial Stand-By Letters Of Credit
Debt And Receivables Securitization [Line Items]
Outstanding stand-by letters of credit amount for third-party beneficiaries	14,254,000
Financial Stand-By Letters Of Credit | Unsecured Revolving Credit Facility
Debt And Receivables Securitization [Line Items]
Outstanding stand-by letters of credit amount for third-party beneficiaries	$ 11,732,000