Schedule of Acquisition of Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Feb. 28, 2014
TWB
Business Acquisition [Line Items]
Total acquired identifiable intangible assets	$ 22,028
TWB | Trade Names
Business Acquisition [Line Items]
Acquired indefinite lived intangible assets	4,120
TWB | Customer Relationships
Business Acquisition [Line Items]
Acquired finite lived intangible assets	17,438
TWB | Customer Relationships | Minimum
Business Acquisition [Line Items]
Useful Life (Years)	5 years
TWB | Customer Relationships | Maximum
Business Acquisition [Line Items]
Useful Life (Years)	6 years
TWB | Non-compete Agreements
Business Acquisition [Line Items]
Acquired finite lived intangible assets	470
Useful Life (Years)	5 years
Worthington Aritas
Business Acquisition [Line Items]
Total acquired identifiable intangible assets	16,800
Worthington Aritas | Customer Relationships
Business Acquisition [Line Items]
Acquired finite lived intangible assets	8,400
Useful Life (Years)	20 years
Worthington Aritas | Non-compete Agreements
Business Acquisition [Line Items]
Acquired finite lived intangible assets	120
Useful Life (Years)	3 years
Worthington Aritas | Technological know-how
Business Acquisition [Line Items]
Acquired finite lived intangible assets	8,100
Useful Life (Years)	20 years
Worthington Aritas | Trade Names
Business Acquisition [Line Items]
Acquired finite lived intangible assets	$ 180
Useful Life (Years)	2 years