Certain Transactions (detail) (USD $)	Mar. 31, 2013	Mar. 31, 2012
Related Party [Line Items]
Raw Materials and Supplies	$ 118,467,000	$ 108,438,000
Director [Member]
Related Party [Line Items]
Raw Materials and Supplies	$ 1,184,000	$ 872,000

Gross amount of unprocessed materials to be used in manufacturing or production process and supplies that will be consumed.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 6

-Subparagraph a

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.6(a)(4),(5))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_InventoryRawMaterialsAndSupplies
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant