Schedule of Carrying Value of Trust Assets, Including Unrealized Gains or Losses (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Investments held in Rabbi Trust	$ 10,285	$ 10,486
Unrealized (loss) gains in carrying value of trust assets	92	(121)
Unrealized (loss) gains in carrying value of trust assets are net of income tax expense of	49	(65)
Obligations under the supplemental plan	$ 21,918	$ 21,431

Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.17)

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 17

-Article 5

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