Schedule of Carrying Value of Trust Assets, Including Unrealized Gains or Losses (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Mar. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Investments held in Rabbi Trust	$ 10,344	$ 10,285
Unrealized gains (losses) in fair value of trust assets	193	92
Unrealized gains (losses) in fair value of trust assets are net of income tax expense of	104	49
Obligations under the supplemental plan	$ 22,354	$ 21,918

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