Investments which are intended to be sold in the short term (usually less than one year or the normal operating cycle, whichever is longer) including trading securities, available-for-sale securities, held-to-maturity securities, and other short-term investments not otherwise listed in the existing taxonomy.

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 210.5-02.2)

-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 03

-Paragraph 1

-Subparagraph g

-Article 7

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

Short Term Investments - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2013 Certificates of Deposit	Mar. 31, 2012 Certificates of Deposit	Jun. 30, 2013 Certificates of Deposit Maturing in August 2013	Jun. 30, 2013 Certificates of Deposit Maturing in September 2013	Jun. 30, 2013 Certificates of Deposit Maturing in December 2013
Investment [Line Items]
Short-term Investments	$ 45,337	$ 45,235	$ 45,300	$ 45,200
Certificate of deposit, maturity year and month					2013-08	2013-09	2013-12