Components of Intangible Assets Net (Parenthetical) (Detail) (Packettrap, Trademarks and trade names, USD $) In Millions, unless otherwise specified	Jun. 30, 2012
Packettrap \| Trademarks and trade names
Finite-Lived Intangible Assets
Acquired indefinite-lived intangible assets	$ 0.8

The aggregate cost of a major indefinite-lived intangible asset class acquired, during the period, either individually or as part of a group of assets (in either an asset acquisition or business combination).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7658586&loc=d3e16265-109275

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 44

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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