Subsequent Event - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended	3 Months Ended	1 Months Ended
Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013 Antenna	Oct. 09, 2013 Subsequent Event Antenna	Oct. 09, 2013 Subsequent Event Antenna Expected Incremental Expense
Subsequent Event [Line Items]
Purchase price of acquired company				$ 26,300,000
Acquisition-related costs	$ 545,000	$ 545,000	$ 500,000		$ 2,200,000

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 25

-Paragraph 23

-URI http://asc.fasb.org/extlink&oid=21917927&loc=d3e1043-128460

Name:	us-gaap_BusinessCombinationAcquisitionRelatedCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration