Annual report pursuant to Section 13 and 15(d)

Basis of Presentation (Details Textual)

v2.4.0.6
Basis of Presentation (Details Textual) (USD $)
3 Months Ended 12 Months Ended 12 Months Ended 3 Months Ended 12 Months Ended 3 Months Ended 12 Months Ended 12 Months Ended 12 Months Ended
Dec. 31, 2012
Mar. 31, 2012
Dec. 31, 2011
Sep. 30, 2011
Jun. 30, 2011
Mar. 31, 2013
employees
Mar. 31, 2012
Mar. 31, 2011
May 15, 2012
Mar. 31, 2013
Kentrox [Member]
Apr. 01, 2013
Kentrox [Member]
Mar. 31, 2013
Sale of Conference Plus, Inc [Member]
Dec. 31, 2012
Sale of Conference Plus, Inc [Member]
Mar. 31, 2012
Sale of Conference Plus, Inc [Member]
Dec. 31, 2011
Sale of Conference Plus, Inc [Member]
Dec. 31, 2012
Sale of Customer Networking Solutions Assets [Member]
Sep. 30, 2012
Sale of Customer Networking Solutions Assets [Member]
Mar. 31, 2013
Sale of Customer Networking Solutions Assets [Member]
Mar. 31, 2012
Sale of Customer Networking Solutions Assets [Member]
Mar. 31, 2013
ANTONE Wireless Corporation [Member]
May 15, 2012
ANTONE Wireless Corporation [Member]
employees
Mar. 31, 2013
Technology [Member]
May 15, 2012
Technology [Member]
Mar. 31, 2013
Customer Relationships [Member]
May 15, 2012
Customer Relationships [Member]
Business Acquisition [Line Items]                                                  
Number of employees affected by planned relocation           35                                      
Cash consideration transferred for business acquisition                 $ 2,524,000   $ 30,000,000                   $ 2,500,000        
Business Combination, Acquisition Related Costs                   300,000                   0          
Contingent cash consideration           3,500,000                             3,500,000        
Number of Employees Hired                                         9        
Acquired intangible assets from ANTONE                 3,230,000                           2,800,000   400,000
Estimated useful lives for acquired intangible assets                                           8 years   8 years  
Business Acquisition, Purchase Price Allocation, Goodwill Amount                 2,086,000                                
Warranty obligation for pre-acquisition sales made by ANTONE           303,000                           303,000          
Pre-acquisition warranty costs                                       25,000          
Sale of conference plus                             40,300,000                    
Escrow deposit made                 3,000           4,100,000       3,400,000            
Loss Contingency, Loss in Period 900,000                       1,500,000                        
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax           (1,358,000) 3,509,000 4,868,000                                  
Escrow Deposit Released                       1,600,000           2,600,000              
Gain (Loss) on Sale of Business             20,489,000             20,489,000                      
Proceeds from CNS asset sale             36,729,000                       36,700,000            
Litigation Settlement, Gross                               900,000                  
Loss Contingency Accrual, at Carrying Value   800,000       1,700,000 800,000                       400,000            
Additional expense related to CNS claim                                 500,000                
Payments for Legal Settlements                                   900,000              
Pre-tax gain on CNS asset sale   $ 0 $ 0 $ 46,000 $ 31,608,000   $ 31,654,000             $ 32,848,000         $ 31,654,000