Commitments and Contingencies - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended				9 Months Ended		9 Months Ended		0 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Mar. 27, 2013	Sep. 30, 2013 Cost of Revenues [Member]	Sep. 30, 2014 Office Equipment [Member]	Sep. 30, 2014 Antenna [Member]	Sep. 30, 2014 Scanning [Member]	Oct. 10, 2014 Other Party [Member] Subsequent Event [Member]	Sep. 30, 2014 Acquisition Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Office equipment								$ 161,000
Accumulated depreciation	17,348,000		17,348,000		15,397,000			10,000
Property and equipment, net	14,898,000		14,898,000		14,971,000			151,000
Operating leases for office facilities and office equipment expiration years			Operating leases for office facilities through 2020 and office equipment through 2019
Allowance for sales returns	100,000		100,000		200,000
Repair and replacement warranty									2 years	3 years
Warranty reserve	300,000		300,000		300,000
Restructuring expenses	0	29,000	0	254,000			300,000
Cash payments	4,300,000		4,300,000
Working capital adjustment provisions			1,000,000
Potential contingent consideration earnable under the Original Agreement	1,500,000		1,500,000
Fair value in the form common stock	600,000		600,000
Parties agreed to the elimination of the holdback	500,000		500,000
Notice period for termination of leaves under option			180 days
Settlement agreement fair value						5,400,000
Settlement agreement remaining consideration						4,300,000
Cash agreed to be paid to company under agreement						3,200,000
Asset purchase agreement contingent consideration						600,000
Asset purchase agreement escrow deposit						500,000
Lease expiration period			5 years
Rental payments			200,000
Acquisition related legal settlements											$ 800,000	$ 100,000