Summary of Significant Accounting Policies - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Cash and cash equivalents	$ 26,169,000	$ 16,142,000	$ 26,028,000
Short-term investments	5,000,000
Asset impairment charges	0		0
Money market funds, at cost	10,606,000	$ 1,807,000
Stipulation of settlement, payment to plaintiff, warrants		250,000
Expected volatility rate		41.00%
Risk free interest rate		1.50%
Stipulation of settlement, payment to plaintiff, warrants, term		5 years
Warrants, fair value per share		$ 6.59
Fair value adjustment of warrants		$ 400,000
Warrants exercised		152,500
Warrants outstanding		97,500
Accounts receivable	14,837,000	$ 17,533,000
Prepaid expenses included in other assets		1,200,000
Other current assets	6,851,000	2,742,000
Capitalized costs for internally developed software	0
Advertising expense	$ 400,000	$ 900,000	$ 900,000
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (shares)	295,366	309,309	325,837
Fair Value, Inputs, Level 1
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Cash and cash equivalents, fair value	$ 10,606,000	$ 1,807,000
United States
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Cash and cash equivalents	$ 21,600,000
Concentration risk percentage	67.00%	72.00%	68.00%
Foreign
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Cash and cash equivalents	$ 4,600,000
Software License Arrangement
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Impairment of intangible assets		$ 100,000
Major customer one | Accounts Receivable
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Concentration risk percentage	15.00%	22.00%
Other Current Assets
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Prepaid expenses included in other assets	$ 1,200,000	$ 1,200,000
Other current assets	900,000	$ 1,500,000
Tecnonet | Other Current Assets
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Accounts receivable	$ 4,800,000
Minimum
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Standard product warranty period	90 days
Maximum
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Standard product warranty period	3 years