Description of Business and Basis of Presentation (Details Textual) (USD $)	3 Months Ended	0 Months Ended
	Mar. 31, 2015 Segment manufacturing_location	Apr. 23, 2015	Dec. 31, 2014	Jun. 03, 2014	Mar. 31, 2014	Dec. 31, 2013
Description of Business and Basis of Presentation (Textual) [Abstract]
Manufacturing locations	3
Operating segments	1
Cumulative valuation allowance	$ 64,200,000
Warranty period, minimum, in years	1 year
Warranty period, maximum, in years	8 years
Accrued warranty liability	823,000		716,000
Deferred revenue and customer deposits	1,235,000		703,000
Cash and cash equivalents	23,101,000		24,732,000		31,585,000	30,647,000
Working capital amount	57,100,000
Debt outstanding	15,300,000
Aggregate value of securities permitted for issuance				125,000,000
Equity Offering Sales Agreement under Shelf Registration Statement | Cowen and Company | Subsequent Event
Description of Business and Basis of Presentation (Textual) [Abstract]
Number of shares the Company may sell per equity offering sales agreement (up to $10 million)		10,000,000
Revolving Credit Facility
Description of Business and Basis of Presentation (Textual) [Abstract]
Amount outstanding under line of credit	9,900,000
Revolving line of credit	10,000,000
Revolving Credit Facility | Revolving Line of Credit
Description of Business and Basis of Presentation (Textual) [Abstract]
Revolving line of credit	$ 10,000,000.0
High Reliability
Description of Business and Basis of Presentation (Textual) [Abstract]
Number of product lines	3
China
Description of Business and Basis of Presentation (Textual) [Abstract]
Number of contract manufacturers	2