Organization and Summary of significant accounting policies (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended			3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 segment	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014 Restatement Adjustment [Member]	Jun. 30, 2014 Restatement Adjustment [Member]	Jun. 30, 2014 Restatement Adjustment [Member]	Sep. 30, 2014 Restatement Adjustment [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of Business Segments			2
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue	$ 43,170,000	$ 38,385,000	$ 128,612,000	$ 115,465,000			$ (2,000,000)
Net loss			(7,524,000)	(5,573,000)		(200,000)	(100,000)	(100,000)	(300,000)
Cost of sales	28,454,000	23,411,000	85,863,000	74,092,000		200,000	(1,800,000)
Gross Profit	14,716,000	14,974,000	42,749,000	41,373,000			(200,000)
Provision for income taxes	727,000	12,000	1,659,000	433,000			(100,000)
Inventories	23,071,000		23,071,000		22,981,000	(200,000)	1,900,000	1,900,000	(200,000)
Deferred revenue			2,899,000	2,438,000			2,000,000
Deferred income taxes	1,139,000		1,139,000		1,219,000		100,000	100,000
Accumulated deficit	(1,215,860,000)		(1,215,860,000)		(1,208,337,000)		(100,000)	(100,000)
Intercompany profit in inventory						$ (200,000)