3. Business acquisitions (Details) - Business Combination Purchase Price Allocation (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
3. Business acquisitions (Details) - Business Combination Purchase Price Allocation [Line Items]
Receivables	$ 673,000
Inventories	677,000
Fixed assets	11,000
Other current assets	6,000
Intangible assets	2,280
Goodwill	1,152,000
Other assets	22,000
Initial estimate for liability related to potential future contingent consideration	(680,000)
Other liabilities	(141)
Total purchase price	4,000,000	4,000,000
Intangible Assets:
Customer relationships	1,300,000	1,300,000
Trademark	480,000	480,000
Developed technology	420,000
Other	80,000
Total Intangible assets	$ 2,280,000
Intangible Asset Weighted Average Amortization Period:
Total weighted average	7 years 73 days
Customer Relationships [Member]
Intangible Asset Weighted Average Amortization Period:
Intangible Asset Weighted Average Amortization Period	6 years
Trademarks [Member]
Intangible Asset Weighted Average Amortization Period:
Intangible Asset Weighted Average Amortization Period	10 years
Developed Technology Rights [Member]
Intangible Asset Weighted Average Amortization Period:
Intangible Asset Weighted Average Amortization Period	9 years
Other Intangible Assets [Member]
Intangible Asset Weighted Average Amortization Period:
Intangible Asset Weighted Average Amortization Period	1 year 73 days