Investment (Details Textual) (USD $)	3 Months Ended
	Mar. 31, 2015
Qualstar [Member]
Investment Owned, Balance, Shares (in shares)	3,095,875
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum	25.27%
Investment Owned, at Fair Value (in dollars)	$ 705,000
Investment Owned, Face Amount (in dollars)	4,600,000
Equity Method Investment, Realized Gain (Loss) on Disposal	62,000
Interlink Electronics [Member]
Investment Owned, Balance, Shares (in shares)	691,020
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum	11.80%
Investment Owned, at Fair Value (in dollars)	2,500,000
Investment Owned, Face Amount (in dollars)	6,200,000
Equity Method Investment, Realized Gain (Loss) on Disposal	$ 93,000