Note 11 - Related Party Transactions (Details Textual) - Interlink Electronics, Inc. [Member] - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Due from Related Parties, Total	$ 1,000		$ 1,000		$ 2,000
Due to Related Parties, Total	0		0		$ 17,000
Administrative Services Provided to Related Party [Member]
Related Party Transaction, Amounts of Transaction	4,000	$ 3,000	12,000	$ 8,000
Reimbursement of Expenses Paid by Company [Member]
Related Party Transaction, Amounts of Transaction	$ 50,000	$ 1,000	$ 180,000	$ 8,000