Note 12 - Related Party Transactions (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Interlink Electronics, Inc. [Member]
Due to Related Parties, Total	$ 0		$ 0		$ 2,000
Interlink Electronics, Inc. [Member] | Administrative Services Provided to Related Party [Member]
Related Party Transaction, Amounts of Transaction	15,000	$ 4,000	25,000	$ 12,000
Due from Related Parties, Total	7,000		7,000		2,000
Interlink Electronics, Inc. [Member] | Reimbursement of Expenses Paid by Company [Member]
Related Party Transaction, Amounts of Transaction	45,000	$ 50,000	103,000	180,000
BKF Capital Group, Inc. [Member]
Due to Related Parties, Total	0		$ 0		$ 2,000
BKF Capital Group, Inc. [Member] | Reimbursement of Expenses Paid by Company [Member]
Related Party Transaction, Amounts of Transaction	$ 0			$ 2,000