Note 2 - Summary of Significant Accounting Policies (Details Textual)	3 Months Ended
	Mar. 31, 2019 USD ($) shares	Mar. 31, 2018 shares	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)
Operating Lease, Right-of-Use Asset	$ 941,000
Operating Lease, Liability, Total	948,000
Contract with Customer, Liability, Revenue Recognized	383,000
Contract with Customer, Liability, Current	764,000			485,000
Contract with Customer, Liability, Noncurrent	$ 300,000			$ 303,000
Number of Reportable Segments	2
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares	70,558,337	6,340,367
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares	2,465,000
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset			$ 966,000
Operating Lease, Liability, Total			$ 966,000