Note 6 - Leases - Operating Leases Balance Sheet Information (Details) - USD ($)		Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Other noncurrent assets	[1]	$ 1,004,000
Accrued and other current liabilities		553,000
Noncurrent operating lease liabilities		451,000	$ 595,000	$ 0
Total liabilities		$ 1,004,000

[1] Operating lease assets balance at June 30, 2019.