Note 8 - Leases (Details Textual) $ in Thousands		6 Months Ended
	Jan. 01, 2019 USD ($)	Jun. 30, 2019 USD ($)
Number of Operating Leases Sites		9
Operating Lease, Liability, Total		$ 3,994
Operating Lease, Right-of-use Assets, Reduction for Amounts Recognized Previously	$ 458
Operating Lease, Right-of-Use Asset		$ 3,569
Accounting Standards Update 2016-02 [Member]
Operating Lease, Liability, Total	4,400
Operating Lease, Right-of-Use Asset	4,400
Other Liabilities [Member] | Accounting Standards Update 2016-02 [Member]
Operating Lease, Liability, Total	4,400
Other Assets [Member] | Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset	$ 4,400