Note 8 - Leases (Details Textual) $ in Thousands		3 Months Ended
	Jan. 01, 2019 USD ($)	Mar. 31, 2019 USD ($)
Number of Operating Leases Sites		9
Operating Lease, Liability, Total		$ 4,180
Operating Lease, Right-of-use Assets, Reduction for Amounts Recognized Previously	$ 458
Operating Lease, Right-of-Use Asset		$ 3,738
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