Note 2 - Notes Payable - New Credit Facility (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt issuance cost, current	$ (2,100)
Notes payable, net of debt issuance cost, current	3,903	$ 3,891
Notes payable, net of debt issuance cost, long-term	71,101	80,058
New Credit Facility [Member]
Notes payable, current	4,350
Notes payable, long-term	72,300
Notes payable, face amount	76,650	85,912
Debt issuance cost, current	(447)
Debt issuance cost, long-term	(1,199)
Debt issuance cost	(1,646)	(1,963)
Notes payable, net of debt issuance cost, current	3,903
Notes payable, net of debt issuance cost, long-term	71,101
Notes payable, net of debt issuance cost	$ 75,004	$ 83,949