Note 6 - Fair Value of Financial Instruments - Fair Value Measurements, Not Recorded (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Liabilities
Revolver	$ 192,971	$ 164,599
Carrying Value [Member]
Liabilities
Total liabilities not recorded at fair value	194,796	166,424
Revolver [Member]
Liabilities
Revolver	192,971	164,599
Fair Value, Inputs, Level 1 [Member] | Carrying Value [Member]
Liabilities
Total liabilities not recorded at fair value	1,825	1,825
Fair Value, Inputs, Level 1 [Member] | Revolver [Member]
Liabilities
Revolver
Fair Value, Inputs, Level 2 [Member] | Carrying Value [Member]
Liabilities
Total liabilities not recorded at fair value	192,971	164,599
Fair Value, Inputs, Level 2 [Member] | Revolver [Member]
Liabilities
Revolver	192,971	164,599
Fair Value, Inputs, Level 3 [Member] | Carrying Value [Member]
Liabilities
Total liabilities not recorded at fair value
Fair Value, Inputs, Level 3 [Member] | Revolver [Member]
Liabilities
Revolver
Industrial Revenue Bonds [Member]
Liabilities
IRB	1,825	1,825
Industrial Revenue Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Liabilities
IRB	1,825	1,825
Industrial Revenue Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities
IRB
Industrial Revenue Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Liabilities
IRB