Note 11 - Fair Value Accounting - Carrying Values and Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Jan. 01, 2018
Reported Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Equity securities (Level 1)				$ 1
Reported Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Senior notes (Level 3)		$ 86,824		$ 85,938
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Equity securities (Level 1)			$ 1
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Senior notes (Level 3)	$ 21,289		$ 24,659