Note 4 - Fair Value Measurements - Financial Instruments Fair Value (Details) - USD ($)		Jun. 30, 2022	Dec. 31, 2021
Reported Value Measurement [Member]
Cash and cash equivalents		$ 22,417,000	$ 34,869,000
Senior notes (a)	[1]	225,000,000	0
Estimate of Fair Value Measurement [Member]
Cash and cash equivalents		22,417,000	34,869,000
Senior notes (a)	[1]	$ 225,000,000	$ 0

[1] Fair value is determined using Level 2 inputs. The Company’s senior unsecured notes are quoted, but not actively traded on major exchanges; therefore, fair value is based on periodic values as quoted on major exchanges. See Note 7 for additional information.