Note 7 - Fair Value - Changes in Level 3 Assets Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Balance at the beginning of the period	$ 4,022	$ 3,500	$ 4,022	$ 3,500
Included in earnings
Included in other comprehensive income
Transfers in and/or out of Level 3		(500)		(500)
Balance at the end of the period	$ 4,022	$ 3,000	$ 4,022	$ 3,000