Note 12 - Other Comprehensive Income - Changes in Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Balances	$ 129,706	$ 123,782	$ 97,219	$ 87,125	$ 86,738	$ 89,191	$ 97,219	$ 89,191
Total other comprehensive income (loss)	1,252	4,302	3,551	(1,819)	(1,450)	(3,932)	9,105	(7,201)
Reclassification from Accumulated Other Comprehensive Income to Retained Earnings
Balances	132,567	129,706	123,782	86,577	87,125	86,738	132,567	86,577
AOCI Attributable to Parent [Member]
Balances	3,313	(989)	(4,540)	(7,062)	(5,612)	(1,745)	(4,540)	(1,745)
Other comprehensive income (loss) before reclassifications	1,552			(1,819)			9,660	(7,204)
Amount reclassified from accumulated other comprehensive income (loss)	(300)						(555)	3
Total other comprehensive income (loss)	1,252	4,302	3,551	(1,819)	(1,450)	(3,932)	9,105	(7,201)
Reclassification from Accumulated Other Comprehensive Income to Retained Earnings						65		65
Balances	$ 4,565	$ 3,313	$ (989)	$ (8,881)	$ (7,062)	$ (5,612)	$ 4,565	$ (8,881)