Note 8 - Benefit Plans - Defined Benefit Plans Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Changes in benefit obligation
Benefit obligation at beginning of year	$ 28,386	$ 25,258
Service cost - benefits earned during the period	108	65	$ 57
Interest cost on projected benefit obligation	970	965	988
Actuarial (gain) loss	(1,597)	3,755
Benefits paid	(742)	(1,657)
Benefit obligation at end of year	27,125	28,386	25,258
Changes in plan assets
Fair value of plan assets at beginning of year	22,145	15,791
Actual return on assets	(1,526)	2,413
Employer contributions	103	5,598
Benefits paid	(742)	(1,657)
Fair value of plan assets at end of year	19,980	22,145	$ 15,791
Funded status at end of year	(7,145)	(6,241)
Amounts recognized in consolidated balance sheet
Other assets	1,663	2,181
Other current liabilities	(103)	(103)
Long-term pension liability	(8,705)	(8,319)
	(7,145)	(6,241)
Amounts recognized in accumulated other comprehensive income consist of:
Net actuarial loss	$ 11,417	$ 10,903