Note 8 - Employee Benefit Plans - Defined Benefit Plan Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair value of plan assets at beginning of year	$ 23,428
Fair value of plan assets at end of year	21,786	$ 23,428
Amortization of prior service cost	86	71	$ 72
Pension Plan [Member]
Projected benefit obligation at beginning of year	23,492	21,059	20,427
Service cost	868	692	694
Interest cost	802	743	757
Actuarial loss	(423)	1,417	198
Benefits paid	(1,051)	(419)	(1,017)
Projected benefit obligation at end of year	23,688	23,492	21,059
Fair value of plan assets at beginning of year	23,428	17,038	16,131
Actual return on plan assets	(591)	2,302	1,113
Employer contribution		4,507	811
Benefits paid	(1,051)	(419)	(1,017)
Fair value of plan assets at end of year	21,786	23,428	17,038
Funded status at the end of the year	(1,902)	(64)	(4,021)
Deferred tax asset	399	13	1,407
Other liabilities	(1,902)	(64)	(4,021)
Total amounts recognized in the Consolidated Balance Sheet	(1,503)	(51)	(2,614)
Net loss	(9,107)	(7,923)	(8,250)
Prior service cost	230	340	449
Deferred tax asset	1,864	1,592	2,730
Amount recognized	(7,013)	(5,991)	(5,071)
Benefit obligation	(23,688)	(23,492)	(21,059)
Fair value of assets	21,786	23,428	17,038
Unrecognized net actuarial loss	9,107	7,923	8,250
Unrecognized prior service cost	(230)	(340)	(449)
Deferred tax liability	(1,465)	(1,579)	(1,323)
Prepaid benefit cost included in other assets	5,510	5,940	2,457
Expected return on plan assets	(1,601)	(1,097)	(1,110)
Amortization of prior service cost	(110)	(110)	(110)
Recognized net actuarial loss	585	540	572
Net periodic benefit cost	544	768	803
Net (gain) loss	1,184	(328)	(377)
Amortization of prior service cost	110	110	110
Deferred income tax expense (benefit)	(272)	46	93
Total recognized	1,022	(172)	(174)
Total recognized in net periodic benefit cost and other comprehensive loss	$ 1,838	$ 550	$ 536
Discount rate used for net periodic pension cost	3.50%	4.00%	4.00%
Discount rate used for disclosure	4.00%	3.50%	4.00%
Expected return on plan assets	7.50%	7.50%	7.50%
Rate of compensation increase	3.00%	3.00%	3.00%