Note 8 - Employee Benefit Plans - Defined Benefit Plan Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair value of plan assets at beginning of year	$ 16,131
Fair value of plan assets at end of year	17,038	$ 16,131
Amortization of prior service cost	72	72	$ 71
Pension Plan [Member]
Projected benefit obligation at beginning of year	20,427	19,324	17,185
Service cost	694	620	524
Interest cost	757	669	663
Actuarial loss	198	798	1,674
Benefits paid	(1,017)	(984)	(722)
Projected benefit obligation at end of year	21,059	20,427	19,324
Fair value of plan assets at beginning of year	16,131	17,130	16,605
Actual return on plan assets	1,113	(155)	884
Employer contribution	811	140	363
Fair value of plan assets at end of year	17,038	16,131	17,130
Funded status at the end of the year	(4,021)	(4,296)	(2,194)
Deferred tax asset	1,407	1,504	768
Other liabilities	(4,021)	(4,296)	(2,194)
Total amounts recognized in the Consolidated Balance Sheet	(2,614)	(2,792)	(1,426)
Net loss	(8,250)	(8,627)	(6,922)
Prior service cost	449	559	669
Deferred tax asset	2,730	2,798	2,163
Amount recognized	(5,071)	(5,270)	(4,090)
Benefit obligation	(21,059)	(20,427)	(19,324)
Fair value of assets	17,038	16,131	17,130
Unrecognized net actuarial loss	8,250	8,627	6,922
Unrecognized prior service cost	(449)	(559)	(669)
Deferred tax liability	(1,323)	(1,294)	(1,395)
Prepaid benefit cost included in other assets	2,457	2,478	2,664
Expected return on plan assets	(1,110)	(1,166)	(1,112)
Amortization of prior service cost	(110)	(110)	(110)
Recognized net actuarial loss	572	414	262
Net periodic benefit cost	803	427	227
Net (gain) loss	(377)	1,705	1,640
Amortization of prior service cost	110	110	110
Deferred income tax expense (benefit)	93	(635)	(612)
Total recognized	(174)	1,180	1,138
Total recognized in net periodic benefit cost and other comprehensive loss	$ 536	$ 2,242	$ 1,977
Discount rate used for net periodic pension cost	4.00%	3.75%	4.50%
Discount rate used for disclosure	4.00%	4.00%	3.75%
Expected return on plan assets	7.50%	7.50%	7.50%
Rate of compensation increase	3.00%	3.00%	3.00%