Note 11 - Retirement Plans - Estimated Cost Amortized From Accumulated Other Comprehensive Income Into Net Periodic Cost (Details) - Supplemental Employee Retirement Plan [Member] $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($)
Unrecognized net actuarial loss	$ 5
Total	$ 5

Amount included in accumulated other comprehensive income (AOCI) expected to be recognized as components of net periodic benefit cost for the fiscal year that follows the most recent annual statement of financial position, including gain (loss), prior service cost (credit), and transition asset (obligation).

No definition available.

Name:	us-gaap_DefinedBenefitPlanAmountToBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossNextFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration