Note 7 - Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Notes Tables
Lessee, Lease, Liability, Maturity [Table Text Block]	<div style="display: inline; font-family: times new roman; font-size: 10pt"><table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font: 10pt Times New Roman, Times, Serif; margin-left: 0.5in; min-; min-width: 700px;"> <tr style="vertical-align: bottom"> <td style="border-bottom: Black 1pt solid"><div style=" font: 10pt Times New Roman, Times, Serif; margin: 0"><div style="display: inline; font-weight: bold;">Remaining Maturities of Lease Liabilities</div></div> <div style=" font: 10pt Times New Roman, Times, Serif; margin: 0"><div style="display: inline; font-weight: bold;">Year Ending December 31,</div></div></td> <td style="font-weight: bold; padding-bottom: 1pt"> </td> <td colspan="3" style="font-weight: bold; text-align: center; border-bottom: Black 1pt solid; white-space: nowrap">Operating Leases</td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204,238,255)"> <td style="text-align: left; width: 86%">2019</td> <td style="width: 2%"> </td> <td style="width: 1%; text-align: left">$</td> <td style="width: 10%; text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">790</div></td> <td style="width: 1%; text-align: left"> </td> </tr> <tr style="vertical-align: bottom; background-color: White"> <td style="text-align: left">2020</td> <td> </td> <td style="text-align: left"> </td> <td style="text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">1,432</div></td> <td style="text-align: left"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204,238,255)"> <td style="text-align: left">2021</td> <td> </td> <td style="text-align: left"> </td> <td style="text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">562</div></td> <td style="text-align: left"> </td> </tr> <tr style="vertical-align: bottom; background-color: White"> <td style="text-align: left">2022</td> <td> </td> <td style="text-align: left"> </td> <td style="text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">510</div></td> <td style="text-align: left"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204,238,255)"> <td style="text-align: left">2023</td> <td> </td> <td style="text-align: left"> </td> <td style="text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">512</div></td> <td style="text-align: left"> </td> </tr> <tr style="vertical-align: bottom; background-color: White"> <td style="padding-bottom: 1pt">Thereafter</td> <td style="padding-bottom: 1pt"> </td> <td style="border-bottom: Black 1pt solid; text-align: left"> </td> <td style="border-bottom: Black 1pt solid; text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">7,766</div></td> <td style="border-bottom: Black 1pt solid; text-align: left"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204,238,255)"> <td style="text-align: left; padding-left: 11pt">Total lease payments</td> <td> </td> <td style="text-align: left"> </td> <td style="text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">11,572</div></td> <td style="text-align: left"> </td> </tr> <tr style="vertical-align: bottom; background-color: White"> <td style="text-align: left; padding-bottom: 1pt">Less imputed interest</td> <td style="padding-bottom: 1pt"> </td> <td style="border-bottom: Black 1pt solid; text-align: left"> </td> <td style="border-bottom: Black 1pt solid; text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">6,379</div></td> <td style="border-bottom: Black 1pt solid; text-align: left"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204,238,255)"> <td style="padding-bottom: 2.5pt; padding-left: 11pt">Total</td> <td style="padding-bottom: 2.5pt"> </td> <td style="border-bottom: Black 2.5pt double; text-align: left">$</td> <td style="border-bottom: Black 2.5pt double; text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">5,193</div></td> <td style="border-bottom: Black 2.5pt double; text-align: left"> </td> </tr> </table></div>