Note 11 - Income Taxes - Unrecognized Tax Benefit Roll Forward (Details) - USD ($) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Balance | $ 397,000 | $ 268,000 |
| Additions based upon tax positions related to the current year | 53,000 | 129,000 |
| Balance | $ 450,000 | $ 397,000 |
| X | ||||||||||
- Definition Amount of unrecognized tax benefits. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|