Note 5 - Asset Retirement Obligations (Tables) |
6 Months Ended | ||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Jun. 30, 2019 | |||||||||||||||||||||||||||||||||||||||||
| Notes Tables | |||||||||||||||||||||||||||||||||||||||||
| Schedule of Change in Asset Retirement Obligation [Table Text Block] |
|
| X | ||||||||||
- Definition Tabular disclosure of the changes in carrying amount of a liability for asset retirement obligations, for changes such as new obligations, changes in estimates of existing obligations, spending on existing obligations, property dispositions, and foreign currency translation. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- References No definition available.
|