Note 7 - East Tennessee Materials and Energy Corporation ("M&EC") (Tables)
|6 Months Ended|
Jun. 30, 2017
|Schedule of Change in Asset Retirement Obligation [Table Text Block]||
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://www.xbrl.org/2003/role/presentationRef