| The following table presents the major class
of assets of discontinued operations as of March 31, 2018 and December 31, 2017.   
    | (Amounts in Thousands) |  | March 31, 2018 |  |  | December 31, 2017 |  |  
    | Current assets |  |  |  |  |  |  |  |  |  
    | Other assets |  | $ | 94 |  |  | $ | 89 |  |  
    | Total current assets |  |  | 94 |  |  |  | 89 |  |  
    | Long-term assets |  |  |  |  |  |  |  |  |  
    | Property, plant and equipment, net (1) |  |  | 81 |  |  |  | 81 |  |  
    | Other assets |  |  | 176 |  |  |  | 195 |  |  
    | Total long-term assets |  |  | 257 |  |  |  | 276 |  |  
    | Total assets |  | $ | 351 |  |  | $ | 365 |  |  
    | Current liabilities |  |  |  |  |  |  |  |  |  
    | Accounts payable |  | $ | 11 |  |  | $ | 8 |  |  
    | Accrued expenses and other liabilities |  |  | 262 |  |  |  | 265 |  |  
    | Environmental liabilities |  |  | 619 |  |  |  | 632 |  |  
    | Total current liabilities |  |  | 892 |  |  |  | 905 |  |  
    | Long-term liabilities |  |  |  |  |  |  |  |  |  
    | Closure liabilities |  |  | 122 |  |  |  | 120 |  |  
    | Environmental liabilities |  |  | 229 |  |  |  | 239 |  |  
    | Total long-term liabilities |  |  | 351 |  |  |  | 359 |  |  
    | Total liabilities |  | $ | 1,243 |  |  | $ | 1,264 |  |    
    |  | (1) | net of accumulated depreciation of $10,000 for each period presented. |  |