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Asset Impairment Review
6 Months Ended
Jun. 30, 2017
Asset Impairment Review [Abstract]  
Asset Impairment Review

(7)Asset Impairment Review

In December 2016, the deterioration of the North End of the Carlisle Mine (the North End), coupled with lower coal prices led us to determine that the North End could no longer be mined safely and profitably.  The sealing of the North End was completed in March 2017.



With the Carlisle Mine remaining in hot idle status, we conducted a review of the Carlisle Mine assets as of June 30, 2017, based on estimated future net cash flows, and determined that no impairment was necessary.



The Carlisle Mine assets had an aggregate net carrying value of $113 million at June 30, 2017.  If in future periods, we reduce our estimate of the future net cash flows attributable to the Carlisle Mine, it may result in future impairment of such assets and such charges could be significant.  None of our other assets are considered impaired.