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Basis of Presentation Basis of Presentation (Policies) | 9 Months Ended
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Sep. 30, 2018
Basis of Presentation [Abstract] |
Plan of Reorganization and Emergence from Chapter 11 Cases [Policy Text Block] | In connection with fresh start reporting, the Company made certain prospective accounting policy elections that impact the Successor periods presented herein. The Company now classifies the amortization associated with its asset retirement obligation assets within “Depreciation, depletion and amortization” in its consolidated statements of operations, rather than within “Asset retirement obligation expenses,” as in Predecessor periods. With respect to its accrued postretirement benefit and pension obligations, the Company now records amounts attributable to prior service cost and actuarial valuation changes, as applicable, currently in earnings rather than recording such amounts within accumulated other comprehensive income and amortizing to expense over the applicable time periods.

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