Fresh Start Accounting - Reorganization property (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Oct. 21, 2016
Fresh start accounting adjustments
Accumulated depreciation, depletion, amortization and impairment	$ 12,974
Fresh Start Adjustments
Fresh start accounting adjustments
Accumulated depreciation, depletion, amortization and impairment		$ (3,449,241)
Fresh Start Adjustments | Oil and Gas Properties
Fresh start accounting adjustments
Accumulated depreciation, depletion, amortization and impairment		3,400,000
Increase in oil and gas properties		269,700
Decrease in the asset retirement obligation		$ 6,400