Supplemental Oil and Gas Information (Schedule of Capitalized Costs Related to Oil and Gas Producing Activities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Capitalized Costs Relating To Oil And Gas Producing Activities By Geographic Area [Line Items]
Proved properties	$ 717,839
Unproved properties	74,434
Support equipment	14,180
Predecessor
Capitalized Costs Relating To Oil And Gas Producing Activities By Geographic Area [Line Items]
Proved properties		$ 3,585,839
Unproved properties		213,047
Support equipment		130,691
Capitalized Costs Related To Oil And Gas Producing Activities
Capitalized Costs Relating To Oil And Gas Producing Activities By Geographic Area [Line Items]
Proved properties	717,839
Unproved properties	74,434
Support equipment	2,643
Total natural gas and oil properties	794,916
Accumulated depreciation, depletion and amortization	(21,056)
Net capitalized costs	$ 773,860
Capitalized Costs Related To Oil And Gas Producing Activities | Predecessor
Capitalized Costs Relating To Oil And Gas Producing Activities By Geographic Area [Line Items]
Proved properties		3,585,839
Unproved properties		213,047
Support equipment		44,921
Total natural gas and oil properties		3,843,807
Accumulated depreciation, depletion and amortization		(2,691,692)
Net capitalized costs		$ 1,152,115