Supplemental Quarterly Information (Details) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended							11 Months Ended	12 Months Ended
	Feb. 08, 2018	Mar. 31, 2018	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Line Items]
Total operating revenue and other		$ 34,090	$ 185,589	$ 122,873	$ 66,459	$ 46,567	$ 57,923	$ 79,800	$ 95,079	$ 409,011
Income (loss) from continuing operations		(34,571)	(2,037,170)	17,844	(22,477)	(35,733)	(22,163)	15,620	29,430	(2,076,374)	$ (2,000,000)
Income (loss) from discontinued operations		0	0	0	0	(27,325)	(2,041)	(30,934)	(4,515)	0
Net income (loss)		(34,571)	(2,037,170)	17,844	(22,477)	(63,058)	(24,204)	(15,314)	24,915	(2,076,374)
Impairment of assets			2,000,000						1,200	2,033,712
Gain (loss) on derivatives		(22,600)	$ 52,800	$ (11,200)	$ (29,200)	(29,700)	(10,500)	$ 18,300	$ 30,200	(10,247)
Gain on sale of assets		$ 6,000								$ 4,751
Gain (Loss) on Sale of Assets and Asset Impairment Charges						(22,200)
Predecessor
Quarterly Financial Information Disclosure [Line Items]
Total operating revenue and other	$ 47,639											$ 279,369	$ 101,899
Income (loss) from continuing operations	(7,116)											(12,846)	(134,279)
Income (loss) from discontinued operations	(7,746)											(64,815)	(33,642)
Net income (loss)	(14,862)											(77,661)	(167,921)
Impairment of assets	0											1,188	382
Gain (loss) on derivatives	6,663											8,287	(40,460)
Gain (loss) on acquisition of oil and gas property						$ (3,600)	$ 5,300
Gain on sale of assets	$ 840											$ 28	$ 3