Consolidated Statements of Cash Flows - USD ($) $ in Thousands	5 Months Ended	7 Months Ended	12 Months Ended
	May 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income (loss)		$ 23,969
Adjustments to reconcile net income (loss) to net cash flows provided by operating activities:
Accretion expense on obligations		5,420
Depreciation, depletion and amortization		16,012
Share-based compensation cost		1,227
Impairment of oil and natural gas properties		3,065
(Gain) loss on sales of oil and natural gas properties		(697)
Loss on equity securities		11,130
(Gain) loss on derivatives, net		(16,962)
Cash settlements of matured derivatives contracts		(5,824)
Other		1,020
Changes in operating assets and liabilities:
Accounts receivable		7,823
Other current assets		(53)
Accounts payable and accrued liabilities	$ (2,177)	(513)
Other, net		(60)
Net cash flows provided by operating activities		45,557
Cash flows from investing activities:
Additions to oil and natural gas properties		(27,368)
Reimbursements related to oil and natural gas properties		1,294
Proceeds from sale of oil and natural gas properties		140,324
Other		29
Net cash flows provided by (used in) investing activities		114,279
Cash flows from financing activities:
Repayment of long-term debt borrowings		(182,000)
Purchase of treasury stock		(247)
Contributions from general partner	40
Other		(8)
Net cash flows provided by (used in) financing activities		(182,255)
Increase (decrease) in cash, cash equivalents and restricted cash		(22,419)
Cash, cash equivalents and restricted cash – beginning of period		28,732
Cash, cash equivalents and restricted cash – end of period	28,732	6,313
Predecessor
Cash flows from operating activities:
Net income (loss)	(610,525)		$ (134,201)	$ (242,895)
Adjustments to reconcile net income (loss) to net cash flows provided by operating activities:
Amortization of volumetric production payment liability				(4,108)
Accretion expense on obligations	3,176		7,653	8,225
Depreciation, depletion and amortization	46,196		96,901	119,171
Share-based compensation cost	3,784		4,266	6,611
Impairment of oil and natural gas properties	3		93,607	131,260
(Gain) loss on sales of oil and natural gas properties	5		(981)	(69)
(Gain) loss on derivatives, net	(444)		(22,854)	35,950
Cash settlements of matured derivatives contracts	3,099		(2,235)	54,884
Gain on early extinguishment of debt				(47,695)
Deferred taxes				(404)
Reorganization items, net	573,304
Other	248		1,411	2,523
Changes in operating assets and liabilities:
Accounts receivable	(3,518)		(2,670)	(11,403)
Other current assets	1,853		(1,585)	(361)
Accounts payable and accrued liabilities	4,405		(6,783)	(5,862)
Income taxes				(11,657)
Other, net	69		(829)	(295)
Net cash flows provided by operating activities	21,655		31,700	33,875
Cash flows from investing activities:
Acquisition of oil and natural gas properties			(61,400)
Additions to oil and natural gas properties	(29,727)		(27,268)	(15,258)
Reimbursements related to oil and natural gas properties	652		2,517
Proceeds from sale of oil and natural gas properties	3		3,654	54,509
Cash settlements from acquired derivative contracts				3,003
Other	26		60	56
Net cash flows provided by (used in) investing activities	(29,046)		(82,437)	42,310
Cash flows from financing activities:
Repayment of long-term debt borrowings			(28,000)	(57,000)
Long-term debt borrowings	34,000		26,000	57,000
Redemption of 8% Senior Notes due 2019				(34,978)
Loan costs incurred	(2,813)			(121)
Contributions from general partner	40
Distributions				(3,868)
Net cash flows provided by (used in) financing activities	31,227		(2,000)	(38,967)
Increase (decrease) in cash, cash equivalents and restricted cash	23,836		(52,737)	37,218
Cash, cash equivalents and restricted cash – beginning of period	4,896	$ 28,732	57,633	20,415
Cash, cash equivalents and restricted cash – end of period	$ 28,732		$ 4,896	$ 57,633