Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating activities:
Net income	$ 64,527	$ 109,983
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion, amortization and accretion	110,680	114,807
Amortization of debt items and other items	3,914	1,796
Share-based compensation	2,429	3,808
Derivative (gain) loss	41,228	5,931
Cash receipts (payments) on derivative settlements, net	17,583	(3,091)
Income taxes	(55,764)	363
Changes in operating assets and liabilities:
Oil and natural gas receivables	(3,822)	(4,039)
Joint interest receivables	(15,850)	3,261
Prepaid expenses and other assets	(14,211)	(8,467)
Income tax receivables	17,165	(139)
Asset retirement obligation settlements	(7,740)	(22,764)
Cash advances from JV partners	15,847	27,014
Accounts payable, accrued liabilities and other	10,610	66,389
Net cash provided by operating activities	186,596	294,852
Investing activities:
Investment in oil and natural gas properties and equipment	(93,482)	(79,422)
Acquisition of property interest	(167,718)	(16,782)
Proceeds from sale of assets		50,474
Purchases of furniture, fixtures and other	(20)
Net cash used in investing activities	(261,220)	(45,730)
Financing activities:
Borrowings of long-term debt - revolving bank credit facility	150,000
Repayments of long-term debt - revolving bank credit facility	(66,000)
Payment of interest on 1.5 Lien Term Loan		(6,171)
Payment of interest on 2nd Lien PIK Toggle Notes		(2,920)
Debt issuance costs and other	(928)	(26)
Net cash provided by (used in) financing activities	83,072	(9,117)
Increase in cash and cash equivalents	8,448	240,005
Cash and cash equivalents, beginning of period	33,293	99,058
Cash and cash equivalents, end of period	$ 41,741	$ 339,063