STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income (Loss)	$ (76,318)	$ 143,689	$ (9,194)
Adjustments to Reconcile Net Income (Loss) to Net Cash Provided by Operating Activities:
Depletion, Depreciation, Amortization and Accretion	210,201	119,780	59,500
Amortization of Debt Issuance Costs	5,307	5,147	4,122
Write-off of Debt Issuance Costs	0	0	95
(Gain) Loss on Extinguishment of Debt	23,187	173,430	993
Amortization of Bond (Premium) Discount on Long-term Debt	(2,705)	(563)	496
Deferred Income Taxes	210	365	(785)
Unrealized (Gain) Loss on Derivative Instruments	173,214	(207,892)	18,443
Legal Settlement	0	0	2,820
Loss on Debt Exchange Derivative	(1,390)	598	0
Loss on Contingent Consideration	29,512	28,968	0
PIK Interest on Second Lien Notes	1,742	2,599	0
Share-Based Compensation Expense	7,955	3,995	3,287
Impairment of Other Current Assets	6,398	0	0
Other	(41)	(120)	32
Changes in Working Capital and Other Items:
Accounts Receivable, Net	(11,542)	(49,122)	(9,717)
Prepaid and Other Expenses	3,997	19,397	(750)
Accounts Payable	(16,928)	(2,704)	3,229
Accrued Liabilities	27,166	(3,517)	254
Accrued Interest	(3,084)	10,212	142
Payment of Contingent Consideration	(37,131)	0	0
Net Cash Provided By Operating Activities	339,750	244,262	72,967
CASH FLOWS FROM INVESTING ACTIVITIES
Drilling and Development Capital Expenditures	(338,788)	(216,692)	(104,998)
Acquisition of Oil and Natural Gas Properties	(229,182)	(257,807)	(14,410)
Proceeds from Sale of Oil and Natural Gas Properties	0	22	171
Proceeds from Sale of Other Property and Equipment	0	46	0
Purchases of Other Property and Equipment	(1,158)	(88)	(3)
Net Cash Used For Investing Activities	(569,128)	(474,519)	(119,240)
CASH FLOWS FROM FINANCING ACTIVITIES
Advances on Revolving Credit Facility	953,000	190,000	36,000
Repayments on Revolving Credit Facility	(513,000)	(50,000)	(180,000)
Borrowings on Term Loan Credit Agreement	0	60,000	300,000
Repayments on Term Loan Credit Agreement	0	(420,105)	0
Issuance of Second Lien Notes	0	364,369	0
Repayments of Second Lien Notes	(227,470)	0	0
Repayments of Senior Unsecured Notes	0	(104,215)	0
Debt Issuance Costs Paid	(12,219)	(26,648)	(13,362)
Debt Derivative Exchange Settlements	(1,044)	(1,769)	0
Contingent Consideration Settlements	(11,278)	0	0
Issuance of Common Stock	0	141,674	0
Repurchases of Common Stock	(15,108)	(22,195)	0
Issuance of Preferred Stock	70,868	0	0
Restricted Stock Surrenders - Tax Obligations	(660)	(680)	(668)
Net Cash Provided By Financing Activities	243,088	130,431	141,970
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	13,710	(99,825)	95,697
CASH AND CASH EQUIVALENTS – BEGINNING OF PERIOD	2,358	102,183	6,486
CASH AND CASH EQUIVALENTS – END OF PERIOD	$ 16,068	$ 2,358	$ 102,183