Chord Energy (WLLBW) 10-Q 5 May 21 2021 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	Apr. 30, 2021
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	001-31899
Entity Registrant Name	WHITING PETROLEUM CORP
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-0098515
Entity Address, Address Line One	1700 Lincoln Street, Suite 4700
Entity Address, City or Town	Denver
Entity Address, State or Province	CO
Entity Address, Postal Zip Code	80203-4547
City Area Code	303
Local Phone Number	837-1661
Title of 12(b) Security	Common Stock
Trading Symbol	WLL
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Bankruptcy Proceedings, Reporting Current	true
Entity Common Stock, Shares Outstanding		39,054,196
Entity Central Index Key	0001255474
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 24,704	$ 25,607
Restricted cash	2,400	2,760
Accounts receivable trade, net	203,058	142,830
Prepaid expenses and other	15,318	19,224
Total current assets	245,480	190,421
Property and equipment:
Oil and gas properties, successful efforts method	1,872,469	1,812,601
Other property and equipment	66,613	74,064
Total property and equipment	1,939,082	1,886,665
Less accumulated depreciation, depletion and amortization	(126,072)	(73,869)
Total property and equipment, net	1,813,010	1,812,796
Other long-term assets	38,458	40,723
TOTAL ASSETS	2,096,948	2,043,940
Current liabilities:
Accounts payable trade	53,642	23,697
Revenues and royalties payable	171,895	151,196
Accrued capital expenditures	28,832	20,155
Accrued liabilities and other	36,074	42,007
Accrued lease operating expenses	20,594	23,457
Taxes payable	16,201	11,997
Derivative liabilities	134,422	49,485
Total current liabilities	461,660	321,994
Long-term debt	245,000	360,000
Asset retirement obligations	99,271	91,864
Operating lease obligations	16,907	17,415
Other long-term liabilities	45,300	23,863
Total liabilities	868,138	815,136
Commitments and contingencies
Equity:
Successor common stock, $0.001 par value, 500,000,000 shares authorized; 39,054,196 issued and outstanding as of March 31, 2021 and 38,051,125 issued and outstanding as of December 31, 2020	39	38
Additional paid-in capital	1,190,644	1,189,693
Accumulated earnings	38,127	39,073
Total equity	1,228,810	1,228,804
TOTAL LIABILITIES AND EQUITY	$ 2,096,948	$ 2,043,940

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
CONSOLIDATED BALANCE SHEETS [Abstract]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	39,054,196	38,051,125
Common stock, shares outstanding	39,054,196	38,051,125

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
OPERATING REVENUES
Operating revenues	$ 307,391	$ 244,846
OPERATING EXPENSES
Lease operating expenses	59,339	72,340
Transportation, gathering, compression and other	7,028	8,963
Purchased gas expense	1,902
Production and ad valorem taxes	24,150	22,423
Depreciation, depletion and amortization	53,729	183,968
Exploration and impairment	2,622	3,753,457
General and administrative	10,291	47,167
Derivative (gain) loss, net	146,693	(231,371)
Gain on sale of properties		(864)
Amortization of deferred gain on sale		(2,037)
Total operating expenses	305,754	3,854,046
INCOME (LOSS) FROM OPERATIONS	1,637	(3,609,200)
OTHER INCOME (EXPENSE)
Interest expense	(5,103)	(45,250)
Gain on extinguishment of debt		25,883
Other income	2,520	(4)
Total other expense	(2,583)	(19,371)
LOSS BEFORE INCOME TAXES	(946)	(3,628,571)
INCOME TAX EXPENSE (BENEFIT)
Current		3,746
Deferred		(3,746)
Total income tax expense (benefit)	0	0
NET LOSS	$ (946)	$ (3,628,571)
LOSS PER COMMON SHARE
Basic (in dollars per share)	$ (0.02)	$ (39.70)
Diluted (in dollars per share)	$ (0.02)	$ (39.70)
WEIGHTED AVERAGE SHARES OUTSTANDING
Basic (in shares)	38,698	91,390
Diluted (in shares)	38,698	91,390
Oil, NGL and natural gas sales [Member]
OPERATING REVENUES
Operating revenues	$ 304,679	$ 244,846
Purchased gas sales [Member]
OPERATING REVENUES
Operating revenues	$ 2,712

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (946)	$ (3,628,571)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, depletion and amortization	53,729	183,968
Deferred income tax benefit		(3,746)
Amortization of debt issuance costs, debt discount and debt premium	887	4,536
Stock-based compensation	2,309	2,068
Amortization of deferred gain on sale		(2,037)
Gain on sale of properties		(864)
Oil and gas property impairments	1,441	3,745,092
Gain on extinguishment of debt		(25,883)
Non-cash derivative (gain) loss	107,399	(199,550)
Other, net	(973)	805
Changes in current assets and liabilities:
Accounts receivable trade, net	(58,032)	62,289
Prepaid expenses and other	3,906	(22,624)
Accounts payable trade and accrued liabilities	18,570	(55,561)
Revenues and royalties payable	20,699	(9,629)
Taxes payable	4,204	(13,080)
Net cash provided by operating activities	153,193	37,213
CASH FLOWS FROM INVESTING ACTIVITIES
Drilling and development capital expenditures	(35,728)	(146,299)
Acquisition of oil and gas properties	(470)	(350)
Other property and equipment	(2,597)	(985)
Proceeds from sale of properties	1,945	27,453
Net cash used in investing activities	(36,850)	(120,181)
CASH FLOWS FROM FINANCING ACTIVITIES
Repurchase of 1.25% Convertible Senior Notes due 2020		(52,890)
Restricted stock used for tax withholdings	(1,357)	(304)
Principal payments on finance lease obligations	(1,249)	(1,217)
Net cash provided by (used in) financing activities	(117,606)	640,589
NET CHANGE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	(1,263)	557,621
CASH, CASH EQUIVALENTS AND RESTRICTED CASH
Beginning of period	28,367	8,652
End of period	27,104	566,273
SUPPLEMENTAL CASH FLOW DISCLOSURES
Cash paid for reorganization items	396
NONCASH INVESTING ACTIVITIES
Accrued capital expenditures and accounts payable related to property additions	34,121	88,424
Predecessor Credit Agreement [Member]
CASH FLOWS FROM FINANCING ACTIVITIES
Borrowings under credit agreement		1,185,000
Repayments of borrowings under credit agreement		$ (490,000)
Credit Agreement [Member]
CASH FLOWS FROM FINANCING ACTIVITIES
Borrowings under credit agreement	250,000
Repayments of borrowings under credit agreement	$ (365,000)

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical)	Aug. 31, 2020	Mar. 31, 2020
1.25% Convertible Senior Notes due 2020 [Member]
Interest Rate (as a percent)	1.25%	1.25%

CONSOLIDATED STATEMENTS OF EQUI

CONSOLIDATED STATEMENTS OF EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Total
BALANCES at Dec. 31, 2019	$ 92	$ 6,409,991	$ (2,385,112)	$ 4,024,971
BALANCES (in shares) at Dec. 31, 2019	91,744
Increase (Decrease) in Shareholders' Equity
Net loss			(3,628,571)	(3,628,571)
Adjustment to equity component of Convertible Senior Notes upon extinguishment		(3,461)		(3,461)
Restricted stock issued (in shares)	185
Restricted stock forfeited (in shares)	(238)
Restricted stock used for tax withholdings		(304)		(304)
Restricted stock used for tax withholdings (in shares)	(54)
Stock-based compensation		2,068		2,068
BALANCES at Mar. 31, 2020	$ 92	6,408,294	(6,013,683)	394,703
BALANCES (in shares) at Mar. 31, 2020	91,637
BALANCES at Dec. 31, 2020	$ 38	1,189,693	39,073	1,228,804
BALANCES (in shares) at Dec. 31, 2020	38,051
Increase (Decrease) in Shareholders' Equity
Net loss			(946)	(946)
Common stock issued in settlement of bankruptcy claims	$ 1	(1)
Common stock issued in settlement of bankruptcy claims (in shares)	949
Restricted stock issued (in shares)	95
Restricted stock used for tax withholdings		(1,357)		(1,357)
Restricted stock used for tax withholdings (in shares)	(41)
Stock-based compensation		2,309		2,309
BALANCES at Mar. 31, 2021	$ 39	$ 1,190,644	$ 38,127	$ 1,228,810
BALANCES (in shares) at Mar. 31, 2021	39,054

BASIS OF PRESENTATION

BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 2021
BASIS OF PRESENTATION [Abstract]
BASIS OF PRESENTATION	1. BASIS OF PRESENTATION Description of Operations Voluntary Reorganization under Chapter 11 of the Bankruptcy Code Upon emergence, the Company adopted fresh start accounting in accordance with FASB ASC Topic 852 – Reorganizations (“ASC 852”), which specifies the accounting and financial reporting requirements for entities reorganizing through chapter 11 bankruptcy proceedings. The application of fresh start accounting resulted in a new basis of accounting and the Company becoming a new entity for financial reporting purposes. As a result of the implementation of the Plan and the application of fresh start accounting, the consolidated financial statements after the Emergence Date are not comparable to the consolidated financial statements before that date and the historical financial statements on or before the Emergence Date are not a reliable indicator of the Company’s financial condition and results of operations for any period after its adoption of fresh start accounting. Refer to the “Fresh Start Accounting” footnote for more information. References to “Successor” refer to the Company and its financial position and results of operations after the Emergence Date. References to “Predecessor” refer to the Company and its financial position and results of operations on or before the Emergence Date. References to “Successor Period” refer to the three months ended March 31, 2021. References to “Predecessor Period” refer to the three months ended March 31, 2020. Condensed Consolidated Financial Statements Reclassifications — ​ Cash, Cash Equivalents and Restricted Cash — Restricted cash as of March 31, 2021 and December 31, 2020 consist of funds remaining in a professional fee escrow account that were reserved to pay certain professional fees upon emergence from the Chapter 11 Cases. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets and statements of cash flows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ March 31, ​ December 31, ​ ​ 2021 ​ 2020 Cash and cash equivalents ​ $ 24,704 ​ $ 25,607 Restricted cash ​ ​ 2,400 ​ ​ 2,760 Total cash, cash equivalents and restricted cash ​ $ 27,104 ​ $ 28,367 ​ Accounts Receivable Trade — The Company routinely evaluates expected credit losses for all material trade and other receivables to determine if an allowance for credit losses is warranted. Expected credit losses are estimated based on (i) historic loss experience for pools of receivable balances with similar characteristics, (ii) the length of time balances have been outstanding and (iii) the economic status of each counterparty. These loss estimates are then adjusted for current and expected future economic conditions, which may include an assessment of the probability of non-payment, financial distress or expected future commodity prices and the impact that any current or future conditions could have on a counterparty’s credit quality and liquidity. As of March 31, 2021 and December 31, 2020 (Successor), the Company had immaterial allowances for credit losses.

CHAPTER 11 EMERGENCE

CHAPTER 11 EMERGENCE	3 Months Ended
	Mar. 31, 2021
CHAPTER 11 EMERGENCE [Abstract]
CHAPTER 11 EMERGENCE	2. CHAPTER 11 EMERGENCE Plan of Reorganization under Chapter 11 of the Bankruptcy Code — On April 1, 2020, the Debtors commenced the Chapter 11 Cases as described in the “Basis of Presentation” footnote above. On April 23, 2020, the Debtors entered into a restructuring support agreement with certain holders of the Company’s senior notes to support a restructuring in accordance with the terms set forth in the Plan. On August 14, 2020, the Bankruptcy Court confirmed the Plan. On September 1, 2020 the Debtors satisfied all conditions required for Plan effectiveness and emerged from the Chapter 11 Cases. On the Emergence Date and pursuant to the Plan: (1) The Company amended and restated its certificate of incorporation and bylaws. (2) The Company constituted a new Successor board of directors. (3) The Company appointed a new Chief Executive Officer and a new Chief Financial Officer. (4) The Company issued: ● 36,817,630 shares of the Successor ’s common stock pro rata to holders of the Predecessor ’s senior notes, ● 1,233,495 shares of the Successor’s common stock pro rata to holders of the Predecessor’s common stock, ● 4,837,387 Series A Warrants to purchase the same number of shares of the Successor’s common stock pro rata to holders of the Predecessor’s common stock and ● 2,418,840 Series B Warrants to purchase the same number of shares of the Successor’s common stock pro rata to holders of the Predecessor’s common stock. The Company also reserved 3,070,201 shares of the Successor’s common stock for potential future distribution to certain general unsecured claimants whose claim values were pending resolution in the Bankruptcy Court. In February 2021, the Company issued 948,897 shares out of this reserve to a general unsecured claimant in full settlement of such claimant’s claims pending before the Bankruptcy Court and for rejection damages relating to an executory contract. Any remaining reserved shares that are not distributed to resolve pending claims will be cancelled. In addition, 4,035,885 shares have been reserved for distribution under the Company’s 2020 equity incentive plan, as further detailed in the “Stock-Based Compensation” footnote below. (5) Whiting Petroleum Corporation, as parent guarantor, and Whiting Oil and Gas, as borrower, entered into a reserves-based credit agreement with a syndicate of banks (the “Credit Agreement”) with initial aggregate commitments in the amount of $750 million, with the ability to increase the aggregate commitments by up to an additional $750 million, subject to certain conditions. Refer to the “Long-Term Debt” footnote for more information on the Credit Agreement. The Company utilized borrowings from the Credit Agreement and cash on hand to repay all borrowings and accrued interest outstanding on its pre-emergence credit facility (the “Predecessor Credit Agreement”) as of the Emergence Date, and the Predecessor Credit Agreement terminated on that date. (6) The holders of trade claims, administrative expense claims, other secured claims and other priority claims received payment in full in cash upon emergence or through the ordinary course of business after the Emergence Date. Executory Contracts Claims Resolution Process

FRESH START ACCOUNTING

FRESH START ACCOUNTING	3 Months Ended
	Mar. 31, 2021
FRESH START ACCOUNTING [Abstract]
FRESH START ACCOUNTING	3. FRESH START ACCOUNTING Fresh Start Fair Value Measurement Business Combinations For further information on the Company’s reorganization value and the resulting fresh start adjustments made on the Emergence Date, refer to the “Fresh Start Accounting” footnote in the notes to the consolidated financial statements in Item 8 of the Company’s 2020 Annual Report on Form 10-K.

OIL AND GAS PROPERTIES

OIL AND GAS PROPERTIES	3 Months Ended
	Mar. 31, 2021
OIL AND GAS PROPERTIES [Abstract]
OIL AND GAS PROPERTIES	4. OIL AND GAS PROPERTIES Net capitalized costs related to the Company’s oil and gas producing activities at March 31, 2021 and December 31, 2020 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ March 31, ​ December 31, ​ 2021 ​ 2020 Proved oil and gas properties ​ $ 1,743,530 ​ $ 1,701,163 Unproved leasehold costs ​ ​ 102,841 ​ ​ 105,073 Wells and facilities in progress ​ ​ 26,098 ​ ​ 6,365 Total oil and gas properties, successful efforts method ​ ​ 1,872,469 ​ ​ 1,812,601 Accumulated depletion ​ ​ (121,277) ​ ​ (71,064) Oil and gas properties, net ​ $ 1,751,192 ​ $ 1,741,537 ​ Impairment expense for unproved properties totaled $1 million and $12 million for the three months ended March 31, 2021 (Successor) and March 31, 2020 (Predecessor), respectively, and is reported in exploration and impairment expense in the condensed consolidated statements of operations. Refer to the “Fair Value Measurements” footnote for more information on proved property measurements recorded during the periods presented.

ACQUISITIONS AND DIVESTITURES

ACQUISITIONS AND DIVESTITURES	3 Months Ended
	Mar. 31, 2021
ACQUISITIONS AND DIVESTITURES [Abstract]
ACQUISITIONS AND DIVESTITURES	5. ACQUISITIONS AND DIVESTITURES 2021 Acquisitions and Divestitures There were no significant acquisitions or divestitures during the three months ended March 31, 2021. 2020 Acquisitions and Divestitures On January 9, 2020, the Predecessor completed the divestiture of its interests in 30 non-operated, producing oil and gas wells and related undeveloped acreage located in McKenzie County, North Dakota for aggregate sales proceeds of $25 million (before closing adjustments). There were no significant acquisitions during the three months ended March 31, 2020.

LONG-TERM DEBT

LONG-TERM DEBT	3 Months Ended
	Mar. 31, 2021
LONG-TERM DEBT [Abstract]
LONG-TERM DEBT	6. LONG-TERM DEBT Long-term debt consisted of the following at March 31, 2021 and December 31, 2020 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ March 31, ​ December 31, ​ 2021 ​ 2020 Credit Agreement ​ $ 245,000 ​ $ 360,000 Total long-term debt ​ $ 245,000 ​ $ 360,000 ​ Credit Agreement (Successor) On the Emergence Date, Whiting Petroleum Corporation, as parent guarantor, and Whiting Oil and Gas, as borrower, entered into the Credit Agreement, a reserves-based credit facility, with a syndicate of banks . As of March 31, 2021, the Credit Agreement had a borrowing base and aggregate commitments of $750 million. As of March 31, 2021, the Company had $503 million of available borrowing capacity under the Credit Agreement, which was net of $245 million of borrowings outstanding and $2 The borrowing base under the Credit Agreement is determined at the discretion of the lenders, based on the collateral value of the Company’s proved reserves that have been mortgaged to such lenders, and is subject to regular redeterminations on April 1 and October 1 of each year, as well as special redeterminations described in the Credit Agreement, in each case which may increase or decrease the amount of the borrowing base. In April 2021, the Company’s borrowing base and aggregate commitments of $750 million were reaffirmed in connection with our regular borrowing base redetermination. Future asset sales that materially impact the value of the Company’s proved reserves may result in a reduction of the borrowing base. However, the Company can increase the aggregate commitments by up to an additional $750 million, subject to certain conditions. A portion of the revolving credit facility in an aggregate amount not to exceed $50 million may be used to issue letters of credit for the account of Whiting Oil and Gas or other designated subsidiaries of the Company. As of March 31, 2021, $48 million was available for additional letters of credit under the Credit Agreement. The Credit Agreement provides for interest only payments until maturity on April 1, 2024, when the agreement terminates and all outstanding borrowings are due. In addition, the Credit Agreement provides for certain mandatory prepayments, including a provision pursuant to which, if the Company’s cash balances are in excess of approximately $75 million during any given week, such excess must be utilized to repay borrowings under the Credit Agreement. Interest under the Credit Agreement accrues at the Company’s option at either (i) a base rate for a base rate loan plus a margin between 1.75% and 2.75% based on the ratio of outstanding borrowings and letters of credit to the lower of the current borrowing base or total commitments, where the base rate is defined as the greatest of the prime rate, the federal funds rate plus 0.5% per annum, or an adjusted LIBOR plus 1.0% per annum, or (ii) an adjusted LIBOR for a eurodollar loan plus a margin between 2.75% and 3.75% based on the ratio of outstanding borrowings and letters of credit to the lower of the current borrowing base or total commitments. Additionally, the Company incurs commitment fees of 0.5% on the unused portion of the aggregate commitments of the lenders under the Credit Agreement, which are included as a component of interest expense. At March 31, 2021, the weighted average interest rate on the outstanding principal balance under the Credit Agreement was 4.2%. The Credit Agreement contains restrictive covenants that may limit the Company’s ability to, among other things, incur additional indebtedness, sell assets, make loans to others, make investments, enter into mergers, enter into hedging contracts, incur liens and engage in certain other transactions without the prior consent of its lenders. Except for limited exceptions, the Credit Agreement also restricts the Company’s ability to make any dividend payments or distributions on its common stock prior to September 1, 2021, and thereafter only to the extent that the Company has distributable free cash flow and (i) has at least 20% of available borrowing capacity, (ii) has a consolidated net leverage ratio of less than or equal to 2.0 to 1.0, (iii) does not have a borrowing base deficiency and (iv) is not in default under the Credit Agreement. These restrictions apply to all of the Company’s restricted subsidiaries and are calculated in accordance with definitions contained in the Credit Agreement. The Credit Agreement requires the Company, as of the last day of any quarter, to maintain commodity hedges covering a minimum of 65% of its projected production for the succeeding twelve months, and 35% of its projected production for the next succeeding twelve months, both as reflected in the reserves report most recently provided by the Company to the lenders under the Credit Agreement. The Company is also limited to hedging a maximum of 85% of its production from proved reserves. The Credit Agreement requires the Company to maintain the following ratios: (i) a consolidated current assets to consolidated current liabilities ratio of not less than 1.0 to 1.0 and (ii) a total debt to last four quarters’ EBITDAX ratio of not greater than 3.5 to 1.0. As of March 31, 2021, the Company was in compliance with the covenants under the Credit Agreement. The obligations of Whiting Oil and Gas under the Credit Agreement are secured by a first lien on substantially all of the Company’s properties. The Company has also guaranteed the obligations of Whiting Oil and Gas under the Credit Agreement and has pledged the stock of its subsidiaries as security for its guarantee. Senior Notes and Convertible Senior Notes (Predecessor) Prior to the Emergence Date, the Company had outstanding notes consisting of $774 million 5.75% Senior Notes due 2021, $408 million 6.25% Senior Notes due 2023 and $1.0 billion 6.625% Senior Notes due 2026 (the “Senior Notes”) and $187 million of 1.25% Convertible Senior Notes due 2020 (the “Convertible Senior Notes”). On the Emergence Date, through implementation of the Plan, all outstanding obligations under the Senior Notes and the Convertible Senior Notes were cancelled and 36,817,630 shares of Successor common stock were issued to the holders of those outstanding notes. In addition, the remaining unamortized debt issuance costs and debt premium were written off to reorganization items, net in the condensed consolidated statements of operations. Refer to the “Chapter 11 Emergence” and “Fresh Start Accounting” footnotes for more information. In March 2020, the Company paid $53 million to repurchase $73 million aggregate principal amount of the Convertible Senior Notes, which payment consisted of the average 72.5% purchase price plus all accrued and unpaid interest on the notes, which were allocated to the liability and equity components based on their relative fair values. The Company financed the repurchases with borrowings under the Predecessor Credit Agreement. As a result of these repurchases, the Company recognized a $23 million gain on extinguishment of debt during the Predecessor Period, which was net of a $0.2 million charge for the non-cash write-off of unamortized debt issuance costs and debt discount. In addition, the Company recorded a $3 million reduction to the equity component of the Convertible Senior Notes. There was no deferred tax impact associated with this reduction due to the full valuation allowance in effect as of March 31, 2020.

ASSET RETIREMENT OBLIGATIONS

ASSET RETIREMENT OBLIGATIONS	3 Months Ended
	Mar. 31, 2021
ASSET RETIREMENT OBLIGATIONS [Abstract]
ASSET RETIREMENT OBLIGATIONS	7. ASSET RETIREMENT OBLIGATIONS The Company’s asset retirement obligations represent the present value of estimated future costs associated with the plugging and abandonment of oil and gas wells, removal of equipment and facilities from leased acreage and land restoration in accordance with applicable local, state and federal laws and the terms of the Company’s lease agreements. The current portions as of March 31, 2021 and December 31, 2020 (Successor) were $7 million and $6 million, respectively, and have been included in accrued liabilities and other in the condensed consolidated balance sheets. The following table provides a reconciliation of the Company’s asset retirement obligations for the three months ended March 31, 2021 (in thousands): ​ ​ ​ ​ ​ Asset retirement obligation at January 1, 2021 (Successor) ​ $ 98,130 Additional liability incurred ​ ​ 265 Revisions to estimated cash flows ​ ​ 6,821 Accretion expense ​ ​ 2,222 Obligations on sold properties ​ ​ (123) Liabilities settled ​ ​ (1,309) Asset retirement obligation at March 31, 2021 (Successor) ​ $ 106,006 ​

DERIVATIVE FINANCIAL INSTRUMENT

DERIVATIVE FINANCIAL INSTRUMENTS	3 Months Ended
	Mar. 31, 2021
DERIVATIVE FINANCIAL INSTRUMENTS [Abstract]
DERIVATIVE FINANCIAL INSTRUMENTS	8. DERIVATIVE FINANCIAL INSTRUMENTS The Company is exposed to certain risks relating to its ongoing business operations, and it uses derivative instruments to manage its commodity price risk. Commodity Derivative Contracts — the Credit Agreement. Refer to the “Long Term Debt” footnote for a detailed discussion of the minimum and maximum hedging requirements of the Credit Agreement. The Company does not enter into derivative contracts for speculative or trading purposes. Crude Oil, Natural Gas and Natural Gas Liquids Swaps and Collars, Natural Gas Basis Swaps and Crude Oil Differential Swaps. The table below details the Successor’s swap and collar derivatives entered into to hedge forecasted crude oil, NGL and natural gas production revenues as of March 31, 2021 (Successor). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average Settlement Period ​ Index ​ Derivative Instrument ​ Total Volumes ​ Units ​ Swap Price ​ Floor ​ Ceiling Crude Oil ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2021 ​ NYMEX WTI ​ Fixed Price Swaps ​ 4,723,500 ​ Bbl ​ $44.44 ​ - ​ - 2021 ​ NYMEX WTI ​ Two-way Collars ​ 4,796,000 ​ Bbl ​ - ​ $38.95 ​ $47.05 2022 ​ NYMEX WTI ​ Fixed Price Swaps ​ 630,000 ​ Bbl ​ $54.30 ​ - ​ - 2022 ​ NYMEX WTI ​ Two-way Collars ​ 9,197,000 ​ Bbl ​ - ​ $42.61 ​ $52.87 Q1 2023 ​ NYMEX WTI ​ Two-way Collars ​ 2,160,000 ​ Bbl ​ - ​ $46.13 ​ $56.25 ​ ​ ​ ​ Total ​ 21,506,500 ​ ​ ​ ​ ​ ​ ​ ​ Natural Gas ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2021 ​ NYMEX Henry Hub ​ Fixed Price Swaps ​ 14,430,000 ​ MMBtu ​ $2.81 ​ - ​ - 2021 ​ NYMEX Henry Hub ​ Two-way Collars ​ 8,250,000 ​ MMBtu ​ - ​ $2.60 ​ $2.79 2022 ​ NYMEX Henry Hub ​ Fixed Price Swaps ​ 3,530,000 ​ MMBtu ​ $2.65 ​ - ​ - 2022 ​ NYMEX Henry Hub ​ Two-way Collars ​ 10,720,000 ​ MMBtu ​ - ​ $2.35 ​ $2.85 Q1 2023 ​ NYMEX Henry Hub ​ Two-way Collars ​ 2,700,000 ​ MMBtu ​ - ​ $2.58 ​ $3.08 ​ ​ ​ ​ Total ​ 39,630,000 ​ ​ ​ ​ ​ ​ ​ ​ Natural Gas Basis (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2021 ​ NNG Ventura to NYMEX ​ Fixed Price Swaps ​ 5,500,000 ​ MMBtu ​ -$0.18 ​ - ​ - 2022 ​ NNG Ventura to NYMEX ​ Fixed Price Swaps ​ 2,165,000 ​ MMBtu ​ $0.50 ​ - ​ - Q1 2023 ​ NNG Ventura to NYMEX ​ Fixed Price Swaps ​ 3,375,000 ​ MMBtu ​ $0.37 ​ - ​ - ​ ​ ​ ​ Total ​ 11,040,000 ​ ​ ​ ​ ​ ​ ​ ​ NGL - Propane ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2021 ​ Mont Belvieu ​ Fixed Price Swaps ​ 17,325,000 ​ Gallons ​ $0.76 ​ - ​ - ​ ​ ​ ​ Total ​ 17,325,000 ​ ​ ​ ​ ​ ​ ​ ​ (1) The weighted average price associated with the natural gas basis swaps shown in the table above represents the average fixed differential to NYMEX as stated in the related contracts, which is compared to the Northern Natural Gas Ventura Index (“NNG Ventura”) for each period. If NYMEX combined with the fixed differential as stated in each contract is higher than the NNG Ventura index price at any settlement date, the Company receives the difference. Conversely, if the NNG Ventura index price is higher than NYMEX combined with the fixed differential, the Company pays the difference. ​ Subsequent to March 31, 2021, the Company entered into additional crude oil and natural gas swaps and collars for the remainder of 2021, 2022 and the second quarter of 2023. The table below details the Company’s additional swap and collar derivatives entered into during April 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average Settlement Period ​ Index ​ Derivative Instrument ​ Total Volumes ​ Units ​ Swap Price ​ Floor ​ Ceiling Crude Oil ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Q2 2023 ​ NYMEX WTI ​ Two-way Collars ​ 546,000 ​ Bbl ​ - ​ $47.50 ​ $59.23 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Crude Oil Differential (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2021 ​ UHC Clearbrook to NYMEX ​ Fixed Price Swaps ​ 107,000 ​ Bbl ​ -$1.95 ​ - ​ - ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Natural Gas ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 ​ NYMEX Henry Hub ​ Fixed Price Swaps ​ 1,365,000 ​ MMBtu ​ $2.49 ​ - ​ - Q2 2023 ​ NYMEX Henry Hub ​ Two-way Collars ​ 1,365,000 ​ MMBtu ​ - ​ $2.25 ​ $2.50 ​ ​ ​ ​ Total ​ 2,730,000 ​ ​ ​ ​ ​ ​ ​ ​ Natural Gas Basis ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 ​ NNG Ventura to NYMEX ​ Fixed Price Swaps ​ 1,365,000 ​ MMBtu ​ -$0.22 ​ - ​ - Q2 2023 ​ NNG Ventura to NYMEX ​ Fixed Price Swaps ​ 1,365,000 ​ MMBtu ​ -$0.22 ​ - ​ - ​ ​ ​ ​ Total ​ 2,730,000 ​ ​ ​ ​ ​ ​ ​ ​ (1) The weighted average price associated with the crude oil differential swaps shown in the table above represents the average fixed differential to NYMEX as stated in the related contracts, which is compared to the NE2 Canadian Monthly Index for UHC Clearbrook (“UHC Clearbrook”) for each period. If NYMEX combined with the fixed differential as stated in each contract is higher than the UHC Clearbrook index price at any settlement date, the Company receives the difference. Conversely, if the UHC Clearbrook index price is higher than NYMEX combined with the fixed differential, the Company pays the difference. Derivative Instrument Reporting ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Gain) Loss Recognized in Income ​ ​ ​ ​ Successor ​ ​ Predecessor Not Designated as ASC 815 Hedges Statements of Operations Classification Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Commodity contracts ​ Derivative (gain) loss, net ​ $ 146,693 ​ ​ $ (231,371) ​ Offsetting of Derivative Assets and Liabilities. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2021 (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net ​ ​ ​ ​ Gross ​ ​ ​ ​ Recognized ​ ​ ​ ​ Recognized ​ Gross ​ Fair Value Not Designated as ​ ​ ​ Assets/ ​ Amounts ​ Assets/ ASC 815 Hedges Balance Sheet Classification Liabilities Offset Liabilities Derivative assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity contracts - current ​ Prepaid expenses and other ​ $ 11,517 ​ $ (11,517) ​ $ - Commodity contracts - non-current ​ Other long-term assets ​ ​ 42,716 ​ ​ (42,716) ​ ​ - Total derivative assets ​ ​ ​ $ 54,233 ​ $ (54,233) ​ $ - Derivative liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity contracts - current ​ Derivative liabilities ​ $ 145,939 ​ $ (11,517) ​ $ 134,422 Commodity contracts - non-current ​ Other long-term liabilities ​ ​ 74,928 ​ ​ (42,716) ​ ​ 32,212 Total derivative liabilities ​ ​ ​ $ 220,867 ​ $ (54,233) ​ $ 166,634 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net ​ ​ ​ ​ Gross ​ ​ ​ ​ Recognized ​ ​ ​ ​ Recognized ​ Gross ​ Fair Value Not Designated as ​ ​ ​ Assets/ ​ Amounts ​ Assets/ ASC 815 Hedges Balance Sheet Classification Liabilities Offset Liabilities Derivative assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity contracts - current ​ Prepaid expenses and other ​ $ 14,287 ​ $ (14,287) ​ $ - Commodity contracts - non-current ​ Other long-term assets ​ ​ 19,991 ​ ​ (19,991) ​ ​ - Total derivative assets ​ ​ ​ $ 34,278 ​ $ (34,278) ​ $ - Derivative liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity contracts - current ​ Derivative liabilities ​ $ 63,772 ​ $ (14,287) ​ $ 49,485 Commodity contracts - non-current ​ Other long-term liabilities ​ ​ 29,741 ​ ​ (19,991) ​ ​ 9,750 Total derivative liabilities ​ ​ ​ $ 93,513 ​ $ (34,278) ​ $ 59,235 (1) All of the counterparties to the Company’s financial derivative contracts subject to master netting arrangements are lenders under the Credit Agreement, which eliminates the need to post or receive collateral associated with its derivative positions. Therefore, columns for cash collateral pledged or received have not been presented in these tables. Contingent Features in Financial Derivative Instruments.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	3 Months Ended
	Mar. 31, 2021
FAIR VALUE MEASUREMENTS [Abstract]
FAIR VALUE MEASUREMENTS	9. FAIR VALUE MEASUREMENTS The Company follows ASC 820 which establishes a three-level valuation hierarchy for disclosure of fair value measurements. The valuation hierarchy categorizes assets and liabilities measured at fair value into one of three different levels depending on the observability of the inputs employed in the measurement. The three levels are defined as follows: ● Level 1: Quoted Prices in Active Markets for Identical Assets – inputs to the valuation methodology are quoted prices (unadjusted) for identical assets or liabilities in active markets. ● Level 2: Significant Other Observable Inputs – inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument. ● Level 3: Significant Unobservable Inputs – inputs to the valuation methodology are unobservable and significant to the fair value measurement. A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. Cash, cash equivalents, restricted cash, accounts receivable and accounts payable are carried at cost, which approximates their fair value because of the short-term maturity of these instruments. The Company’s Credit Agreement has a recorded value that approximates its fair value since its variable interest rate is tied to current market rates and the applicable margins represent market rates. The Company’s derivative financial instruments are recorded at fair value and include a measure of the Company’s own nonperformance risk or that of its counterparty, as appropriate. The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis as of March 31, 2021 and December 31, 2020 (Successor), and indicate the fair value hierarchy of the valuation techniques utilized by the Company to determine such fair values (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Fair Value ​ Level 1 Level 2 Level 3 March 31, 2021 Financial Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity derivatives – current ​ $ - ​ $ 134,422 ​ $ - ​ $ 134,422 Commodity derivatives – non-current ​ ​ - ​ ​ 32,212 ​ ​ - ​ ​ 32,212 Total financial liabilities ​ $ - ​ $ 166,634 ​ $ - ​ $ 166,634 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Fair Value ​ Level 1 Level 2 Level 3 December 31, 2020 Financial Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity derivatives – current ​ $ - ​ $ 49,485 ​ $ - ​ $ 49,485 Commodity derivatives – non-current ​ ​ - ​ ​ 9,750 ​ ​ - ​ ​ 9,750 Total financial liabilities ​ $ - ​ $ 59,235 ​ $ - ​ $ 59,235 ​ The following methods and assumptions were used to estimate the fair values of the Company’s financial assets and liabilities that are measured on a recurring basis: Commodity Derivatives Non-recurring Fair Value Measurements — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Predecessor ​ ​ Net Carrying ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loss (Before ​ ​ Value as of ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Tax) During the ​ ​ March 31, ​ Fair Value Measurements Using ​ Predecessor ​ 2020 Level 1 Level 2 Level 3 Period Proved property (1) ​ $ 816,234 ​ $ - ​ $ - ​ $ 816,234 ​ $ 3,732,096 (1) During the first quarter of 2020, certain proved oil and gas properties across the Company’s Williston Basin resource play with a previous carrying amount of $4.5 billion were written down to their fair value as of March 31, 2020 of $816 million, resulting in a non-cash impairment charge of $3.7 billion, which was recorded within exploration and impairment expense. These impaired properties were written down due to a reduction in anticipated future cash flows primarily driven by an expectation of sustained depressed oil prices and a resultant decline in future development plans for the properties. Predecessor Proved Property Impairments

REVENUE RECOGNITION

REVENUE RECOGNITION	3 Months Ended
	Mar. 31, 2021
REVENUE RECOGNITION [Abstract]
REVENUE RECOGNITION	10. REVENUE RECOGNITION The Company recognizes revenue in accordance with FASB ASC Topic 606 – Revenue from Contracts with Customers ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor OPERATING REVENUES ​ Three Months Ended March 31, 2021 ​ ​ Three Months Ended March 31, 2020 Oil sales ​ $ 256,709 ​ ​ $ 231,945 NGL and natural gas sales ​ ​ 47,970 ​ ​ ​ 12,901 Oil, NGL and natural gas sales ​ ​ 304,679 ​ ​ ​ 244,846 Purchased gas sales ​ ​ 2,712 ​ ​ ​ - Total operating revenues ​ $ 307,391 ​ ​ $ 244,846 ​ Whiting receives payment for product sales from one The Company has elected to utilize the practical expedient in ASC 606 that states the Company is not required to disclose the transaction price allocated to remaining performance obligations if the variable consideration is allocated entirely to a wholly unsatisfied performance obligation. Under the Company’s contracts, each monthly delivery of product represents a separate performance obligation, therefore, future volumes are wholly unsatisfied and disclosure of the transaction price allocated to remaining performance obligations is not required.

SHAREHOLDERS' EQUITY

SHAREHOLDERS' EQUITY	3 Months Ended
	Mar. 31, 2021
SHAREHOLDERS' EQUITY
SHAREHOLDERS' EQUITY	11. SHAREHOLDERS’ EQUITY Common Stock — Upon emergence from the Chapter 11 Cases on the Emergence Date, all existing shares of the Predecessor’s common stock were cancelled and the Successor issued 38,051,125 shares of New Common Stock. Refer to the “Chapter 11 Emergence” footnote for more information. Warrants — The Series A Warrants are exercisable from the date of issuance until the fourth anniversary of the Emergence Date, at which time all unexercised Series A Warrants will expire, and the rights of the holders of such warrants to purchase New Common Stock will terminate. The Series A Warrants are initially exercisable for one share of New Common Stock per Series A Warrant at an initial exercise price of $73.44 per Series A Warrant (the “Series A Exercise Price”). The Series B Warrants are exercisable from the date of issuance until the fifth anniversary of the Emergence Date, at which time all unexercised Series B Warrants will expire, and the rights of the holders of such warrants to purchase New Common Stock will terminate. The Series B Warrants are initially exercisable for one share of New Common Stock per Series B Warrant at an initial exercise price of $83.45 per Series B Warrant (the “Series B Exercise Price” and together with the Series A Exercise Price, the “Exercise Prices”). Pursuant to the warrant agreements, no holder of a Warrant, by virtue of holding or having a beneficial interest in a Warrant, will have the right to vote, receive dividends, receive notice as stockholders with respect to any meeting of stockholders for the election of Whiting’s directors or any other matter, or exercise any rights whatsoever as a stockholder of Whiting unless, until and only to the extent such holders become holders of record of shares of New Common Stock issued upon settlement of the Warrants. The number of shares of New Common Stock for which a Warrant is exercisable and the Exercise Prices, are subject to adjustment from time to time upon the occurrence of certain events, including stock splits, reverse stock splits or stock dividends to holders of New Common Stock or a reclassification in respect of New Common Stock. Settlement of Bankruptcy Claims —

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	3 Months Ended
	Mar. 31, 2021
STOCK-BASED COMPENSATION [Abstract]
STOCK-BASED COMPENSATION	12. STOCK-BASED COMPENSATION Equity Incentive Plan Historically, the Company has granted service-based restricted stock awards (“RSAs”) and restricted stock units (“RSUs”) to executive officers and employees, which generally vest ratably over a two three Successor Awards During September and October 2020, 89,021 shares of service-based RSUs were granted to executive officers and directors under the 2020 Equity Plan. The Company determines compensation expense for these share-settled awards using their fair value at the grant date based on the closing bid price of the Company’s common stock on such date. The weighted average grant date fair value of these RSUs was $17.47 per share. In September 2020, 189,900 shares of market-based RSUs were granted to executive officers under the 2020 Equity Plan. The awards will vest upon the Successor’s common stock trading for 20 consecutive trading days above a certain daily volume weighted average price (“VWAP”) as follows: 50% will vest if the VWAP exceeds $32.57 per share, an additional 25% if the daily VWAP exceeds $48.86 per share and the final 25% if the daily VWAP exceeds $65.14 per share. The Company recognizes compensation expense based on the fair value as determined by a Monte Carlo valuation model (the “Monte Carlo Model”) over the expected vesting period, which is estimated to be between 1.8 and 3.8 years. The weighted average grant date fair value of these RSUs was $6.54 per share. More information on the inputs of the Monte Carlo Model are explained below. During the three months ended March 31, 2021, the first 50% of these awards vested as the Company’s VWAP exceeded $32.57 per share for 20 consecutive trading days during the period. During the three months ended March 31, 2021, 358,123 shares of service-based RSUs were granted to executive officers and employees under the 2020 Equity Plan, which vest ratably over either a two or three-year service period. Additionally, during the three months ended March 31, 2021, 117,607 shares of service-based RSUs were granted to executive officers under the 2020 Equity Plan, which cliff vest on the fifth anniversary of the grant date. The Company determines compensation expense for these share-settled awards using their fair value at the grant date, which is based on the closing bid price of the Company’s common stock on such date. The weighted average grant date fair value of serviced-based RSUs was $22.46 per share for the three months ended March 31, 2021. During the three months ended March 31, 2021, 232,150 shares of PSUs subject to certain market-based vesting criteria were granted to executive officers under the 2020 Equity Plan. These market-based awards vest at the end of the performance period, which is December 31, 2023, and the number of shares that vest at the end of the performance period is determined based on two performance goals: (i) 116,075 shares vest based on the Company’s annualized absolute total stockholder return (“ATSR”) over the performance period as compared to certain preestablished target returns and (ii) 116,075 shares vest based on the Company’s relative total stockholder return (“RTSR”) compared to the stockholder returns of a peer group of companies over the performance period. The number of awards earned could range from zero up to two times the number of shares initially granted, all of which will be settled in shares. The weighted average grant date fair value of the market-based awards was $29.32 per share and $32.33 per share for the ATSR and RTSR awards, respectively, as determined by the Monte Carlo Model, which is described further below. For awards subject to market conditions, the grant date fair value is estimated using the Monte Carlo Model, which ​ ​ ​ ​ ​ ​ ​ ​ 2020 ​ 2021 ​ RSUs PSUs Number of simulations 100,000 500,000 Expected volatility 40% ​ 81% Risk-free interest rate 0.66% ​ 0.17% Dividend yield - - ​ The following table shows a summary of the Company’s service-based and market-based awards activity for the three months ended March 31, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of Awards ​ Weighted Average ​ ​ Service ‑ Based ​ Market-Based ​ Market-Based ​ Grant Date ​ RSUs RSUs PSUs Fair Value Nonvested awards, January 1 89,021 189,900 ​ - ​ $ 10.03 Granted 475,730 - ​ 232,150 ​ 25.21 Vested - (94,950) ​ - ​ 6.54 Forfeited (950) - ​ - ​ 22.46 Nonvested awards, March 31 563,801 94,950 ​ 232,150 ​ $ 22.45 ​ The Company recognized $2 million in stock-based compensation expense during the three months ended March 31, 2021. Predecessor Awards During the three months ended March 31, 2020, 53,198 shares of share-settled, service-based RSAs and RSUs were granted to executive officers and directors under the Predecessor Equity Plan. The Company determined compensation expense for these awards using their fair value at the grant date, which was based on the closing bid price of the Company’s common stock on such date. The weighted average grant date fair value of these service-based RSAs and RSUs was $4.94 per share for the three months ended March 31, 2020. On March 31, 2020, all of the RSAs issued to executive officers in 2020 were forfeited and concurrently replaced with cash incentives. Refer to “2020 Compensation Adjustments” below for more information. During the three months ended March 31, 2020, 1,616,504 shares of cash-settled, service-based RSUs were granted to executive officers and employees under the Predecessor Equity Plan. The company determined compensation expense for these awards using the fair value at the end of each reporting period, which was based on the closing bid price of the Company’s common stock on such date. On March 31, 2020, all of the RSUs issued to executive officers in 2020 were forfeited and concurrently replaced with cash incentives. Refer to “2020” Compensation Adjustments” below for more information. During the three months ended March 31, 2020, 1,665,153 shares of PSAs and PSUs subject to certain market-based vesting criteria were granted to executive officers under the Predecessor Equity Plan. These market-based awards were to cliff vest on the third anniversary of the grant date, however, on March 31, 2020, all of the PSAs and PSUs issued to executive officers in 2020 were forfeited and concurrently replaced with cash incentives. Refer to “2020 Compensation Adjustments” below for more information. The weighted average grant date fair value of the market-based awards that were to be settled in shares, as determined by the Monte Carlo valuation model, was $4.31 per share in 2020. The cash-settled component of such awards was recorded as a liability in the consolidated balance sheets and was remeasured at fair value using a Monte Carlo valuation model at the end of each reporting period. The Company recognized $1 million in total stock-based compensation expense during the three months ended March 31, 2020. 2020 Compensation Adjustments.

INCOME TAXES

INCOME TAXES	3 Months Ended
	Mar. 31, 2021
INCOME TAXES [Abstract]
INCOME TAXES	13. INCOME TAXES Income tax expense during interim periods is based on applying an estimated annual effective income tax rate to year-to-date income, plus any significant unusual or infrequently occurring items which are recorded in the interim period. The provisions for income taxes for the three months ended March 31, 2021 (Successor) and March 31, 2020 (Predecessor) differ from the amounts that would be provided by applying the statutory U.S. federal income tax rate of 21% to pre-tax income primarily due to a full valuation allowance in effect on the Company’s U.S. deferred tax assets (“DTAs”), resulting in no income tax expense for the periods presented and an effective tax rate of 0%. In assessing the realizability of DTAs, management considers whether it is more likely than not that some portion, or all, of the Company’s DTAs will not be realized. In making such determination, the Company considers all available positive and negative evidence, including future reversals of temporary differences, tax-planning strategies and projected future taxable income and results of operations. If the Company concludes that it is more likely than not that some portion, or all, of its DTAs will not be realized, the tax asset is reduced by a valuation allowance. The Company assesses the appropriateness of its valuation allowance on a quarterly basis. At March 31, 2021 and December 31, 2020 (Successor), the Company had a full valuation allowance on its DTAs. The computation of the annual estimated effective tax rate at each interim period requires certain estimates and significant judgment including, but not limited to, the expected operating income for the year, projections of the proportion of income earned and taxed in various jurisdictions, permanent and temporary differences, and the likelihood of recovering DTAs generated in the current year. The accounting estimates used to compute the provision for income taxes may change as new events occur, more experience is obtained, additional information becomes known or as the tax environment changes. Internal Revenue Code (“IRC”) Section 382 addresses company ownership changes and specifically limits the utilization of certain deductions and other tax attributes on an annual basis following an ownership change. As a result of the chapter 11 reorganization and related transactions, the Successor experienced an ownership change within the meaning of IRC Section 382 on the Emergence Date. This ownership change subjected certain of the Company’s tax attributes to an IRC Section 382 limitation. The ownership changes and resulting annual limitation will result in the expiration of net operating loss carryforwards (“NOLs”) or other tax attributes otherwise available, with a corresponding decrease in the Company’s valuation allowance. The Company estimates that it has federal NOLs of $3.1 billion as of December 31, 2020, which are subject to limitation under IRC Section 382. The Company currently estimates that approximately $2.3 billion of these federal NOLs will expire before they are able to be used. The remaining non-expiring NOLs remain subject to a full valuation allowance. These estimates are subject to revision through the filing of the tax return for the year ending December 31, 2020.

EARNINGS PER SHARE

EARNINGS PER SHARE	3 Months Ended
	Mar. 31, 2021
EARNINGS PER SHARE [Abstract]
EARNINGS PER SHARE	14. EARNINGS PER SHARE The reconciliations between basic and diluted earnings (loss) per share are as follows (in thousands, except per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor ​ Three Months Ended March 31, 2021 ​ ​ Three Months Ended March 31, 2020 Basic loss per share ​ ​ ​ ​ ​ ​ ​ Net loss ​ $ (946) ​ ​ $ (3,628,571) Weighted average shares outstanding, basic ​ ​ 38,698 ​ ​ ​ 91,390 Loss per common share, basic ​ $ (0.02) ​ ​ $ (39.70) ​ ​ ​ ​ ​ ​ ​ ​ Diluted loss per share ​ ​ ​ ​ ​ ​ ​ Net loss ​ $ (946) ​ ​ $ (3,628,571) Weighted average shares outstanding ​ ​ 38,698 ​ ​ ​ 91,390 Loss per common share, diluted ​ $ (0.02) ​ ​ $ (39.70) ​ Successor During the Successor Period, the diluted earnings per share calculation excludes the effect of 4,837,376 common shares for Series A Warrants and 2,418,832 common shares for Series B Warrants that were out-of-the-money as of March 31, 2021, as well as 2,121,304 contingently issuable shares related to the settlement of general unsecured claims associated with the Chapter 11 Cases, as all necessary conditions had not been met to be considered dilutive shares as of March 31, 2021. Further, the calculation excludes the effect of 194,469 shares of service-based awards and 90,352 shares of market-based awards that were anti-dilutive as a result of the net loss incurred during the period and 94,950 shares of market-based awards that did not meet the market-based vesting criteria as of March 31, 2021. Refer to the “Stock-Based Compensation” footnote for more information on the Company’s service-based and market-based awards. Predecessor During the three months ended March 31, 2020, the Company had a net loss and therefore the diluted earnings per share calculation for that period excludes the anti-dilutive effect of 392,367 shares of service-based awards. In addition, the diluted earnings per share calculation for the three months ended March 31, 2020 excludes the effect of 39,660 common shares for stock options that were out-of-the-money as of March 31, 2020. The Company had the option to settle conversions of the Convertible Senior Notes with cash, shares of common stock or any combination thereof. As the conversion value of the Convertible Senior Notes did not exceed the principal amount of the notes for any time during the Predecessor Period, there was no impact to diluted earnings per share or the related disclosures for the periods presented.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Mar. 31, 2021
COMMITMENTS AND CONTINGENCIES [Abstract]
COMMITMENTS AND CONTINGENCIES	15. COMMITMENTS AND CONTINGENCIES Chapter 11 Cases — these claims remain subject to the jurisdiction of the Bankruptcy Court. To the extent that these Bankruptcy Court proceedings result in unsecured claims being allowed against the Company, such claims will be satisfied through the issuance of shares of the Successor’s common stock. As a result, the Company has not established material liabilities in connection with these claims. However, it is reasonably possible that as a result of the legal proceedings associated with the bankruptcy claims administration process or the matter detailed below, the Bankruptcy Court may rule, or it may be determined, that (i) the applicable contracts cannot be rejected, or (ii) a claim is not a general unsecured claim. Any of these outcomes could require the Company to make cash payments to settle those claims instead of or in addition to issuing shares of the Successor’s common stock, and such cash payments would result in losses in future periods. Arguello Inc. and Freeport-McMoRan Oil & Gas LLC . WOG had interests in federal oil and gas leases in the Point Arguello Unit located offshore in California. While those interests have expired, pursuant to certain related agreements (the “Point Arguello Agreements”), WOG may be subject to abandonment and decommissioning obligations. WOG and Whiting Petroleum Corporation rejected the related contracts pursuant to the Plan. On October 1, 2020, Arguello Inc. and Freeport-McMoRan Oil & Gas LLC, individually and in its capacity as the designated Point Arguello Unit operator (collectively, the “FMOG Entities”) filed with the Bankruptcy Court an application for allowance of certain administrative claims arguing the FMOG Entities were entitled to recover Whiting’s proportionate share of decommissioning obligations owed to the U.S. government through subrogation to the U.S. government’s economic rights. The FMOG Entities’ application alleged administrative claims of approximately $25 million for estimated decommissioning costs owed to the U.S. government, at least $60 million of estimated decommissioning costs owed to the FMOG Entities and other insignificant amounts. On September 14, 2020, the FMOG Entities also filed with the Bankruptcy Court proofs of claim for rejection damages to serve as an alternative course of action in the event that a court should determine that the FMOG Entities do not hold any applicable administrative claims. The U.S. government may also be able to bring claims against WOG directly for decommissioning costs. On February 18, 2021, WOG entered into a stipulation and agreed order with the United States Department of the Interior, Bureau of Safety & Environmental Enforcement (“BSEE”) pursuant to which the BSEE withdrew its proofs of claims against Whiting Petroleum Corporation and WOG and acknowledged their respective rights and obligations pursuant to the Plan. On March 26, 2021, the FMOG Entities withdrew their administrative claim for the recovery of Whiting’s proportionate share of costs incurred after August 31, 2020 to fulfill obligations owed to the U.S. Government on the basis of subrogation to the Government’s economic rights. The FMOG Entities continue to assert certain other administrative claims and have reserved the right to assert claims for the recovery of Whiting’s share of the decommissioning costs incurred after August 31, 2020 based on the theory of equitable subrogation. The Bankruptcy Court has not issued a ruling on the damages for rejection of the Point Arguello Agreements. Although WOG intends to vigorously defend this legal proceeding, if the FMOG Entities were to prevail on certain of their respective claims (including the reserved claims) on the merits or the U.S. government were to bring claims against WOG, Whiting could be liable for claims that must be paid pursuant to the Plan. At this time, the Company is not able to determine the likelihood or range of amounts attributable to the FMOG Entities’ claims or any potential claims by the U.S. government due to uncertainties with respect to, among other things, the nature of the claims and defenses and the ultimate potential outcomes of the claims (including the reserved claims). Litigation — The Company was involved in litigation related to a payment arrangement with a third party. In June 2020, the Company and the third party reached a settlement agreement resulting in the Company paying the third party a settlement amount of $14 million. Upon settlement, the Company agreed to indemnify a party involved in the litigation for any further claims resulting from these matters up to $25 million. This indemnity will terminate on the later of: (i) June 1, 2021 or (ii) the date on which the statute of limitations for the relevant claims expires. The Company does not expect to pay additional amounts to this party as a result of this indemnity and thus has not recorded any liability related to the indemnity as of March 31, 2021 (Successor). ​

BASIS OF PRESENTATION (Policies

BASIS OF PRESENTATION (Policies)	3 Months Ended
	Mar. 31, 2021
BASIS OF PRESENTATION [Abstract]
Voluntary Reorganization under Chapter 11 of the Bankruptcy Code	Voluntary Reorganization under Chapter 11 of the Bankruptcy Code Upon emergence, the Company adopted fresh start accounting in accordance with FASB ASC Topic 852 – Reorganizations (“ASC 852”), which specifies the accounting and financial reporting requirements for entities reorganizing through chapter 11 bankruptcy proceedings. The application of fresh start accounting resulted in a new basis of accounting and the Company becoming a new entity for financial reporting purposes. As a result of the implementation of the Plan and the application of fresh start accounting, the consolidated financial statements after the Emergence Date are not comparable to the consolidated financial statements before that date and the historical financial statements on or before the Emergence Date are not a reliable indicator of the Company’s financial condition and results of operations for any period after its adoption of fresh start accounting. Refer to the “Fresh Start Accounting” footnote for more information. References to “Successor” refer to the Company and its financial position and results of operations after the Emergence Date. References to “Predecessor” refer to the Company and its financial position and results of operations on or before the Emergence Date. References to “Successor Period” refer to the three months ended March 31, 2021. References to “Predecessor Period” refer to the three months ended March 31, 2020.
Condensed Consolidated Financial Statements	Condensed Consolidated Financial Statements
Reclassifications	Reclassifications — ​
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash — Restricted cash as of March 31, 2021 and December 31, 2020 consist of funds remaining in a professional fee escrow account that were reserved to pay certain professional fees upon emergence from the Chapter 11 Cases. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets and statements of cash flows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ March 31, ​ December 31, ​ ​ 2021 ​ 2020 Cash and cash equivalents ​ $ 24,704 ​ $ 25,607 Restricted cash ​ ​ 2,400 ​ ​ 2,760 Total cash, cash equivalents and restricted cash ​ $ 27,104 ​ $ 28,367 ​
Accounts Receivable Trade	Accounts Receivable Trade — The Company routinely evaluates expected credit losses for all material trade and other receivables to determine if an allowance for credit losses is warranted. Expected credit losses are estimated based on (i) historic loss experience for pools of receivable balances with similar characteristics, (ii) the length of time balances have been outstanding and (iii) the economic status of each counterparty. These loss estimates are then adjusted for current and expected future economic conditions, which may include an assessment of the probability of non-payment, financial distress or expected future commodity prices and the impact that any current or future conditions could have on a counterparty’s credit quality and liquidity. As of March 31, 2021 and December 31, 2020 (Successor), the Company had immaterial allowances for credit losses.

BASIS OF PRESENTATION (Tables)

BASIS OF PRESENTATION (Tables)	3 Months Ended
	Mar. 31, 2021
BASIS OF PRESENTATION [Abstract]
Reconciliation Of cash, cash equivalents and restricted cash	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets and statements of cash flows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ March 31, ​ December 31, ​ ​ 2021 ​ 2020 Cash and cash equivalents ​ $ 24,704 ​ $ 25,607 Restricted cash ​ ​ 2,400 ​ ​ 2,760 Total cash, cash equivalents and restricted cash ​ $ 27,104 ​ $ 28,367

OIL AND GAS PROPERTIES (Tables)

OIL AND GAS PROPERTIES (Tables)	3 Months Ended
	Mar. 31, 2021
OIL AND GAS PROPERTIES [Abstract]
Net capitalized costs related to the Company's oil and gas producing activities	Net capitalized costs related to the Company’s oil and gas producing activities at March 31, 2021 and December 31, 2020 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ March 31, ​ December 31, ​ 2021 ​ 2020 Proved oil and gas properties ​ $ 1,743,530 ​ $ 1,701,163 Unproved leasehold costs ​ ​ 102,841 ​ ​ 105,073 Wells and facilities in progress ​ ​ 26,098 ​ ​ 6,365 Total oil and gas properties, successful efforts method ​ ​ 1,872,469 ​ ​ 1,812,601 Accumulated depletion ​ ​ (121,277) ​ ​ (71,064) Oil and gas properties, net ​ $ 1,751,192 ​ $ 1,741,537

LONG-TERM DEBT (Tables)

LONG-TERM DEBT (Tables)	3 Months Ended
	Mar. 31, 2021
LONG-TERM DEBT [Abstract]
Schedule of long-term debt	Long-term debt consisted of the following at March 31, 2021 and December 31, 2020 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ March 31, ​ December 31, ​ 2021 ​ 2020 Credit Agreement ​ $ 245,000 ​ $ 360,000 Total long-term debt ​ $ 245,000 ​ $ 360,000

ASSET RETIREMENT OBLIGATIONS (T

ASSET RETIREMENT OBLIGATIONS (Tables)	3 Months Ended
	Mar. 31, 2021
ASSET RETIREMENT OBLIGATIONS [Abstract]
Schedule of reconciliation of the Company's asset retirement obligations	​ ​ ​ ​ ​ Asset retirement obligation at January 1, 2021 (Successor) ​ $ 98,130 Additional liability incurred ​ ​ 265 Revisions to estimated cash flows ​ ​ 6,821 Accretion expense ​ ​ 2,222 Obligations on sold properties ​ ​ (123) Liabilities settled ​ ​ (1,309) Asset retirement obligation at March 31, 2021 (Successor) ​ $ 106,006

DERIVATIVE FINANCIAL INSTRUME_2

DERIVATIVE FINANCIAL INSTRUMENTS (Tables)	3 Months Ended
	Mar. 31, 2021
DERIVATIVE FINANCIAL INSTRUMENTS [Abstract]
Derivative instruments	The table below details the Successor’s swap and collar derivatives entered into to hedge forecasted crude oil, NGL and natural gas production revenues as of March 31, 2021 (Successor). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average Settlement Period ​ Index ​ Derivative Instrument ​ Total Volumes ​ Units ​ Swap Price ​ Floor ​ Ceiling Crude Oil ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2021 ​ NYMEX WTI ​ Fixed Price Swaps ​ 4,723,500 ​ Bbl ​ $44.44 ​ - ​ - 2021 ​ NYMEX WTI ​ Two-way Collars ​ 4,796,000 ​ Bbl ​ - ​ $38.95 ​ $47.05 2022 ​ NYMEX WTI ​ Fixed Price Swaps ​ 630,000 ​ Bbl ​ $54.30 ​ - ​ - 2022 ​ NYMEX WTI ​ Two-way Collars ​ 9,197,000 ​ Bbl ​ - ​ $42.61 ​ $52.87 Q1 2023 ​ NYMEX WTI ​ Two-way Collars ​ 2,160,000 ​ Bbl ​ - ​ $46.13 ​ $56.25 ​ ​ ​ ​ Total ​ 21,506,500 ​ ​ ​ ​ ​ ​ ​ ​ Natural Gas ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2021 ​ NYMEX Henry Hub ​ Fixed Price Swaps ​ 14,430,000 ​ MMBtu ​ $2.81 ​ - ​ - 2021 ​ NYMEX Henry Hub ​ Two-way Collars ​ 8,250,000 ​ MMBtu ​ - ​ $2.60 ​ $2.79 2022 ​ NYMEX Henry Hub ​ Fixed Price Swaps ​ 3,530,000 ​ MMBtu ​ $2.65 ​ - ​ - 2022 ​ NYMEX Henry Hub ​ Two-way Collars ​ 10,720,000 ​ MMBtu ​ - ​ $2.35 ​ $2.85 Q1 2023 ​ NYMEX Henry Hub ​ Two-way Collars ​ 2,700,000 ​ MMBtu ​ - ​ $2.58 ​ $3.08 ​ ​ ​ ​ Total ​ 39,630,000 ​ ​ ​ ​ ​ ​ ​ ​ Natural Gas Basis (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2021 ​ NNG Ventura to NYMEX ​ Fixed Price Swaps ​ 5,500,000 ​ MMBtu ​ -$0.18 ​ - ​ - 2022 ​ NNG Ventura to NYMEX ​ Fixed Price Swaps ​ 2,165,000 ​ MMBtu ​ $0.50 ​ - ​ - Q1 2023 ​ NNG Ventura to NYMEX ​ Fixed Price Swaps ​ 3,375,000 ​ MMBtu ​ $0.37 ​ - ​ - ​ ​ ​ ​ Total ​ 11,040,000 ​ ​ ​ ​ ​ ​ ​ ​ NGL - Propane ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2021 ​ Mont Belvieu ​ Fixed Price Swaps ​ 17,325,000 ​ Gallons ​ $0.76 ​ - ​ - ​ ​ ​ ​ Total ​ 17,325,000 ​ ​ ​ ​ ​ ​ ​ ​ (1) The weighted average price associated with the natural gas basis swaps shown in the table above represents the average fixed differential to NYMEX as stated in the related contracts, which is compared to the Northern Natural Gas Ventura Index (“NNG Ventura”) for each period. If NYMEX combined with the fixed differential as stated in each contract is higher than the NNG Ventura index price at any settlement date, the Company receives the difference. Conversely, if the NNG Ventura index price is higher than NYMEX combined with the fixed differential, the Company pays the difference. ​ Subsequent to March 31, 2021, the Company entered into additional crude oil and natural gas swaps and collars for the remainder of 2021, 2022 and the second quarter of 2023. The table below details the Company’s additional swap and collar derivatives entered into during April 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average Settlement Period ​ Index ​ Derivative Instrument ​ Total Volumes ​ Units ​ Swap Price ​ Floor ​ Ceiling Crude Oil ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Q2 2023 ​ NYMEX WTI ​ Two-way Collars ​ 546,000 ​ Bbl ​ - ​ $47.50 ​ $59.23 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Crude Oil Differential (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2021 ​ UHC Clearbrook to NYMEX ​ Fixed Price Swaps ​ 107,000 ​ Bbl ​ -$1.95 ​ - ​ - ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Natural Gas ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 ​ NYMEX Henry Hub ​ Fixed Price Swaps ​ 1,365,000 ​ MMBtu ​ $2.49 ​ - ​ - Q2 2023 ​ NYMEX Henry Hub ​ Two-way Collars ​ 1,365,000 ​ MMBtu ​ - ​ $2.25 ​ $2.50 ​ ​ ​ ​ Total ​ 2,730,000 ​ ​ ​ ​ ​ ​ ​ ​ Natural Gas Basis ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 ​ NNG Ventura to NYMEX ​ Fixed Price Swaps ​ 1,365,000 ​ MMBtu ​ -$0.22 ​ - ​ - Q2 2023 ​ NNG Ventura to NYMEX ​ Fixed Price Swaps ​ 1,365,000 ​ MMBtu ​ -$0.22 ​ - ​ - ​ ​ ​ ​ Total ​ 2,730,000 ​ ​ ​ ​ ​ ​ ​ ​ (1) The weighted average price associated with the crude oil differential swaps shown in the table above represents the average fixed differential to NYMEX as stated in the related contracts, which is compared to the NE2 Canadian Monthly Index for UHC Clearbrook (“UHC Clearbrook”) for each period. If NYMEX combined with the fixed differential as stated in each contract is higher than the UHC Clearbrook index price at any settlement date, the Company receives the difference. Conversely, if the UHC Clearbrook index price is higher than NYMEX combined with the fixed differential, the Company pays the difference.
Schedule of effects of commodity derivative instruments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Gain) Loss Recognized in Income ​ ​ ​ ​ Successor ​ ​ Predecessor Not Designated as ASC 815 Hedges Statements of Operations Classification Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Commodity contracts ​ Derivative (gain) loss, net ​ $ 146,693 ​ ​ $ (231,371)
Location and fair value of derivative instruments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2021 (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net ​ ​ ​ ​ Gross ​ ​ ​ ​ Recognized ​ ​ ​ ​ Recognized ​ Gross ​ Fair Value Not Designated as ​ ​ ​ Assets/ ​ Amounts ​ Assets/ ASC 815 Hedges Balance Sheet Classification Liabilities Offset Liabilities Derivative assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity contracts - current ​ Prepaid expenses and other ​ $ 11,517 ​ $ (11,517) ​ $ - Commodity contracts - non-current ​ Other long-term assets ​ ​ 42,716 ​ ​ (42,716) ​ ​ - Total derivative assets ​ ​ ​ $ 54,233 ​ $ (54,233) ​ $ - Derivative liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity contracts - current ​ Derivative liabilities ​ $ 145,939 ​ $ (11,517) ​ $ 134,422 Commodity contracts - non-current ​ Other long-term liabilities ​ ​ 74,928 ​ ​ (42,716) ​ ​ 32,212 Total derivative liabilities ​ ​ ​ $ 220,867 ​ $ (54,233) ​ $ 166,634 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net ​ ​ ​ ​ Gross ​ ​ ​ ​ Recognized ​ ​ ​ ​ Recognized ​ Gross ​ Fair Value Not Designated as ​ ​ ​ Assets/ ​ Amounts ​ Assets/ ASC 815 Hedges Balance Sheet Classification Liabilities Offset Liabilities Derivative assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity contracts - current ​ Prepaid expenses and other ​ $ 14,287 ​ $ (14,287) ​ $ - Commodity contracts - non-current ​ Other long-term assets ​ ​ 19,991 ​ ​ (19,991) ​ ​ - Total derivative assets ​ ​ ​ $ 34,278 ​ $ (34,278) ​ $ - Derivative liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity contracts - current ​ Derivative liabilities ​ $ 63,772 ​ $ (14,287) ​ $ 49,485 Commodity contracts - non-current ​ Other long-term liabilities ​ ​ 29,741 ​ ​ (19,991) ​ ​ 9,750 Total derivative liabilities ​ ​ ​ $ 93,513 ​ $ (34,278) ​ $ 59,235 (1) All of the counterparties to the Company’s financial derivative contracts subject to master netting arrangements are lenders under the Credit Agreement, which eliminates the need to post or receive collateral associated with its derivative positions. Therefore, columns for cash collateral pledged or received have not been presented in these tables.

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	3 Months Ended
	Mar. 31, 2021
FAIR VALUE MEASUREMENTS [Abstract]
Fair value assets and liabilities measured on a recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Fair Value ​ Level 1 Level 2 Level 3 March 31, 2021 Financial Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity derivatives – current ​ $ - ​ $ 134,422 ​ $ - ​ $ 134,422 Commodity derivatives – non-current ​ ​ - ​ ​ 32,212 ​ ​ - ​ ​ 32,212 Total financial liabilities ​ $ - ​ $ 166,634 ​ $ - ​ $ 166,634 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Fair Value ​ Level 1 Level 2 Level 3 December 31, 2020 Financial Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity derivatives – current ​ $ - ​ $ 49,485 ​ $ - ​ $ 49,485 Commodity derivatives – non-current ​ ​ - ​ ​ 9,750 ​ ​ - ​ ​ 9,750 Total financial liabilities ​ $ - ​ $ 59,235 ​ $ - ​ $ 59,235
Non-financial assets and liabilities measured at fair value on a nonrecurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Predecessor ​ ​ Net Carrying ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loss (Before ​ ​ Value as of ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Tax) During the ​ ​ March 31, ​ Fair Value Measurements Using ​ Predecessor ​ 2020 Level 1 Level 2 Level 3 Period Proved property (1) ​ $ 816,234 ​ $ - ​ $ - ​ $ 816,234 ​ $ 3,732,096 (1) During the first quarter of 2020, certain proved oil and gas properties across the Company’s Williston Basin resource play with a previous carrying amount of $4.5 billion were written down to their fair value as of March 31, 2020 of $816 million, resulting in a non-cash impairment charge of $3.7 billion, which was recorded within exploration and impairment expense. These impaired properties were written down due to a reduction in anticipated future cash flows primarily driven by an expectation of sustained depressed oil prices and a resultant decline in future development plans for the properties.

REVENUE RECOGNITION (Tables)

REVENUE RECOGNITION (Tables)	3 Months Ended
	Mar. 31, 2021
REVENUE RECOGNITION [Abstract]
Summary of revenue disaggregation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor OPERATING REVENUES ​ Three Months Ended March 31, 2021 ​ ​ Three Months Ended March 31, 2020 Oil sales ​ $ 256,709 ​ ​ $ 231,945 NGL and natural gas sales ​ ​ 47,970 ​ ​ ​ 12,901 Oil, NGL and natural gas sales ​ ​ 304,679 ​ ​ ​ 244,846 Purchased gas sales ​ ​ 2,712 ​ ​ ​ - Total operating revenues ​ $ 307,391 ​ ​ $ 244,846

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	3 Months Ended
	Mar. 31, 2021
STOCK-BASED COMPENSATION [Abstract]
Assumption for valuing market based awards	​ ​ ​ ​ ​ ​ ​ ​ 2020 ​ 2021 ​ RSUs PSUs Number of simulations 100,000 500,000 Expected volatility 40% ​ 81% Risk-free interest rate 0.66% ​ 0.17% Dividend yield - -
Summary of nonvested shares	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of Awards ​ Weighted Average ​ ​ Service ‑ Based ​ Market-Based ​ Market-Based ​ Grant Date ​ RSUs RSUs PSUs Fair Value Nonvested awards, January 1 89,021 189,900 ​ - ​ $ 10.03 Granted 475,730 - ​ 232,150 ​ 25.21 Vested - (94,950) ​ - ​ 6.54 Forfeited (950) - ​ - ​ 22.46 Nonvested awards, March 31 563,801 94,950 ​ 232,150 ​ $ 22.45

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	3 Months Ended
	Mar. 31, 2021
EARNINGS PER SHARE [Abstract]
Reconciliations between basic and diluted earnings per share	The reconciliations between basic and diluted earnings (loss) per share are as follows (in thousands, except per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor ​ Three Months Ended March 31, 2021 ​ ​ Three Months Ended March 31, 2020 Basic loss per share ​ ​ ​ ​ ​ ​ ​ Net loss ​ $ (946) ​ ​ $ (3,628,571) Weighted average shares outstanding, basic ​ ​ 38,698 ​ ​ ​ 91,390 Loss per common share, basic ​ $ (0.02) ​ ​ $ (39.70) ​ ​ ​ ​ ​ ​ ​ ​ Diluted loss per share ​ ​ ​ ​ ​ ​ ​ Net loss ​ $ (946) ​ ​ $ (3,628,571) Weighted average shares outstanding ​ ​ 38,698 ​ ​ ​ 91,390 Loss per common share, diluted ​ $ (0.02) ​ ​ $ (39.70)

BASIS OF PRESENTATION (Reconcil

BASIS OF PRESENTATION (Reconciliation) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
BASIS OF PRESENTATION [Abstract]
Cash and cash equivalents	$ 24,704	$ 25,607
Restricted cash	2,400	2,760
Total cash, cash equivalents and restricted cash	$ 27,104	$ 28,367	$ 566,273	$ 8,652

CHAPTER 11 EMERGENCE (Details)

CHAPTER 11 EMERGENCE (Details) - USD ($) $ in Millions	Sep. 01, 2020	Aug. 31, 2020	Feb. 28, 2021	Apr. 30, 2021	Mar. 31, 2021
Chapter 11 Cases
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Predecessor
Common stock issued	38,051,125
Number of shares authorized upon shareholder's approval	4,035,885
Credit Agreement [Member]
Chapter 11 Cases
Maximum borrowing capacity of credit facility	$ 750			$ 750	$ 750
Additional contingent borrowings	$ 750
Series A [Member]
Chapter 11 Cases
Warrants outstanding (in shares)	4,837,387
Series B [Member]
Chapter 11 Cases
Warrants outstanding (in shares)	2,418,840
Senior Notes Holders [Member]
Chapter 11 Cases
Common stock issued	36,817,630
Existing Stockholders [Member]
Chapter 11 Cases
Common stock issued	1,233,495
General Unsecured Claimants [Member]
Chapter 11 Cases
Common stock issued			948,897
Reserved for future issuance (in shares)	3,070,201

OIL AND GAS PROPERTIES (Details

OIL AND GAS PROPERTIES (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Oil and gas properties
Proved oil and gas properties	$ 1,743,530		$ 1,701,163
Unproved leasehold costs	102,841		105,073
Wells and facilities in progress	26,098		6,365
Total oil and gas properties, successful efforts method	1,872,469		1,812,601
Accumulated depletion	(121,277)		(71,064)
Oil and gas properties, net	1,751,192		$ 1,741,537
Unproved Properties [Member]
Oil and gas properties
Impairment of properties	$ 1,000	$ 12,000

ACQUISITIONS AND DIVESTITURES (

ACQUISITIONS AND DIVESTITURES (Details) $ in Thousands	Jan. 09, 2020USD ($)item	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)
Dispositions
Proceeds from sale of properties		$ 1,945	$ 27,453
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | McKenzie, Mountrail And Williams Counties [Member]
Dispositions
Number of well sold | item	30
Proceeds from sale of properties	$ 25,000

LONG-TERM DEBT (Schedule of lon

LONG-TERM DEBT (Schedule of long-term debt) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Total long-term debt	$ 245,000	$ 360,000
Credit Agreement [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 245,000	$ 360,000

LONG-TERM DEBT (Credit agreemen

LONG-TERM DEBT (Credit agreement) (Details) - USD ($) $ in Millions	Sep. 01, 2020	Apr. 30, 2021	Mar. 31, 2021
Letter of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity of credit facility	$ 50
Borrowing capacity of credit facility, net of letter of credit			$ 48
Credit Agreement [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity of credit facility	750	$ 750	750
Borrowing capacity of credit facility, net of letter of credit			503
Outstanding borrowings under credit facility			245
Letters of credit borrowings outstanding			$ 2
Additional contingent borrowings	750
Maximum cash balance prior to mandatory repayment	$ 75
Commitment fees (as a percent)	0.50%
Weighted average interest rate			4.20%
Debt threshold, dividend payments and distributions (as a percent)	20.00%
Leverage ratio	2
Current year production covered by hedges (as a percent)	65.00%
Maximum percentage of production from proved reserves (as a percent)	85.00%
Subsequent year production covered by hedges (as a percent)	35.00%
Minimum consolidated current assets to consolidated current liabilities ratio	1
Total debt to EBITDAX ratio	3.5
Credit Agreement [Member] | Base Rate [Member] | Minimum [Member]
Debt Instrument [Line Items]
Basis points added to reference rate (as a percent)	1.75%
Credit Agreement [Member] | Base Rate [Member] | Maximum [Member]
Debt Instrument [Line Items]
Basis points added to reference rate (as a percent)	2.75%
Credit Agreement [Member] | Fed Funds Rate [Member]
Debt Instrument [Line Items]
Basis points added to reference rate (as a percent)	0.50%
Credit Agreement [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis points added to reference rate (as a percent)	1.00%
Credit Agreement [Member] | Eurodollar [Member] | Minimum [Member]
Debt Instrument [Line Items]
Basis points added to reference rate (as a percent)	2.75%
Credit Agreement [Member] | Eurodollar [Member] | Maximum [Member]
Debt Instrument [Line Items]
Basis points added to reference rate (as a percent)	3.75%

LONG-TERM DEBT (Senior notes) (

LONG-TERM DEBT (Senior notes) (Details) - USD ($) $ in Thousands	Sep. 01, 2020	Mar. 31, 2020	Mar. 31, 2020	Aug. 31, 2020
Debt Instrument [Line Items]
Common stock issued in settlement of bankruptcy claims (in shares)	38,051,125
Gain (loss) on extinguishment of debt			$ 25,883
Adjustment to equity component of 2020 Convertible Senior Notes			$ 3,461
Senior Notes [Member]
Debt Instrument [Line Items]
Common stock issued in settlement of bankruptcy claims (in shares)	36,817,630
5.75% Senior Notes due 2021 [Member]
Debt Instrument [Line Items]
Notes Issued				$ 774,000
Interest rate on debt instrument (as a percent)				5.75%
6.25% Senior Notes due 2023 [Member]
Debt Instrument [Line Items]
Notes Issued				$ 408,000
Interest rate on debt instrument (as a percent)				6.25%
6.625% Senior Notes due 2026 [Member]
Debt Instrument [Line Items]
Notes Issued				$ 1,000,000
Interest rate on debt instrument (as a percent)				6.625%
1.25% Convertible Senior Notes due 2020 [Member]
Debt Instrument [Line Items]
Notes Issued				$ 187,000
Interest rate on debt instrument (as a percent)		1.25%	1.25%	1.25%
Notes repurchased, principal amount		$ 73,000	$ 73,000
Principal amount of debt redeemed (as a percent)		72.50%
Gain (loss) on extinguishment of debt		$ 23,000
Repurchase of notes		53,000
Adjustment to equity component of 2020 Convertible Senior Notes		3,000
Non cash charges		$ 200

ASSET RETIREMENT OBLIGATIONS (D

ASSET RETIREMENT OBLIGATIONS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Asset Retirement Obligations
Asset retirement obligations, current portion	$ 7,000	$ 6,000
Reconciliation of the Company's asset retirement obligations
Balance at the beginning of the period	98,130
Additional liability incurred	265
Revisions to estimated cash flows	6,821
Accretion expense	2,222
Obligations on sold properties	(123)
Liabilities settled	(1,309)
Balance at the end of the period	$ 106,006

DERIVATIVE FINANCIAL INSTRUME_3

DERIVATIVE FINANCIAL INSTRUMENTS (Instruments) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)item$ / item	Mar. 31, 2020USD ($)	Apr. 30, 2021item$ / item	Dec. 31, 2020USD ($)
Derivative Financial Instruments [Line Items]
Derivative gain (loss), net | $	$ (146,693)	$ 231,371
Derivative liability | $	$ 166,634			$ 59,235
Crude Oil [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	21,506,500
Crude Oil [Member] | 2021 [Member] | Fixed Price Swaps [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	4,723,500
Swap Price (in dollars per unit)	44.44
Crude Oil [Member] | 2021 [Member] | Two-way Collars [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	4,796,000
Floor Price (in dollars per unit)	38.95
Ceiling Price (in dollars per unit)	47.05
Crude Oil [Member] | 2022 [Member] | Fixed Price Swaps [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	630,000
Swap Price (in dollars per unit)	54.30
Crude Oil [Member] | 2022 [Member] | Two-way Collars [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	9,197,000
Floor Price (in dollars per unit)	42.61
Ceiling Price (in dollars per unit)	52.87
Crude Oil [Member] | 2023 [Member] | Two-way Collars [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	2,160,000		546,000
Floor Price (in dollars per unit)	46.13		47.50
Ceiling Price (in dollars per unit)	56.25		59.23
Natural Gas [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	39,630,000		2,730,000
Natural Gas [Member] | 2021 [Member] | Fixed Price Swaps [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	14,430,000
Swap Price (in dollars per unit)	2.81
Natural Gas [Member] | 2021 [Member] | Two-way Collars [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	8,250,000
Floor Price (in dollars per unit)	2.60
Ceiling Price (in dollars per unit)	2.79
Natural Gas [Member] | 2022 [Member] | Fixed Price Swaps [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	3,530,000		1,365,000
Swap Price (in dollars per unit)	2.65		2.49
Natural Gas [Member] | 2022 [Member] | Two-way Collars [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	10,720,000
Floor Price (in dollars per unit)	2.35
Ceiling Price (in dollars per unit)	2.85
Natural Gas [Member] | 2023 [Member] | Two-way Collars [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	2,700,000		1,365,000
Floor Price (in dollars per unit)	2.58		2.25
Ceiling Price (in dollars per unit)	3.08		2.50
Natural Gas Basis [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	11,040,000		2,730,000
Natural Gas Basis [Member] | 2021 [Member] | Fixed Price Swaps [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	5,500,000
Swap Price (in dollars per unit)	0.18
Natural Gas Basis [Member] | 2022 [Member] | Fixed Price Swaps [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	2,165,000		1,365,000
Swap Price (in dollars per unit)	0.50		0.22
Natural Gas Basis [Member] | 2023 [Member] | Fixed Price Swaps [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	3,375,000		1,365,000
Swap Price (in dollars per unit)	0.37		0.22
Crude Oil Basis [Member] | 2021 [Member] | Fixed Price Swaps [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item			107,000
Swap Price (in dollars per unit)			1.95
NGL - Propane [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	17,325,000
NGL - Propane [Member] | 2021 [Member] | Fixed Price Swaps [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	17,325,000
Swap Price (in dollars per unit)	0.76

DERIVATIVE FINANCIAL INSTRUME_4

DERIVATIVE FINANCIAL INSTRUMENTS (Effects of derivatives) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Derivative Financial Instruments [Line Items]
Derivative (gain) loss, net	$ 146,693	$ (231,371)
Commodity contracts [Member] | Not Designated as ASC 815 Hedges [Member]
Derivative Financial Instruments [Line Items]
Derivative (gain) loss, net	$ 146,693	$ (231,371)

DERIVATIVE FINANCIAL INSTRUME_5

DERIVATIVE FINANCIAL INSTRUMENTS (Asset location) (Details) - Commodity contracts [Member] - Not Designated as ASC 815 Hedges [Member] - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Gross amounts of derivative assets and gross amounts offset [Line Items]
Gross Amounts of Recognized Assets	$ 54,233	$ 34,278
Gross Amounts Offset	(54,233)	(34,278)
Prepaid Expenses and Other [Member]
Gross amounts of derivative assets and gross amounts offset [Line Items]
Gross Amounts of Recognized Assets	11,517	14,287
Gross Amounts Offset	(11,517)	(14,287)
Other long-term assets [Member]
Gross amounts of derivative assets and gross amounts offset [Line Items]
Gross Amounts of Recognized Assets	42,716	19,991
Gross Amounts Offset	$ (42,716)	$ (19,991)

DERIVATIVE FINANCIAL INSTRUME_6

DERIVATIVE FINANCIAL INSTRUMENTS (Liability location) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Gross amounts of derivative liabilities and gross amounts offset [Line Items]
Total financial liabilities	$ 166,634	$ 59,235
Commodity contracts [Member] | Not Designated as ASC 815 Hedges [Member]
Gross amounts of derivative liabilities and gross amounts offset [Line Items]
Gross Amounts of Recognized Liabilities	220,867	93,513
Gross Amounts Offset	(54,233)	(34,278)
Total financial liabilities	166,634	59,235
Commodity contracts [Member] | Accrued liabilities and other [Member] | Not Designated as ASC 815 Hedges [Member]
Gross amounts of derivative liabilities and gross amounts offset [Line Items]
Gross Amounts of Recognized Liabilities	145,939	63,772
Gross Amounts Offset	(11,517)	(14,287)
Total financial liabilities	134,422	49,485
Commodity contracts [Member] | Other long-term liabilities [Member] | Not Designated as ASC 815 Hedges [Member]
Gross amounts of derivative liabilities and gross amounts offset [Line Items]
Gross Amounts of Recognized Liabilities	74,928	29,741
Gross Amounts Offset	(42,716)	(19,991)
Total financial liabilities	$ 32,212	$ 9,750

FAIR VALUE MEASUREMENTS (Recurr

FAIR VALUE MEASUREMENTS (Recurring basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financial Liabilities
Total financial liabilities	$ 166,634	$ 59,235
Commodity contracts [Member]
Financial Liabilities
Financial liabilities - current	134,422	49,485
Financial liabilities - non-current	32,212	9,750
Level 2 [Member]
Financial Liabilities
Total financial liabilities	166,634	59,235
Level 2 [Member] | Commodity contracts [Member]
Financial Liabilities
Financial liabilities - current	134,422	49,485
Financial liabilities - non-current	$ 32,212	$ 9,750

FAIR VALUE MEASUREMENTS (Non-re

FAIR VALUE MEASUREMENTS (Non-recurring) (Details) - Proved Properties [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-recurring assets at fair value, impairment loss (before tax)	$ 3,700,000
Measurement Input, Discount Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Value of measurement input	16.00%
Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Proved property	$ 816,234	$ 4,500,000
Non-recurring assets at fair value, impairment loss (before tax)	3,732,096
Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Proved property	$ 816,234

REVENUE RECOGNITION (Revenue Re

REVENUE RECOGNITION (Revenue Reclassification) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue
Sales	$ 307,391	$ 244,846
Oil, NGL and natural gas sales [Member]
Revenue
Sales	304,679	244,846
Oil sales [Member]
Revenue
Sales	256,709	231,945
NGL and natural gas sales [Member]
Revenue
Sales	47,970	$ 12,901
Purchased gas sales [Member]
Revenue
Sales	$ 2,712

REVENUE RECOGNITION (Narrative)

REVENUE RECOGNITION (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Revenue
Receivable balance	$ 126	$ 88
Revenue, Practical Expedient, Initial Application and Transition, Nondisclosure of Transaction Price Allocation to Remaining Performance Obligation [true false]	true
Minimum [Member]
Revenue
Payment received for product sales, period	1 month
Maximum [Member]
Revenue
Payment received for product sales, period	3 months

SHAREHOLDERS' EQUITY (Details)

SHAREHOLDERS' EQUITY (Details) - USD ($) $ / shares in Units, $ in Millions	Sep. 01, 2020	Feb. 28, 2021	Mar. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Capital stock, shares authorized	550,000,000
Common stock, shares authorized	500,000,000		500,000,000	500,000,000
Common stock, par value (in dollars per share)	$ 0.001		$ 0.001	$ 0.001
Preferred stock, shares authorized	50,000,000
Preferred Stock, par value (in dollars per share)	$ 0.001
Common stock issued in settlement of bankruptcy claims (in shares)	38,051,125
General Unsecured Claimants [Member]
Class of Stock [Line Items]
Common stock issued in settlement of bankruptcy claims (in shares)		948,897
Bankruptcy claims, amount paid		$ 2
Series A [Member]
Class of Stock [Line Items]
Warrants outstanding (in shares)	4,837,387
Warrant exercise price (in dollars per share)	$ 73.44
Series A [Member] | Maximum [Member]
Class of Stock [Line Items]
Warrants outstanding (in shares)	4,837,821
Series B [Member]
Class of Stock [Line Items]
Warrants outstanding (in shares)	2,418,840
Warrant exercise price (in dollars per share)	$ 83.45
Series B [Member] | Maximum [Member]
Class of Stock [Line Items]
Warrants outstanding (in shares)	2,418,910

STOCK-BASED COMPENSATION (Narra

STOCK-BASED COMPENSATION (Narrative) (Details)	Sep. 01, 2020USD ($)shares	Sep. 30, 2020D$ / sharesshares	Oct. 31, 2020$ / sharesshares	Mar. 31, 2021USD ($)item$ / sharesshares	Mar. 31, 2020USD ($)$ / sharesshares
Share-based compensation disclosures
Common stock issued in settlement of bankruptcy claims (in shares)	38,051,125
Number of shares authorized upon shareholder's approval	4,035,885
Maximum fair value non-employee director grant | $	$ 500,000
Number of shares available for grant				3,050,034
Granted (in dollars per share) | $ / shares				$ 25.21
Stock compensation expense | $				$ 2,000,000	$ 1,000,000
Service-based [Member]
Share-based compensation disclosures
Granted (in shares)					53,198
Granted (in dollars per share) | $ / shares					$ 4.94
Service-based [Member] | Share-based Payment Arrangement, Employee [Member] | Vesting Period, Scenario 1 [Member]
Share-based compensation disclosures
Vesting (service) period				2 years
Service-based [Member] | Share-based Payment Arrangement, Employee [Member] | Vesting Period, Scenario 2 [Member]
Share-based compensation disclosures
Vesting (service) period				3 years
Service-based [Member] | Share-based Payment Arrangement, Employee [Member] | Vesting Period, Scenario 3 [Member]
Share-based compensation disclosures
Vesting (service) period				5 years
Service-based [Member] | Share-based Payment Arrangement, Nonemployee [Member]
Share-based compensation disclosures
Vesting (service) period				1 year
Cash Retention Incentives [Member]
Share-based compensation disclosures
Replacement award fair value | $					$ 12,000,000
Cash bonus paid taxes | $					$ 9,000,000
RSU [Member]
Share-based compensation disclosures
Granted (in shares)					1,616,504
Service Based Restricted Stock [Member]
Share-based compensation disclosures
Granted (in shares)			89,021	475,730
Granted (in dollars per share) | $ / shares			$ 17.47
Service Based Restricted Stock [Member] | Share-based Payment Arrangement, Employee [Member]
Share-based compensation disclosures
Granted (in shares)				358,123
Service Based Restricted Stock [Member] | Share-based Payment Arrangement, Employee [Member] | Minimum [Member]
Share-based compensation disclosures
Vesting (service) period				2 years
Service Based Restricted Stock [Member] | Share-based Payment Arrangement, Employee [Member] | Maximum [Member]
Share-based compensation disclosures
Vesting (service) period				3 years
Service Based Restricted Stock [Member] | Executive officers [Member]
Share-based compensation disclosures
Granted (in shares)				117,607
Granted (in dollars per share) | $ / shares				$ 22.46
Market Based Restricted Stock [Member]
Share-based compensation disclosures
Granted (in shares)		189,900
Granted (in dollars per share) | $ / shares		$ 6.54
Threshold consecutive trading day | D		20
Market Based Restricted Stock [Member] | Minimum [Member]
Share-based compensation disclosures
Weighted average period over which cost will be recognized		1 year 9 months 18 days
Market Based Restricted Stock [Member] | Maximum [Member]
Share-based compensation disclosures
Weighted average period over which cost will be recognized		3 years 9 months 18 days
Market Based Restricted Stock [Member] | Share-based Payment Arrangement, Tranche One [Member]
Share-based compensation disclosures
Vesting (as a percent)		50.00%
Share price (in dollars per share) | $ / shares		$ 32.57
Market Based Restricted Stock [Member] | Share-based Payment Arrangement, Tranche Two [Member]
Share-based compensation disclosures
Vesting (as a percent)		25.00%
Share price (in dollars per share) | $ / shares		$ 48.86
Market Based Restricted Stock [Member] | Share-based Payment Arrangement, Tranche Three [Member]
Share-based compensation disclosures
Vesting (as a percent)		25.00%
Share price (in dollars per share) | $ / shares		$ 65.14
PSAs and PSUs [Member]
Share-based compensation disclosures
Vesting (service) period				3 years
Granted (in shares)					1,665,153
Granted (in dollars per share) | $ / shares					$ 4.31
PSU [Member]
Share-based compensation disclosures
Granted (in shares)				232,150
PSU [Member] | Minimum [Member]
Share-based compensation disclosures
Possible multiplier of shares earned | item				0
PSU [Member] | Maximum [Member]
Share-based compensation disclosures
Possible multiplier of shares earned | item				2
PSU [Member] | ATSR PSUs [Member]
Share-based compensation disclosures
Granted (in shares)				116,075
Granted (in dollars per share) | $ / shares				$ 29.32
PSU [Member] | RTSR PSUs [Member]
Share-based compensation disclosures
Granted (in shares)				116,075
Granted (in dollars per share) | $ / shares				$ 32.33
Existing Stockholders [Member]
Share-based compensation disclosures
Common stock issued in settlement of bankruptcy claims (in shares)	1,233,495

STOCK-BASED COMPENSATION (Assum

STOCK-BASED COMPENSATION (Assumptions) (Details) - item	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
RSU [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of simulations		100,000
Expected volatility (as a percent)		40.00%
Risk-free interest rate (as a percent)		0.66%
PSU [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of simulations	500,000
Expected volatility (as a percent)	81.00%
Risk-free interest rate (as a percent)	0.17%

STOCK-BASED COMPENSATION (Nonve

STOCK-BASED COMPENSATION (Nonvested awards) (Details) - $ / shares	1 Months Ended	2 Months Ended	3 Months Ended
	Sep. 30, 2020	Oct. 31, 2020	Mar. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance at the beginning of the period (in dollars per share)			$ 10.03
Granted (in dollars per share)			25.21
Vested (in dollars per share)			6.54
Forfeited (in dollars per share)			22.46
Balance at the end of the period (in dollars per share)			$ 22.45
Service Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance at the beginning of the period (in shares)			89,021
Granted (in shares)		89,021	475,730
Forfeited (in shares)			(950)
Balance at the end of the period (in shares)			563,801
Granted (in dollars per share)		$ 17.47
Market Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance at the beginning of the period (in shares)			189,900
Granted (in shares)	189,900
Vested (in shares)			(94,950)
Balance at the end of the period (in shares)			94,950
Granted (in dollars per share)	$ 6.54
PSU [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			232,150
Balance at the end of the period (in shares)			232,150

INCOME TAXES (Narrative) (Detai

INCOME TAXES (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
INCOME TAXES [Abstract]
U.S. statutory income tax rate (as a percent)	21.00%	21.00%
Income tax benefit (expense)	$ 0	$ 0
Effective tax rate	0.00%	0.00%
Federal operating loss carryforwards			$ 3,100,000
Carryforwards expected to expire	$ 2,300,000

EARNINGS PER SHARE (Reconciliat

EARNINGS PER SHARE (Reconciliation) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Basic loss per share
Net loss	$ (946)	$ (3,628,571)
Weighted average shares outstanding, basic	38,698	91,390
Loss per common share, basic	$ (0.02)	$ (39.70)
Diluted loss per share
Net loss	$ (946)	$ (3,628,571)
Weighted average shares outstanding	38,698	91,390
Loss per common share, diluted	$ (0.02)	$ (39.70)

EARNINGS PER SHARE (Narrative)

EARNINGS PER SHARE (Narrative) (Details) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Series A [Member]
Shares excluded from Earnings Per Share calculation [Line Items]
Antidilutive securities excluded from computation of earnings per share	4,837,376
Series B [Member]
Shares excluded from Earnings Per Share calculation [Line Items]
Antidilutive securities excluded from computation of earnings per share	2,418,832
Contingently Issuable Shares [Member]
Shares excluded from Earnings Per Share calculation [Line Items]
Antidilutive securities excluded from computation of earnings per share	2,121,304
PSAs and PSUs [Member]
Shares excluded from Earnings Per Share calculation [Line Items]
Antidilutive securities excluded from computation of earnings per share	90,352
Service-based [Member]
Shares excluded from Earnings Per Share calculation [Line Items]
Antidilutive securities excluded from computation of earnings per share	194,469	392,367
Market Based Restricted Stock Units [Member]
Shares excluded from Earnings Per Share calculation [Line Items]
Antidilutive securities excluded from computation of earnings per share	94,950
Stock Option [Member]
Shares excluded from Earnings Per Share calculation [Line Items]
Antidilutive securities excluded from computation of earnings per share		39,660

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Narrative) (Details) - USD ($) $ in Millions	Oct. 01, 2020	Jun. 30, 2020
Commitments
Payment made		$ 14
Indemnity amount		$ 25
US Government [Member]
Commitments
Bankruptcy Claims, Amount of Claims Filed	$ 25
FMOG Entities [Member]
Commitments
Bankruptcy Claims, Amount of Claims Filed	$ 60