Chord Energy (WLLBW) 10-Q 6 Nov 20 2020 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2020	Oct. 30, 2020
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
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	Large 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		38,051,210
Entity Central Index Key	0001255474
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 13,702	$ 8,652
Restricted cash	13,233
Accounts receivable trade, net	128,577	308,249
Prepaid expenses and other	22,056	14,082
Total current assets	177,568	330,983
Property and equipment:
Oil and gas properties, successful efforts method	1,829,472	12,812,007
Other property and equipment	72,856	178,689
Total property and equipment	1,902,328	12,990,696
Less accumulated depreciation, depletion and amortization	(19,447)	(5,735,239)
Total property and equipment, net	1,882,881	7,255,457
Other long-term assets	38,007	50,281
TOTAL ASSETS	2,098,456	7,636,721
Current liabilities:
Accounts payable trade	44,171	80,100
Revenues and royalties payable	146,767	202,010
Accrued capital expenditures	14,809	64,263
Accrued liabilities and other	63,987	85,007
Accrued lease operating expenses	23,757	38,262
Accrued interest	1,432	53,928
Taxes payable	16,985	26,844
Total current liabilities	311,908	550,414
Long-term debt	400,328	2,799,885
Asset retirement obligations	119,262	131,208
Operating lease obligations	17,749	31,722
Deferred income taxes		73,593
Other long-term liabilities	19,723	24,928
Total liabilities	868,970	3,611,750
Commitments and contingencies
Equity (Deficit):
Common stock	38	92
Additional paid-in capital	1,189,178	6,409,991
Accumulated earnings (deficit)	40,270	(2,385,112)
Total equity	1,229,486	4,024,971
TOTAL LIABILITIES AND EQUITY	$ 2,098,456	$ 7,636,721

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2020	Dec. 31, 2019
CONSOLIDATED BALANCE SHEETS [Abstract]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	500,000,000	225,000,000
Common stock, shares issued	38,051,210	91,743,571
Common stock, shares outstanding	38,051,210	91,326,469

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended	8 Months Ended	9 Months Ended
	Sep. 30, 2020	Aug. 31, 2020	Sep. 30, 2019	Aug. 31, 2020	Sep. 30, 2019
OPERATING REVENUES
Oil, NGL and natural gas sales	$ 61,084	$ 122,558	$ 375,891	$ 459,004	$ 1,191,644
OPERATING EXPENSES
Lease operating expenses	18,526	32,646	85,320	158,228	256,384
Transportation, gathering, compression and other	1,980	4,259	11,176	22,266	32,145
Production and ad valorem taxes	5,908	10,362	35,220	41,204	102,796
Depreciation, depletion and amortization	20,110	71,240	211,025	338,757	612,166
Exploration and impairment	4,207	10,217	10,890	4,184,830	44,045
General and administrative	10,345	16,513	29,890	91,816	97,437
Derivative (gain) loss, net	(30,594)	43,125	(30,597)	(181,614)	7,431
Loss on sale of properties	395	1,280	595	927	1,681
Amortization of deferred gain on sale		(1,171)	(2,266)	(5,116)	(6,963)
Total operating expenses	30,877	188,471	351,253	4,651,298	1,147,122
INCOME (LOSS) FROM OPERATIONS	30,207	(65,913)	24,638	(4,192,294)	44,522
OTHER INCOME (EXPENSE)
Interest expense	(2,128)	(11,379)	(48,447)	(73,054)	(145,274)
Gain on extinguishment of debt			4,598	25,883	4,598
Interest income and other	6	139	144	211	1,102
Reorganization items, net		259,232		217,419
Total other income (expense)	(2,122)	247,992	(43,705)	170,459	(139,574)
INCOME (LOSS) BEFORE INCOME TAXES	28,085	182,079	(19,067)	(4,021,835)	(95,052)
INCOME TAX EXPENSE (BENEFIT)
Current	2,316			2,718
Deferred	(14,501)	(55,346)		(59,092)	(1,373)
Total income tax benefit	(12,185)	(55,346)		(56,374)	(1,373)
NET INCOME (LOSS)	$ 40,270	$ 237,425	$ (19,067)	$ (3,965,461)	$ (93,679)
INCOME (LOSS) PER COMMON SHARE
Basic (in dollars per share)	$ 1.06	$ 2.60	$ (0.21)	$ (43.37)	$ (1.03)
Diluted (in dollars per share)	$ 1.06	$ 2.60	$ (0.21)	$ (43.37)	$ (1.03)
WEIGHTED AVERAGE SHARES OUTSTANDING
Basic (in shares)	38,051	91,464	91,299	91,423	91,274
Diluted (in shares)	38,051	91,464	91,299	91,423	91,274

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	1 Months Ended	8 Months Ended	9 Months Ended
	Sep. 30, 2020	Aug. 31, 2020	Sep. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ 40,270	$ (3,965,461)	$ (93,679)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization	20,110	338,757	612,166
Deferred income tax benefit	(14,501)	(59,092)	(1,373)
Amortization of debt issuance costs, debt discount and debt premium	371	13,535	23,707
Stock-based compensation		4,188	5,086
Amortization of deferred gain on sale		(5,116)	(6,963)
Loss on sale of properties	395	927	1,681
Oil and gas property impairments		4,161,885	15,729
Gain on extinguishment of debt		(25,883)	(4,598)
Non-cash derivative (gain) loss	(29,563)	(136,131)	22,228
Non-cash reorganization items, net		(274,588)
Other, net	(438)	(223)	1,141
Changes in current assets and liabilities:
Accounts receivable trade, net	7,752	181,416	(4,076)
Prepaid expenses and other	1,133	(5,491)	4,998
Accounts payable trade and accrued liabilities	(18,163)	(46,734)	(18,397)
Revenues and royalties payable	1,261	(56,504)	(28,110)
Taxes payable	3,013	(12,872)	(8,615)
Net cash provided by operating activities	11,640	112,613	520,925
CASH FLOWS FROM INVESTING ACTIVITIES
Drilling and development capital expenditures	(9,040)	(238,456)	(624,707)
Acquisition of oil and gas properties	(162)	(493)	(5,955)
Other property and equipment		(1,072)	(7,525)
Other property and equipment	56
Proceeds from sale of properties	532	29,273	66,738
Net cash used in investing activities	(8,614)	(210,748)	(571,449)
CASH FLOWS FROM FINANCING ACTIVITIES
Repurchase of 1.25% Convertible Senior Notes due 2020		(52,890)	(297,000)
Repurchase of 5.75% Senior Notes due 2021			(23,461)
Debt issuance and extinguishment costs		(12,784)	(36)
Restricted stock used for tax withholdings		(307)	(3,696)
Principal payments on finance lease obligations	(498)	(3,198)	(3,890)
Net cash provided by (used in) financing activities	(25,498)	138,890	36,917
NET CHANGE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	(22,472)	40,755	(13,607)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH
Beginning of period	49,407	8,652	13,607
End of period	26,935	49,407
SUPPLEMENTAL CASH FLOW DISCLOSURES
Interest paid, net of amounts capitalized	301	80,220	156,664
Cash paid for reorganization items	14,353	33,238
NONCASH INVESTING AND FINANCING ACTIVITIES
Accrued capital expenditures and accounts payable related to property additions	23,245	26,796	147,295
Derivative termination settlement payments used to repay borrowings under Predecessor Credit Agreement		157,741
Predecessor Credit Agreement [Member]
CASH FLOWS FROM FINANCING ACTIVITIES
Borrowings under credit agreement		1,185,000	1,980,000
Repayments of borrowings under credit agreement		(1,402,259)	$ (1,615,000)
Exit Credit Agreement [Member]
CASH FLOWS FROM FINANCING ACTIVITIES
Borrowings under credit agreement	75,000	$ 425,328
Repayments of borrowings under credit agreement	$ (100,000)

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical)	Sep. 30, 2020	Aug. 31, 2020	Dec. 31, 2019
1.25% Convertible Senior Notes due 2020 [Member]
Interest Rate (as a percent)	1.25%	1.25%	1.25%
5.75% Senior Notes due 2021 [Member]
Interest Rate (as a percent)	5.75%	5.75%	5.75%

CONSOLIDATED STATEMENTS OF EQUI

CONSOLIDATED STATEMENTS OF EQUITY (DEFICIT) - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Total
BALANCES at Dec. 31, 2018	$ 92	$ 6,414,170	$ (2,143,946)	$ 4,270,316
BALANCES (in shares) at Dec. 31, 2018	92,067
Increase (Decrease) in Shareholders' Equity
Net income (loss)			(68,925)	(68,925)
Restricted stock forfeited (in shares)	(106)
Restricted stock used for tax withholdings		(3,693)		(3,693)
Restricted stock used for tax withholdings (in shares)	(130)
Stock-based compensation		4,651		4,651
BALANCES at Mar. 31, 2019	$ 92	6,415,128	(2,212,871)	4,202,349
BALANCES (in shares) at Mar. 31, 2019	91,831
BALANCES at Dec. 31, 2018	$ 92	6,414,170	(2,143,946)	4,270,316
BALANCES (in shares) at Dec. 31, 2018	92,067
Increase (Decrease) in Shareholders' Equity
Net income (loss)				(93,679)
BALANCES at Sep. 30, 2019	$ 92	6,407,490	(2,237,625)	4,169,957
BALANCES (in shares) at Sep. 30, 2019	91,761
BALANCES at Mar. 31, 2019	$ 92	6,415,128	(2,212,871)	4,202,349
BALANCES (in shares) at Mar. 31, 2019	91,831
Increase (Decrease) in Shareholders' Equity
Net income (loss)			(5,687)	(5,687)
Restricted stock issued (in shares)	63
Restricted stock forfeited (in shares)	(3)
Stock-based compensation		3,965		3,965
BALANCES at Jun. 30, 2019	$ 92	6,419,093	(2,218,558)	4,200,627
BALANCES (in shares) at Jun. 30, 2019	91,891
Increase (Decrease) in Shareholders' Equity
Net income (loss)			(19,067)	(19,067)
Restricted stock issued (in shares)	45
Restricted stock forfeited (in shares)	(175)
Restricted stock used for tax withholdings		(3)		(3)
Stock-based compensation		(3,530)		(3,530)
Adjustment to equity component of Convertible Senior Notes upon extinguishment		(8,070)		(8,070)
BALANCES at Sep. 30, 2019	$ 92	6,407,490	(2,237,625)	4,169,957
BALANCES (in shares) at Sep. 30, 2019	91,761
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 income (loss)			(3,628,571)	(3,628,571)
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
Adjustment to equity component of Convertible Senior Notes upon extinguishment		(3,461)		(3,461)
BALANCES at Mar. 31, 2020	$ 92	6,408,294	(6,013,683)	394,703
BALANCES (in shares) at Mar. 31, 2020	91,637
Increase (Decrease) in Shareholders' Equity
Net income (loss)			(574,315)	(574,315)
Stock-based compensation		1,333		1,333
BALANCES at Jun. 30, 2020	$ 92	$ 6,409,627	$ (6,587,998)	$ (178,279)
BALANCES (in shares) at Jun. 30, 2020	91,637

CONSOLIDATED STATEMENTS OF EQ_2

CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) $ in Thousands	1 Months Ended
	Sep. 30, 2020USD ($)shares
Net income (loss)	$ 40,270
Successor Bankruptcy [Member]
Net income (loss)	40,270
Issuance of Successor equity	1,159,856
Issuance of Successor warrants	29,360
Balance Successor	1,189,216
BALANCES	1,229,486
Common Stock [Member] | Successor Bankruptcy [Member]
Issuance of Successor equity	$ 38
Issuance of Successor equity (in shares) | shares	38,051,000
Balance Successor	$ 38
Balance Successor, Shares | shares	38,051,000
BALANCES	$ 38
BALANCES (in shares) | shares	38,051,000
Additional Paid-in Capital [Member] | Successor Bankruptcy [Member]
Issuance of Successor equity	$ 1,159,818
Issuance of Successor warrants	29,360
Balance Successor	1,189,178
BALANCES	1,189,178
Accumulated Deficit [Member] | Successor Bankruptcy [Member]
Net income (loss)	40,270
BALANCES	$ 40,270

BASIS OF PRESENTATION

BASIS OF PRESENTATION	9 Months Ended
	Sep. 30, 2020
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 During the Current Predecessor YTD Period, the Company applied ASC 852 in preparing the condensed consolidated financial statements, which requires distinguishing transactions associated with the reorganization separate from activities related to the ongoing operations of the business. Accordingly, pre-petition liabilities that could have been impacted by the chapter 11 proceedings were classified as liabilities subject to compromise. Additionally, certain expenses, realized gains and losses and provisions for losses that were realized or incurred during the Chapter 11 Cases, including adjustments to the carrying value of certain indebtedness were recorded as reorganization items, net in the condensed consolidated statements of operations for the relevant Predecessor periods. Ability to Continue as a Going Concern Condensed Consolidated Financial Statements not control, over the investee are accounted for using the equity method. Under the equity method, investments are stated at cost plus the Company’s equity in undistributed earnings and losses. All intercompany balances and transactions have been eliminated upon consolidation. These financial statements have been prepared in accordance with GAAP and the SEC rules and regulations for interim financial reporting. In the opinion of management, the accompanying financial statements include all adjustments (consisting of normal recurring accruals and adjustments) necessary to present fairly, in all material respects, the Company’s interim results. However, operating results for the periods presented are not necessarily indicative of the results that may be expected for the full year. The condensed consolidated financial statements and related notes included in this Quarterly Report on Form 10-Q should be read in conjunction with Whiting’s consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the period ended December 31, 2019. Except as disclosed herein, there have been no material changes to the information disclosed in the notes to consolidated financial statements included in the Company’s 2019 Annual Report on Form 10-K. Reclassifications — Cash, Cash Equivalents and Restricted Cash — Restricted cash as of September 30, 2020 (Successor) includes $13 million 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 “Professional Fee Escrow Account”). 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 ​ ​ Predecessor ​ ​ September 30, ​ ​ December 31, ​ ​ 2020 ​ ​ 2019 Cash and cash equivalents ​ $ 13,702 ​ ​ $ 8,652 Restricted cash ​ ​ 13,233 ​ ​ ​ - Total cash, cash equivalents and restricted cash ​ $ 26,935 ​ ​ $ 8,652 ​ 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 December 31, 2019 (Predecessor), the Company had an allowance for credit losses of $9 million.

CHAPTER 11 EMERGENCE

CHAPTER 11 EMERGENCE	9 Months Ended
	Sep. 30, 2020
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 the RSA 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, ● 1,233,580 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 are currently pending resolution in the Bankruptcy Court. Any remaining reserved shares that are not distributed to resolve these 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 “Exit 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 Exit Credit Agreement. The Company utilized borrowings from the Exit 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, which 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 from the rejection of any executory contract or unexpired lease and the Debtors expressly preserve all of their rights thereto. Refer to the “Commitments and Contingencies” footnote for more information on potential future rejection damages related to general unsecured claims. Interest Expense

FRESH START ACCOUNTING

FRESH START ACCOUNTING	9 Months Ended
	Sep. 30, 2020
FRESH START ACCOUNTING [Abstract]
FRESH START ACCOUNTING	3. FRESH START ACCOUNTING Fresh Start In accordance with ASC 852, with the application of fresh start accounting, the Company allocated its reorganization value to its individual assets based on their estimated fair values in conformity with FASB ASC Topic 820 – Fair Value Measurement Business Combinations Reorganization Value The Company’s principal assets are its oil and natural gas properties. The fair value of proved reserves was estimated using an income approach, which was based on the anticipated future cash flows associated with those proved reserves, risked by reserve category and discounted using a weighted average cost of capital rate of 14%. The proved reserve locations included in this analysis were limited to wells included in the Company's five-year development plan. Future prices for the income approach were based on forward strip price curves (adjusted for basis differentials). The fair value of the Company’s unproved reserves was estimated using a combination of income and market approaches. See further discussion below in “Fresh Start Accounting Adjustments.” The following table reconciles the Company’s enterprise value to the implied value of the Successor’s common stock as of September 1, 2020 (in thousands, except per share data): ​ ​ ​ ​ Enterprise value ​ $ 1,591,887 Plus: Cash and cash equivalents ​ ​ 22,657 Less: Fair value of debt ​ ​ (425,328) Implied value of Successor common stock ​ $ 1,189,216 ​ The following table reconciles the Company’s enterprise value to its reorganization value as of September 1, 2020 (in thousands): ​ ​ ​ ​ Enterprise value ​ $ 1,591,887 Plus: ​ ​ ​ Cash and cash equivalents ​ ​ 22,657 Accounts payable trade ​ ​ 56,432 Revenues and royalties payable ​ ​ 145,506 Other current liabilities ​ ​ 143,790 Asset retirement obligations ​ ​ 121,343 Operating lease obligations ​ ​ 17,839 Deferred income taxes ​ ​ 14,501 Other long-term liabilities ​ ​ 28,773 Reorganization value ​ $ 2,142,728 ​ Although the Company believes the assumptions and estimates used to develop enterprise value and reorganization value are reasonable and appropriate, different assumptions and estimates could materially impact the analysis and resulting conclusions. The assumptions used in estimating these values are inherently uncertain and require judgment. See below under the caption “Fresh Start Adjustments” for additional information regarding assumptions used in the valuation of the Company’s significant assets and liabilities. Condensed Consolidated Balance Sheet at Emergence (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 1, 2020 ​ ​ ​ ​ Reorganization ​ ​ Fresh Start ​ ​ ​ ​ ​ Predecessor ​ Adjustments ​ ​ Adjustments ​ ​ Successor ASSETS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 547,354 ​ $ (524,697) (a) ​ $ - ​ ​ $ 22,657 Restricted cash ​ ​ 28,955 ​ ​ (2,205) (b) ​ ​ - ​ ​ ​ 26,750 Accounts receivable trade, net ​ ​ 136,881 ​ ​ - ​ ​ ​ 81 (o) ​ ​ 136,962 Prepaid expenses and other ​ ​ 18,722 ​ ​ 231 (c) ​ ​ 2,260 (p) ​ ​ 21,213 Total current assets ​ ​ 731,912 ​ ​ (526,671) ​ ​ ​ 2,341 ​ ​ ​ 207,582 Property and equipment: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Oil and gas properties, successful efforts method ​ ​ 4,885,013 ​ ​ - ​ ​ ​ (3,058,899) (q) ​ ​ 1,826,114 Other property and equipment ​ ​ 159,866 ​ ​ (909) (d) ​ ​ (87,642) (o)(r) ​ ​ 71,315 Total property and equipment ​ ​ 5,044,879 ​ ​ (909) ​ ​ ​ (3,146,541) ​ ​ ​ 1,897,429 Less accumulated depreciation, depletion and amortization ​ ​ (2,085,266) ​ ​ - ​ ​ ​ 2,085,266 (o)(q)(r) ​ ​ - Total property and equipment, net ​ ​ 2,959,613 ​ ​ (909) ​ ​ ​ (1,061,275) ​ ​ ​ 1,897,429 Debt issuance costs ​ ​ 1,834 ​ ​ 10,950 (e) ​ ​ - ​ ​ ​ 12,784 Other long-term assets ​ ​ 37,010 ​ ​ (8,760) (d) ​ ​ (3,317) (o)(s) ​ ​ 24,933 TOTAL ASSETS ​ $ 3,730,369 ​ $ (525,390) ​ ​ $ (1,062,251) ​ ​ $ 2,142,728 LIABILITIES AND EQUITY (DEFICIT) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current portion of long-term debt ​ $ 912,259 ​ $ (912,259) (f) ​ $ - ​ ​ $ - Accounts payable trade ​ ​ 47,168 ​ ​ 9,264 (g)(h) ​ ​ - ​ ​ ​ 56,432 Revenues and royalties payable ​ ​ 145,506 ​ ​ - ​ ​ ​ - ​ ​ ​ 145,506 Accrued capital expenditures ​ ​ 14,037 ​ ​ 1,305 (g) ​ ​ - ​ ​ ​ 15,342 Accrued liabilities and other ​ ​ 46,327 ​ ​ 21,942 (g)(i) ​ ​ (6,529) (o)(t) ​ ​ 61,740 Accrued lease operating expenses ​ ​ 25,344 ​ ​ 1,394 (g) ​ ​ - ​ ​ ​ 26,738 Accrued interest ​ ​ 3,459 ​ ​ (3,332) (g)(j) ​ ​ (127) (o) ​ ​ - Taxes payable ​ ​ 13,972 ​ ​ - ​ ​ ​ - ​ ​ ​ 13,972 Derivative liabilities ​ ​ 25,998 ​ ​ - ​ ​ ​ - ​ ​ ​ 25,998 Total current liabilities ​ ​ 1,234,070 ​ ​ (881,686) ​ ​ ​ (6,656) ​ ​ ​ 345,728 Long-term debt ​ ​ - ​ ​ 425,328 (k) ​ ​ - ​ ​ ​ 425,328 Asset retirement obligations ​ ​ 150,925 ​ ​ - ​ ​ ​ (29,582) (u) ​ ​ 121,343 Operating lease obligations ​ ​ - ​ ​ 17,652 (d)(g) ​ ​ 187 (o) ​ ​ 17,839 Deferred income taxes ​ ​ 69,847 ​ ​ - ​ ​ ​ (55,346) (v) ​ ​ 14,501 Other long-term liabilities ​ ​ 18,160 ​ ​ 11,071 (g) ​ ​ (458) (o)(t) ​ ​ 28,773 Total liabilities not subject to compromise ​ ​ 1,473,002 ​ ​ (427,635) ​ ​ ​ (91,855) ​ ​ ​ 953,512 Liabilities subject to compromise ​ ​ 2,526,925 ​ ​ (2,526,925) (g) ​ ​ - ​ ​ ​ - Total liabilities ​ ​ 3,999,927 ​ ​ (2,954,560) ​ ​ ​ (91,855) ​ ​ ​ 953,512 Commitments and contingencies ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Equity (deficit): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Predecessor common stock ​ ​ 92 ​ ​ (92) (l) ​ ​ - ​ ​ ​ - Successor common stock ​ ​ - ​ ​ 38 (m) ​ ​ - ​ ​ ​ 38 Predecessor additional paid-in capital ​ ​ 6,410,410 ​ ​ (6,410,410) (l) ​ ​ - ​ ​ ​ - Successor additional paid-in capital ​ ​ - ​ ​ 1,189,178 (m) ​ ​ - ​ ​ ​ 1,189,178 Accumulated earnings (deficit) ​ ​ (6,680,060) ​ ​ 7,650,456 (n) ​ ​ (970,396) (w) ​ ​ - Total equity (deficit) ​ ​ (269,558) ​ ​ 2,429,170 ​ ​ ​ (970,396) ​ ​ ​ 1,189,216 TOTAL LIABILITIES AND EQUITY (DEFICIT) ​ $ 3,730,369 ​ $ (525,390) ​ ​ $ (1,062,251) ​ ​ $ 2,142,728 ​ Reorganization Adjustments (a) The table below reflects the sources and uses of cash on the Emergence Date pursuant to the terms of the Plan (in thousands): ​ ​ ​ ​ Sources: ​ ​ ​ Release of restricted cash upon bankruptcy emergence ​ $ 28,205 Borrowings under the Exit Credit Agreement ​ ​ 425,328 Total sources of cash ​ ​ 453,533 Uses: ​ ​ ​ Payment of outstanding borrowings under the Predecessor Credit Agreement ​ ​ (912,259) Payment of accrued interest on the Predecessor Credit Agreement ​ ​ (3,437) Payment of debt issuance costs related to Exit Credit Agreement ​ ​ (10,950) Funding of the Professional Fee Escrow Account ​ ​ (26,000) Payment of professional fees upon emergence ​ ​ (14,470) Payment of contract cure amounts ​ ​ (11,114) Total uses of cash ​ ​ (978,230) ​ ​ ​ ​ Net uses of cash ​ $ (524,697) ​ (b) The table below reflects the net reclassification of cash balances to and from restricted cash on the Emergence Date pursuant to terms of the Plan (in thousands): ​ ​ ​ ​ Funding of the Professional Fee Escrow Account ​ $ 26,000 Release of restricted cash upon bankruptcy emergence (1) ​ ​ (28,205) Net reclassifications from restricted cash ​ $ (2,205) (1) Includes $23 million of funds related to derivative termination settlements that were directed by the counterparty to be held in a segregated account until the Company emerged from bankruptcy, as well as $5 million of amounts set aside as adequate assurance for utility providers that were restricted until emergence. (c) Reflects the payment of professional fee retainers upon emergence. (d) The Company amended a corporate office lease agreement and terminated the lease of certain floors within that agreement, which amendment was effective upon emergence from the Chapter 11 Cases. As a result of the lease modification and terminations, the Company reduced the associated right-of-use assets and operating lease obligations by $10 million and $15 million, respectively, resulting in a $5 million gain on settlement of liabilities subject to compromise, which was recorded to reorganization items, net in the condensed consolidated statements of operations. The corporate office lease was classified as an operating lease and the modification did not result in a change to the lease’s classification. Additionally, $18 million of long-term operating lease obligations in liabilities subject to compromise were reinstated to be satisfied in the ordinary course of business. (e) Represents $11 million of financing costs related to the Exit Credit Agreement which were capitalized as debt issuance costs and will be amortized to interest expense through the maturity date of April 1, 2024. (f) Reflects the payment in full of the borrowings outstanding under the Predecessor Credit Agreement on the Emergence Date. (g) As part of the Plan, the Bankruptcy Court approved the settlement of certain claims reported within liabilities subject to compromise in the Company's condensed consolidated balance sheet at their respective allowed claim amounts. The table below indicates the reinstatement or disposition of liabilities subject to compromise (in thousands): ​ ​ ​ ​ ​ Liabilities subject to compromise pre-emergence ​ $ 2,526,925 Amounts reinstated on the Emergence Date: ​ ​ ​ Accounts payable trade ​ ​ (10,866) Accrued capital expenditures ​ ​ (1,305) Accrued lease operating expenses ​ ​ (1,394) Accrued liabilities and other ​ ​ (13,961) Accrued interest ​ ​ (105) Operating lease obligations ​ ​ (17,652) Other long-term liabilities ​ ​ (11,071) Total liabilities reinstated ​ ​ (56,354) Less: Amounts settled per the Plan ​ ​ ​ Issuance of common stock to general unsecured claim holders ​ ​ (1,125,062) Payment of contract cure amounts ​ ​ (10,836) Operating lease modification and terminations ​ ​ (9,669) Issuance of Successor common stock to holders of unvested cash-settled equity awards (1) ​ ​ (64) Total amounts settled ​ ​ (1,145,631) Gain on settlement of liabilities subject to compromise ​ $ 1,324,940 (1) Holders of unvested cash-settled restricted stock awards were included as existing equity interests in the Plan and thus received Successor common stock on a pro rata basis based on the amount of unvested awards held. This amount represents the gain on the liability related to those awards, which was included in liabilities subject to compromise prior to emergence. (h) Reflects the reinstatement of $11 million of accounts payable included in liabilities subject to compromise to be satisfied in the ordinary course of business, partially offset by $2 million of professional fees paid on the Emergence Date. (i) Represents the accrual of success fees payable upon emergence as well as certain other expenses, the payment of certain professional fees that were accrued for prior to emergence and the reinstatement of certain accrued liabilities included in liabilities subject to compromise to be satisfied in the ordinary course of business, as detailed in the following table (in thousands): ​ ​ ​ ​ ​ Reinstatement of accrued expenses from liabilities subject to compromise ​ $ 13,961 Recognition of success fee payable upon emergence ​ ​ 11,500 Other expenses accrued at emergence ​ ​ 3,315 Payment of certain professional fees accrued prior to emergence ​ ​ (6,834) Net impact to accrued liabilities and other ​ $ 21,942 ​ (j) Represents a $3 million payment of accrued interest on the Predecessor Credit Agreement and reinstated accrued interest that was included within liabilities subject to compromise to be satisfied in the ordinary course of business. (k) Reflects borrowings drawn under the Exit Credit Agreement upon emergence. Refer to the "Long-Term Debt" footnote for more information on the Exit Credit Agreement. (l) Pursuant to the terms of the Plan, on the Emergence Date, all Predecessor common stock interests were cancelled. As a result of the cancellation, the Company accelerated the recognition of $4 million in compensation expense related to the unrecognized portion of share-based compensation as of the Emergence Date, which was recorded to reorganization items, net in the condensed consolidated statements of operations. (m) Reflects the issuance of Successor equity, including the issuance of 38,051,210 shares of common stock at a par value of $0.001 per share and warrants to purchase 7,256,227 shares of common stock in exchange for claims against or interests in the Debtors pursuant to the Plan. Equity issued to each class of claims is detailed in the table below (in thousands): ​ ​ ​ ​ ​ Issuance of common stock to general unsecured claim holders ​ $ 1,125,062 Issuance of common stock to Predecessor common stockholders and holders of unvested cash-settled equity awards ​ ​ 34,794 Issuance of warrants to Predecessor common stockholders and holders of unvested cash-settled equity awards ​ ​ 29,360 Fair value of Successor equity ​ $ 1,189,216 ​ (n) The table below reflects the cumulative impact of the reorganization adjustments discussed above (in thousands): ​ ​ ​ ​ Gain on settlement of liabilities subject to compromise ​ $ 1,324,940 Cancellation of Predecessor equity (1) ​ ​ 6,414,541 Fair value of equity issued to Predecessor common stockholders and holders of unvested cash-settled equity awards ​ ​ (34,794) Fair value of warrants issued to Predecessor common stockholders and holders of unvested cash-settled equity awards ​ ​ (29,360) Success fees incurred upon emergence ​ ​ (17,303) Acceleration of unvested stock-based compensation awards ​ ​ (4,161) Other expenses incurred upon emergence ​ ​ (3,407) Net impact on accumulated earnings (deficit) ​ $ 7,650,456 (1) This value is reflective of Predecessor common stock, Predecessor additional paid in capital and the recognition of $4 million in compensation expense related to the unrecognized portion of share-based compensation. Fresh Start Adjustments (o) Reflects the adjustments to fair value made to operating and finance lease assets and liabilities. Upon adoption of fresh start accounting, the Company's remaining lease obligations were recalculated using the incremental borrowing rate applicable to the Company upon emergence and commensurate with the Successor's capital structure. The fair value adjustments related to leases are summarized in the table below (in thousands): ​ ​ ​ ​ ​ ​ ​ Lease Asset/Liability ​ Balance Sheet Classification ​ Fair Value Adjustment Accounts receivable, net ​ Accounts receivable, net ​ $ 81 Operating lease assets, net ​ Other long-term assets ​ ​ (1,480) Finance lease assets ​ Other property and equipment ​ ​ (10,765) Accumulated depreciation - finance leases ​ Less accumulated depreciation, depletion and amortization ​ ​ 15,099 Accrued interest - finance leases ​ Accrued interest ​ ​ 127 Short-term finance lease obligation ​ Accrued liabilities and other ​ ​ (576) Short-term operating lease obligation ​ Accrued liabilities and other ​ ​ 319 Long-term finance lease obligation ​ Other long-term liabilities ​ ​ (1,174) Long-term operating lease obligation ​ Operating lease obligations ​ ​ (187) ​ ​ ​ ​ $ 1,444 ​ (p) Reflects the adjustment to fair value of the Company's oil in tank inventory based on market prices as of the Emergence Date. (q) Reflects the adjustments to fair value of the Company's oil and natural gas properties and undeveloped properties, as well as the elimination of accumulated depletion, depreciation and amortization. For purposes of estimating the fair value of the Company's proved oil and gas properties, an income approach was used which estimated the fair value based on the anticipated future cash flows associated with the Company's proved reserves, risked by reserve category and discounted using a weighted average cost of capital rate of 14%. The proved reserve locations included in this analysis were limited to wells included in the Company's five-year development plan. Future prices for the income approach were based on forward strip price curves (adjusted for basis differentials) as of the Emergence Date. In estimating the fair value of the Company's unproved properties, a combination of income and market approaches were utilized. The income approach consistent with that utilized for proved properties was utilized for properties which had positive future cash flows associated with reserve locations that did not qualify as proved reserves. A market approach was used to value the remainder of the Company’s unproved properties. (r) Reflects the fair value adjustment to recognize the Company’s land, buildings and other property, plant and equipment as of the Emergence Date based on the fair values of such land, buildings and other property, plant and equipment as well as the elimination of related historical depletion, depreciation and amortization balances. Land and buildings were valued using a market approach. Other property, plant and equipment were valued using a cost approach based on the current replacement costs of the assets, less depreciation based on the estimated economic useful lives of the assets and the age of the assets. The fair value adjustments consisted of a decrease of $16 million in land and buildings, a decrease of $61 million in other property, plant and equipment and a corresponding write-off of $66 million in accumulated depletion, depreciation and amortization. (s) Reflects the adjustment to fair value of the Company's other long-term assets, including line fill and pipeline imbalances, based on the commodity market prices as of the Emergence Date, which resulted in a $2 million decrease to other long-term assets. (t) Represents the write-off of a deferred gain balance associated with the Predecessor. The deferred gain does not relate to the Successor and therefore the unamortized balance was written off in full in the Predecessor's condensed consolidated statements of operations. $7 million of the write-off related to the short-term portion of the deferred gain (included in accrued liabilities and other in the condensed consolidated balance sheets at emergence) and the remaining $2 million related to the long-term portion of the deferred gain (included in other long-term liabilities in the condensed consolidated balance sheets at emergence). (u) Reflects the adjustment to fair value of the Company's asset retirement obligations including using a credit-adjusted risk-free rate as of the Emergence Date. (v) Reflects the adjustment to fair value of the Company's deferred tax liability related to Whiting Canadian Holding Company ULC's outside basis difference in its ownership of a portion of Whiting's U.S. assets obtained through the acquisition of Kodiak Oil and Gas Corporation in 2014. (w) Reflects the cumulative impact of the fresh start adjustments discussed above. Reorganization Items, Net ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor ​ ​ One Month Ended September 30, 2020 ​ ​ Two Months Ended August 31, 2020 ​ Eight Months Ended August 31, 2020 Legal and professional advisory fees (1) ​ $ - ​ ​ $ 30,502 ​ $ 57,170 Net gain on liabilities subject to compromise ​ ​ - ​ ​ ​ (1,324,940) ​ ​ (1,324,940) Fresh start adjustments, net ​ ​ - ​ ​ ​ 1,025,742 ​ ​ 1,025,742 Write-off of unamortized debt issuance costs and premium (2) ​ ​ - ​ ​ ​ - ​ ​ 15,145 Other items, net ​ ​ - ​ ​ ​ 9,464 ​ ​ 9,464 Total reorganization items, net ​ $ - ​ ​ $ (259,232) ​ $ (217,419) (1) As of September 30, 2020, $10 million of these fees are accrued and unpaid and are presented in accounts payable and accrued liabilities and other in the condensed consolidated balance sheets. These amounts will be paid in the ordinary course of business. (2) As a result of the Chapter 11 Cases and the adoption of ASC 852, the Company wrote off all unamortized premium and issuance cost balances related to its senior notes on the Petition Date.

OIL AND GAS PROPERTIES

OIL AND GAS PROPERTIES	9 Months Ended
	Sep. 30, 2020
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 September 30, 2020 and December 31, 2019 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor ​ ​ September 30, ​ ​ December 31, ​ 2020 ​ ​ 2019 Proved oil and gas properties ​ $ 1,693,217 ​ ​ $ 12,549,395 Unproved leasehold costs ​ ​ 124,838 ​ ​ ​ 103,278 Wells and facilities in progress ​ ​ 11,417 ​ ​ ​ 159,334 Total oil and gas properties, successful efforts method ​ ​ 1,829,472 ​ ​ ​ 12,812,007 Accumulated depletion ​ ​ (18,735) ​ ​ ​ (5,656,929) Oil and gas properties, net ​ $ 1,810,737 ​ ​ $ 7,155,078 ​ The following tables present impairment expense for unproved properties for the periods presented, which is reported in exploration and impairment expense in the condensed consolidated statements of operations (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor ​ ​ One Month Ended September 30, 2020 ​ ​ Two Months Ended August 31, 2020 ​ Three Months Ended September 30, 2019 Impairment expense for unproved properties ​ $ - ​ ​ $ 83 ​ $ 2,233 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor ​ ​ One Month Ended September 30, 2020 ​ ​ Eight Months Ended August 31, 2020 ​ Nine Months Ended September 30, 2019 Impairment expense for unproved properties ​ $ - ​ ​ $ 12,566 ​ $ 8,063 ​ 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	9 Months Ended
	Sep. 30, 2020
ACQUISITIONS AND DIVESTITURES [Abstract]
ACQUISITIONS AND DIVESTITURES	5. ACQUISITIONS AND DIVESTITURES 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 nine months ended September 30, 2020. 2019 Acquisitions and Divestitures On July 29, 2019, the Predecessor completed the divestiture of its interests in 137 non-operated, producing oil and gas wells located in the McKenzie, Mountrail and Williams counties of North Dakota for aggregate sales proceeds of $27 million (before closing adjustments). On August 15, 2019, the Predecessor completed the divestiture of its interests in 58 non-operated, producing oil and gas wells located in Richland County, Montana and Mountrail and Williams counties of North Dakota for aggregate sales proceeds of $26 million (before closing adjustments). There were no significant acquisitions during the nine months ended September 30, 2019.

LONG-TERM DEBT

LONG-TERM DEBT	9 Months Ended
	Sep. 30, 2020
LONG-TERM DEBT [Abstract]
LONG-TERM DEBT	6. LONG-TERM DEBT Long-term debt consisted of the following at September 30, 2020 and December 31, 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor ​ ​ September 30, ​ ​ December 31, ​ 2020 ​ ​ 2019 Exit Credit Agreement ​ $ 400,328 ​ ​ $ - Predecessor Credit Agreement ​ ​ - ​ ​ ​ 375,000 1.25% Convertible Senior Notes due 2020 ​ ​ - ​ ​ ​ 262,075 5.75% Senior Notes due 2021 ​ ​ - ​ ​ ​ 773,609 6.25% Senior Notes due 2023 ​ ​ - ​ ​ ​ 408,296 6.625% Senior Notes due 2026 ​ ​ - ​ ​ ​ 1,000,000 Total principal ​ ​ 400,328 ​ ​ ​ 2,818,980 Unamortized debt discounts and premiums ​ ​ - ​ ​ ​ (2,575) Unamortized debt issuance costs on notes ​ ​ - ​ ​ ​ (16,520) Total long-term debt ​ $ 400,328 ​ ​ $ 2,799,885 ​ Exit Credit Agreement On the Emergence Date, Whiting Petroleum Corporation, as parent guarantor, and Whiting Oil and Gas, as borrower, entered into the Exit Credit Agreement, a reserves-based credit facility, with a syndicate of banks . As of September 30, 2020, the Exit Credit Agreement had a borrowing base and aggregate commitments of $750 million. As of September 30, 2020, the Company had $348 million of available borrowing capacity under the Exit Credit Agreement, which was net of $400 million of borrowings outstanding and $2 The borrowing base under the Exit 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 initial redetermination on April 1, 2021, regular redeterminations on April 1 and October 1 of each year thereafter, as well as special redeterminations described in the Exit Credit Agreement, in each case which may increase or decrease the amount of the borrowing base. Additionally, 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 September 30, 2020, $48 million was available for additional letters of credit under the Exit Credit Agreement. The Exit 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 Exit Credit Agreement provides for certain mandatory prepayments, including if the Company’s cash balances are in excess of approximately $75 million on any given week, such excess must be utilized to repay borrowings under the Exit Credit Agreement. Interest under the Exit 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 rate plus 1.0% per annum, or (ii) an adjusted LIBOR rate 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 Exit Credit Agreement, which are included as a component of interest expense. At September 30, 2020, the weighted average interest rate on the outstanding principal balance under the Exit Credit Agreement was 4.3%. The Exit 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 Exit 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) at least 20% of available borrowing capacity, (ii) 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 Exit Credit Agreement. These restrictions apply to all of the Company’s restricted subsidiaries (as defined in the Exit Credit Agreement). The Exit 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. The Exit Credit Agreement requires the Company, as of the last day of any quarter beginning with the quarter ending December 31, 2020, 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. The obligations of Whiting Oil and Gas under the Exit Credit Agreement are secured by a first lien on substantially all of the Company’s, Whiting Oil and Gas’ and Whiting Resource Corporation’s properties. The Company has also guaranteed the obligations of Whiting Oil and Gas under the Exit Credit Agreement and has pledged the stock of its subsidiaries as security for its guarantee. Predecessor Credit Agreement Whiting Oil and Gas, the Company’s wholly owned subsidiary, had the Predecessor Credit Agreement that had a borrowing base of $2.05 billion and aggregate commitments of $1.75 billion prior to the Predecessor filing the Chapter 11 Cases. On the Emergence Date, the Predecessor Credit Agreement was terminated and the outstanding borrowings of $912 million and accrued interest of $3 million were paid in full. These payments were funded with cash on hand and proceeds from the Exit Credit Agreement. Predecessor Senior Notes and Convertible Senior Notes 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”). These notes were unsecured obligations of Whiting Petroleum Corporation in the Chapter 11 Cases and were therefore included in liabilities subject to compromise on the condensed consolidated balance sheets of the Predecessor as of August 31, 2020. 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 Current Predecessor YTD 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	9 Months Ended
	Sep. 30, 2020
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. The current portions as of September 30, 2020 (Successor), September 1, 2020 (Successor) and December 31, 2019 (Predecessor) were $8 million, $5 million and $4 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 periods presented (in thousands): ​ ​ ​ ​ Asset retirement obligation at January 1, 2020 (Predecessor) ​ $ 134,893 Additional liability incurred ​ ​ 76 Revisions to estimated cash flows ​ ​ 56,702 Accretion expense ​ ​ 8,199 Obligations on sold properties ​ ​ (693) Liabilities settled (1) ​ ​ (42,854) Ending balance as of August 31, 2020 (Predecessor) ​ ​ 156,323 ​ ​ ​ ​ Fresh start adjustment (2) ​ ​ (29,582) ​ ​ ​ ​ ​ ​ ​ ​ Asset retirement obligation at September 1, 2020 (Successor) ​ ​ 126,741 Additional liability incurred ​ ​ 20 Accretion expense ​ ​ 929 Asset retirement obligation at September 30, 2020 (Successor) ​ $ 127,690 (1) A portion of the Predecessor’s asset retirement obligations related to a contractual obligation to remove certain offshore facilities in California. The Company included the related contract in its schedule of rejected contracts as part of the Plan, and the related amounts of the obligations were included in liabilities subject to compromise on the condensed consolidated balance sheets of the Predecessor as of August 31, 2020. A final ruling from the Bankruptcy Court on the rejection of this contract has not yet been issued. Refer to the “Fresh Start Accounting” and “Commitments and Contingencies” footnotes for additional information. (2) Refer to the “Fresh Start Accounting” footnote for more information on fresh start adjustments .

DERIVATIVE FINANCIAL INSTRUMENT

DERIVATIVE FINANCIAL INSTRUMENTS	9 Months Ended
	Sep. 30, 2020
DERIVATIVE FINANCIAL INSTRUMENTS [Abstract]
DERIVATIVE FINANCIAL INSTRUMENTS	8 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 — management of returns on drilling programs and acquisitions. The Company does not enter into derivative contracts for speculative or trading purposes. Crude Oil and Natural Gas Swaps and Collars. The table below details the Company’s swap and collar derivatives entered into to hedge forecasted crude oil and natural gas production revenues as of September 30, 2020 (Successor). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Settlement Period ​ Index ​ Derivative Instrument ​ Total Volumes (1) ​ Units ​ Weighted Average Swap Price ​ Weighted Average Floor ​ Weighted Average Ceiling Crude Oil ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 ​ NYMEX WTI ​ Fixed Price Swaps ​ 1,058,000 ​ Bbl ​ $41.01 ​ - ​ - 2020 ​ NYMEX WTI ​ Two-way Collars ​ 1,794,000 ​ Bbl ​ - ​ $37.63 ​ $45.36 2021 ​ NYMEX WTI ​ Fixed Price Swaps ​ 2,737,500 ​ Bbl ​ $40.05 ​ - ​ - 2021 ​ NYMEX WTI ​ Two-way Collars ​ 6,043,500 ​ Bbl ​ - ​ $38.11 ​ $46.61 2022 (2) ​ NYMEX WTI ​ Two-way Collars ​ 3,518,000 ​ Bbl ​ - ​ $38.36 ​ $49.16 ​ ​ ​ ​ Total ​ 15,151,000 ​ Bbl ​ ​ ​ ​ ​ ​ Natural Gas ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 ​ NYMEX Henry Hub ​ Fixed Price Swaps ​ 2,440,000 ​ MMBtu ​ $2.50 ​ - ​ - 2020 ​ NYMEX Henry Hub ​ Two-way Collars ​ 1,830,000 ​ MMBtu ​ - ​ $2.17 ​ $2.36 2021 ​ NYMEX Henry Hub ​ Fixed Price Swaps ​ 11,840,000 ​ MMBtu ​ $2.66 ​ - ​ - 2021 ​ NYMEX Henry Hub ​ Two-way Collars ​ 10,950,000 ​ MMBtu ​ - ​ $2.60 ​ $2.79 2022 ​ NYMEX Henry Hub ​ Fixed Price Swaps ​ 1,365,000 ​ MMBtu ​ $2.60 ​ - ​ - 2022 ​ NYMEX Henry Hub ​ Two-way Collars ​ 8,190,000 ​ MMBtu ​ - ​ $2.30 ​ $2.80 ​ ​ ​ ​ Total ​ 36,615,000 ​ MMBtu ​ ​ ​ ​ ​ ​ (1) Subsequent to September 30, 2020, the Company entered into additional swap contracts for 690,000 MMBtu of natural gas volumes for the last three months of 2021 and additional collar contracts for 2,530,000 MMBtu of natural gas volumes for the last three months of 2022. (2) The Company’s crude oil contract terms cover only the first nine months of 2022. Effect of Chapter 11 Cases Derivative Instrument Reporting ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Gain) Loss Recognized in Income ​ ​ ​ ​ Successor ​ ​ Predecessor Not Designated as ASC 815 Hedges Statements of Operations Classification One Month Ended September 30, 2020 ​ ​ Two Months Ended August 31, 2020 ​ Three Months Ended September 30, 2019 Commodity contracts ​ Derivative (gain) loss, net ​ $ (30,594) ​ ​ $ 43,125 ​ $ (30,597) Total ​ ​ ​ $ (30,594) ​ ​ $ 43,125 ​ $ (30,597) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Gain) Loss Recognized in Income ​ ​ ​ ​ Successor ​ ​ Predecessor Not Designated as ASC 815 Hedges Statements of Operations Classification One Month Ended September 30, 2020 ​ ​ Eight Months Ended August 31, 2020 ​ Nine Months Ended September 30, 2019 Commodity contracts ​ Derivative (gain) loss, net ​ $ (30,594) ​ ​ $ (181,614) ​ $ 7,431 Total ​ ​ ​ $ (30,594) ​ ​ $ (181,614) ​ $ 7,431 ​ Offsetting of Derivative Assets and Liabilities. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ ​ ​ September 30, 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 ​ $ 23,607 ​ $ (21,631) ​ $ 1,976 Commodity contracts - non-current ​ Other long-term assets ​ ​ 22,817 ​ ​ (22,368) ​ ​ 449 Total derivative assets ​ ​ ​ $ 46,424 ​ $ (43,999) ​ $ 2,425 Derivative liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity contracts - current ​ Accrued liabilities and other ​ $ 29,298 ​ $ (21,631) ​ $ 7,667 Commodity contracts - non-current ​ Other long-term liabilities ​ ​ 26,027 ​ ​ (22,368) ​ ​ 3,659 Total derivative liabilities ​ ​ ​ $ 55,325 ​ $ (43,999) ​ $ 11,326 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Predecessor ​ ​ ​ ​ December 31, 2019 (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 ​ $ 75,654 ​ $ (74,768) ​ $ 886 Commodity contracts - non-current ​ Other long-term assets ​ ​ 5,648 ​ ​ (5,648) ​ ​ - Total derivative assets ​ ​ ​ $ 81,302 ​ $ (80,416) ​ $ 886 Derivative liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity contracts - current ​ Accrued liabilities and other ​ $ 85,053 ​ $ (74,768) ​ $ 10,285 Commodity contracts - non-current ​ Other long-term liabilities ​ ​ 6,534 ​ ​ (5,648) ​ ​ 886 Total derivative liabilities ​ ​ ​ $ 91,587 ​ $ (80,416) ​ $ 11,171 (1) All of the counterparties to the Company’s financial derivative contracts subject to master netting arrangements are lenders under both the Exit Credit Agreement and the Predecessor 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	9 Months Ended
	Sep. 30, 2020
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 Exit Credit Agreement and Predecessor Credit Agreement have a recorded value that approximates their fair values since their variable interest rates are tied to current market rates and the applicable margins represent market rates. The Predecessor’s Senior Notes were recorded at cost and the Predecessor’s Convertible Senior Notes were recorded at fair value at the date of issuance. The following table summarizes the fair values and carrying values of these instruments as of December 31, 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Predecessor ​ ​ December 31, 2019 ​ ​ Fair ​ Carrying ​ Value (1) Value (2) 1.25% Convertible Senior Notes due 2020 ​ $ 260,214 ​ $ 259,026 5.75% Senior Notes due 2021 ​ ​ 732,995 ​ ​ 772,080 6.25% Senior Notes due 2023 ​ ​ 343,989 ​ ​ 405,392 6.625% Senior Notes due 2026 ​ ​ 681,250 ​ ​ 988,387 Total ​ $ 2,018,448 ​ $ 2,424,885 (1) Fair values are based on quoted market prices for these debt securities, and such fair values are therefore designated as Level 1 within the valuation hierarchy. (2) Carrying values are presented net of unamortized debt issuance costs and debt discounts or premiums. 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 September 30, 2020 (Successor) and December 31, 2019 (Predecessor), and indicate the fair value hierarchy of the valuation techniques utilized by the Company to determine such fair values (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Fair Value ​ Level 1 Level 2 Level 3 September 30, 2020 Financial Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity derivatives – current ​ $ - ​ $ 1,976 ​ $ - ​ $ 1,976 Commodity derivatives – non-current ​ ​ - ​ ​ 449 ​ ​ - ​ ​ 449 Total financial assets ​ $ - ​ $ 2,425 ​ $ - ​ $ 2,425 Financial Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity derivatives – current ​ $ - ​ $ 7,667 ​ $ - ​ $ 7,667 Commodity derivatives – non-current ​ ​ - ​ ​ 3,659 ​ ​ - ​ ​ 3,659 Total financial liabilities ​ $ - ​ $ 11,326 ​ $ - ​ $ 11,326 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Predecessor ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Fair Value ​ Level 1 Level 2 Level 3 December 31, 2019 Financial Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity derivatives – current ​ $ - ​ $ 886 ​ $ - ​ $ 886 Total financial assets ​ $ - ​ $ 886 ​ $ - ​ $ 886 Financial Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity derivatives – current ​ $ - ​ $ 10,285 ​ $ - ​ $ 10,285 Commodity derivatives – non-current ​ ​ - ​ ​ 886 ​ ​ - ​ ​ 886 Total financial liabilities ​ $ - ​ $ 11,171 ​ $ - ​ $ 11,171 ​ 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 assumptions, such as quoted forward prices for commodities, time value and volatility factors. These assumptions are observable in the marketplace throughout the full term of the contract, can be derived from observable data or are supported by observable levels at which transactions are executed in the marketplace, and are therefore designated as Level 2 within the valuation hierarchy. The discount rates used in the fair values of these instruments include a measure of either the Company’s or the counterparty’s nonperformance risk, as appropriate. The Company utilizes its counterparties’ valuations to assess the reasonableness of its own valuations. Non-recurring Fair Value Measurements — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Predecessor ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loss (Before ​ ​ Net Carrying ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Tax) During the ​ ​ Value as of ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current ​ ​ March 31, ​ Fair Value Measurements Using ​ Predecessor YTD ​ 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 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loss (Before ​ ​ Net Carrying ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Tax) During the ​ ​ Value as of ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current ​ ​ June 30, ​ Fair Value Measurements Using ​ Predecessor YTD ​ 2020 Level 1 Level 2 Level 3 Period Proved property (2) ​ $ 85,418 ​ $ - ​ $ - ​ $ 85,418 ​ $ 409,079 (2) During the second quarter of 2020, other proved oil and gas properties in the Company’s Williston Basin resource play with a previous carrying amount of $494 million were written down to their fair value as of June 30, 2020 of $85 million, resulting in a non-cash impairment charge of $409 million, 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 assessed during the second quarter of 2020. Predecessor Proved Property Impairments Level 3 inputs within the fair value hierarchy). The impairment tests indicated that a proved property impairment had occurred, and the Company therefore recorded non-cash impairment charges to reduce the carrying value of the impaired properties to their fair value at March 31, 2020 and June 30, 2020. Additional impairments may be recorded in future periods if commodity prices deteriorate or further reductions to the development plans of the properties are indicated by market conditions. Chapter 11 Emergence and Fresh Start Accounting.

REVENUE RECOGNITION

REVENUE RECOGNITION	9 Months Ended
	Sep. 30, 2020
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 ​ One Month Ended September 30, 2020 ​ ​ Two Months Ended August 31, 2020 ​ Three Months Ended September 30, 2019 Oil sales ​ $ 60,392 ​ ​ $ 116,971 ​ $ 369,940 NGL and natural gas sales ​ ​ 692 ​ ​ ​ 5,587 ​ ​ 5,951 Oil, NGL and natural gas sales ​ $ 61,084 ​ ​ $ 122,558 ​ $ 375,891 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor OPERATING REVENUES ​ One Month Ended September 30, 2020 ​ ​ Eight Months Ended August 31, 2020 ​ Nine Months Ended September 30, 2019 Oil sales ​ $ 60,392 ​ ​ $ 440,820 ​ $ 1,133,264 NGL and natural gas sales ​ ​ 692 ​ ​ ​ 18,184 ​ ​ 58,380 Oil, NGL and natural gas sales ​ $ 61,084 ​ ​ $ 459,004 ​ $ 1,191,644 ​ Whiting receives payment for product sales from one (Predecessor), such receivable balances were $70 million and $161 million, respectively. Variances between the Company’s estimated revenue and actual payments are recorded in the month the payment is received, however, differences have been and are insignificant. Accordingly, the variable consideration is not constrained. 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	9 Months Ended
	Sep. 30, 2020
SHAREHOLDERS' EQUITY
SHAREHOLDERS' EQUITY	11. SHAREHOLDERS’ EQUITY Common Stock — On the Emergence Date, upon emergence from the Chapter 11 Cases, all existing shares of the Predecessor’s common stock were cancelled and the Successor issued 38,051,210 shares of New Common Stock. Refer to the “Chapter 11 Emergence” and “Fresh Start Accounting” footnotes 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.

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	9 Months Ended
	Sep. 30, 2020
STOCK-BASED COMPENSATION [Abstract]
STOCK-BASED COMPENSATION	12. STOCK-BASED COMPENSATION Equity Incentive Plan issue 4,035,885 shares of the Successor’s common stock. Any shares forfeited under the 2020 Equity Plan will be available for future issuance under the 2020 Equity Plan. However, shares netted for tax withholding under the 2020 Equity Plan will be cancelled and will not be available for future issuance. Under the 2020 Equity Plan, during any calendar year no non-employee director participant may be granted awards having a grant date fair value in excess of $500,000. As of September 30, 2020, 3,758,814 shares of common stock remained available for grant under the 2020 Equity 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 three-year service period. The Company has granted service-based RSAs to directors, which generally vest over a one-year service period. In addition, the Company has granted performance share awards (“PSAs”) and performance share units (“PSUs”) to executive officers that are subject to market-based vesting criteria, which generally vest over a three-year service period. The Company accounts for forfeitures of awards granted under these plans as they occur in determining compensation expense. The Company recognizes compensation expense for all awards subject to market-based vesting conditions regardless of whether it becomes probable that these conditions will be achieved or not, and compensation expense for share-settled awards is not reversed if vesting does not actually occur. Successor Awards On September 29, 2020, 87,171 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. On September 29, 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 grant date fair value of these awards was estimated using a Monte Carlo valuation model (the “Monte Carlo Model”). ​ ​ ​ ​ Number of simulations 100,000 Expected volatility 40% Risk-free interest rate 0.66% Dividend yield — ​ The Company will recognize compensation expense based on the fair value as determined by 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. Predecessor Awards During the eight months ended August 31, 2020 and the nine months ended September 30, 2019, 53,198 and 464,140 shares, respectively, 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 and $24.76 per share for the eight months ended August 31, 2020 and the nine months ended September 30, 2019, respectively. 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 eight months ended August 31, 2020 and the nine months ended September 30, 2019, 1,616,504 and 774,665 shares, respectively, 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 eight months ended August 31, 2020 and the nine months ended September 30, 2019, 1,665,153 and 347,493, respectively, 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, and the number of shares that would vest at the end of that three-year performance period was determined based on the rank of Whiting’s cumulative stockholder return compared to the stockholder return of a peer group of companies on each anniversary of the grant date over the three-year performance period. The number of awards earned could range from zero up to two times the number of shares initially granted. However, awards earned up to the target shares granted (or 100%) would have been settled in shares, while awards earned in excess of the target shares granted would have been settled in cash. 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. 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. For the PSAs and PSUs subject to market conditions, the grant date fair value was estimated using the Monte Carlo Model. Expected volatility was calculated based on the historical volatility and implied volatility of Whiting’s common stock, and the risk-free interest rate was based on U.S. Treasury yield curve rates with maturities consistent with the three-year vesting period. The key assumptions used in valuing these market-based awards were as follows: ​ ​ ​ ​ ​ ​ ​ 2020 2019 Number of simulations 2,500,000 2,500,000 Expected volatility 76.52% ​ 72.95% Risk-free interest rate 1.51% ​ 2.60% Dividend yield — — ​ 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 and $25.97 per share in 2020 and 2019, respectively. 2020 Compensation Adjustments. Total stock compensation expense recognized for restricted stock was expense of $1 million for Current Predecessor Quarter, a benefit of $5 million for the Prior Predecessor Quarter, expense of $3 million for the Current Predecessor YTD Period and expense of $6 million for the Prior Predecessor YTD Period. As a result of the implementation of the Plan, the Company accelerated $4 million of expense related to unvested awards, which was recorded to reorganization items, net in the condensed consolidated statements of operations during the Current Predecessor Quarter and Current Predecessor YTD Period. Refer to the “Fresh Start Accounting” footnote for more information.

INCOME TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2020
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 month ended September 30, 2020 and eight months ended August 31, 2020 differ from the amount that would be provided by applying the statutory U.S. federal income tax rate of 21% to pre-tax income primarily as a result of a full valuation allowance on the Company’s U.S. deferred tax assets (“DTAs”) and the revision of the Company’s Canadian deferred tax liability (“DTL”) related to its outside basis difference in Whiting Canadian Holding Company ULC. The Company also recognized a $1 million U.S. income tax benefit during the eight months ended August 31, 2020 related to an alternative minimum tax refund received. As a result of the full valuation on the Company’s DTAs as of September 30, 2020 (Successor) and August 31, 2020 (Predecessor), no additional U.S. tax benefit or expense was recognized during the periods presented. During the fourth quarter of 2019, the Company determined it no longer had the ability to indefinitely prevent the reversal of the outside basis difference related to Whiting Canadian Holding Company ULC, Whiting’s wholly owned subsidiary, which owns a portion of Whiting’s U.S. assets obtained through the acquisition of Kodiak Oil and Gas Corporation in 2014. Accordingly, the Company revised its assessment related to noncurrent Canadian deferred taxes pursuant to ASC 740-30-25-17 and recognized a $74 million deferred tax liability as well as the same amount of deferred income tax expense as of and for the year ended December 31, 2019 (Predecessor). During the Successor Period, the Company partially executed a legal entity restructuring plan to reduce administrative expenses and burden with a simplified corporate structure. Several steps of the restructuring plan were executed during the Successor Period, with the remaining steps expected to be completed in the fourth quarter of 2020. As part of the completed steps to date, Whiting US Holding Company merged into Whiting Oil and Gas Corporation. Additionally, as a result of fresh start accounting and the legal entity restructuring, the Company reduced its deferred tax liability for its outside basis difference related to Whiting Canadian Holding Company ULC and recorded tax benefits of $15 million and $55 million during the Successor Period and Current Predecessor Quarter, respectively. The Company’s total Canadian tax liability is $6 million as of September 30, 2020 (Successor), which is expected to be payable in the fourth quarter of 2020. ​ The Company’s overall effective tax rates for the month ended September 30, 2020 (Successor) and the eight months ended August 31, 2020 (Predecessor) of (43.4)% and 1.4%, respectively, were lower than the U.S. statutory income tax rate as a result of the full valuation on the Company’s DTAs and the reduction of the overall Canadian DTL as discussed above. The provision for income taxes for the nine months ended September 30, 2019 (Predecessor) differs from the amount that would be provided by applying the statutory U.S. federal income tax rate of 21% to pre-tax income primarily due to the full valuation allowance on the Company’s U.S. DTAs. 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 September 30, 2020 (Successor), the Company had a full valuation allowance on its U.S. 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. The ownership changes and resulting annual limitation may 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 $3.5 billion as of the Emergence Date, which are subject to limitation under IRC Section 382. The Company currently estimates that approximately $2.6 billion of these federal NOLs will expire before they are able to be used. 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	9 Months Ended
	Sep. 30, 2020
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 ​ One Month Ended September 30, 2020 ​ ​ Two Months Ended August 31, 2020 ​ Three Months Ended September 30, 2019 Basic Earnings (Loss) Per Share ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) ​ $ 40,270 ​ ​ $ 237,425 ​ $ (19,067) Weighted average shares outstanding ​ ​ 38,051 ​ ​ ​ 91,464 ​ ​ 91,299 Earnings (loss) per common share ​ $ 1.06 ​ ​ $ 2.60 ​ $ (0.21) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Diluted Earnings (Loss) Per Share ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) ​ $ 40,270 ​ ​ $ 237,425 ​ $ (19,067) Weighted average shares outstanding ​ ​ 38,051 ​ ​ ​ 91,464 ​ ​ 91,299 Earnings (loss) per common share ​ $ 1.06 ​ ​ $ 2.60 ​ $ (0.21) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor ​ One Month Ended September 30, 2020 ​ ​ Eight Months Ended August 31, 2020 ​ Nine Months Ended September 30, 2019 Basic Earnings (Loss) Per Share ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) ​ $ 40,270 ​ ​ $ (3,965,461) ​ $ (93,679) Weighted average shares outstanding ​ ​ 38,051 ​ ​ ​ 91,423 ​ ​ 91,274 Earnings (loss) per common share ​ $ 1.06 ​ ​ $ (43.37) ​ $ (1.03) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Diluted Earnings (Loss) Per Share ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) ​ $ 40,270 ​ ​ $ (3,965,461) ​ $ (93,679) Weighted average shares outstanding ​ ​ 38,051 ​ ​ ​ 91,423 ​ ​ 91,274 Earnings (loss) per common share ​ $ 1.06 ​ ​ $ (43.37) ​ $ (1.03) ​ Successor During the Successor Period, the diluted earnings per share calculation excludes the effect of 4,837,387 common shares for Series A Warrants and 2,418,840 common shares for Series B warrants that were out-of-the-money as of September 30, 2020, as well as 3,070,201 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 September 30, 2020. Further, the calculation excludes the effect of 87,171 shares of service-based awards that were anti-dilutive and 189,900 shares of market-based awards that did not meet the market-based vesting criteria as of September 30, 2020. Predecessor During the Current Predecessor Quarter, although the Company had net income, the treasury stock method resulted in a larger number of shares assumed to be reacquired by the Company than weighted average unvested awards outstanding. Thus, the diluted earnings per share calculation excludes the anti-dilutive effect of 239,186 shares of service-based awards. During the Current Predecessor YTD Period, Prior Predecessor Quarter and Prior Predecessor YTD Period, the Company had a net loss and therefore the diluted earnings per share calculations exclude the anti-dilutive effect of (i) 314,896 shares of service-based awards for the Current Predecessor YTD Period, (ii) 35,433 shares of service-based awards and 7,159 shares of market-based awards for the Prior Predecessor Quarter and (iii) 344,419 shares of service-based awards and 64,407 market-based awards for Prior Predecessor YTD Period. In addition, the diluted earnings per share calculations exclude the effect of (i) 18,310 and 29,465 common shares for the Current Predecessor Quarter and Current Predecessor YTD Period, respectively, for stock options that were out-of-the-money as of August 31, 2020 and (ii) 43,367 and 46,095 common shares for the Prior Predecessor Quarter and Prior Predecessor YTD Period, respectively, for stock options that were out-of-the-money as of September 30, 2019. Refer to the “Stock-Based Compensation” footnote for more information on the Company’s service-based awards, market-based awards and stock options. 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 conversion period ending April 1, 2020, there was no impact to diluted earnings per share or the related disclosures for the periods presented.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2020
COMMITMENTS AND CONTINGENCIES [Abstract]
COMMITMENTS AND CONTINGENCIES	15. COMMITMENTS AND CONTINGENCIES Chapter 11 Cases — However, it is reasonably possible that as a result of the legal proceedings associated with the two counterparties detailed below, the Bankruptcy Court may rule that the applicable contracts cannot be rejected or allow the claim amounts as administrative claims. Either of these outcomes could require the Company to make cash payments to settle those claims instead of issuing shares of the Successor’s common stock, and such cash payments would result in losses in future periods. BNN Western, LLC. 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 (collectively, “Whiting”) 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 are 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 alleges 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. The Bankruptcy Court has not issued a ruling on the damages for rejection of the Point Arguello Agreements or the FMOG Entities’ application for administrative claims. Although WOG intends to vigorously defend this legal proceeding, if the FMOG Entities were to prevail on certain of their respective claims on the merits or the U.S. government were to bring claims against WOG, Whiting could be liable for administrative claims that must be paid in cash pursuant to the Plan. 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. Certain amounts were recognized in accrued liabilities and other in the consolidated balance sheets as of December 31, 2019 and general and administrative expenses in the consolidated statements of operations for the year ended December 31, 2019 as it was determined that a loss as a result of this litigation was probable. The Company recorded $3 million of additional litigation settlement expense in general and administrative expenses in the condensed consolidated statements of operations for the Current Predecessor YTD Period upon settling this litigation. 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 September 30, 2020 (Successor). Delivery Commitments —

COMPANY RESTRUCTURINGS

COMPANY RESTRUCTURINGS	9 Months Ended
	Sep. 30, 2020
COMPANY RESTRUCTURINGS [Abstract]
COMPANY RESTRUCTURINGS	16. COMPANY RESTRUCTURINGS During September 2020 and August 2019, the Company executed workforce reductions as part of an organizational redesign and cost reduction strategy to better align its business with the current operating environment and drive long-term value. The Company incurred one-time net charges related to these restructurings of $7 million and $8 million, respectively, in net restructuring costs associated with one-time employee termination benefits. These charges were recorded to general and administrative expenses during the relevant periods in the condensed consolidated statement of operations.

BASIS OF PRESENTATION (Policies

BASIS OF PRESENTATION (Policies)	9 Months Ended
	Sep. 30, 2020
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 During the Current Predecessor YTD Period, the Company applied ASC 852 in preparing the condensed consolidated financial statements, which requires distinguishing transactions associated with the reorganization separate from activities related to the ongoing operations of the business. Accordingly, pre-petition liabilities that could have been impacted by the chapter 11 proceedings were classified as liabilities subject to compromise. Additionally, certain expenses, realized gains and losses and provisions for losses that were realized or incurred during the Chapter 11 Cases, including adjustments to the carrying value of certain indebtedness were recorded as reorganization items, net in the condensed consolidated statements of operations for the relevant Predecessor periods.
Ability to Continue as a Going Concern	Ability to Continue as a Going Concern
Condensed Consolidated Financial Statements	Condensed Consolidated Financial Statements not control, over the investee are accounted for using the equity method. Under the equity method, investments are stated at cost plus the Company’s equity in undistributed earnings and losses. All intercompany balances and transactions have been eliminated upon consolidation. These financial statements have been prepared in accordance with GAAP and the SEC rules and regulations for interim financial reporting. In the opinion of management, the accompanying financial statements include all adjustments (consisting of normal recurring accruals and adjustments) necessary to present fairly, in all material respects, the Company’s interim results. However, operating results for the periods presented are not necessarily indicative of the results that may be expected for the full year. The condensed consolidated financial statements and related notes included in this Quarterly Report on Form 10-Q should be read in conjunction with Whiting’s consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the period ended December 31, 2019. Except as disclosed herein, there have been no material changes to the information disclosed in the notes to consolidated financial statements included in the Company’s 2019 Annual Report on Form 10-K.
Reclassifications	Reclassifications —
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash — Restricted cash as of September 30, 2020 (Successor) includes $13 million 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 “Professional Fee Escrow Account”). 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 ​ ​ Predecessor ​ ​ September 30, ​ ​ December 31, ​ ​ 2020 ​ ​ 2019 Cash and cash equivalents ​ $ 13,702 ​ ​ $ 8,652 Restricted cash ​ ​ 13,233 ​ ​ ​ - Total cash, cash equivalents and restricted cash ​ $ 26,935 ​ ​ $ 8,652 ​
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 December 31, 2019 (Predecessor), the Company had an allowance for credit losses of $9 million.

BASIS OF PRESENTATION (Tables)

BASIS OF PRESENTATION (Tables)	9 Months Ended
	Sep. 30, 2020
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 ​ ​ Predecessor ​ ​ September 30, ​ ​ December 31, ​ ​ 2020 ​ ​ 2019 Cash and cash equivalents ​ $ 13,702 ​ ​ $ 8,652 Restricted cash ​ ​ 13,233 ​ ​ ​ - Total cash, cash equivalents and restricted cash ​ $ 26,935 ​ ​ $ 8,652

FRESH START ACCOUNTING (Tables)

FRESH START ACCOUNTING (Tables)	9 Months Ended
	Sep. 30, 2020
FRESH START ACCOUNTING [Abstract]
Schedule of the reconciliation of the enterprise value to the implied value of the successor company's common stock	The following table reconciles the Company’s enterprise value to the implied value of the Successor’s common stock as of September 1, 2020 (in thousands, except per share data): ​ ​ ​ ​ Enterprise value ​ $ 1,591,887 Plus: Cash and cash equivalents ​ ​ 22,657 Less: Fair value of debt ​ ​ (425,328) Implied value of Successor common stock ​ $ 1,189,216
Schedule of the reconciliation of the enterprise value to the reorganization value	The following table reconciles the Company’s enterprise value to its reorganization value as of September 1, 2020 (in thousands): ​ ​ ​ ​ Enterprise value ​ $ 1,591,887 Plus: ​ ​ ​ Cash and cash equivalents ​ ​ 22,657 Accounts payable trade ​ ​ 56,432 Revenues and royalties payable ​ ​ 145,506 Other current liabilities ​ ​ 143,790 Asset retirement obligations ​ ​ 121,343 Operating lease obligations ​ ​ 17,839 Deferred income taxes ​ ​ 14,501 Other long-term liabilities ​ ​ 28,773 Reorganization value ​ $ 2,142,728
Schedule of reorganization balance sheet and fresh-start accounting adjustments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 1, 2020 ​ ​ ​ ​ Reorganization ​ ​ Fresh Start ​ ​ ​ ​ ​ Predecessor ​ Adjustments ​ ​ Adjustments ​ ​ Successor ASSETS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 547,354 ​ $ (524,697) (a) ​ $ - ​ ​ $ 22,657 Restricted cash ​ ​ 28,955 ​ ​ (2,205) (b) ​ ​ - ​ ​ ​ 26,750 Accounts receivable trade, net ​ ​ 136,881 ​ ​ - ​ ​ ​ 81 (o) ​ ​ 136,962 Prepaid expenses and other ​ ​ 18,722 ​ ​ 231 (c) ​ ​ 2,260 (p) ​ ​ 21,213 Total current assets ​ ​ 731,912 ​ ​ (526,671) ​ ​ ​ 2,341 ​ ​ ​ 207,582 Property and equipment: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Oil and gas properties, successful efforts method ​ ​ 4,885,013 ​ ​ - ​ ​ ​ (3,058,899) (q) ​ ​ 1,826,114 Other property and equipment ​ ​ 159,866 ​ ​ (909) (d) ​ ​ (87,642) (o)(r) ​ ​ 71,315 Total property and equipment ​ ​ 5,044,879 ​ ​ (909) ​ ​ ​ (3,146,541) ​ ​ ​ 1,897,429 Less accumulated depreciation, depletion and amortization ​ ​ (2,085,266) ​ ​ - ​ ​ ​ 2,085,266 (o)(q)(r) ​ ​ - Total property and equipment, net ​ ​ 2,959,613 ​ ​ (909) ​ ​ ​ (1,061,275) ​ ​ ​ 1,897,429 Debt issuance costs ​ ​ 1,834 ​ ​ 10,950 (e) ​ ​ - ​ ​ ​ 12,784 Other long-term assets ​ ​ 37,010 ​ ​ (8,760) (d) ​ ​ (3,317) (o)(s) ​ ​ 24,933 TOTAL ASSETS ​ $ 3,730,369 ​ $ (525,390) ​ ​ $ (1,062,251) ​ ​ $ 2,142,728 LIABILITIES AND EQUITY (DEFICIT) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current portion of long-term debt ​ $ 912,259 ​ $ (912,259) (f) ​ $ - ​ ​ $ - Accounts payable trade ​ ​ 47,168 ​ ​ 9,264 (g)(h) ​ ​ - ​ ​ ​ 56,432 Revenues and royalties payable ​ ​ 145,506 ​ ​ - ​ ​ ​ - ​ ​ ​ 145,506 Accrued capital expenditures ​ ​ 14,037 ​ ​ 1,305 (g) ​ ​ - ​ ​ ​ 15,342 Accrued liabilities and other ​ ​ 46,327 ​ ​ 21,942 (g)(i) ​ ​ (6,529) (o)(t) ​ ​ 61,740 Accrued lease operating expenses ​ ​ 25,344 ​ ​ 1,394 (g) ​ ​ - ​ ​ ​ 26,738 Accrued interest ​ ​ 3,459 ​ ​ (3,332) (g)(j) ​ ​ (127) (o) ​ ​ - Taxes payable ​ ​ 13,972 ​ ​ - ​ ​ ​ - ​ ​ ​ 13,972 Derivative liabilities ​ ​ 25,998 ​ ​ - ​ ​ ​ - ​ ​ ​ 25,998 Total current liabilities ​ ​ 1,234,070 ​ ​ (881,686) ​ ​ ​ (6,656) ​ ​ ​ 345,728 Long-term debt ​ ​ - ​ ​ 425,328 (k) ​ ​ - ​ ​ ​ 425,328 Asset retirement obligations ​ ​ 150,925 ​ ​ - ​ ​ ​ (29,582) (u) ​ ​ 121,343 Operating lease obligations ​ ​ - ​ ​ 17,652 (d)(g) ​ ​ 187 (o) ​ ​ 17,839 Deferred income taxes ​ ​ 69,847 ​ ​ - ​ ​ ​ (55,346) (v) ​ ​ 14,501 Other long-term liabilities ​ ​ 18,160 ​ ​ 11,071 (g) ​ ​ (458) (o)(t) ​ ​ 28,773 Total liabilities not subject to compromise ​ ​ 1,473,002 ​ ​ (427,635) ​ ​ ​ (91,855) ​ ​ ​ 953,512 Liabilities subject to compromise ​ ​ 2,526,925 ​ ​ (2,526,925) (g) ​ ​ - ​ ​ ​ - Total liabilities ​ ​ 3,999,927 ​ ​ (2,954,560) ​ ​ ​ (91,855) ​ ​ ​ 953,512 Commitments and contingencies ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Equity (deficit): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Predecessor common stock ​ ​ 92 ​ ​ (92) (l) ​ ​ - ​ ​ ​ - Successor common stock ​ ​ - ​ ​ 38 (m) ​ ​ - ​ ​ ​ 38 Predecessor additional paid-in capital ​ ​ 6,410,410 ​ ​ (6,410,410) (l) ​ ​ - ​ ​ ​ - Successor additional paid-in capital ​ ​ - ​ ​ 1,189,178 (m) ​ ​ - ​ ​ ​ 1,189,178 Accumulated earnings (deficit) ​ ​ (6,680,060) ​ ​ 7,650,456 (n) ​ ​ (970,396) (w) ​ ​ - Total equity (deficit) ​ ​ (269,558) ​ ​ 2,429,170 ​ ​ ​ (970,396) ​ ​ ​ 1,189,216 TOTAL LIABILITIES AND EQUITY (DEFICIT) ​ $ 3,730,369 ​ $ (525,390) ​ ​ $ (1,062,251) ​ ​ $ 2,142,728
Schedule of sources and uses of cash on the effective date	(a) The table below reflects the sources and uses of cash on the Emergence Date pursuant to the terms of the Plan (in thousands):
Schedule of reclassification of cash balances to and from restricted cash	(b) The table below reflects the net reclassification of cash balances to and from restricted cash on the Emergence Date pursuant to terms of the Plan (in thousands):
Schedule of disposition of liabilities subject to compromise	​ ​ ​ ​ ​ Liabilities subject to compromise pre-emergence ​ $ 2,526,925 Amounts reinstated on the Emergence Date: ​ ​ ​ Accounts payable trade ​ ​ (10,866) Accrued capital expenditures ​ ​ (1,305) Accrued lease operating expenses ​ ​ (1,394) Accrued liabilities and other ​ ​ (13,961) Accrued interest ​ ​ (105) Operating lease obligations ​ ​ (17,652) Other long-term liabilities ​ ​ (11,071) Total liabilities reinstated ​ ​ (56,354) Less: Amounts settled per the Plan ​ ​ ​ Issuance of common stock to general unsecured claim holders ​ ​ (1,125,062) Payment of contract cure amounts ​ ​ (10,836) Operating lease modification and terminations ​ ​ (9,669) Issuance of Successor common stock to holders of unvested cash-settled equity awards (1) ​ ​ (64) Total amounts settled ​ ​ (1,145,631) Gain on settlement of liabilities subject to compromise ​ $ 1,324,940 (1) Holders of unvested cash-settled restricted stock awards were included as existing equity interests in the Plan and thus received Successor common stock on a pro rata basis based on the amount of unvested awards held. This amount represents the gain on the liability related to those awards, which was included in liabilities subject to compromise prior to emergence. (h) Reflects the reinstatement of $11 million of accounts payable included in liabilities subject to compromise to be satisfied in the ordinary course of business, partially offset by $2 million of professional fees paid on the Emergence Date. (i) Represents the accrual of success fees payable upon emergence as well as certain other expenses, the payment of certain professional fees that were accrued for prior to emergence and the reinstatement of certain accrued liabilities included in liabilities subject to compromise to be satisfied in the ordinary course of business, as detailed in the following table (in thousands):
Schedule of accrued liabilities and other	​ ​ ​ ​ ​ Reinstatement of accrued expenses from liabilities subject to compromise ​ $ 13,961 Recognition of success fee payable upon emergence ​ ​ 11,500 Other expenses accrued at emergence ​ ​ 3,315 Payment of certain professional fees accrued prior to emergence ​ ​ (6,834) Net impact to accrued liabilities and other ​ $ 21,942
Schedule of equity issued to each class of claims	​ ​ ​ ​ ​ Issuance of common stock to general unsecured claim holders ​ $ 1,125,062 Issuance of common stock to Predecessor common stockholders and holders of unvested cash-settled equity awards ​ ​ 34,794 Issuance of warrants to Predecessor common stockholders and holders of unvested cash-settled equity awards ​ ​ 29,360 Fair value of Successor equity ​ $ 1,189,216
Schedule of impact on accumulated earnings (deficit)	(n) The table below reflects the cumulative impact of the reorganization adjustments discussed above (in thousands):
Schedule of fair value adjustment to the Company's leases	​ ​ ​ ​ ​ ​ ​ Lease Asset/Liability ​ Balance Sheet Classification ​ Fair Value Adjustment Accounts receivable, net ​ Accounts receivable, net ​ $ 81 Operating lease assets, net ​ Other long-term assets ​ ​ (1,480) Finance lease assets ​ Other property and equipment ​ ​ (10,765) Accumulated depreciation - finance leases ​ Less accumulated depreciation, depletion and amortization ​ ​ 15,099 Accrued interest - finance leases ​ Accrued interest ​ ​ 127 Short-term finance lease obligation ​ Accrued liabilities and other ​ ​ (576) Short-term operating lease obligation ​ Accrued liabilities and other ​ ​ 319 Long-term finance lease obligation ​ Other long-term liabilities ​ ​ (1,174) Long-term operating lease obligation ​ Operating lease obligations ​ ​ (187) ​ ​ ​ ​ $ 1,444
Schedule of components of reorganization items	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor ​ ​ One Month Ended September 30, 2020 ​ ​ Two Months Ended August 31, 2020 ​ Eight Months Ended August 31, 2020 Legal and professional advisory fees (1) ​ $ - ​ ​ $ 30,502 ​ $ 57,170 Net gain on liabilities subject to compromise ​ ​ - ​ ​ ​ (1,324,940) ​ ​ (1,324,940) Fresh start adjustments, net ​ ​ - ​ ​ ​ 1,025,742 ​ ​ 1,025,742 Write-off of unamortized debt issuance costs and premium (2) ​ ​ - ​ ​ ​ - ​ ​ 15,145 Other items, net ​ ​ - ​ ​ ​ 9,464 ​ ​ 9,464 Total reorganization items, net ​ $ - ​ ​ $ (259,232) ​ $ (217,419) (1) As of September 30, 2020, $10 million of these fees are accrued and unpaid and are presented in accounts payable and accrued liabilities and other in the condensed consolidated balance sheets. These amounts will be paid in the ordinary course of business. (2) As a result of the Chapter 11 Cases and the adoption of ASC 852, the Company wrote off all unamortized premium and issuance cost balances related to its senior notes on the Petition Date.

OIL AND GAS PROPERTIES (Tables)

OIL AND GAS PROPERTIES (Tables)	9 Months Ended
	Sep. 30, 2020
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 September 30, 2020 and December 31, 2019 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor ​ ​ September 30, ​ ​ December 31, ​ 2020 ​ ​ 2019 Proved oil and gas properties ​ $ 1,693,217 ​ ​ $ 12,549,395 Unproved leasehold costs ​ ​ 124,838 ​ ​ ​ 103,278 Wells and facilities in progress ​ ​ 11,417 ​ ​ ​ 159,334 Total oil and gas properties, successful efforts method ​ ​ 1,829,472 ​ ​ ​ 12,812,007 Accumulated depletion ​ ​ (18,735) ​ ​ ​ (5,656,929) Oil and gas properties, net ​ $ 1,810,737 ​ ​ $ 7,155,078 ​
Schedule of impairment expense	The following tables present impairment expense for unproved properties for the periods presented, which is reported in exploration and impairment expense in the condensed consolidated statements of operations (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor ​ ​ One Month Ended September 30, 2020 ​ ​ Two Months Ended August 31, 2020 ​ Three Months Ended September 30, 2019 Impairment expense for unproved properties ​ $ - ​ ​ $ 83 ​ $ 2,233 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor ​ ​ One Month Ended September 30, 2020 ​ ​ Eight Months Ended August 31, 2020 ​ Nine Months Ended September 30, 2019 Impairment expense for unproved properties ​ $ - ​ ​ $ 12,566 ​ $ 8,063

LONG-TERM DEBT (Tables)

LONG-TERM DEBT (Tables)	9 Months Ended
	Sep. 30, 2020
LONG-TERM DEBT [Abstract]
Schedule of long-term debt	Long-term debt consisted of the following at September 30, 2020 and December 31, 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor ​ ​ September 30, ​ ​ December 31, ​ 2020 ​ ​ 2019 Exit Credit Agreement ​ $ 400,328 ​ ​ $ - Predecessor Credit Agreement ​ ​ - ​ ​ ​ 375,000 1.25% Convertible Senior Notes due 2020 ​ ​ - ​ ​ ​ 262,075 5.75% Senior Notes due 2021 ​ ​ - ​ ​ ​ 773,609 6.25% Senior Notes due 2023 ​ ​ - ​ ​ ​ 408,296 6.625% Senior Notes due 2026 ​ ​ - ​ ​ ​ 1,000,000 Total principal ​ ​ 400,328 ​ ​ ​ 2,818,980 Unamortized debt discounts and premiums ​ ​ - ​ ​ ​ (2,575) Unamortized debt issuance costs on notes ​ ​ - ​ ​ ​ (16,520) Total long-term debt ​ $ 400,328 ​ ​ $ 2,799,885

ASSET RETIREMENT OBLIGATIONS (T

ASSET RETIREMENT OBLIGATIONS (Tables)	9 Months Ended
	Sep. 30, 2020
ASSET RETIREMENT OBLIGATIONS [Abstract]
Schedule of reconciliation of the Company's asset retirement obligations	​ ​ ​ ​ Asset retirement obligation at January 1, 2020 (Predecessor) ​ $ 134,893 Additional liability incurred ​ ​ 76 Revisions to estimated cash flows ​ ​ 56,702 Accretion expense ​ ​ 8,199 Obligations on sold properties ​ ​ (693) Liabilities settled (1) ​ ​ (42,854) Ending balance as of August 31, 2020 (Predecessor) ​ ​ 156,323 ​ ​ ​ ​ Fresh start adjustment (2) ​ ​ (29,582) ​ ​ ​ ​ ​ ​ ​ ​ Asset retirement obligation at September 1, 2020 (Successor) ​ ​ 126,741 Additional liability incurred ​ ​ 20 Accretion expense ​ ​ 929 Asset retirement obligation at September 30, 2020 (Successor) ​ $ 127,690 (1) A portion of the Predecessor’s asset retirement obligations related to a contractual obligation to remove certain offshore facilities in California. The Company included the related contract in its schedule of rejected contracts as part of the Plan, and the related amounts of the obligations were included in liabilities subject to compromise on the condensed consolidated balance sheets of the Predecessor as of August 31, 2020. A final ruling from the Bankruptcy Court on the rejection of this contract has not yet been issued. Refer to the “Fresh Start Accounting” and “Commitments and Contingencies” footnotes for additional information. (2) Refer to the “Fresh Start Accounting” footnote for more information on fresh start adjustments .

DERIVATIVE FINANCIAL INSTRUME_2

DERIVATIVE FINANCIAL INSTRUMENTS (Tables)	9 Months Ended
	Sep. 30, 2020
DERIVATIVE FINANCIAL INSTRUMENTS [Abstract]
Derivative instruments	The table below details the Company’s swap and collar derivatives entered into to hedge forecasted crude oil and natural gas production revenues as of September 30, 2020 (Successor). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Settlement Period ​ Index ​ Derivative Instrument ​ Total Volumes (1) ​ Units ​ Weighted Average Swap Price ​ Weighted Average Floor ​ Weighted Average Ceiling Crude Oil ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 ​ NYMEX WTI ​ Fixed Price Swaps ​ 1,058,000 ​ Bbl ​ $41.01 ​ - ​ - 2020 ​ NYMEX WTI ​ Two-way Collars ​ 1,794,000 ​ Bbl ​ - ​ $37.63 ​ $45.36 2021 ​ NYMEX WTI ​ Fixed Price Swaps ​ 2,737,500 ​ Bbl ​ $40.05 ​ - ​ - 2021 ​ NYMEX WTI ​ Two-way Collars ​ 6,043,500 ​ Bbl ​ - ​ $38.11 ​ $46.61 2022 (2) ​ NYMEX WTI ​ Two-way Collars ​ 3,518,000 ​ Bbl ​ - ​ $38.36 ​ $49.16 ​ ​ ​ ​ Total ​ 15,151,000 ​ Bbl ​ ​ ​ ​ ​ ​ Natural Gas ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 ​ NYMEX Henry Hub ​ Fixed Price Swaps ​ 2,440,000 ​ MMBtu ​ $2.50 ​ - ​ - 2020 ​ NYMEX Henry Hub ​ Two-way Collars ​ 1,830,000 ​ MMBtu ​ - ​ $2.17 ​ $2.36 2021 ​ NYMEX Henry Hub ​ Fixed Price Swaps ​ 11,840,000 ​ MMBtu ​ $2.66 ​ - ​ - 2021 ​ NYMEX Henry Hub ​ Two-way Collars ​ 10,950,000 ​ MMBtu ​ - ​ $2.60 ​ $2.79 2022 ​ NYMEX Henry Hub ​ Fixed Price Swaps ​ 1,365,000 ​ MMBtu ​ $2.60 ​ - ​ - 2022 ​ NYMEX Henry Hub ​ Two-way Collars ​ 8,190,000 ​ MMBtu ​ - ​ $2.30 ​ $2.80 ​ ​ ​ ​ Total ​ 36,615,000 ​ MMBtu ​ ​ ​ ​ ​ ​ (1) Subsequent to September 30, 2020, the Company entered into additional swap contracts for 690,000 MMBtu of natural gas volumes for the last three months of 2021 and additional collar contracts for 2,530,000 MMBtu of natural gas volumes for the last three months of 2022. (2) The Company’s crude oil contract terms cover only the first nine months of 2022.
Schedule of effects of commodity derivative instruments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Gain) Loss Recognized in Income ​ ​ ​ ​ Successor ​ ​ Predecessor Not Designated as ASC 815 Hedges Statements of Operations Classification One Month Ended September 30, 2020 ​ ​ Two Months Ended August 31, 2020 ​ Three Months Ended September 30, 2019 Commodity contracts ​ Derivative (gain) loss, net ​ $ (30,594) ​ ​ $ 43,125 ​ $ (30,597) Total ​ ​ ​ $ (30,594) ​ ​ $ 43,125 ​ $ (30,597) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Gain) Loss Recognized in Income ​ ​ ​ ​ Successor ​ ​ Predecessor Not Designated as ASC 815 Hedges Statements of Operations Classification One Month Ended September 30, 2020 ​ ​ Eight Months Ended August 31, 2020 ​ Nine Months Ended September 30, 2019 Commodity contracts ​ Derivative (gain) loss, net ​ $ (30,594) ​ ​ $ (181,614) ​ $ 7,431 Total ​ ​ ​ $ (30,594) ​ ​ $ (181,614) ​ $ 7,431 ​
Location and fair value of derivative instruments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ ​ ​ September 30, 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 ​ $ 23,607 ​ $ (21,631) ​ $ 1,976 Commodity contracts - non-current ​ Other long-term assets ​ ​ 22,817 ​ ​ (22,368) ​ ​ 449 Total derivative assets ​ ​ ​ $ 46,424 ​ $ (43,999) ​ $ 2,425 Derivative liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity contracts - current ​ Accrued liabilities and other ​ $ 29,298 ​ $ (21,631) ​ $ 7,667 Commodity contracts - non-current ​ Other long-term liabilities ​ ​ 26,027 ​ ​ (22,368) ​ ​ 3,659 Total derivative liabilities ​ ​ ​ $ 55,325 ​ $ (43,999) ​ $ 11,326 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Predecessor ​ ​ ​ ​ December 31, 2019 (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 ​ $ 75,654 ​ $ (74,768) ​ $ 886 Commodity contracts - non-current ​ Other long-term assets ​ ​ 5,648 ​ ​ (5,648) ​ ​ - Total derivative assets ​ ​ ​ $ 81,302 ​ $ (80,416) ​ $ 886 Derivative liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity contracts - current ​ Accrued liabilities and other ​ $ 85,053 ​ $ (74,768) ​ $ 10,285 Commodity contracts - non-current ​ Other long-term liabilities ​ ​ 6,534 ​ ​ (5,648) ​ ​ 886 Total derivative liabilities ​ ​ ​ $ 91,587 ​ $ (80,416) ​ $ 11,171 (1) All of the counterparties to the Company’s financial derivative contracts subject to master netting arrangements are lenders under both the Exit Credit Agreement and the Predecessor 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)	9 Months Ended
	Sep. 30, 2020
FAIR VALUE MEASUREMENTS [Abstract]
Summary of the fair values and carrying value of debt instruments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Predecessor ​ ​ December 31, 2019 ​ ​ Fair ​ Carrying ​ Value (1) Value (2) 1.25% Convertible Senior Notes due 2020 ​ $ 260,214 ​ $ 259,026 5.75% Senior Notes due 2021 ​ ​ 732,995 ​ ​ 772,080 6.25% Senior Notes due 2023 ​ ​ 343,989 ​ ​ 405,392 6.625% Senior Notes due 2026 ​ ​ 681,250 ​ ​ 988,387 Total ​ $ 2,018,448 ​ $ 2,424,885 (1) Fair values are based on quoted market prices for these debt securities, and such fair values are therefore designated as Level 1 within the valuation hierarchy. (2) Carrying values are presented net of unamortized debt issuance costs and debt discounts or premiums.
Fair value assets and liabilities measured on a recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Fair Value ​ Level 1 Level 2 Level 3 September 30, 2020 Financial Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity derivatives – current ​ $ - ​ $ 1,976 ​ $ - ​ $ 1,976 Commodity derivatives – non-current ​ ​ - ​ ​ 449 ​ ​ - ​ ​ 449 Total financial assets ​ $ - ​ $ 2,425 ​ $ - ​ $ 2,425 Financial Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity derivatives – current ​ $ - ​ $ 7,667 ​ $ - ​ $ 7,667 Commodity derivatives – non-current ​ ​ - ​ ​ 3,659 ​ ​ - ​ ​ 3,659 Total financial liabilities ​ $ - ​ $ 11,326 ​ $ - ​ $ 11,326 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Predecessor ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Fair Value ​ Level 1 Level 2 Level 3 December 31, 2019 Financial Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity derivatives – current ​ $ - ​ $ 886 ​ $ - ​ $ 886 Total financial assets ​ $ - ​ $ 886 ​ $ - ​ $ 886 Financial Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity derivatives – current ​ $ - ​ $ 10,285 ​ $ - ​ $ 10,285 Commodity derivatives – non-current ​ ​ - ​ ​ 886 ​ ​ - ​ ​ 886 Total financial liabilities ​ $ - ​ $ 11,171 ​ $ - ​ $ 11,171
Non-financial assets and liabilities measured at fair value on a nonrecurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Predecessor ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loss (Before ​ ​ Net Carrying ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Tax) During the ​ ​ Value as of ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current ​ ​ March 31, ​ Fair Value Measurements Using ​ Predecessor YTD ​ 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 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loss (Before ​ ​ Net Carrying ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Tax) During the ​ ​ Value as of ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current ​ ​ June 30, ​ Fair Value Measurements Using ​ Predecessor YTD ​ 2020 Level 1 Level 2 Level 3 Period Proved property (2) ​ $ 85,418 ​ $ - ​ $ - ​ $ 85,418 ​ $ 409,079 (2) During the second quarter of 2020, other proved oil and gas properties in the Company’s Williston Basin resource play with a previous carrying amount of $494 million were written down to their fair value as of June 30, 2020 of $85 million, resulting in a non-cash impairment charge of $409 million, 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 assessed during the second quarter of 2020.

REVENUE RECOGNITION (Tables)

REVENUE RECOGNITION (Tables)	9 Months Ended
	Sep. 30, 2020
REVENUE RECOGNITION [Abstract]
Summary of revenue disaggregation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor OPERATING REVENUES ​ One Month Ended September 30, 2020 ​ ​ Two Months Ended August 31, 2020 ​ Three Months Ended September 30, 2019 Oil sales ​ $ 60,392 ​ ​ $ 116,971 ​ $ 369,940 NGL and natural gas sales ​ ​ 692 ​ ​ ​ 5,587 ​ ​ 5,951 Oil, NGL and natural gas sales ​ $ 61,084 ​ ​ $ 122,558 ​ $ 375,891 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor OPERATING REVENUES ​ One Month Ended September 30, 2020 ​ ​ Eight Months Ended August 31, 2020 ​ Nine Months Ended September 30, 2019 Oil sales ​ $ 60,392 ​ ​ $ 440,820 ​ $ 1,133,264 NGL and natural gas sales ​ ​ 692 ​ ​ ​ 18,184 ​ ​ 58,380 Oil, NGL and natural gas sales ​ $ 61,084 ​ ​ $ 459,004 ​ $ 1,191,644

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	9 Months Ended
	Sep. 30, 2020
Successor Awards [Member]
Share-based compensation disclosures
Assumption for valuing market based restricted shares	​ ​ ​ ​ Number of simulations 100,000 Expected volatility 40% Risk-free interest rate 0.66% Dividend yield —
Predecessor Awards [Member]
Share-based compensation disclosures
Assumption for valuing market based restricted shares	​ ​ ​ ​ ​ ​ ​ 2020 2019 Number of simulations 2,500,000 2,500,000 Expected volatility 76.52% ​ 72.95% Risk-free interest rate 1.51% ​ 2.60% Dividend yield — —

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	9 Months Ended
	Sep. 30, 2020
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 ​ One Month Ended September 30, 2020 ​ ​ Two Months Ended August 31, 2020 ​ Three Months Ended September 30, 2019 Basic Earnings (Loss) Per Share ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) ​ $ 40,270 ​ ​ $ 237,425 ​ $ (19,067) Weighted average shares outstanding ​ ​ 38,051 ​ ​ ​ 91,464 ​ ​ 91,299 Earnings (loss) per common share ​ $ 1.06 ​ ​ $ 2.60 ​ $ (0.21) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Diluted Earnings (Loss) Per Share ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) ​ $ 40,270 ​ ​ $ 237,425 ​ $ (19,067) Weighted average shares outstanding ​ ​ 38,051 ​ ​ ​ 91,464 ​ ​ 91,299 Earnings (loss) per common share ​ $ 1.06 ​ ​ $ 2.60 ​ $ (0.21) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Successor ​ ​ Predecessor ​ One Month Ended September 30, 2020 ​ ​ Eight Months Ended August 31, 2020 ​ Nine Months Ended September 30, 2019 Basic Earnings (Loss) Per Share ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) ​ $ 40,270 ​ ​ $ (3,965,461) ​ $ (93,679) Weighted average shares outstanding ​ ​ 38,051 ​ ​ ​ 91,423 ​ ​ 91,274 Earnings (loss) per common share ​ $ 1.06 ​ ​ $ (43.37) ​ $ (1.03) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Diluted Earnings (Loss) Per Share ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) ​ $ 40,270 ​ ​ $ (3,965,461) ​ $ (93,679) Weighted average shares outstanding ​ ​ 38,051 ​ ​ ​ 91,423 ​ ​ 91,274 Earnings (loss) per common share ​ $ 1.06 ​ ​ $ (43.37) ​ $ (1.03)

BASIS OF PRESENTATION (Details)

BASIS OF PRESENTATION (Details) $ in Millions	Dec. 31, 2019USD ($)
BASIS OF PRESENTATION [Abstract]
Allowance for credit losses	$ 9

BASIS OF PRESENTATION (Reconcil

BASIS OF PRESENTATION (Reconciliation) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 01, 2020	Aug. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
BASIS OF PRESENTATION [Abstract]
Cash and cash equivalents	$ 13,702	$ 22,657	$ 547,354	$ 8,652
Restricted cash	13,233	$ 26,750	28,955
Total cash, cash equivalents and restricted cash	$ 26,935		$ 49,407	$ 8,652	$ 13,607

CHAPTER 11 EMERGENCE (Details)

CHAPTER 11 EMERGENCE (Details) - USD ($) $ in Thousands	Sep. 01, 2020	Sep. 30, 2020	Jun. 30, 2020	Aug. 31, 2020
Chapter 11 Cases
Financial Designation, Predecessor and Successor [Fixed List]		Successor		Predecessor
Issuance of Successor equity (in shares)	38,051,210
Interest expense not recognized			$ 57,000
Liabilities Subject to Compromise
Liabilities subject to compromise pre-emergence				$ 2,526,925
Exit Credit Agreement [Member]
Chapter 11 Cases
Maximum borrowing capacity of credit facility	$ 750,000	$ 750,000
Additional contingent borrowings	$ 750,000
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
Issuance of Successor equity (in shares)	36,817,630
Existing Stockholders [Member]
Chapter 11 Cases
Issuance of Successor equity (in shares)	1,233,580
General Unsecured Claimants [Member]
Chapter 11 Cases
Reserved for future issuance (in shares)	3,070,201
Management Incentive Plan [Member]
Chapter 11 Cases
Reserved for future issuance (in shares)	4,035,885

FRESH START ACCOUNTING - Fresh

FRESH START ACCOUNTING - Fresh start (Details) $ in Thousands	Sep. 01, 2020USD ($)
Fresh-Start Adjustment [Line Items]
Enterprise value	$ 1,591,887
Weighted average cost of capital rate	14.00%
Minimum [Member]
Fresh-Start Adjustment [Line Items]
Enterprise value	$ 1,350,000
Maximum [Member]
Fresh-Start Adjustment [Line Items]
Enterprise value	$ 1,750,000

FRESH START ACCOUNTING - Enterp

FRESH START ACCOUNTING - Enterprise value (Details) - USD ($) $ in Thousands	Sep. 01, 2020	Sep. 30, 2020	Aug. 31, 2020	Dec. 31, 2019
Fresh-Start Adjustment [Line Items]
Enterprise value	$ 1,591,887
Plus: Cash and cash equivalents	22,657	$ 13,702	$ 547,354	$ 8,652
Less: Fair value of debt	(425,328)	$ (400,328)		$ (2,799,885)
Implied value of Successor common stock	$ 1,189,216
Issuance of Successor equity (in shares)	38,051,210
Senior Notes Holders [Member]
Fresh-Start Adjustment [Line Items]
Issuance of Successor equity (in shares)	36,817,630
Existing Stockholders [Member]
Fresh-Start Adjustment [Line Items]
Issuance of Successor equity (in shares)	1,233,580
General Unsecured Claimants [Member]
Fresh-Start Adjustment [Line Items]
Reserved for future issuance (in shares)	3,070,201

FRESH START ACCOUNTING - Reorga

FRESH START ACCOUNTING - Reorganization value (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 01, 2020	Aug. 31, 2020	Dec. 31, 2019
FRESH START ACCOUNTING [Abstract]
Enterprise value		$ 1,591,887
Cash and cash equivalents	$ 13,702	22,657	$ 547,354	$ 8,652
Accounts payable trade	44,171	56,432	47,168	80,100
Revenues and royalties payable	146,767	145,506	145,506	202,010
Other current liabilities		143,790
Asset retirement obligations	119,262	121,343	150,925	131,208
Operating lease obligations	17,749	17,839		31,722
Deferred income taxes		14,501	69,847	73,593
Other long-term liabilities	$ 19,723	28,773	$ 18,160	$ 24,928
Reorganization value		$ 2,142,728

FRESH START ACCOUNTING - Balanc

FRESH START ACCOUNTING - Balance sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 01, 2020	Aug. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 13,702	$ 22,657	$ 547,354	$ 8,652
Restricted cash	13,233	26,750	28,955
Accounts receivable trade, net	128,577	136,962	136,881	308,249
Prepaid expenses and other	22,056	21,213	18,722	14,082
Total current assets	177,568	207,582	731,912	330,983
Property and equipment:
Oil and gas properties, successful efforts method	1,829,472	1,826,114	4,885,013	12,812,007
Other property and equipment	72,856	71,315	159,866	178,689
Total property and equipment	1,902,328	1,897,429	5,044,879	12,990,696
Less accumulated depreciation, depletion and amortization			(2,085,266)
Total property and equipment, net	1,882,881	1,897,429	2,959,613	7,255,457
Debt issuance costs		12,784	1,834
Other long-term assets	38,007	24,933	37,010	50,281
TOTAL ASSETS	2,098,456	2,142,728	3,730,369	7,636,721
Current liabilities:
Current portion of long-term debt			912,259
Accounts payable trade	44,171	56,432	47,168	80,100
Revenues and royalties payable	146,767	145,506	145,506	202,010
Accrued capital expenditures	14,809	15,342	14,037	64,263
Accrued liabilities and other	63,987	61,740	46,327	85,007
Accrued lease operating expenses	23,757	26,738	25,344	38,262
Accrued interest	1,432		3,459	53,928
Taxes payable	16,985	13,972	13,972	26,844
Derivative liabilities		25,998	25,998
Total current liabilities	311,908	345,728	1,234,070	550,414
Long-term debt	400,328	425,328		2,799,885
Asset retirement obligations	119,262	121,343	150,925	131,208
Operating lease obligations	17,749	17,839		31,722
Deferred income taxes		14,501	69,847	73,593
Other long-term liabilities	19,723	28,773	18,160	24,928
Total liabilities not subject to compromise		953,512	1,473,002
Liabilities subject to compromise			2,526,925
Total liabilities	868,970	953,512	3,999,927	3,611,750
Commitments and contingencies
Equity (Deficit):
Common stock	38			92
Additional paid-in capital	1,189,178			6,409,991
Accumulated earnings (deficit)	40,270		(6,680,060)	(2,385,112)
Total equity	1,229,486	1,189,216	(269,558)	4,024,971
TOTAL LIABILITIES AND EQUITY	$ 2,098,456	2,142,728	3,730,369	$ 7,636,721
Predecessor adjustment
Equity (Deficit):
Common stock			92
Additional paid-in capital			6,410,410
Successor adjustment
Equity (Deficit):
Common stock		38
Additional paid-in capital		1,189,178
Reorganization Adjustments [Member]
Current assets:
Cash and cash equivalents		(524,697)
Restricted cash		(2,205)
Prepaid expenses and other		231
Total current assets		(526,671)
Property and equipment:
Other property and equipment		(909)
Total property and equipment		(909)
Total property and equipment, net		(909)
Debt issuance costs		10,950
Other long-term assets		(8,760)
TOTAL ASSETS		(525,390)
Current liabilities:
Current portion of long-term debt		(912,259)
Accounts payable trade		9,264
Accrued capital expenditures		1,305
Accrued liabilities and other		21,942
Accrued lease operating expenses		1,394
Accrued interest		(3,332)
Total current liabilities		(881,686)
Long-term debt		425,328
Operating lease obligations		17,652
Other long-term liabilities		11,071
Total liabilities not subject to compromise		(427,635)
Liabilities subject to compromise		(2,526,925)	$ 2,526,925
Total liabilities		(2,954,560)
Equity (Deficit):
Accumulated earnings (deficit)		7,650,456
Total equity		2,429,170
TOTAL LIABILITIES AND EQUITY		(525,390)
Reorganization Adjustments [Member] | Predecessor adjustment
Equity (Deficit):
Common stock		(92)
Additional paid-in capital		(6,410,410)
Reorganization Adjustments [Member] | Successor adjustment
Equity (Deficit):
Common stock		38
Additional paid-in capital		1,189,178
Fresh Start Accounting Adjustments [Member]
Current assets:
Accounts receivable trade, net		81
Prepaid expenses and other		2,260
Total current assets		2,341
Property and equipment:
Oil and gas properties, successful efforts method		(3,058,899)
Other property and equipment		(87,642)
Total property and equipment		(3,146,541)
Less accumulated depreciation, depletion and amortization		2,085,266
Total property and equipment, net		(1,061,275)
Other long-term assets		(3,317)
TOTAL ASSETS		(1,062,251)
Current liabilities:
Accrued liabilities and other		(6,529)
Accrued interest		(127)
Total current liabilities		(6,656)
Asset retirement obligations		(29,582)
Operating lease obligations		187
Deferred income taxes		(55,346)
Other long-term liabilities		(458)
Total liabilities not subject to compromise		(91,855)
Total liabilities		(91,855)
Equity (Deficit):
Accumulated earnings (deficit)		(970,396)
Total equity		(970,396)
TOTAL LIABILITIES AND EQUITY		$ (1,062,251)

FRESH START ACCOUNTING - Source

FRESH START ACCOUNTING - Sources and uses of cash (Details) - Reorganization Adjustments [Member] $ in Thousands	Sep. 01, 2020USD ($)
Fresh-Start Adjustment [Line Items]
Net uses of cash	$ (524,697)
Source of Cash [Member]
Fresh-Start Adjustment [Line Items]
Net uses of cash	453,533
Release of restricted cash upon bankruptcy emergence [Member]
Fresh-Start Adjustment [Line Items]
Net uses of cash	28,205
Borrowings Under the Exit Credit Agreement [Member]
Fresh-Start Adjustment [Line Items]
Net uses of cash	425,328
Use of Cash [Member]
Fresh-Start Adjustment [Line Items]
Net uses of cash	(978,230)
Payment of outstanding borrowings under the Predecessor Credit Agreement [Member]
Fresh-Start Adjustment [Line Items]
Net uses of cash	(912,259)
Payment of accrued interest on the Predecessor Credit Agreement [Member]
Fresh-Start Adjustment [Line Items]
Net uses of cash	(3,437)
Payment of debt issuance costs related to Exit Credit Agreement [Member]
Fresh-Start Adjustment [Line Items]
Net uses of cash	(10,950)
Funding of the Professional Fee Escrow Account [Member]
Fresh-Start Adjustment [Line Items]
Net uses of cash	(26,000)
Payment of professional fees [Member]
Fresh-Start Adjustment [Line Items]
Net uses of cash	(14,470)
Payment of contract cure amounts [Member]
Fresh-Start Adjustment [Line Items]
Net uses of cash	$ (11,114)

FRESH START ACCOUNTING - Reclas

FRESH START ACCOUNTING - Reclassification of cash balance (Details) - Reorganization Adjustments [Member] $ in Thousands	Sep. 01, 2020USD ($)
Fresh-Start Adjustment [Line Items]
Net reclassifications from restricted cash	$ (2,205)
Funding of the Professional Fee Escrow Account [Member]
Fresh-Start Adjustment [Line Items]
Net reclassifications from restricted cash	26,000
Release of restricted cash upon bankruptcy emergence [Member]
Fresh-Start Adjustment [Line Items]
Net reclassifications from restricted cash	(28,205)
Derivative Settlement Amount [Member]
Fresh-Start Adjustment [Line Items]
Net reclassifications from restricted cash	23,000
Assurance For Utility Providers [Member]
Fresh-Start Adjustment [Line Items]
Net reclassifications from restricted cash	$ 5,000

FRESH START ACCOUNTING - Effect

FRESH START ACCOUNTING - Effect on leases and other liabilities (Details) - USD ($) $ in Thousands	Sep. 01, 2020	Aug. 31, 2020	Aug. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Fresh-Start Adjustment [Line Items]
Long-term operating lease obligations	$ 17,839			$ 17,749	$ 31,722
Gain on settlement of liabilities		$ 1,324,940	$ 1,324,940
Debt issuance costs	12,784	$ 1,834	$ 1,834
Reorganization Adjustments [Member]
Fresh-Start Adjustment [Line Items]
Long-term operating lease obligations	17,652
Gain on settlement of liabilities	1,324,940
Debt issuance costs	10,950
Reorganization Adjustments [Member] | Corporate office lease agreement modification [Member]
Fresh-Start Adjustment [Line Items]
Operating lease ROU assets, net	10,000
Operating Lease, Liability	15,000
Gain on settlement of liabilities	5,000
Reorganization Adjustments [Member] | Operating lease obligations reinstated [Member]
Fresh-Start Adjustment [Line Items]
Operating Lease, Liability	18,000
Reorganization Adjustments [Member] | Financing Cost Credit Agreement [Member]
Fresh-Start Adjustment [Line Items]
Debt issuance costs	$ (11,000)

FRESH START ACCOUNTING - Dispos

FRESH START ACCOUNTING - Disposition of liabilities (Details) - USD ($) $ in Thousands	Sep. 01, 2020	Aug. 31, 2020	Aug. 31, 2020
Liabilities subject to compromise pre-emergence
Liabilities subject to compromise		$ 2,526,925	$ 2,526,925
Less: Amounts settled per the Plan
Gain on settlement of liabilities subject to compromise		1,324,940	1,324,940
Reorganization Adjustments [Member]
Liabilities subject to compromise pre-emergence
Liabilities subject to compromise	$ (2,526,925)	$ 2,526,925	$ 2,526,925
Accounts payable trade	(10,866)
Accrued capital expenditures	(1,305)
Accrued lease operating expenses	(1,394)
Accrued liabilities and other	(13,961)
Accrued interest	(105)
Operating lease obligations	(17,652)
Other long-term liabilities	(11,071)
Total liabilities reinstated	56,354
Less: Amounts settled per the Plan
Total amounts settled	(1,145,631)
Gain on settlement of liabilities subject to compromise	1,324,940
Reorganization Adjustments [Member] | Issuance of common stock to general unsecured claim holders [Member]
Less: Amounts settled per the Plan
Total amounts settled	(1,125,062)
Reorganization Adjustments [Member] | Payment of contract cure amounts [Member]
Less: Amounts settled per the Plan
Total amounts settled	(10,836)
Reorganization Adjustments [Member] | Operating lease modification and terminations [Member]
Less: Amounts settled per the Plan
Total amounts settled	(9,669)
Reorganization Adjustments [Member] | Issuance of Successor common stock to holders of unvested cash-settled equity awards [Member]
Less: Amounts settled per the Plan
Total amounts settled	(64)
Reorganization Adjustments [Member] | Payment of professional fees [Member]
Less: Amounts settled per the Plan
Accounts payable	2
Reorganization Adjustments [Member] | Reinstatement of accounts payable subject to compromise [Member]
Less: Amounts settled per the Plan
Accounts payable	$ 11

FRESH START ACCOUNTING - Accrue

FRESH START ACCOUNTING - Accrued Liabilities and Other (Details) - USD ($) $ in Thousands	Sep. 01, 2020	Aug. 31, 2020	Jun. 30, 2020	Sep. 30, 2020	Dec. 31, 2019
Fresh-Start Adjustment [Line Items]
Accrued liabilities and other	$ 61,740	$ 46,327		$ 63,987	$ 85,007
Accelerated expense		$ 4,000	$ 4,000
Reorganization Adjustments [Member]
Fresh-Start Adjustment [Line Items]
Accrued liabilities and other	21,942
Net uses of cash	(524,697)
Accelerated expense	4,161
Reorganization Adjustments [Member] | Reinstatement of accrued expenses from liabilities subject to compromise [Member]
Fresh-Start Adjustment [Line Items]
Accrued liabilities and other	13,961
Reorganization Adjustments [Member] | Recognition of success fee payable upon emergence [Member]
Fresh-Start Adjustment [Line Items]
Accrued liabilities and other	11,500
Reorganization Adjustments [Member] | Other expenses accrued at emergence [Member]
Fresh-Start Adjustment [Line Items]
Accrued liabilities and other	3,315
Reorganization Adjustments [Member] | Payment of professional fees [Member]
Fresh-Start Adjustment [Line Items]
Accrued liabilities and other	(6,834)
Net uses of cash	(14,470)
Reorganization Adjustments [Member] | Accrued Interest Predecessor Credit Agreement [Member]
Fresh-Start Adjustment [Line Items]
Net uses of cash	$ (3,000)

FRESH START ACCOUNTING - Equity

FRESH START ACCOUNTING - Equity Issued (Details) - USD ($) $ / shares in Units, $ in Thousands	Sep. 01, 2020	Sep. 30, 2020	Dec. 31, 2019
Fresh-Start Adjustment [Line Items]
Common stock issued	38,051,210
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001	$ 0.001
Reorganization Adjustments [Member]
Fresh-Start Adjustment [Line Items]
Common stock issued	38,051,210
Warrants to purchase shares	7,256,227
Common stock, par value (in dollars per share)	$ 0.001
Fair value of Successor equity	$ 1,189,216
Reorganization Adjustments [Member] | Issuance of common stock to general unsecured claim holders [Member]
Fresh-Start Adjustment [Line Items]
Issuance of Successor equity	1,125,062
Reorganization Adjustments [Member] | Issuance of common stock to Predecessor common stockholders and holders of unvested cash-settled equity awards
Fresh-Start Adjustment [Line Items]
Issuance of Successor equity	34,794
Reorganization Adjustments [Member] | Issuance of warrants to Predecessor common stockholders and holders of unvested cash-settled equity awards
Fresh-Start Adjustment [Line Items]
Issuance of Successor warrants	$ 29,360

FRESH START ACCOUNTING - Cumula

FRESH START ACCOUNTING - Cumulative impact (Details) - USD ($) $ in Thousands	Sep. 01, 2020	Aug. 31, 2020	Jun. 30, 2020	Aug. 31, 2020
Fresh-Start Adjustment [Line Items]
Gain on settlement of liabilities		$ 1,324,940		$ 1,324,940
Acceleration of unvested stock-based compensation awards		(4,000)	$ (4,000)
Other expenses incurred upon emergence		$ (9,464)		$ (9,464)
Cancellation of Predecessor Equity [Member]
Fresh-Start Adjustment [Line Items]
Acceleration of unvested stock-based compensation awards	$ (4,000)
Reorganization Adjustments [Member]
Fresh-Start Adjustment [Line Items]
Gain on settlement of liabilities	1,324,940
Cancellation of Predecessor equity	6,414,541
Fair value of equity issued to Predecessor common stockholders and holders of unvested cash-settled equity awards	(34,794)
Fair value of warrants issued to Predecessor common stockholders and holders of unvested cash-settled equity awards	(29,360)
Success fees incurred upon emergence	(17,303)
Acceleration of unvested stock-based compensation awards	(4,161)
Other expenses incurred upon emergence	(3,407)
Net impact on accumulated earnings (deficit)	$ 7,650,456

FRESH START ACCOUNTING - Fres_2

FRESH START ACCOUNTING - Fresh Start Adjustments (Details) $ in Thousands	Sep. 01, 2020USD ($)
Fresh-Start Adjustment [Line Items]
Weighted average cost of capital rate	14.00%
Fresh Start Accounting Adjustments [Member]
Fresh-Start Adjustment [Line Items]
Accounts receivable, net	$ 81
Operating lease assets, net	(1,480)
Finance lease assets	(10,765)
Accumulated depreciation - finance leases	15,099
Accrued interest - finance leases	127
Short-term finance lease obligation	(576)
Short-term operating lease obligation	319
Long-term finance lease obligation	(1,174)
Long-term operating lease obligation	(187)
Fresh start adjustments to lease assets and liabilities	$ 1,444
Weighted average cost of capital rate	14.00%
Decrease in land and building	$ (16,000)
Decrease in other property and equipment	(61,000)
Decrease in accumulated depletion, depreciation and amortization.	(66,000)
Fresh start adjustments to other long-term assets	2,000
Fresh Start Accounting Adjustments [Member] | Revaluation of Assets [Member]
Fresh-Start Adjustment [Line Items]
Write-off of deferred gain, short term	7,000
Fresh Start Accounting Adjustments [Member] | Revaluation of Liabilities [Member]
Fresh-Start Adjustment [Line Items]
Write-off of deferred gain, long term	$ 2,000

FRESH START ACCOUNTING - Reor_2

FRESH START ACCOUNTING - Reorganization Items, Net (Details) - USD ($) $ in Thousands	2 Months Ended	8 Months Ended	9 Months Ended
	Aug. 31, 2020	Aug. 31, 2020	Sep. 30, 2020
FRESH START ACCOUNTING [Abstract]
Legal and professional advisory fees	$ 30,502	$ 57,170
Net gain on Liabilities subject to compromise	(1,324,940)	(1,324,940)
Fresh start adjustments, net	1,025,742	1,025,742
Write-off of unamortized debt issuance costs and premium		15,145
Other items, net	9,464	9,464
Total reorganization items, net	$ (259,232)	$ (217,419)
Reorganization legal and professional fees accrued			$ 10,000

OIL AND GAS PROPERTIES (Details

OIL AND GAS PROPERTIES (Details) - USD ($) $ in Thousands	2 Months Ended	3 Months Ended	8 Months Ended	9 Months Ended
	Aug. 31, 2020	Sep. 30, 2019	Aug. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 01, 2020	Dec. 31, 2019
Oil and gas properties
Proved oil and gas properties					$ 1,693,217		$ 12,549,395
Unproved leasehold costs					124,838		103,278
Wells and facilities in progress					11,417		159,334
Total oil and gas properties, successful efforts method	$ 4,885,013		$ 4,885,013		1,829,472	$ 1,826,114	12,812,007
Accumulated depletion					(18,735)		(5,656,929)
Oil and gas properties, net					$ 1,810,737		$ 7,155,078
Unproved Properties [Member]
Oil and gas properties
Impairment of properties	$ 83	$ 2,233	$ 12,566	$ 8,063

ACQUISITIONS AND DIVESTITURES (

ACQUISITIONS AND DIVESTITURES (Divestitures) (Details) $ in Thousands	Jan. 09, 2020USD ($)item	Aug. 15, 2019USD ($)item	Jul. 29, 2019USD ($)item	Sep. 30, 2020USD ($)	Aug. 31, 2020USD ($)	Sep. 30, 2019USD ($)
Dispositions
Proceeds from sale of properties				$ 532	$ 29,273	$ 66,738
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | McKenzie, Mountrail And Williams Counties [Member]
Dispositions
Number of well sold | item	30		137
Proceeds from sale of properties	$ 25,000
Proceeds from sale of oil and gas properties			$ 27,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Richland County, Montana And Mountrail and Williams Counties [Member]
Dispositions
Number of well sold | item		58
Proceeds from sale of oil and gas properties		$ 26,000

LONG-TERM DEBT (Schedule of lon

LONG-TERM DEBT (Schedule of long-term debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 01, 2020	Aug. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Total principal	$ 400,328			$ 2,818,980
Unamortized debt discounts and premiums				(2,575)
Unamortized debt issuance costs on notes				(16,520)
Less current portion of long-term debt			$ (912,259)
Total long-term debt	400,328	$ 425,328		2,799,885
Exit Credit Agreement [Member]
Debt Instrument [Line Items]
Total principal	$ 400,328
Predecessor Credit Agreement [Member]
Debt Instrument [Line Items]
Total principal				375,000
1.25% Convertible Senior Notes due 2020 [Member]
Debt Instrument [Line Items]
Total principal				$ 262,075
Interest rate on debt instrument (as a percent)	1.25%		1.25%	1.25%
5.75% Senior Notes due 2021 [Member]
Debt Instrument [Line Items]
Total principal				$ 773,609
Interest rate on debt instrument (as a percent)	5.75%		5.75%	5.75%
6.25% Senior Notes due 2023 [Member]
Debt Instrument [Line Items]
Total principal				$ 408,296
Interest rate on debt instrument (as a percent)	6.25%		6.25%	6.25%
6.625% Senior Notes due 2026 [Member]
Debt Instrument [Line Items]
Total principal				$ 1,000,000
Interest rate on debt instrument (as a percent)	6.625%		6.625%	6.625%

LONG-TERM DEBT (Credit agreemen

LONG-TERM DEBT (Credit agreement) (Details) - USD ($) $ in Thousands	Sep. 01, 2020	Sep. 30, 2020	Aug. 31, 2020	Sep. 30, 2019
Exit Credit Agreement [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity of credit facility	$ 750,000	$ 750,000
Borrowing capacity of credit facility, net of letter of credit		348,000
Outstanding borrowings under credit facility		400,000
Letters of credit borrowings outstanding		$ 2,000
Additional contingent borrowings	750,000
Maximum cash balance prior to mandatory repayment	$ 75,000
Commitment fees (as a percent)	0.50%
Weighted average interest rate		4.30%
Threshold amount of debt (as a percent)	20.00%
Leverage ratio	2
Current year production covered by hedges (as a percent)	65.00%
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
Repayments of borrowings under credit agreement		$ 100,000
Exit Credit Agreement [Member] | Base Rate [Member] | Minimum [Member]
Debt Instrument [Line Items]
Basis points added to reference rate (as a percent)	1.75%
Exit Credit Agreement [Member] | Base Rate [Member] | Maximum [Member]
Debt Instrument [Line Items]
Basis points added to reference rate (as a percent)	2.75%
Exit Credit Agreement [Member] | Fed Funds Rate [Member]
Debt Instrument [Line Items]
Basis points added to reference rate (as a percent)	0.50%
Exit Credit Agreement [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis points added to reference rate (as a percent)	1.00%
Exit Credit Agreement [Member] | Eurodollar [Member] | Minimum [Member]
Debt Instrument [Line Items]
Basis points added to reference rate (as a percent)	2.75%
Exit Credit Agreement [Member] | Eurodollar [Member] | Maximum [Member]
Debt Instrument [Line Items]
Basis points added to reference rate (as a percent)	3.75%
Letter of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity of credit facility	$ 50,000
Borrowing capacity of credit facility, net of letter of credit		$ 48,000
Predecessor Credit Agreement [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity of credit facility			$ 2,050,000
Maximum aggregate commitments			1,750,000
Repayments of borrowings under credit agreement	912,000		$ 1,402,259	$ 1,615,000
Interest paid	$ 3,000

LONG-TERM DEBT (Senior notes) (

LONG-TERM DEBT (Senior notes) (Details) - USD ($) $ in Thousands	Sep. 01, 2020	Mar. 31, 2020	Mar. 31, 2020	Sep. 30, 2019	Aug. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Issuance of Successor equity (in shares)	38,051,210
Gain (loss) on extinguishment of debt				$ 4,598	$ 25,883	$ 4,598
Repurchase of notes						$ 23,461
Total principal							$ 400,328	$ 2,818,980
Adjustment to equity component of 2020 Convertible Senior Notes			$ 3,461	$ 8,070
Senior Notes [Member]
Debt Instrument [Line Items]
Issuance of Successor equity (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%		5.75%	5.75%
Total principal								$ 773,609
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%		6.25%	6.25%
Total principal								$ 408,296
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%		6.625%	6.625%
Total principal								$ 1,000,000
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
Total principal								$ 262,075
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	1 Months Ended	8 Months Ended
	Sep. 30, 2020	Aug. 31, 2020	Sep. 30, 2020	Sep. 01, 2020	Dec. 31, 2019	Sep. 01, 2019
Asset Retirement Obligations
Asset retirement obligations, current portion			$ 8,000	$ 5,000	$ 4,000
Asset retirement obligation	$ 127,690	$ 156,323	$ 127,690		$ 134,893	$ 126,741
Reconciliation of the Company's asset retirement obligations
Balance at the beginning of the period	156,323	134,893
Additional liability incurred	20	76
Revisions to estimated cash flows		56,702
Accretion expense	929	8,199
Obligations on sold properties		(693)
Liabilities settled		(42,854)
Balance at the end of the period	$ 127,690	$ 156,323
Fresh Start Accounting Adjustments [Member]
Asset Retirement Obligations
Asset retirement obligation				$ (29,582)

DERIVATIVE FINANCIAL INSTRUME_3

DERIVATIVE FINANCIAL INSTRUMENTS (Instruments) (Details) $ in Thousands	1 Months Ended		2 Months Ended	3 Months Ended	8 Months Ended	9 Months Ended
	Sep. 30, 2020USD ($)item$ / item	Apr. 30, 2020USD ($)	Aug. 31, 2020USD ($)	Sep. 30, 2019USD ($)	Aug. 31, 2020USD ($)	Sep. 30, 2019USD ($)	Oct. 01, 2020bblMMBTU
Derivative Financial Instruments [Line Items]
Derivative settlement | $		$ 145,000
Derivative gain (loss), net | $	$ 30,594		$ (43,125)	$ 30,597	$ 181,614	$ (7,431)
Derivative instrument proceeds held in escrow | $		23,000
March 2020 [Member]
Derivative Financial Instruments [Line Items]
Derivative gain (loss), net | $		$ 13,000
Crude Oil [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	15,151,000
Crude Oil [Member] | 2020 [Member] | Fixed Price Swaps [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	1,058,000
Swap Price	41.01
Crude Oil [Member] | 2020 [Member] | Two-way Collars [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	1,794,000
Derivative, Floor Price (in dollars per unit)	37.63
Derivative, Ceiling Price (in dollars per unit)	45.36
Crude Oil [Member] | 2021 [Member] | Fixed Price Swaps [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	2,737,500
Swap Price	40.05
Crude Oil [Member] | 2021 [Member] | Two-way Collars [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	6,043,500
Derivative, Floor Price (in dollars per unit)	38.11
Derivative, Ceiling Price (in dollars per unit)	46.61
Crude Oil [Member] | 2022 [Member] | Two-way Collars [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	3,518,000
Derivative, Floor Price (in dollars per unit)	38.36
Derivative, Ceiling Price (in dollars per unit)	49.16
Natural Gas [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	36,615,000
Natural Gas [Member] | 2020 [Member] | Fixed Price Swaps [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	2,440,000
Swap Price	2.50
Natural Gas [Member] | 2020 [Member] | Two-way Collars [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	1,830,000
Derivative, Floor Price (in dollars per unit)	2.17
Derivative, Ceiling Price (in dollars per unit)	2.36
Natural Gas [Member] | 2021 [Member] | Fixed Price Swaps [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives	11,840,000						690,000
Swap Price	2.66
Natural Gas [Member] | 2021 [Member] | Two-way Collars [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives | item	10,950,000
Derivative, Floor Price (in dollars per unit)	2.60
Derivative, 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	1,365,000
Swap Price	2.60
Natural Gas [Member] | 2022 [Member] | Two-way Collars [Member]
Derivative Financial Instruments [Line Items]
Aggregate notional amount of price risk derivatives	8,190,000						2,530,000
Derivative, Floor Price (in dollars per unit)	2.30
Derivative, Ceiling Price (in dollars per unit)	2.80

DERIVATIVE FINANCIAL INSTRUME_4

DERIVATIVE FINANCIAL INSTRUMENTS (Effects of derivatives) (Details) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended	8 Months Ended	9 Months Ended
	Sep. 30, 2020	Aug. 31, 2020	Sep. 30, 2019	Aug. 31, 2020	Sep. 30, 2019
Derivative Financial Instruments [Line Items]
Derivative (gain) loss, net	$ (30,594)	$ 43,125	$ (30,597)	$ (181,614)	$ 7,431
Not Designated as ASC 815 Hedges [Member]
Derivative Financial Instruments [Line Items]
Derivative (gain) loss, net	(30,594)	43,125	(30,597)	(181,614)	7,431
Commodity contracts [Member] | Not Designated as ASC 815 Hedges [Member]
Derivative Financial Instruments [Line Items]
Derivative (gain) loss, net	$ (30,594)	$ 43,125	$ (30,597)	$ (181,614)	$ 7,431

DERIVATIVE FINANCIAL INSTRUME_5

DERIVATIVE FINANCIAL INSTRUMENTS (Asset location) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Gross amounts of derivative assets and gross amounts offset [Line Items]
Total financial assets	$ 2,425	$ 886
Commodity contracts [Member] | Not Designated as ASC 815 Hedges [Member]
Gross amounts of derivative assets and gross amounts offset [Line Items]
Gross Amounts of Recognized Assets	46,424	81,302
Gross Amounts Offset	(43,999)	(80,416)
Total financial assets	2,425	886
Commodity contracts [Member] | Not Designated as ASC 815 Hedges [Member] | Prepaid Expenses and Other [Member]
Gross amounts of derivative assets and gross amounts offset [Line Items]
Gross Amounts of Recognized Assets	23,607	75,654
Gross Amounts Offset	(21,631)	(74,768)
Total financial assets	1,976	886
Commodity contracts [Member] | Not Designated as ASC 815 Hedges [Member] | Other long-term assets [Member]
Gross amounts of derivative assets and gross amounts offset [Line Items]
Gross Amounts of Recognized Assets	22,817	5,648
Gross Amounts Offset	(22,368)	$ (5,648)
Total financial assets	$ 449

DERIVATIVE FINANCIAL INSTRUME_6

DERIVATIVE FINANCIAL INSTRUMENTS (Liability location) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Gross amounts of derivative liabilities and gross amounts offset [Line Items]
Total financial liabilities	$ 11,326	$ 11,171
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	55,325	91,587
Gross Amounts Offset	(43,999)	(80,416)
Total financial liabilities	11,326	11,171
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	29,298	85,053
Gross Amounts Offset	(21,631)	(74,768)
Total financial liabilities	7,667	10,285
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	26,027	6,534
Gross Amounts Offset	(22,368)	(5,648)
Total financial liabilities	$ 3,659	$ 886

FAIR VALUE MEASUREMENTS (Debt i

FAIR VALUE MEASUREMENTS (Debt instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Aug. 31, 2020	Dec. 31, 2019
Fair Value [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure			$ 2,018,448
Carrying Value [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure			$ 2,424,885
1.25% Convertible Senior Notes due 2020 [Member]
Debt Instrument [Line Items]
Interest Rate (as a percent)	1.25%	1.25%	1.25%
1.25% Convertible Senior Notes due 2020 [Member] | Fair Value [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure			$ 260,214
1.25% Convertible Senior Notes due 2020 [Member] | Carrying Value [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure			$ 259,026
5.75% Senior Notes due 2021 [Member]
Debt Instrument [Line Items]
Interest Rate (as a percent)	5.75%	5.75%	5.75%
5.75% Senior Notes due 2021 [Member] | Fair Value [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure			$ 732,995
5.75% Senior Notes due 2021 [Member] | Carrying Value [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure			$ 772,080
6.25% Senior Notes due 2023 [Member]
Debt Instrument [Line Items]
Interest Rate (as a percent)	6.25%	6.25%	6.25%
6.25% Senior Notes due 2023 [Member] | Fair Value [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure			$ 343,989
6.25% Senior Notes due 2023 [Member] | Carrying Value [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure			$ 405,392
6.625% Senior Notes due 2026 [Member]
Debt Instrument [Line Items]
Interest Rate (as a percent)	6.625%	6.625%	6.625%
6.625% Senior Notes due 2026 [Member] | Fair Value [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure			$ 681,250
6.625% Senior Notes due 2026 [Member] | Carrying Value [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure			$ 988,387

FAIR VALUE MEASUREMENTS (Recurr

FAIR VALUE MEASUREMENTS (Recurring basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financial Assets
Total financial assets	$ 2,425	$ 886
Financial Liabilities
Total financial liabilities	11,326	11,171
Commodity contracts [Member]
Financial Assets
Financial assets - current	1,976	886
Financial assets - non-current	449
Financial Liabilities
Financial liabilities - current	7,667	10,285
Financial liabilities - non-current	3,659	886
Level 2 [Member]
Financial Assets
Total financial assets	2,425	886
Financial Liabilities
Total financial liabilities	11,326	11,171
Level 2 [Member] | Commodity contracts [Member]
Financial Assets
Financial assets - current	1,976	886
Financial assets - non-current	449
Financial Liabilities
Financial liabilities - current	7,667	10,285
Financial liabilities - non-current	$ 3,659	$ 886

FAIR VALUE MEASUREMENTS (Non-re

FAIR VALUE MEASUREMENTS (Non-recurring) (Details) - Proved Properties [Member] - USD ($) $ in Thousands	Sep. 01, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Proved property		$ 85,000	$ 494,000
Non-recurring assets at fair value, impairment loss (before tax)		$ 409,000	$ 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	14.00%	17.00%	16.00%
Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Proved property		$ 85,418	$ 816,234	$ 4,500,000
Non-recurring assets at fair value, impairment loss (before tax)		409,079	3,732,096
Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Proved property		$ 85,418	$ 816,234

REVENUE RECOGNITION (Revenue Re

REVENUE RECOGNITION (Revenue Reclassification) (Details) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended	8 Months Ended	9 Months Ended
	Sep. 30, 2020	Aug. 31, 2020	Sep. 30, 2019	Aug. 31, 2020	Sep. 30, 2019
Revenue
Sales	$ 61,084	$ 122,558	$ 375,891	$ 459,004	$ 1,191,644
Oil sales [Member]
Revenue
Sales	60,392	116,971	369,940	440,820	1,133,264
NGL and natural gas sales [Member]
Revenue
Sales	$ 692	$ 5,587	$ 5,951	$ 18,184	$ 58,380

REVENUE RECOGNITION (Narrative)

REVENUE RECOGNITION (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Revenue
Receivable balance	$ 70	$ 161
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) - $ / shares	Sep. 01, 2020	Sep. 30, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Capital stock, shares authorized	550,000,000
Common stock, shares authorized	500,000,000	500,000,000	225,000,000
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
Issuance of Successor equity (in shares)	38,051,210
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. 29, 2020D$ / sharesshares	Sep. 01, 2020USD ($)shares	Aug. 31, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2020USD ($)	Aug. 31, 2020USD ($)item$ / sharesshares	Sep. 30, 2020shares	Sep. 30, 2019USD ($)$ / sharesshares
Share-based compensation disclosures
Issuance of Successor equity (in shares)		38,051,210
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								3,758,814
Accelerated expense | $			$ 4,000,000			$ 4,000,000
Service Based Restricted Stock [Member]
Share-based compensation disclosures
Granted (in shares)	87,171
Granted (in dollars per share) | $ / shares	$ 17.47
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
Service-based [Member]
Share-based compensation disclosures
Stock compensation expense | $			$ 1,000,000		$ (5,000,000)		$ 3,000,000		$ 6,000,000
Service-based [Member] | Share-based Payment Arrangement, Employee [Member]
Share-based compensation disclosures
Vesting (service) period								3 years
Service-based [Member] | Share-based Payment Arrangement, Nonemployee [Member]
Share-based compensation disclosures
Vesting (service) period								1 year
Granted (in shares)							53,198		464,140
Granted (in dollars per share) | $ / shares							$ 4.94		$ 24.76
RSU [Member] | Share-based Payment Arrangement, Employee [Member]
Share-based compensation disclosures
Granted (in shares)							1,616,504		774,665
Market-based [Member]
Share-based compensation disclosures
Vesting (service) period								3 years
Granted (in shares)							1,665,153		347,493
Granted (in dollars per share) | $ / shares							$ 4.31		$ 25.97
Target share granted percent, will be share-settled							100.00%
Market-based [Member] | Minimum [Member]
Share-based compensation disclosures
Possible multiplier of shares earned | item							0
Market-based [Member] | Maximum [Member]
Share-based compensation disclosures
Possible multiplier of shares earned | item							2
PSU [Member]
Share-based compensation disclosures
Vesting (service) period							3 years
Cash Retention Incentives [Member]
Share-based compensation disclosures
Replacement award fair value | $				$ 12,000,000
Cash bonus paid taxes | $				$ 9,000,000
Existing Stockholders [Member]
Share-based compensation disclosures
Issuance of Successor equity (in shares)		1,233,580

STOCK-BASED COMPENSATION (Assum

STOCK-BASED COMPENSATION (Assumptions) (Details) - item	1 Months Ended	8 Months Ended	9 Months Ended
	Sep. 30, 2020	Aug. 31, 2020	Sep. 30, 2019
Market Based Restricted Stock [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%
Dividend yield (as a percent)	0.00%
Market-based [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of simulations		2,500,000	2,500,000
Expected volatility (as a percent)		76.52%	72.95%
Risk-free interest rate (as a percent)		1.51%	2.60%
Dividend yield (as a percent)		0.00%	0.00%

INCOME TAXES (Narrative) (Detai

INCOME TAXES (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended		8 Months Ended	9 Months Ended
	Sep. 30, 2020	Aug. 31, 2020	Sep. 30, 2020	Sep. 30, 2019	Aug. 31, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 01, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
U.S. statutory income tax rate (as a percent)			21.00%	21.00%		21.00%	21.00%
Income tax expense	$ (12,185)	$ (55,346)			$ (56,374)		$ (1,373)
Federal operating loss carryforwards								$ 3,500,000
Carryforwards expected to expire	2,600,000		$ 2,600,000			$ 2,600,000
CANADA
Operating Loss Carryforwards [Line Items]
Foreign outside basis difference									$ 74,000
Income tax expense	(15,000)	$ (55,000)
Deferred tax liabilities	$ 6,000		$ 6,000			$ 6,000

EARNINGS PER SHARE (Reconciliat

EARNINGS PER SHARE (Reconciliation) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended					8 Months Ended	9 Months Ended
	Sep. 30, 2020	Aug. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Aug. 31, 2020	Sep. 30, 2019
Basic Earnings (Loss) Per Share
Net income (loss)	$ 40,270	$ 237,425	$ (574,315)	$ (3,628,571)	$ (19,067)	$ (5,687)	$ (68,925)	$ (3,965,461)	$ (93,679)
Weighted average shares outstanding	38,051	91,464			91,299			91,423	91,274
Earnings (loss) per common share	$ 1.06	$ 2.60			$ (0.21)			$ (43.37)	$ (1.03)
Diluted Earnings (Loss) Per Share
Net income (loss)	$ 40,270	$ 237,425			$ (19,067)			$ (3,965,461)	$ (93,679)
Weighted average shares outstanding	38,051	91,464			91,299			91,423	91,274
Earnings (loss) per common share	$ 1.06	$ 2.60			$ (0.21)			$ (43.37)	$ (1.03)

EARNINGS PER SHARE (Narrative)

EARNINGS PER SHARE (Narrative) (Details) - shares	1 Months Ended	2 Months Ended	3 Months Ended	8 Months Ended	9 Months Ended
	Sep. 30, 2020	Aug. 31, 2020	Sep. 30, 2019	Aug. 31, 2020	Sep. 30, 2019
Series A [Member]
Shares excluded from Earnings Per Share calculation [Line Items]
Antidilutive securities excluded from computation of earnings per share	4,837,387
Series B [Member]
Shares excluded from Earnings Per Share calculation [Line Items]
Antidilutive securities excluded from computation of earnings per share	2,418,840
Contingently Issuable Shares [Member]
Shares excluded from Earnings Per Share calculation [Line Items]
Antidilutive securities excluded from computation of earnings per share	3,070,201
Service-based [Member]
Shares excluded from Earnings Per Share calculation [Line Items]
Antidilutive securities excluded from computation of earnings per share	87,171	239,186	35,433	314,896	344,419
Market-based [Member]
Shares excluded from Earnings Per Share calculation [Line Items]
Antidilutive securities excluded from computation of earnings per share	189,900		7,159		64,407
Stock Option [Member]
Shares excluded from Earnings Per Share calculation [Line Items]
Stock options excluded from earnings per share calculation (in shares)		18,310	43,367	29,465	46,095

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Narrative) (Details) $ in Millions	Oct. 01, 2020USD ($)	Sep. 28, 2020USD ($)	Jul. 31, 2020MBbls	Jun. 30, 2020USD ($)	Aug. 31, 2020USD ($)	Sep. 30, 2020MBbls
Commitments
Payment made				$ 14
Additional litigation settlement expense					$ 3
Indemnity amount				$ 25
Delivery commitments, volume per day | MBbls			0			10
Agreement term						7 years
US Government [Member]
Commitments
Bankruptcy Claims, Amount of Claims Filed	$ 25
FMOG Entities [Member]
Commitments
Bankruptcy Claims, Amount of Claims Filed	$ 60
Maximum [Member] | BNN Western, LLC [Member]
Commitments
Bankruptcy Claims, Amount of Claims Filed		$ 60

COMPANY RESTRUCTURINGS (Details

COMPANY RESTRUCTURINGS (Details) - USD ($) $ in Millions	1 Months Ended
	Sep. 30, 2020	Aug. 31, 2019
One-time employee termination benefits [Member]
Restructuring
Restructuring costs incurred	$ 7	$ 8

Uncategorized Items - wll-20200

Label	Element	Value
Cancellation of Predecessor Equity	wll_CancellationOfPredecessorEquity	$ 59,929,000
Adjustments Related to Tax Withholding for Share-based Compensation	us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation	4,000
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	787,000
Retained Earnings [Member]
Cancellation of Predecessor Equity	wll_CancellationOfPredecessorEquity	(6,350,573,000)
Common Stock [Member]
Cancellation of Predecessor Equity	wll_CancellationOfPredecessorEquity	$ 92,000
Stock Issued During Period, Shares, Restricted Stock Award, Gross	us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross	9,000
Cancellation of Predecessor Equity, Shares	wll_CancellationOfPredecessorEquityShares	91,642,000
Shares Paid for Tax Withholding for Share Based Compensation	us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation	4,000
Additional Paid In Capital [Member]
Cancellation of Predecessor Equity	wll_CancellationOfPredecessorEquity	$ 6,410,410,000
Adjustments Related to Tax Withholding for Share-based Compensation	us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation	4,000
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	$ 787,000