SM Energy (SM) 10-Q 30 Apr 21 2021 Q1 Quarterly report Financial data

Cover page

Cover page - shares	3 Months Ended
	Mar. 31, 2021	Apr. 21, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	001-31539
Entity Registrant Name	SM ENERGY CO
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	41-0518430
Entity Address, Address Line One	1775 Sherman Street, Suite 1200
Entity Address, City or Town	Denver
Entity Address, State or Province	CO
Entity Address, Postal Zip Code	80203
City Area Code	(303)
Local Phone Number	861-8140
Title of 12(b) Security	Common stock, $0.01 par value
Trading Symbol	SM
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		117,797,778
Entity Central Index Key	0000893538
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (in thousands, except share data) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 0	$ 10
Accounts receivable	199,631	162,455
Derivative assets	20,859	31,203
Prepaid expenses and other	9,792	10,001
Total current assets	230,282	203,669
Property and equipment (successful efforts method):
Proved oil and gas properties	8,735,538	8,608,522
Accumulated depletion, depreciation, and amortization	(5,051,876)	(4,886,973)
Unproved oil and gas properties	705,822	714,602
Wells in progress	291,146	233,498
Other property and equipment, net of accumulated depreciation of $64,242 and $63,662, respectively	31,986	32,217
Total property and equipment, net	4,712,616	4,701,866
Noncurrent assets:
Derivative assets	13,567	23,150
Other noncurrent assets	59,180	47,746
Total noncurrent assets	72,747	70,896
Total assets	5,015,645	4,976,431
Other property and equipment, accumulated depreciation	64,242	63,662
Current liabilities:
Accounts payable and accrued expenses	394,226	371,670
Derivative liabilities	371,802	200,189
Other current liabilities	10,591	11,880
Total current liabilities	776,619	583,739
Noncurrent liabilities:
Revolving credit facility	135,000	93,000
Senior Notes, net	2,125,651	2,121,319
Asset retirement obligations	84,206	83,325
Derivative liabilities	67,595	22,331
Other noncurrent liabilities	56,902	56,557
Total noncurrent liabilities	2,469,354	2,376,532
Commitments and contingencies (note 6)
Stockholders’ equity:
Common stock, $0.01 par value - authorized: 200,000,000 shares; issued and outstanding: 114,742,304 shares as of March 31, 2021, and December 31, 2020	1,147	1,147
Additional paid-in capital	1,833,651	1,827,914
Retained earnings (deficit)	(51,719)	200,697
Accumulated other comprehensive loss	(13,407)	(13,598)
Total stockholders’ equity	1,769,672	2,016,160
Total liabilities and stockholders’ equity	$ 5,015,645	$ 4,976,431
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	200,000,000	200,000,000
Common Stock, Shares, Issued	114,742,304	114,742,304
Common Stock, Shares, Outstanding	114,742,304	114,742,304

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) (in thousands, except per share data) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating revenues and other income:
Oil, gas, and NGL production revenue	$ 423,165	$ 354,233
Other operating income	20,681	1,501
Total operating revenues and other income	443,846	355,734
Operating expenses:
Oil, gas, and NGL production expense	100,930	119,552
Depletion, depreciation, amortization, and asset retirement obligation liability accretion	166,960	233,489
Exploration	9,323	11,349
Impairment	8,750	989,763
General and administrative	24,714	27,447
Net derivative (gain) loss	344,689	(545,340)
Other operating expense, net	(599)	566
Total operating expenses	654,767	836,826
Loss from operations	(210,921)	(481,092)
Interest expense	(39,871)	(41,512)
Gain (Loss) on Extinguishment of Debt	0	12,195
Other non-operating expense, net	(371)	(494)
Loss before income taxes	(251,163)	(510,903)
Income tax (expense) benefit	(106)	99,008
Net loss	$ (251,269)	$ (411,895)
Basic weighted-average common shares outstanding	114,759	113,009
Diluted weighted-average common shares outstanding	114,759	113,009
Basic net loss per common share	$ (2.19)	$ (3.64)
Diluted net loss per common share	(2.19)	(3.64)
Dividends per common share	$ 0.01	$ 0.01

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (UNAUDITED) (in thousands) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net loss	$ (251,269)	$ (411,895)
Other comprehensive income, net of tax:
Pension liability adjustment	191	190
Total other comprehensive income, net of tax	191	190
Total comprehensive loss	$ (251,078)	$ (411,705)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (UNAUDITED) (in thousands, except share data and dividends per share) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Cash dividends declared per share	$ 0.01
Balances, Common Stock, Shares, Outstanding, Beginning at Dec. 31, 2019		112,987,952
Balances, Total Stockholders' Equity, Beginning at Dec. 31, 2019	$ 2,748,994	$ 1,130	$ 1,791,596	$ 967,587	$ (11,319)
Increase (Decrease) in Stockholders' Equity
Net loss	(411,895)			(411,895)
Other comprehensive income	190				190
Cash dividends	(1,130)			(1,130)
Issuance of common stock upon vesting of RSUs, net of shares used for tax withholdings (Shares)		730
Issuance of common stock upon vesting of RSUs, net of shares used for tax withholdings (Amount)	(3)	$ 0	(3)
Stock-based compensation expense	5,561		5,561
Balances, Common Stock, Shares, Outstanding, Ending at Mar. 31, 2020		112,988,682
Balances, Total Stockholders' Equity, Ending at Mar. 31, 2020	$ 2,341,717	$ 1,130	1,797,154	554,562	(11,129)
Cash dividends declared per share	$ 0.01
Balances, Common Stock, Shares, Outstanding, Beginning at Dec. 31, 2020	114,742,304	114,742,304
Balances, Total Stockholders' Equity, Beginning at Dec. 31, 2020	$ 2,016,160	$ 1,147	1,827,914	200,697	(13,598)
Increase (Decrease) in Stockholders' Equity
Net loss	(251,269)			(251,269)
Other comprehensive income	191				191
Cash dividends	(1,147)			(1,147)
Stock-based compensation expense	$ 5,737		5,737
Balances, Common Stock, Shares, Outstanding, Ending at Mar. 31, 2021	114,742,304	114,742,304
Balances, Total Stockholders' Equity, Ending at Mar. 31, 2021	$ 1,769,672	$ 1,147	$ 1,833,651	$ (51,719)	$ (13,407)

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (in thousands) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net loss	$ (251,269)	$ (411,895)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depletion, depreciation, amortization, and asset retirement obligation liability accretion	166,960	233,489
Impairment	8,750	989,763
Stock-based compensation expense	5,737	5,561
Net derivative (gain) loss	344,689	(545,340)
Derivative settlement gain (loss)	(107,885)	73,437
Amortization of debt discount and deferred financing costs	4,723	3,992
Gain on extinguishment of debt	0	(12,195)
Deferred income taxes	(52)	(99,347)
Other, net	(14,592)	(816)
Net change in working capital	(51,437)	(18,517)
Net cash provided by operating activities	105,624	218,132
Cash flows from investing activities:
Capital expenditures	(147,563)	(139,306)
Other	(71)	0
Net cash used in investing activities	(147,634)	(139,306)
Cash flows from financing activities:
Proceeds from revolving credit facility	440,000	425,500
Repayment of revolving credit facility	(398,000)	(476,000)
Cash paid to repurchase Senior Notes	0	(28,318)
Other	0	(3)
Net cash provided by (used in) financing activities	42,000	(78,821)
Net change in cash, cash equivalents, and restricted cash	(10)	5
Cash, cash equivalents, and restricted cash at beginning of period	10	10
Cash, cash equivalents, and restricted cash at end of period	0	15
Supplemental Cash Flow Information - Operating activities:
Cash paid for interest, net of capitalized interest	(53,449)	(47,469)
Supplemental Cash Flow Information - Investing activities:
Increase in capital expenditure accruals and other	$ 37,409	$ 16,802

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 1 - Summary of Significant Accounting Policies Description of Operations SM Energy Company, together with its consolidated subsidiaries (“SM Energy” or the “Company”), is an independent energy company engaged in the acquisition, exploration, development, and production of oil, gas, and NGLs in the state of Texas. Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial information, the instructions to Quarterly Report on Form 10-Q, and Regulation S-X. These financial statements do not include all information and notes required by GAAP for annual financial statements. However, except as disclosed herein, there has been no material change in the information disclosed in the notes to the consolidated financial statements included in the 2020 Form 10-K . In the opinion of management, all adjustments, consisting of normal recurring adjustments considered necessary for a fair presentation of interim financial information, have been included. Operating results for the periods presented are not necessarily indicative of expected results for the full year. In connection with the preparation of the Company’s unaudited condensed consolidated financial statements, the Company evaluated events subsequent to the balance sheet date of March 31, 2021, and through the filing of this report. Additionally, certain prior period amounts have been reclassified to conform to current period presentation in the accompanying unaudited condensed consolidated financial statements. Significant Accounting Policies The significant accounting policies followed by the Company are set forth in Note 1 - Summary of Significant Accounting Policies in the 2020 Form 10-K and are supplemented by the notes to the unaudited condensed consolidated financial statements included in this report. These unaudited condensed consolidated financial statements should be read in conjunction with the 2020 Form 10-K . Recently Issued Accounting Standards In March 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“ASU 2020-04”) followed by ASU No. 2021-01, Reference Rate Reform (Topic 848): Scope (“ASU 2021-01”), issued in January 2021, to provide clarifying guidance regarding the scope of Topic 848. ASU 2020-04 was issued to provide optional guidance for a limited period of time to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform on financial reporting. Generally, the guidance is to be applied as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the date that the financial statements are available to be issued. ASU 2020-04 and ASU 2021-01 are effective for all entities through December 31, 2022. As of March 31, 2021, the Company has not elected to use the optional guidance and continues to evaluate the options provided by ASU 2020-04 and ASU 2021-01. Please refer to Note 5 - Long-Term Debt for discussion of the use of the London Interbank Offered Rate (“LIBOR”) in connection with borrowings under the Credit Agreement. There are no other ASUs that would have a material effect on the Company’s unaudited condensed consolidated financial statements and related disclosures that have been issued but not yet adopted by the Company as of March 31, 2021, or through the filing of this report.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	Note 2 - Revenue from Contracts with Customers The Company recognizes its share of revenue from the sale of produced oil, gas, and NGLs from its Midland Basin and South Texas assets. Oil, gas, and NGL production revenue presented within the accompanying unaudited condensed consolidated statements of operations (“accompanying statements of operations”) is reflective of the revenue generated from contracts with customers. The table below presents oil, gas, and NGL production revenue by product type for each of the Company’s operating areas for the three months ended March 31, 2021, and 2020: Midland Basin South Texas Total Three Months Ended March 31, Three Months Ended March 31, Three Months Ended March 31, 2021 2020 2021 2020 2021 2020 (in thousands) Oil production revenue $ 286,105 $ 276,136 $ 19,672 $ 15,557 $ 305,777 $ 291,693 Gas production revenue 57,806 11,334 31,852 29,376 89,658 40,710 NGL production revenue 100 58 27,630 21,772 27,730 21,830 Total $ 344,011 $ 287,528 $ 79,154 $ 66,705 $ 423,165 $ 354,233 Relative percentage 81 % 81 % 19 % 19 % 100 % 100 % ____________________________________________ Note: Amounts may not calculate due to rounding. The Company recognizes oil, gas, and NGL production revenue at the point in time when custody and title (“control”) of the product transfers to the purchaser, which differs depending on the applicable contractual terms. Transfer of control drives the presentation of transportation, gathering, processing, and other post-production expenses (“fees and other deductions”) within the accompanying statements of operations. Fees and other deductions incurred by the Company prior to control transfer are recorded within the oil, gas, and NGL production expense line item on the accompanying statements of operations. When control is transferred at or near the wellhead, sales are based on a wellhead market price that is impacted by fees and other deductions incurred by the purchaser subsequent to the transfer of control. Please refer to Note 2 - Revenue from Contracts with Customers in the 2020 Form 10-K for more information regarding the types of contracts under which oil, gas, and NGL production revenue is generated. Significant judgments made in applying the guidance in Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers, relate to the point in time when control transfers to purchasers in gas processing arrangements with midstream processors. The Company does not believe that significant judgments are required with respect to the determination of the transaction price, including amounts that represent variable consideration, as volume and price carry a low level of estimation uncertainty given the precision of volumetric measurements and the use of index pricing with generally predictable differentials. Accordingly, the Company does not consider estimates of variable consideration to be constrained. The Company’s performance obligations arise upon the production of hydrocarbons from wells in which the Company has an ownership interest. The performance obligations are considered satisfied upon control transferring to a purchaser at the wellhead, inlet, or tailgate of the midstream processor’s processing facility, or other contractually specified delivery point. The time period between production and satisfaction of performance obligations is generally less than one day, therefore there are no material unsatisfied or partially unsatisfied performance obligations at the end of the reporting period. Revenue is recorded in the month when performance obligations are satisfied. However, settlement statements from the purchasers of hydrocarbons and the related cash consideration are received 30 to 90 days after production has occurred. As a result, the Company must estimate the amount of production delivered to the customer and the consideration that will ultimately be received for sale of the product. Estimated revenue due to the Company is recorded within the accounts receivable line item on the accompanying unaudited condensed consolidated balance sheets (“accompanying balance sheets”) until payment is received. The accounts receivable balances from contracts with customers within the accompanying balance sheets as of March 31, 2021, and December 31, 2020, were $152.1 million and $108.9 million, respectively. To estimate accounts receivable from contracts with customers, the Company uses knowledge of its properties, historical performance, contractual arrangements, index pricing, quality and transportation differentials, and other factors as the basis for these estimates. Differences between estimates and actual amounts received for product sales are recorded in the month that payment is received from the purchaser.

Equity Equity

Equity Equity	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
Stockholders' Equity Note Disclosure	Note 3 - Equity On June 17, 2020, the Company issued warrants to purchase up to an aggregate of approximately 5.9 million shares, or approximately five percent of its then outstanding common stock, at an exercise price of $0.01 per share. The fair value of the warrants on the issuance date was determined using a stochastic Monte Carlo simulation using geometric Brownian motion (“GBM Model”). The Company evaluated the warrants under authoritative accounting guidance and determined that they should be classified as equity instruments. Upon issuance, the warrants were recorded in additional paid-in capital on the accompanying balance sheets at a fair value of $21.5 million, with no recurring fair value measurement required. There have been no changes to the initial carrying amount of the warrants since issuance. The Warrant Agreement dated as of June 17, 2020 (“Warrant Agreement”), states that the warrants are exercisable any time from and after the Triggering Date, as subsequently defined, until June 30, 2023. The Triggering Date is defined by the Warrant Agreement as the first trading day following five consecutive trading days on which the product of the number of shares of common stock issued and outstanding on four of the five trading days multiplied by the closing price per share of common stock for each such trading day exceeds $1.0 billion (“Triggering Date”). The warrants issued are indexed to the Company’s common stock and are required to be settled through physical settlement or net share settlement, if exercised. The Triggering Date occurred on January 14, 2021, and the warrants became exercisable at the election of the holders. The warrants may be exercised either in full or from time to time in part, until their expiration on June 30, 2023. Subsequent to March 31, 2021, the Company issued 3,083,403 shares of unregistered, restricted common stock as a result of the cashless exercise of 3,086,147 warrants at a weighted-average share price of $11.36 per share, as determined under the terms of the Warrant Agreement. No underwriters were involved in the sales, and the securities bear restrictive legends restricting transfer of the securities without registration under the Securities Act or an applicable exemption from registration.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Note 4 - Income Taxes The provision for income taxes for the three months ended March 31, 2021, and 2020, consisted of the following: For the Three Months Ended March 31, 2021 2020 (in thousands) Current portion of income tax (expense) benefit: Federal $ — $ — State (158) (339) Deferred portion of income tax benefit 52 99,347 Income tax (expense) benefit $ (106) $ 99,008 Effective tax rate — % 19.4 % Recorded income tax expense or benefit differs from the amount that would be provided by applying the statutory United States federal income tax rate to income or loss before income taxes. These differences primarily relate to the effect of state income taxes, excess tax benefits and deficiencies from stock-based compensation awards, tax limitations on the compensation of covered individuals, changes in valuation allowances, the cumulative impact of other smaller permanent differences, and can also reflect the cumulative effect of an enacted tax rate change, in the period of enactment, on the Company’s net deferred tax asset and liability balance. The quarterly rate can also be affected by the proportional impacts of forecasted net income or loss for each period presented, as reflected in the table above. For all years before 2017, the Company is generally no longer subject to United States federal or state income tax examinations by tax authorities.

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Long-Term Debt	Note 5 - Long-Term Debt The following table summarizes the Company’s total outstanding balance on its revolving credit facility, Senior Secured Notes net of unamortized discount and deferred financing costs, and Senior Unsecured Notes, net of unamortized deferred financing costs, as of March 31, 2021, and December 31, 2020: As of March 31, 2021 As of December 31, 2020 (in thousands) Revolving credit facility $ 135,000 $ 93,000 Senior Secured Notes (1) 464,222 460,656 Senior Unsecured Notes (1) 1,661,429 1,660,663 Total $ 2,260,651 $ 2,214,319 ____________________________________________ (1) Senior Secured Notes and Senior Unsecured Notes are defined below. Credit Agreement The Company’s Credit Agreement provides for a senior secured revolving credit facility with a maximum loan amount of $2.5 billion. As of March 31, 2021, the borrowing base and aggregate lender commitments under the Credit Agreement were $1.1 billion. The next scheduled borrowing base redetermination date is October 1, 2021. The Credit Agreement is scheduled to mature on September 28, 2023. The maturity date could, however, occur earlier on August 16, 2022, if the Company has not completed certain repurchase, redemption, or refinancing activities associated with its 6.125% Senior Notes due 2022 (“2022 Senior Notes”), and does not have certain unused availability for borrowing under the Credit Agreement, as outlined in the Credit Agreement. Interest and commitment fees associated with the revolving credit facility are accrued based on a borrowing base utilization grid set forth in the Credit Agreement as presented in Note 5 - Long-Term Debt in the 2020 Form 10-K . At the Company’s election, borrowings under the Credit Agreement may be in the form of Eurodollar, Alternate Base Rate (“ABR”), or Swingline loans. Eurodollar loans accrue interest at LIBOR, plus the applicable margin from the utilization grid, and ABR and Swingline loans accrue interest at a market-based floating rate, plus the applicable margin from the utilization grid. Commitment fees are accrued on the unused portion of the aggregate lender commitment amount at rates from the utilization grid and are included in the interest expense line item on the accompanying statements of operations. The Credit Agreement specifies that if LIBOR is no longer a widely used benchmark rate, or if it is no longer used for determining interest rates for loans in the United States, a replacement interest rate that fairly reflects the cost to the lenders of funding loans shall be established by the Administrative Agent, as defined in the Credit Agreement, in consultation with the Company. Please refer to Note 1 - Summary of Significant Accounting Policies for discussion of FASB ASU 2020-04, which provides guidance related to reference rate reform . The following table presents the outstanding balance, total amount of letters of credit outstanding, and available borrowing capacity under the Credit Agreement as of April 21, 2021, March 31, 2021, and December 31, 2020: As of April 21, 2021 As of March 31, 2021 As of December 31, 2020 (in thousands) Revolving credit facility (1) $ 76,500 $ 135,000 $ 93,000 Letters of credit (2) — — 42,000 Available borrowing capacity 1,023,500 965,000 965,000 Total aggregate lender commitment amount $ 1,100,000 $ 1,100,000 $ 1,100,000 ____________________________________________ (1) Unamortized deferred financing costs attributable to the revolving credit facility are presented as a component of the other noncurrent assets line item on the accompanying balance sheets and totaled $3.9 million and $4.3 million as of March 31, 2021, and December 31, 2020, respectively. These costs are being amortized over the term of the revolving credit facility on a straight-line basis. (2) Letters of credit outstanding reduce the amount available under the revolving credit facility on a dollar-for-dollar basis. Senior Notes Senior Secured Notes . Senior Secured Notes, net of unamortized discount and deferred financing costs, included within the Senior Notes, net line item on the accompanying balance sheets as of March 31, 2021, and December 31, 2020, consisted of the following: As of March 31, 2021 Principal Amount Unamortized Debt Discount Unamortized Deferred Financing Costs Net (in thousands) 1.50% Senior Secured Convertible Notes due 2021 $ 65,485 $ 914 $ 87 $ 64,484 10.0% Senior Secured Notes due 2025 446,675 36,085 10,852 399,738 Total $ 512,160 $ 36,999 $ 10,939 $ 464,222 As of December 31, 2020 Principal Amount Unamortized Debt Discount Unamortized Deferred Financing Costs Net (in thousands) 1.50% Senior Secured Convertible Notes due 2021 $ 65,485 $ 1,828 $ 175 $ 63,482 10.0% Senior Secured Notes due 2025 446,675 37,943 11,558 397,174 Total $ 512,160 $ 39,771 $ 11,733 $ 460,656 The 1.50% Senior Secured Convertible Notes due 2021 (“2021 Senior Secured Convertible Notes”) and the 10.0% Senior Secured Notes due 2025 (“2025 Senior Secured Notes,” and together with the 2021 Senior Secured Convertible Notes, the “Senior Secured Notes”) are senior obligations of the Company, secured on a second-priority basis, ranking junior to the Company’s obligations under the Credit Agreement and equal in priority to one another. The Senior Secured Notes rank senior in right of payment with all of the Company’s existing and any future unsecured senior or subordinated debt. Beginning January 1, 2021, until the maturity date, holders may convert their 2021 Senior Secured Convertible Notes at any time based on a conversion rate of 24.6914 shares of the Company’s common stock per $1,000 principal amount of the 2021 Senior Secured Convertible Notes, which is equal to an initial conversion price of approximately $40.50 per share, subject to adjustment. The if-converted value of the 2021 Senior Secured Convertible Notes did not exceed the principal amount as of March 31, 2021, or through the filing of this report. The Company has elected to settle the 2021 Senior Secured Convertible Notes obligation, due July 1, 2021, in cash and intends to settle the obligation using borrowings under its revolving credit facility. The remaining debt discount and debt-related issuance costs are being amortized to the principal value of the 2021 Senior Secured Convertible Notes as interest expense through the maturity date. Interest expense recognized on the 2021 Senior Secured Convertible Notes related to the stated interest rate and amortization of the debt discount totaled $1.2 million and $2.9 million for the three months ended March 31, 2021, and 2020, respectively. The Company may not redeem the 2021 Senior Secured Convertible Notes prior to the maturity date. The Company may redeem some or all of its 2025 Senior Secured Notes prior to their maturity at redemption prices based on a premium, plus accrued and unpaid interest as described in the indenture governing the 2025 Senior Secured Notes. Please refer to Note 5 - Long-Term Debt in the 2020 Form 10- K for additional detail on the Company’s Senior Secured Notes and capped call transactions associated with the 2021 Senior Secured Convertible Notes. Senior Unsecured Notes . Senior Unsecured Notes, net of unamortized deferred financing costs, included within the Senior Notes, net line item on the accompanying balance sheets as of March 31, 2021, and December 31, 2020, consisted of the following: As of March 31, 2021 As of December 31, 2020 Principal Amount Unamortized Deferred Financing Costs Principal Amount, Net Principal Amount Unamortized Deferred Financing Costs Principal Amount, Net (in thousands) 6.125% Senior Notes due 2022 $ 212,403 $ 743 $ 211,660 $ 212,403 $ 855 $ 211,548 5.0% Senior Notes due 2024 277,034 1,448 275,586 277,034 1,576 275,458 5.625% Senior Notes due 2025 349,118 2,634 346,484 349,118 2,792 346,326 6.75% Senior Notes due 2026 419,235 3,795 415,440 419,235 3,970 415,265 6.625% Senior Notes due 2027 416,791 4,532 412,259 416,791 4,725 412,066 Total $ 1,674,581 $ 13,152 $ 1,661,429 $ 1,674,581 $ 13,918 $ 1,660,663 The senior unsecured notes listed above (collectively referred to as “Senior Unsecured Notes,” and together with the Senior Secured Notes, “Senior Notes”) are unsecured senior obligations and rank equal in right of payment with all of the Company’s existing and any future unsecured senior debt and are senior in right of payment to any future subordinated debt. The Company may redeem some or all of its Senior Unsecured Notes prior to their maturity at redemption prices based on a premium, plus accrued and unpaid interest as described in the indentures governing the Senior Unsecured Notes. During the three months ended March 31, 2020, the Company repurchased a total of $40.7 million in aggregate principal amount of its 2022 Senior Notes in open market transactions for a total settlement amount, excluding accrued interest, of $28.3 million. In connection with the repurchase, the Company recorded a gain on extinguishment of debt of $12.2 million for the three months ended March 31, 2020. This amount included discounts realized upon repurchase of $12.4 million partially offset by approximately $235,000 of accelerated unamortized deferred financing costs. The Company canceled all repurchased 2022 Senior Notes upon settlement. Please refer to Note 5 - Long-Term Debt in the 2020 Form 10-K for additional detail on the Company’s Senior Unsecured Notes. Covenants The Company is subject to certain financial and non-financial covenants under the Credit Agreement and the indentures governing the Senior Notes that, among other terms, limit the Company’s ability to incur additional indebtedness, make restricted payments including dividends, sell assets, with respect to the Company’s restricted subsidiaries, permit the consensual restriction on the ability of such restricted subsidiaries to pay dividends or indebtedness owing to the Company or to any other restricted subsidiaries, create liens that secure debt, enter into transactions with affiliates, and merge or consolidate with another company. The Company was in compliance with all covenants under the Credit Agreement and the indentures governing the Senior Notes as of March 31, 2021, and through the filing of this report. Please refer to Note 5 - Long-Term Debt in the 2020 Form 10-K for additional detail on the Company’s covenants under the Credit Agreement and indentures governing the Senior Notes. Capitalized Interest Capitalized interest costs totaled $4.3 million and $2.7 million for the three months ended March 31, 2021, and 2020, respectively. The amount of interest the Company capitalizes generally fluctuates based on the amount borrowed, the Company’s capital program, and the timing and amount of costs associated with capital projects that are considered in progress. Capitalized interest costs are included in total costs incurred.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 6 - Commitments and Contingencies Commitments Other than those items discussed below, there have been no changes in commitments through the filing of this report that differ materially from those disclosed in the 2020 Form 10-K . Please refer to Note 6 - Commitments and Contingencies in the 2020 Form 10-K for additional discussion of the Company’s commitments. Drilling Rig Service Contracts . During the three months ended March 31, 2021, the Company amended certain of its drilling rig contracts resulting in the extension of contract terms. As of March 31, 2021, the Company’s drilling rig commitments totaled $23.5 million under contract terms extending through the second quarter of 2022. If all of these contracts were terminated as of March 31, 2021, the Company would avoid a portion of the contractual service commitments; however, the Company would be required to pay $14.0 million in early termination fees. No material expenses related to early termination or standby fees were incurred by the Company during the three months ended March 31, 2021, and the Company does not expect to incur material penalties with regard to its drilling rig contracts during the remainder of 2021. Drilling and Completion Commitments . During the three months ended March 31, 2021, the Company amended an agreement that included minimum drilling and completion footage requirements on certain existing leases. If these minimum requirements are not satisfied by March 31, 2022, the Company will be required to pay liquidated damages based on the difference between the actual footage drilled and completed and the minimum requirements. As of March 31, 2021, the liquidated damages could range from zero to a maximum of $51.3 million, with the maximum exposure assuming no additional development activity occurred prior to March 31, 2022. As of the filing of this report, the Company expects to meet its obligations under this agreement. Contingencies The Company is subject to litigation and claims arising in the ordinary course of business. The Company accrues for such items when a liability is both probable and the amount can be reasonably estimated. In the opinion of management, the anticipated results of any pending litigation and claims are not expected to have a material effect on the results of operations, the financial position, or the cash flows of the Company.

Compensation Plans

Compensation Plans	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Compensation Plans	Note 7 - Compensation Plans Equity Incentive Compensation Plan As of March 31, 2021, 3.8 million shares of common stock were available for grant under the Company’s Equity Incentive Compensation Plan (“Equity Plan”). Performance Share Units The Company generally grants performance share units (“PSUs”) to eligible employees as part of its Equity Plan. The number of shares of the Company’s common stock issued to settle PSUs ranges from zero to two times the number of PSUs awarded and is determined based on certain criteria over a three For PSUs granted in 2018 and 2019, the settlement criteria include a combination of the Company’s Total Shareholder Return (“TSR”) relative to the TSR of certain peer companies and the Company’s cash return on total capital invested (“CRTCI”) relative to the CRTCI of certain peer companies over the associated three-year performance period. In addition to these performance criteria, the award agreements for these grants also stipulate that if the Company’s absolute TSR is negative over the three-year performance period, the maximum number of shares of common stock that can be issued to settle outstanding PSUs is capped at one times the number of PSUs granted on the award date, regardless of the Company’s TSR and CRTCI performance relative to its peer group. The fair values of the PSUs granted in 2018 and 2019 were measured on the applicable grant dates using the GBM Model, with the assumption that the associated CRTCI performance condition will be met at the target amount at the end of the respective performance periods. Compensation expense for PSUs is recognized within general and administrative expense and exploration expense over the vesting periods of the respective awards. As these awards depend on a combination of performance-based settlement criteria and market-based settlement criteria, compensation expense may be adjusted in future periods as the number of units expected to vest increases or decreases based on the Company’s expected CRTCI performance relative to the applicable peer companies. No PSUs were granted in 2020. The Company records compensation expense associated with the issuance of PSUs based on the fair value of the awards as of the date of grant. Total compensation expense recorded for PSUs was $3.2 million and $2.6 million for the three months ended March 31, 2021, and 2020, respectively. As of March 31, 2021, there was $4.5 million of total unrecognized compensation expense related to non-vested PSU awards, which is being amortized through 2022. There were no material changes to the outstanding and non-vested PSUs during the three months ended March 31, 2021. Employee Restricted Stock Units The Company grants restricted stock units (“RSUs”) to eligible persons as part of its Equity Plan. Each RSU represents a right to receive one share of the Company’s common stock upon settlement of the award at the end of the specified vesting period. RSUs generally vest one-third of the total grant on each anniversary date of the grant over the applicable vesting period or upon other triggering events as set forth in the Equity Plan. The Company records compensation expense associated with the issuance of RSUs based on the fair value of the awards as of the date of grant. The fair value of an RSU is equal to the closing price of the Company’s common stock on the day of the grant. Compensation expense for RSUs is recognized within general and administrative expense and exploration expense over the vesting periods of the respective awards. Total compensation expense recorded for employee RSUs was $2.2 million and $2.6 million for the three months ended March 31, 2021, and 2020, respectively. As of March 31, 2021, there was $12.5 million of total unrecognized compensation expense related to non-vested RSU awards, which is being amortized through 2023. There were no material changes to the outstanding and non-vested RSUs during the three months ended March 31, 2021. Please refer to Note 7 - Compensation Plans in the 2020 Form 10-K for additional detail on the Company’s Equity Plan.

Earnings per Share

Earnings per Share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	Note 9 - Earnings Per Share Basic net income or loss per common share is calculated by dividing net income or loss available to common stockholders by the basic weighted-average number of common shares outstanding for the respective period. Diluted net income or loss per common share is calculated by dividing net income or loss available to common stockholders by the diluted weighted-average number of common shares outstanding, which includes the effect of potentially dilutive securities. As of March 31, 2021, potentially dilutive securities for this calculation consist primarily of non-vested RSUs, contingent PSUs, and warrants, which were measured using the treasury stock method. The warrants became exercisable at the election of the holders on January 14, 2021, and as a result, they were included as potentially dilutive securities beginning January 1, 2021. Please refer to Note 3 - Equity and Note 7 - Compensation Plans in this report, and Note 9 - Earnings Per Share in the 2020 Form 10-K for additional detail on these potentially dilutive securities. As of March 31, 2020, potentially dilutive securities for this calculation consisted primarily of non-vested RSUs, contingent PSUs, and shares into which the 2021 Senior Convertible Notes were convertible, which were measured using the treasury stock method. Shares of the Company’s common stock traded at an average closing price below the $40.50 conversion price applicable to the 2021 Senior Convertible Notes for the three months ended March 31, 2020, therefore, the 2021 Senior Convertible Notes had no dilutive impact. The Company has elected to satisfy any conversion obligation with respect to the 2021 Senior Convertible Notes solely in cash. As a result, the Company’s 2021 Senior Secured Convertible Notes are no longer convertible into shares of the Company’s common stock and thus, were not considered to be a potentially dilutive instrument as of March 31, 2021. When the Company recognizes a net loss from continuing operations, all potentially dilutive shares are anti-dilutive and are consequently excluded from the calculation of diluted net loss per common share. The following table details the weighted-average number of anti-dilutive securities for the periods presented: For the Three Months Ended March 31, 2021 2020 (in thousands) Anti-dilutive 8,106 1,219 The following table sets forth the calculations of basic and diluted net loss per common share: For the Three Months Ended March 31, 2021 2020 (in thousands, except per share data) Net loss $ (251,269) $ (411,895) Basic weighted-average common shares outstanding 114,759 113,009 Dilutive effect of non-vested RSUs and contingent PSUs — — Dilutive effect of warrants — — Diluted weighted-average common shares outstanding 114,759 113,009 Basic net loss per common share $ (2.19) $ (3.64) Diluted net loss per common share $ (2.19) $ (3.64)

Derivative Financial Instrument

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2021
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Derivative Financial Instruments	Note 10 - Derivative Financial Instruments Summary of Oil, Gas, and NGL Derivative Contracts in Place The Company regularly enters into commodity derivative contracts to mitigate a portion of its exposure to potentially adverse market changes in commodity prices and the associated impact on cash flows. As of March 31, 2021, all derivative counterparties were members of the Company’s Credit Agreement lender group and all contracts were entered into for other-than-trading purposes. The Company’s commodity derivative contracts consist of swap and collar arrangements for oil production and NGL production, and swap arrangements for gas production. In a typical commodity swap agreement, if the agreed upon published third-party index price (“index price”) is lower than the swap fixed price, the Company receives the difference between the index price and the agreed upon swap fixed price. If the index price is higher than the swap fixed price, the Company pays the difference. For collar arrangements, the Company receives the difference between an agreed upon index price and the floor price if the index price is below the floor price. The Company pays the difference between the agreed upon ceiling price and the index price if the index price is above the ceiling price. No amounts are paid or received if the index price is between the floor and ceiling prices. The Company has entered into fixed price oil basis swaps in order to mitigate exposure to adverse pricing differentials between certain industry benchmark prices and the actual physical pricing points where the Company’s production volumes are sold. Currently, the Company has basis swap contracts with fixed price differentials between NYMEX WTI and WTI Midland for a portion of its Midland Basin production with sales contracts that settle at WTI Midland prices, NYMEX WTI and Intercontinental Exchange Brent Crude (“ICE Brent”) for a portion of its Midland Basin oil production with sales contracts that settle at ICE Brent prices, and between NYMEX WTI and Argus WTI Houston Magellan East Houston Terminal (“MEH”) for a portion of its South Texas oil production with sales contracts that settle at Argus WTI Houston MEH prices. The Company has also entered into crude oil swap contracts to fix the differential in pricing between the NYMEX calendar month average and the physical crude oil delivery month (“Roll Differential”) in which the Company pays the periodic variable Roll Differential and receives a weighted-average fixed price differential. The weighted-average fixed price differential represents the amount of net addition (reduction) to delivery month prices for the notional volumes covered by the swap contracts. As of March 31, 2021, the Company had commodity derivative contracts outstanding through the fourth quarter of 2023 as summarized in the tables below. Oil Swaps Contract Period NYMEX WTI Volumes Weighted-Average Contract Price (MBbl) (per Bbl) Second quarter 2021 5,508 $ 40.88 Third quarter 2021 5,363 $ 41.16 Fourth quarter 2021 4,744 $ 39.85 2022 7,823 $ 44.69 2023 1,190 $ 45.20 Total 24,628 Oil Collars Contract Period NYMEX WTI Volumes Weighted-Average Floor Price Weighted-Average Ceiling Price (MBbl) (per Bbl) (per Bbl) 2022 1,224 $ 50.00 $ 54.89 Oil Basis Swaps Contract Period WTI Midland-NYMEX WTI Volumes Weighted-Average Contract Price (1) NYMEX WTI-ICE Brent Volumes Weighted-Average Contract Price (2) WTI Houston MEH-NYMEX WTI Volumes Weighted-Average Contract Price (3) (MBbl) (per Bbl) (MBbl) (per Bbl) (MBbl) (per Bbl) Second quarter 2021 4,172 $ 0.81 910 $ (7.86) 493 $ 0.60 Third quarter 2021 3,756 $ 0.75 920 $ (7.86) 356 $ 0.60 Fourth quarter 2021 3,824 $ 0.71 920 $ (7.86) 466 $ 0.60 2022 9,500 $ 1.15 3,650 $ (7.78) 1,329 $ 1.25 Total 21,252 6,400 2,644 ____________________________________________ (1) Represents the price differential between WTI Midland (Midland, Texas) and NYMEX WTI (Cushing, Oklahoma). (2) Represents the price differential between NYMEX WTI (Cushing, Oklahoma) and ICE Brent (North Sea). (3) Represents the price differential between Argus WTI Houston MEH (Houston, Texas) and NYMEX WTI (Cushing, Oklahoma). Oil Roll Differential Swaps Contract Period NYMEX WTI Volumes Weighted-Average (MBbl) (per Bbl) Second quarter 2021 4,743 $ (0.16) Third quarter 2021 4,326 $ (0.18) Fourth quarter 2021 3,831 $ (0.16) 2022 11,278 $ 0.11 Total 24,178 Gas Swaps Contract Period IF HSC Volumes Weighted-Average WAHA Volumes Weighted-Average Contract Price (BBtu) (per MMBtu) (BBtu) (per MMBtu) Second quarter 2021 13,672 $ 2.45 7,230 $ 1.76 Third quarter 2021 12,575 $ 2.40 8,086 $ 1.88 Fourth quarter 2021 12,412 $ 2.41 7,627 $ 1.82 2022 28,932 $ 2.52 13,716 $ 2.30 Total (1) 67,591 36,659 ____________________________________________ (1) The Company has natural gas swaps in place that settle against Inside FERC Houston Ship Channel (“IF HSC”), Inside FERC West Texas (“IF WAHA”), and Platt’s Gas Daily West Texas (“GD WAHA”). As of March 31, 2021, WAHA volumes were comprised of 65 percent IF WAHA and 35 percent GD WAHA. NGL Swaps OPIS Propane Mont Belvieu Non-TET OPIS Normal Butane Mont Belvieu Non-TET Contract Period Volumes Weighted-Average Contract Price Volumes Weighted-Average (MBbl) (per Bbl) (MBbl) (per Bbl) Second quarter 2021 818 $ 22.14 37 $ 30.87 Third quarter 2021 854 $ 22.16 37 $ 30.87 Fourth quarter 2021 824 $ 22.15 36 $ 30.87 2022 231 $ 22.99 — $ — Total 2,727 110 NGL Collars Contract Period OPIS Propane Mont Belvieu Non-TET Weighted-Average Floor Price Weighted-Average Ceiling Price (MBbl) (per Bbl) (per Bbl) 2022 234 $ 22.05 $ 27.30 Commodity Derivative Contracts Entered Into Subsequent to March 31, 2021 Subsequent to March 31, 2021, the Company entered into a NYMEX WTI costless collar contract for the first quarter of 2022 for a total of 180 MBbl of oil production with a contract floor price of $50.00 per Bbl and a contract ceiling price of $65.00 per Bbl. Derivative Assets and Liabilities Fair Value The Company’s commodity derivatives are measured at fair value and are included in the accompanying balance sheets as derivative assets and liabilities, with the exception of derivative instruments that meet the “normal purchase normal sale” exclusion. The Company does not designate its commodity derivative contracts as hedging instruments. The fair value of the commodity derivative contracts was a net liability of $405.0 million and $168.2 million as of March 31, 2021, and December 31, 2020, respectively. The following table details the fair value of commodity derivative contracts recorded in the accompanying balance sheets, by category: As of March 31, 2021 As of December 31, 2020 (in thousands) Derivative assets: Current assets $ 20,859 $ 31,203 Noncurrent assets 13,567 23,150 Total derivative assets $ 34,426 $ 54,353 Derivative liabilities: Current liabilities $ 371,802 $ 200,189 Noncurrent liabilities 67,595 22,331 Total derivative liabilities $ 439,397 $ 222,520 Offsetting of Derivative Assets and Liabilities As of March 31, 2021, and December 31, 2020, all derivative instruments held by the Company were subject to master netting arrangements with various financial institutions. In general, the terms of the Company’s agreements provide for offsetting of amounts payable or receivable between it and the counterparty, at the election of both parties, for transactions that settle on the same date and in the same currency. The Company’s agreements also provide that in the event of an early termination, the counterparties have the right to offset amounts owed or owing under that and any other agreement with the same counterparty. The Company’s accounting policy is to not offset these positions in its accompanying balance sheets. The following table provides a reconciliation between the gross assets and liabilities reflected on the accompanying balance sheets and the potential effects of master netting arrangements on the fair value of the Company’s commodity derivative contracts: Derivative Assets as of Derivative Liabilities as of March 31, 2021 December 31, 2020 March 31, 2021 December 31, 2020 (in thousands) Gross amounts presented in the accompanying balance sheets $ 34,426 $ 54,353 $ (439,397) $ (222,520) Amounts not offset in the accompanying balance sheets (34,238) (53,598) 34,238 53,598 Net amounts $ 188 $ 755 $ (405,159) $ (168,922) The following table summarizes the commodity components of the derivative settlement (gain) loss, as well as the components of the net derivative (gain) loss line item presented in the accompanying statements of operations: For the Three Months Ended March 31, 2021 2020 (in thousands) Derivative settlement (gain) loss: Oil contracts $ 56,329 $ (53,582) Gas contracts 40,448 (14,625) NGL contracts 11,108 (5,230) Total net derivative settlement (gain) loss $ 107,885 $ (73,437) Net derivative (gain) loss: Oil contracts $ 265,815 $ (542,540) Gas contracts 48,922 6,728 NGL contracts 29,952 (9,528) Total net derivative (gain) loss $ 344,689 $ (545,340) Credit Related Contingent Features As of March 31, 2021, and through the filing of this report, all of the Company’s derivative counterparties were members of the Company’s Credit Agreement lender group. Under the Credit Agreement, the Company is required to provide mortgage liens on assets having a value equal to at least 85 percent of the total PV-9, as defined in the Credit Agreement, of the Company’s proved oil and gas properties evaluated in the most recent reserve report. Collateral securing indebtedness under the Credit Agreement also secures the Company’s derivative agreement obligations.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Disclosures	Note 8 - Fair Value Measurements The Company follows fair value measurement accounting guidance for all assets and liabilities measured at fair value. This guidance defines fair value as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the measurement date. Market or observable inputs are the preferred sources of values, followed by assumptions based on hypothetical transactions in the absence of market inputs. The fair value hierarchy for grouping these assets and liabilities is based on the significance level of the following inputs: • Level 1 – quoted prices in active markets for identical assets or liabilities • Level 2 – quoted prices in active markets for similar assets or liabilities, quoted prices for identical or similar instruments in markets that are not active, and model-derived valuations whose inputs are observable or whose significant value drivers are observable • Level 3 – significant inputs to the valuation model are unobservable. The following table is a listing of the Company’s assets and liabilities that are measured at fair value in the accompanying balance sheets and where they are classified within the fair value hierarchy as of March 31, 2021: Level 1 Level 2 Level 3 (in thousands) Assets: Derivatives (1) $ — $ 34,426 $ — Liabilities: Derivatives (1) $ — $ 439,397 $ — __________________________________________ (1) This represents a financial asset or liability that is measured at fair value on a recurring basis. The following table is a listing of the Company’s assets and liabilities that are measured at fair value in the accompanying balance sheets and where they are classified within the fair value hierarchy as of December 31, 2020: Level 1 Level 2 Level 3 (in thousands) Assets: Derivatives (1) $ — $ 54,353 $ — Liabilities: Derivatives (1) $ — $ 222,520 $ — ____________________________________________ (1) This represents a financial asset or liability that is measured at fair value on a recurring basis. Both financial and non-financial assets and liabilities are categorized within the above fair value hierarchy based on the lowest level of input that is significant to the fair value measurement. The following is a description of the valuation methodologies used by the Company as well as the general classification of such instruments pursuant to the above fair value hierarchy. Derivatives The Company uses Level 2 inputs to measure the fair value of oil, gas, and NGL commodity derivatives. Fair values are based upon interpolated data. The Company derives internal valuation estimates taking into consideration forward commodity price curves, counterparties’ credit ratings, the Company’s credit rating, and the time value of money. These valuations are then compared to the respective counterparties’ mark-to-market statements. The considered factors result in an estimated exit price that management believes provides a reasonable and consistent methodology for valuing derivative instruments. The commodity derivative instruments utilized by the Company are not considered by management to be complex, structured, or illiquid. The oil, gas, and NGL commodity derivative markets are highly active. Please refer to Note 10 - Derivative Financial Instruments and to Note 11 - Fair Value Measurements in the 2020 Form 10-K for more information regarding the Company’s derivative instruments. Oil and Gas Properties and Other Property and Equipment The Company had no assets included in total property and equipment, net, measured at fair value as of March 31, 2021, or December 31, 2020. No proved property impairment expense was recorded during the three months ended March 31, 2021. For the three months ended March 31, 2020, the Company recorded impairment expense of $956.7 million related to its South Texas proved oil and gas properties and related support facilities as a result of the decrease in commodity price forecasts at the end of the first quarter of 2020, specifically decreases in oil and NGL prices. The Company used a discount rate of 11 percent in its calculation of the present value of expected future net cash flows based on the prevailing market-based weighted average cost of capital as of March 31, 2020. For the three months ended March 31, 2021, and 2020, the Company recorded impairment expense related to the abandonment and impairment of unproved properties of $8.8 million, and $33.1 million, respectively. These impairments related to actual and anticipated lease expirations, as well as actual and anticipated losses on acreage due to title defects, changes in development plans, and other inherent acreage risks. The balances in the unproved oil and gas properties line item on the accompanying balance sheets as of March 31, 2021, and December 31, 2020, are recorded at carrying value. Please refer to Note 1 - Summary of Significant Accounting Policies and Note 11 - Fair Value Measurements in the 2020 Form 10-K for more information regarding the Company’s approach in determining the fair value of its properties. Long-Term Debt The following table reflects the fair value of the Company’s Senior Note obligations measured using Level 1 inputs based on quoted secondary market trading prices. These notes were not presented at fair value on the accompanying balance sheets as of March 31, 2021, or December 31, 2020, as they were recorded at carrying value, net of any unamortized discounts and deferred financing costs. Please refer to Note 5 - Long-Term Debt for additional discussion. As of March 31, 2021 As of December 31, 2020 Principal Amount Fair Value Principal Amount Fair Value (in thousands) 1.50% Senior Secured Convertible Notes due 2021 $ 65,485 $ 63,864 $ 65,485 $ 61,449 10.0% Senior Secured Notes due 2025 $ 446,675 $ 502,858 $ 446,675 $ 482,887 6.125% Senior Unsecured Notes due 2022 $ 212,403 $ 209,633 $ 212,403 $ 205,379 5.0% Senior Unsecured Notes due 2024 $ 277,034 $ 261,936 $ 277,034 $ 240,072 5.625% Senior Unsecured Notes due 2025 $ 349,118 $ 323,007 $ 349,118 $ 289,401 6.75% Senior Unsecured Notes due 2026 $ 419,235 $ 387,373 $ 419,235 $ 342,385 6.625% Senior Unsecured Notes due 2027 $ 416,791 $ 384,323 $ 416,791 $ 331,220 The carrying value of the Company’s revolving credit facility approximates its fair value, as the applicable interest rates are floating, based on prevailing market rates.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation, Policy [Policy Text Block]	Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial information, the instructions to Quarterly Report on Form 10-Q, and Regulation S-X. These financial statements do not include all information and notes required by GAAP for annual financial statements. However, except as disclosed herein, there has been no material change in the information disclosed in the notes to the consolidated financial statements included in the 2020 Form 10-K . In the opinion of management, all adjustments, consisting of normal recurring adjustments considered necessary for a fair presentation of interim financial information, have been included. Operating results for the periods presented are not necessarily indicative of expected results for the full year. In connection with the preparation of the Company’s unaudited condensed consolidated financial statements, the Company evaluated events subsequent to the balance sheet date of March 31, 2021, and through the filing of this report. Additionally, certain prior period amounts have been reclassified to conform to current period presentation in the accompanying unaudited condensed consolidated financial statements.
Recently Issued Accounting Standards, Policy [Policy Text Block]	Recently Issued Accounting Standards In March 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“ASU 2020-04”) followed by ASU No. 2021-01, Reference Rate Reform (Topic 848): Scope (“ASU 2021-01”), issued in January 2021, to provide clarifying guidance regarding the scope of Topic 848. ASU 2020-04 was issued to provide optional guidance for a limited period of time to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform on financial reporting. Generally, the guidance is to be applied as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the date that the financial statements are available to be issued. ASU 2020-04 and ASU 2021-01 are effective for all entities through December 31, 2022. As of March 31, 2021, the Company has not elected to use the optional guidance and continues to evaluate the options provided by ASU 2020-04 and ASU 2021-01. Please refer to Note 5 - Long-Term Debt for discussion of the use of the London Interbank Offered Rate (“LIBOR”) in connection with borrowings under the Credit Agreement. There are no other ASUs that would have a material effect on the Company’s unaudited condensed consolidated financial statements and related disclosures that have been issued but not yet adopted by the Company as of March 31, 2021, or through the filing of this report.
Fair Value of Financial Instruments, Policy [Policy Text Block]	Derivatives The Company uses Level 2 inputs to measure the fair value of oil, gas, and NGL commodity derivatives. Fair values are based upon interpolated data. The Company derives internal valuation estimates taking into consideration forward commodity price curves, counterparties’ credit ratings, the Company’s credit rating, and the time value of money. These valuations are then compared to the respective counterparties’ mark-to-market statements. The considered factors result in an estimated exit price that management believes provides a reasonable and consistent methodology for valuing derivative instruments. The commodity derivative instruments utilized by the Company are not considered by management to be complex, structured, or illiquid. The oil, gas, and NGL commodity derivative markets are highly active. Please refer to Note 10 - Derivative Financial Instruments and to Note 11 - Fair Value Measurements in the 2020 Form 10-K for more information regarding the Company’s derivative instruments.

Fair Value Measures and Disclos

Fair Value Measures and Disclosures (Policies)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments, Policy [Policy Text Block]	Derivatives The Company uses Level 2 inputs to measure the fair value of oil, gas, and NGL commodity derivatives. Fair values are based upon interpolated data. The Company derives internal valuation estimates taking into consideration forward commodity price curves, counterparties’ credit ratings, the Company’s credit rating, and the time value of money. These valuations are then compared to the respective counterparties’ mark-to-market statements. The considered factors result in an estimated exit price that management believes provides a reasonable and consistent methodology for valuing derivative instruments. The commodity derivative instruments utilized by the Company are not considered by management to be complex, structured, or illiquid. The oil, gas, and NGL commodity derivative markets are highly active. Please refer to Note 10 - Derivative Financial Instruments and to Note 11 - Fair Value Measurements in the 2020 Form 10-K for more information regarding the Company’s derivative instruments.

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Disaggregation of oil, gas, and NGL production revenue [Table Text Block]	The table below presents oil, gas, and NGL production revenue by product type for each of the Company’s operating areas for the three months ended March 31, 2021, and 2020: Midland Basin South Texas Total Three Months Ended March 31, Three Months Ended March 31, Three Months Ended March 31, 2021 2020 2021 2020 2021 2020 (in thousands) Oil production revenue $ 286,105 $ 276,136 $ 19,672 $ 15,557 $ 305,777 $ 291,693 Gas production revenue 57,806 11,334 31,852 29,376 89,658 40,710 NGL production revenue 100 58 27,630 21,772 27,730 21,830 Total $ 344,011 $ 287,528 $ 79,154 $ 66,705 $ 423,165 $ 354,233 Relative percentage 81 % 81 % 19 % 19 % 100 % 100 % ____________________________________________ Note: Amounts may not calculate due to rounding.

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Schedule of provision for income taxes [Table Text Block]	The provision for income taxes for the three months ended March 31, 2021, and 2020, consisted of the following: For the Three Months Ended March 31, 2021 2020 (in thousands) Current portion of income tax (expense) benefit: Federal $ — $ — State (158) (339) Deferred portion of income tax benefit 52 99,347 Income tax (expense) benefit $ (106) $ 99,008 Effective tax rate — % 19.4 %

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments [Table Text Block]	The following table summarizes the Company’s total outstanding balance on its revolving credit facility, Senior Secured Notes net of unamortized discount and deferred financing costs, and Senior Unsecured Notes, net of unamortized deferred financing costs, as of March 31, 2021, and December 31, 2020: As of March 31, 2021 As of December 31, 2020 (in thousands) Revolving credit facility $ 135,000 $ 93,000 Senior Secured Notes (1) 464,222 460,656 Senior Unsecured Notes (1) 1,661,429 1,660,663 Total $ 2,260,651 $ 2,214,319 ____________________________________________ (1) Senior Secured Notes and Senior Unsecured Notes are defined below.
Schedule of Line of Credit Facilities [Table Text Block]	The following table presents the outstanding balance, total amount of letters of credit outstanding, and available borrowing capacity under the Credit Agreement as of April 21, 2021, March 31, 2021, and December 31, 2020: As of April 21, 2021 As of March 31, 2021 As of December 31, 2020 (in thousands) Revolving credit facility (1) $ 76,500 $ 135,000 $ 93,000 Letters of credit (2) — — 42,000 Available borrowing capacity 1,023,500 965,000 965,000 Total aggregate lender commitment amount $ 1,100,000 $ 1,100,000 $ 1,100,000 ____________________________________________ (1) Unamortized deferred financing costs attributable to the revolving credit facility are presented as a component of the other noncurrent assets line item on the accompanying balance sheets and totaled $3.9 million and $4.3 million as of March 31, 2021, and December 31, 2020, respectively. These costs are being amortized over the term of the revolving credit facility on a straight-line basis. (2) Letters of credit outstanding reduce the amount available under the revolving credit facility on a dollar-for-dollar basis.
Schedule Of Long-term Debt Instruments, Senior Secured Notes [Table Text Block]	Senior Secured Notes, net of unamortized discount and deferred financing costs, included within the Senior Notes, net line item on the accompanying balance sheets as of March 31, 2021, and December 31, 2020, consisted of the following: As of March 31, 2021 Principal Amount Unamortized Debt Discount Unamortized Deferred Financing Costs Net (in thousands) 1.50% Senior Secured Convertible Notes due 2021 $ 65,485 $ 914 $ 87 $ 64,484 10.0% Senior Secured Notes due 2025 446,675 36,085 10,852 399,738 Total $ 512,160 $ 36,999 $ 10,939 $ 464,222 As of December 31, 2020 Principal Amount Unamortized Debt Discount Unamortized Deferred Financing Costs Net (in thousands) 1.50% Senior Secured Convertible Notes due 2021 $ 65,485 $ 1,828 $ 175 $ 63,482 10.0% Senior Secured Notes due 2025 446,675 37,943 11,558 397,174 Total $ 512,160 $ 39,771 $ 11,733 $ 460,656
Schedule Of Long-term Debt Instruments, Senior Unsecured Notes [Table Text Block]	Senior Unsecured Notes, net of unamortized deferred financing costs, included within the Senior Notes, net line item on the accompanying balance sheets as of March 31, 2021, and December 31, 2020, consisted of the following: As of March 31, 2021 As of December 31, 2020 Principal Amount Unamortized Deferred Financing Costs Principal Amount, Net Principal Amount Unamortized Deferred Financing Costs Principal Amount, Net (in thousands) 6.125% Senior Notes due 2022 $ 212,403 $ 743 $ 211,660 $ 212,403 $ 855 $ 211,548 5.0% Senior Notes due 2024 277,034 1,448 275,586 277,034 1,576 275,458 5.625% Senior Notes due 2025 349,118 2,634 346,484 349,118 2,792 346,326 6.75% Senior Notes due 2026 419,235 3,795 415,440 419,235 3,970 415,265 6.625% Senior Notes due 2027 416,791 4,532 412,259 416,791 4,725 412,066 Total $ 1,674,581 $ 13,152 $ 1,661,429 $ 1,674,581 $ 13,918 $ 1,660,663

Earnings per Share (Tables)

Earnings per Share (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Schedule of weighted-average anti-dilutive securities	The following table details the weighted-average number of anti-dilutive securities for the periods presented: For the Three Months Ended March 31, 2021 2020 (in thousands) Anti-dilutive 8,106 1,219
Schedule of calculations of basic and diluted net loss per common share	The following table sets forth the calculations of basic and diluted net loss per common share: For the Three Months Ended March 31, 2021 2020 (in thousands, except per share data) Net loss $ (251,269) $ (411,895) Basic weighted-average common shares outstanding 114,759 113,009 Dilutive effect of non-vested RSUs and contingent PSUs — — Dilutive effect of warrants — — Diluted weighted-average common shares outstanding 114,759 113,009 Basic net loss per common share $ (2.19) $ (3.64) Diluted net loss per common share $ (2.19) $ (3.64)

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2021
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Schedule of notional amounts of outstanding derivative positions [Table Text Block]	As of March 31, 2021, the Company had commodity derivative contracts outstanding through the fourth quarter of 2023 as summarized in the tables below. Oil Swaps Contract Period NYMEX WTI Volumes Weighted-Average Contract Price (MBbl) (per Bbl) Second quarter 2021 5,508 $ 40.88 Third quarter 2021 5,363 $ 41.16 Fourth quarter 2021 4,744 $ 39.85 2022 7,823 $ 44.69 2023 1,190 $ 45.20 Total 24,628 Oil Collars Contract Period NYMEX WTI Volumes Weighted-Average Floor Price Weighted-Average Ceiling Price (MBbl) (per Bbl) (per Bbl) 2022 1,224 $ 50.00 $ 54.89 Oil Basis Swaps Contract Period WTI Midland-NYMEX WTI Volumes Weighted-Average Contract Price (1) NYMEX WTI-ICE Brent Volumes Weighted-Average Contract Price (2) WTI Houston MEH-NYMEX WTI Volumes Weighted-Average Contract Price (3) (MBbl) (per Bbl) (MBbl) (per Bbl) (MBbl) (per Bbl) Second quarter 2021 4,172 $ 0.81 910 $ (7.86) 493 $ 0.60 Third quarter 2021 3,756 $ 0.75 920 $ (7.86) 356 $ 0.60 Fourth quarter 2021 3,824 $ 0.71 920 $ (7.86) 466 $ 0.60 2022 9,500 $ 1.15 3,650 $ (7.78) 1,329 $ 1.25 Total 21,252 6,400 2,644 ____________________________________________ (1) Represents the price differential between WTI Midland (Midland, Texas) and NYMEX WTI (Cushing, Oklahoma). (2) Represents the price differential between NYMEX WTI (Cushing, Oklahoma) and ICE Brent (North Sea). (3) Represents the price differential between Argus WTI Houston MEH (Houston, Texas) and NYMEX WTI (Cushing, Oklahoma). Oil Roll Differential Swaps Contract Period NYMEX WTI Volumes Weighted-Average (MBbl) (per Bbl) Second quarter 2021 4,743 $ (0.16) Third quarter 2021 4,326 $ (0.18) Fourth quarter 2021 3,831 $ (0.16) 2022 11,278 $ 0.11 Total 24,178 Gas Swaps Contract Period IF HSC Volumes Weighted-Average WAHA Volumes Weighted-Average Contract Price (BBtu) (per MMBtu) (BBtu) (per MMBtu) Second quarter 2021 13,672 $ 2.45 7,230 $ 1.76 Third quarter 2021 12,575 $ 2.40 8,086 $ 1.88 Fourth quarter 2021 12,412 $ 2.41 7,627 $ 1.82 2022 28,932 $ 2.52 13,716 $ 2.30 Total (1) 67,591 36,659 ____________________________________________ (1) The Company has natural gas swaps in place that settle against Inside FERC Houston Ship Channel (“IF HSC”), Inside FERC West Texas (“IF WAHA”), and Platt’s Gas Daily West Texas (“GD WAHA”). As of March 31, 2021, WAHA volumes were comprised of 65 percent IF WAHA and 35 percent GD WAHA. NGL Swaps OPIS Propane Mont Belvieu Non-TET OPIS Normal Butane Mont Belvieu Non-TET Contract Period Volumes Weighted-Average Contract Price Volumes Weighted-Average (MBbl) (per Bbl) (MBbl) (per Bbl) Second quarter 2021 818 $ 22.14 37 $ 30.87 Third quarter 2021 854 $ 22.16 37 $ 30.87 Fourth quarter 2021 824 $ 22.15 36 $ 30.87 2022 231 $ 22.99 — $ — Total 2,727 110 NGL Collars Contract Period OPIS Propane Mont Belvieu Non-TET Weighted-Average Floor Price Weighted-Average Ceiling Price (MBbl) (per Bbl) (per Bbl) 2022 234 $ 22.05 $ 27.30
Schedule of fair value of derivatives in accompanying balance sheets [Table Text Block]	The following table details the fair value of commodity derivative contracts recorded in the accompanying balance sheets, by category: As of March 31, 2021 As of December 31, 2020 (in thousands) Derivative assets: Current assets $ 20,859 $ 31,203 Noncurrent assets 13,567 23,150 Total derivative assets $ 34,426 $ 54,353 Derivative liabilities: Current liabilities $ 371,802 $ 200,189 Noncurrent liabilities 67,595 22,331 Total derivative liabilities $ 439,397 $ 222,520
Schedule of the potential effects of master netting arrangements [Table Text Block]	The following table provides a reconciliation between the gross assets and liabilities reflected on the accompanying balance sheets and the potential effects of master netting arrangements on the fair value of the Company’s commodity derivative contracts: Derivative Assets as of Derivative Liabilities as of March 31, 2021 December 31, 2020 March 31, 2021 December 31, 2020 (in thousands) Gross amounts presented in the accompanying balance sheets $ 34,426 $ 54,353 $ (439,397) $ (222,520) Amounts not offset in the accompanying balance sheets (34,238) (53,598) 34,238 53,598 Net amounts $ 188 $ 755 $ (405,159) $ (168,922)
Schedule of the components of the derivative settlement (gain) loss and of the net derivative (gain) loss [Table Text Block]	The following table summarizes the commodity components of the derivative settlement (gain) loss, as well as the components of the net derivative (gain) loss line item presented in the accompanying statements of operations: For the Three Months Ended March 31, 2021 2020 (in thousands) Derivative settlement (gain) loss: Oil contracts $ 56,329 $ (53,582) Gas contracts 40,448 (14,625) NGL contracts 11,108 (5,230) Total net derivative settlement (gain) loss $ 107,885 $ (73,437) Net derivative (gain) loss: Oil contracts $ 265,815 $ (542,540) Gas contracts 48,922 6,728 NGL contracts 29,952 (9,528) Total net derivative (gain) loss $ 344,689 $ (545,340)

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The following table is a listing of the Company’s assets and liabilities that are measured at fair value in the accompanying balance sheets and where they are classified within the fair value hierarchy as of March 31, 2021: Level 1 Level 2 Level 3 (in thousands) Assets: Derivatives (1) $ — $ 34,426 $ — Liabilities: Derivatives (1) $ — $ 439,397 $ — __________________________________________ (1) This represents a financial asset or liability that is measured at fair value on a recurring basis. The following table is a listing of the Company’s assets and liabilities that are measured at fair value in the accompanying balance sheets and where they are classified within the fair value hierarchy as of December 31, 2020: Level 1 Level 2 Level 3 (in thousands) Assets: Derivatives (1) $ — $ 54,353 $ — Liabilities: Derivatives (1) $ — $ 222,520 $ — ____________________________________________ (1) This represents a financial asset or liability that is measured at fair value on a recurring basis.
Long Term Debt Fair Value [Table Text Block]	Long-Term Debt The following table reflects the fair value of the Company’s Senior Note obligations measured using Level 1 inputs based on quoted secondary market trading prices. These notes were not presented at fair value on the accompanying balance sheets as of March 31, 2021, or December 31, 2020, as they were recorded at carrying value, net of any unamortized discounts and deferred financing costs. Please refer to Note 5 - Long-Term Debt for additional discussion. As of March 31, 2021 As of December 31, 2020 Principal Amount Fair Value Principal Amount Fair Value (in thousands) 1.50% Senior Secured Convertible Notes due 2021 $ 65,485 $ 63,864 $ 65,485 $ 61,449 10.0% Senior Secured Notes due 2025 $ 446,675 $ 502,858 $ 446,675 $ 482,887 6.125% Senior Unsecured Notes due 2022 $ 212,403 $ 209,633 $ 212,403 $ 205,379 5.0% Senior Unsecured Notes due 2024 $ 277,034 $ 261,936 $ 277,034 $ 240,072 5.625% Senior Unsecured Notes due 2025 $ 349,118 $ 323,007 $ 349,118 $ 289,401 6.75% Senior Unsecured Notes due 2026 $ 419,235 $ 387,373 $ 419,235 $ 342,385 6.625% Senior Unsecured Notes due 2027 $ 416,791 $ 384,323 $ 416,791 $ 331,220

Disaggregation of oil, gas, and

Disaggregation of oil, gas, and NGL production revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 423,165	$ 354,233
Revenue, Remaining Performance Obligation, Amount	0
Midland Basin [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	344,011	287,528
South Texas [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 79,154	$ 66,705
Revenue Benchmark [Member] | Geographic Concentration Risk [Member]
Segment Reporting Information [Line Items]
Relative percentage	100.00%	100.00%
Revenue Benchmark [Member] | Geographic Concentration Risk [Member] | Midland Basin [Member]
Segment Reporting Information [Line Items]
Relative percentage	81.00%	81.00%
Revenue Benchmark [Member] | Geographic Concentration Risk [Member] | South Texas [Member]
Segment Reporting Information [Line Items]
Relative percentage	19.00%	19.00%
Oil production revenue [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 305,777	$ 291,693
Oil production revenue [Member] | Midland Basin [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	286,105	276,136
Oil production revenue [Member] | South Texas [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	19,672	15,557
Gas production revenue [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	89,658	40,710
Gas production revenue [Member] | Midland Basin [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	57,806	11,334
Gas production revenue [Member] | South Texas [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	31,852	29,376
NGL production revenue [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	27,730	21,830
NGL production revenue [Member] | Midland Basin [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	100	58
NGL production revenue [Member] | South Texas [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 27,630	$ 21,772

Accounts Receivable from Custom

Accounts Receivable from Customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Accounts Receivable [Line Items]
Accounts receivable from contracts with customers	$ 199,631	$ 162,455
Accrued Income Receivable [Member]
Accounts Receivable [Line Items]
Accounts receivable from contracts with customers	$ 152,100	$ 108,900
Minimum [Member]
Accounts Receivable [Line Items]
Revenue receipt, days after sale	30
Maximum [Member]
Accounts Receivable [Line Items]
Revenue receipt, days after sale	90

Equity (Details)

Equity (Details) - USD ($) $ / shares in Units, $ in Millions	Apr. 29, 2021	Jan. 14, 2021	Jun. 17, 2020
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights			5,900,000
Warrants Percent of Outstanding Stock			5.00%
Exercise Price of Warrants			$ 0.01
Issuance of Warrants			$ 21.5
Warrant Triggering Date - Amount			$ 1,000
Class of Warrant or Right, Date from which Warrants or Rights Exercisable		Jan. 14, 2021
Subsequent Event [Member]
Class of Warrant or Right [Line Items]
Restricted Stock, Shares Issued Net of Shares for Tax Withholdings	3,083,403
WarrantsExercised	3,086,147
Weighted Average | Subsequent Event [Member]
Class of Warrant or Right [Line Items]
Shares Issued, Price Per Share	$ 11.36

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Components of the provision for income taxes
Federal	$ 0	$ 0
State	(158)	(339)
Deferred portion of income tax benefit	52	99,347
Income tax (expense) benefit	$ (106)	$ 99,008
Effective tax rate	0.00%	19.40%

Long-Term Debt (Details)

Long-Term Debt (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Long-Term Debt [Line Items]
Total long-term debt, net	$ 2,260,651		$ 2,214,319
Debt Instrument, Covenant Compliance	The Company was in compliance with all covenants under the Credit Agreement and the indentures governing the Senior Notes as of March 31, 2021, and through the filing of this report.
Capitalized interest costs	$ 4,300	$ 2,700

Credit Agreement (Details)

Credit Agreement (Details) - USD ($) $ in Thousands	Apr. 21, 2021	Mar. 31, 2021	Dec. 31, 2020
Line of Credit Facility [Line Items]
Revolving credit facility		$ 135,000	$ 93,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility		135,000	93,000
Revolving credit facility, maximum loan amount		2,500,000
Revolving credit facility, current borrowing base		1,100,000
Revolving credit facility, aggregate lender commitments		1,100,000	1,100,000
Letters of credit		0	42,000
Available borrowing capacity		965,000	965,000
Revolving Credit Facility, unamortized deferred financing costs		$ 3,900	$ 4,300
Revolving Credit Facility [Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Revolving credit facility	$ 76,500
Revolving credit facility, aggregate lender commitments	1,100,000
Letters of credit	0
Available borrowing capacity	$ 1,023,500

Senior Secured Notes (Details)

Senior Secured Notes (Details)	3 Months Ended
	Mar. 31, 2021USD ($)$ / shares	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)
Senior Notes [Line Items]
Secured Long-term Debt, Noncurrent	$ 464,222,000		$ 460,656,000
1.50% Senior Secured Convertible Notes Due 2021 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	1.50%		1.50%
Senior Notes, Principal amount	$ 65,485,000		$ 65,485,000
Senior Secured Notes, Unamortized Debt Discount	914,000		1,828,000
Senior Notes, unamortized deferred financing costs	87,000		175,000
Secured Long-term Debt, Noncurrent	$ 64,484,000		$ 63,482,000
Debt Instrument, Convertible, Conversion Ratio	24.6914
Debt Instrument, Principal Amount of Note	$ 1,000
Senior Convertible Notes, conversion price | $ / shares	$ 40.50
Interest Expense, Debt	$ 1,200,000	$ 2,900,000
10.0% Senior Secured Notes due 2025 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	10.00%		10.00%
Senior Notes, Principal amount	$ 446,675,000		$ 446,675,000
Senior Secured Notes, Unamortized Debt Discount	36,085,000		37,943,000
Senior Notes, unamortized deferred financing costs	10,852,000		11,558,000
Secured Long-term Debt, Noncurrent	399,738,000		397,174,000
Senior Secured Notes [Member]
Senior Notes [Line Items]
Senior Notes, Principal amount	512,160,000		512,160,000
Senior Secured Notes, Unamortized Debt Discount	36,999,000		39,771,000
Senior Notes, unamortized deferred financing costs	$ 10,939,000		$ 11,733,000

Senior Unsecured Notes (Details

Senior Unsecured Notes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Senior Notes [Line Items]
Unsecured Long-term Debt, Noncurrent	$ 1,661,429		$ 1,660,663
Gain (Loss) on Extinguishment of Debt	$ 0	$ 12,195
6.125% Senior Unsecured Notes due 2022 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	6.125%		6.125%
Senior Notes, Principal amount	$ 212,403		$ 212,403
Senior Notes, unamortized deferred financing costs	743		855
Unsecured Long-term Debt, Noncurrent	$ 211,660		$ 211,548
Senior Unsecured Notes, exchanged or repurchased face amount		40,700
Senior Unsecured Notes, repurchased settlement amount		28,300
Gain (Loss) on Extinguishment of Debt		12,200
Discount realized on extinguishment of debt		12,400
Write off of Deferred Debt Issuance Cost		$ 235
5.0% Senior Unsecured Notes due 2024 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	5.00%		5.00%
Senior Notes, Principal amount	$ 277,034		$ 277,034
Senior Notes, unamortized deferred financing costs	1,448		1,576
Unsecured Long-term Debt, Noncurrent	$ 275,586		$ 275,458
5.625% Senior Unsecured Notes due 2025 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	5.625%		5.625%
Senior Notes, Principal amount	$ 349,118		$ 349,118
Senior Notes, unamortized deferred financing costs	2,634		2,792
Unsecured Long-term Debt, Noncurrent	$ 346,484		$ 346,326
6.75% Senior Unsecured Notes due 2026 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	6.75%		6.75%
Senior Notes, Principal amount	$ 419,235		$ 419,235
Senior Notes, unamortized deferred financing costs	3,795		3,970
Unsecured Long-term Debt, Noncurrent	$ 415,440		$ 415,265
6.625% Senior Unsecured Notes due 2027 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	6.625%		6.625%
Senior Notes, Principal amount	$ 416,791		$ 416,791
Senior Notes, unamortized deferred financing costs	4,532		4,725
Unsecured Long-term Debt, Noncurrent	412,259		412,066
Senior Unsecured Notes [Member]
Senior Notes [Line Items]
Senior Notes, Principal amount	1,674,581		1,674,581
Senior Notes, unamortized deferred financing costs	$ 13,152		$ 13,918

Commitments (Details)

Commitments (Details) $ in Millions	Mar. 31, 2021USD ($)
Drilling Rig Leasing Contracts [Member]
Commitments and Contingencies [Line Items]
Contractual Obligation	$ 23.5
Early Termination Penalty for Rig Contract Cancellation	14
Minimum [Member]
Commitments and Contingencies [Line Items]
Potential penalty for not meeting minimum drilling and completion requirements	0
Maximum [Member]
Commitments and Contingencies [Line Items]
Potential penalty for not meeting minimum drilling and completion requirements	$ 51.3

Compensation Plans_ Stock Based

Compensation Plans: Stock Based (Details) $ in Millions	Mar. 31, 2021USD ($)shares	Mar. 31, 2021USD ($)shares	Mar. 31, 2020USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant | shares	3,800,000	3,800,000
Performance Shares (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award Vesting Period	3 years
Stock-based compensation expense		$ 3.2	$ 2.6
Unrecognized stock based compensation expense	$ 4.5	$ 4.5
Performance Shares (PSUs) | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Multiplier applied to PSU awards at settlement	0	0
Performance Shares (PSUs) | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Multiplier applied to PSU awards at settlement	2	2
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		$ 2.2	$ 2.6
Unrecognized stock based compensation expense	$ 12.5	$ 12.5
Number of shares represented by each RSU | shares	1	1

Earnings per Share (Details)

Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings​ Per ​Share​ Basic ​Line ​Items
Anti-dilutive securities excluded from earnings per share	8,106	1,219
Earnings Per Share Reconciliation [Abstract]
Net loss	$ (251,269)	$ (411,895)
Basic weighted-average common shares outstanding	114,759	113,009
Dilutive effect of non-vested RSUs and contingent PSUs	0	0
Dilutive effect of warrants	0	0
Diluted weighted-average common shares outstanding	114,759	113,009
Basic net loss per common share	$ (2.19)	$ (3.64)
Diluted net loss per common share	(2.19)	$ (3.64)
1.50% Senior Secured Convertible Notes Due 2021 [Member]
Earnings​ Per ​Share​ Basic ​Line ​Items
Senior Convertible Notes, conversion price	$ 40.50

Derivative Financial Instrume_3

Derivative Financial Instruments (Details) bbl in Thousands, BTU in Billions	Apr. 29, 2021$ / Barrelsbbl	Mar. 31, 2021BTU$ / Barrels$ / EnergyContentbbl
NYMEX Oil Swap Contract Second Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		5,508
Derivative, Swap Type, Weighted-Average Contract Price | $ / Barrels		40.88
NYMEX Oil Swap Contract Third Quarter, 2021
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		5,363
Derivative, Swap Type, Weighted-Average Contract Price | $ / Barrels		41.16
NYMEX Oil Swap Contract Fourth Quarter, 2021
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		4,744
Derivative, Swap Type, Weighted-Average Contract Price | $ / Barrels		39.85
NYMEX Oil Swap Contract, 2022 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		7,823
Derivative, Swap Type, Weighted-Average Contract Price | $ / Barrels		44.69
NYMEX Oil Swap Contract, 2023
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		1,190
Derivative, Swap Type, Weighted-Average Contract Price | $ / Barrels		45.20
NYMEX Oil Swap Contracts [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		24,628
NYMEX Oil Collar Contract, 2022 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		1,224
Derivative, Weighted-Average Floor Price | $ / Barrels		50
Derivative, Weighted-Average Ceiling Price | $ / Barrels		54.89
NYMEX Oil Calendar Month Average Roll Differential Second Quarter, 2021
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		4,743
Derivative, Roll Differential Swap Type, Weighted-Average Contract Price | $ / Barrels		(0.16)
NYMEX Oil Calendar Month Average Roll Differential Contract Third Quarter, 2021
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		4,326
Derivative, Roll Differential Swap Type, Weighted-Average Contract Price | $ / Barrels		(0.18)
NYMEX Oil Calendar Month Average Roll Differential Fourth Quarter, 2021
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		3,831
Derivative, Roll Differential Swap Type, Weighted-Average Contract Price | $ / Barrels		(0.16)
NYMEX Oil Calendar Month Average Roll Differential Contract, 2022
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		11,278
Derivative, Roll Differential Swap Type, Weighted-Average Contract Price | $ / Barrels		0.11
NYMEX Oil Calendar Month Average Roll Differential Contracts [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		24,178
WTI Midland NYMEX WTI [Member] | Oil Basis Swap Contract Second Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		4,172
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | $ / Barrels		0.81
WTI Midland NYMEX WTI [Member] | Oil Basis Swap Contract Third Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		3,756
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | $ / Barrels		0.75
WTI Midland NYMEX WTI [Member] | Oil Basis Swap Contract Fourth Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		3,824
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | $ / Barrels		0.71
WTI Midland NYMEX WTI [Member] | Oil Basis Swap Contract, 2022 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		9,500
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | $ / Barrels		1.15
WTI Midland NYMEX WTI [Member] | Oil Basis Swap [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		21,252
NYMEX WTI ICE Brent [Member] | Oil Basis Swap Contract Second Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		910
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | $ / Barrels		(7.86)
NYMEX WTI ICE Brent [Member] | Oil Basis Swap Contract Third Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		920
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | $ / Barrels		(7.86)
NYMEX WTI ICE Brent [Member] | Oil Basis Swap Contract Fourth Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		920
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | $ / Barrels		(7.86)
NYMEX WTI ICE Brent [Member] | Oil Basis Swap Contract, 2022 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		3,650
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | $ / Barrels		(7.78)
NYMEX WTI ICE Brent [Member] | Oil Basis Swap [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		6,400
WTI Houston MEH NYMEX WTI | Oil Basis Swap Contract Second Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		493
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | $ / Barrels		0.60
WTI Houston MEH NYMEX WTI | Oil Basis Swap Contract Third Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		356
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | $ / Barrels		0.60
WTI Houston MEH NYMEX WTI | Oil Basis Swap Contract Fourth Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		466
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | $ / Barrels		0.60
WTI Houston MEH NYMEX WTI | Oil Basis Swap Contract, 2022 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		1,329
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | $ / Barrels		1.25
WTI Houston MEH NYMEX WTI | Oil Basis Swap [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		2,644
IF HSC [Member] | Gas Swaps Contract Second Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU		13,672
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent		2.45
IF HSC [Member] | Gas Swaps Contract Third Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU		12,575
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent		2.40
IF HSC [Member] | Gas Swaps Contract Fourth Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU		12,412
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent		2.41
IF HSC [Member] | Gas Swaps Contract, 2022 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU		28,932
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent		2.52
IF HSC [Member] | Gas Swaps Contracts [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU		67,591
WAHA [Member] | Gas Swaps Contract Second Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU		7,230
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent		1.76
WAHA [Member] | Gas Swaps Contract Third Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU		8,086
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent		1.88
WAHA [Member] | Gas Swaps Contract Fourth Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU		7,627
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent		1.82
WAHA [Member] | Gas Swaps Contract, 2022 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU		13,716
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent		2.30
WAHA [Member] | Gas Swaps Contracts [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU		36,659
IF WAHA [Member]
Derivative Financial Instruments
Index percent of natural gas fixed swaps		65.00%
GD WAHA [Member]
Derivative Financial Instruments
Index percent of natural gas fixed swaps		35.00%
OPIS Propane Mont Belvieu Non-TET [Member] | NGL Swaps Contract Second Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		818
Derivative, Swap Type, Weighted-Average Contract Price | $ / Barrels		22.14
OPIS Propane Mont Belvieu Non-TET [Member] | NGL Swaps Contract Third Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		854
Derivative, Swap Type, Weighted-Average Contract Price | $ / Barrels		22.16
OPIS Propane Mont Belvieu Non-TET [Member] | NGL Swaps Contract Fourth Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		824
Derivative, Swap Type, Weighted-Average Contract Price | $ / Barrels		22.15
OPIS Propane Mont Belvieu Non-TET [Member] | NGL Swaps Contract, 2022 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		231
Derivative, Swap Type, Weighted-Average Contract Price | $ / Barrels		22.99
OPIS Propane Mont Belvieu Non-TET [Member] | NGL Swaps Contracts [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		2,727
OPIS Propane Mont Belvieu Non-TET [Member] | NGL Collar Contract, Year 2
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		234
Derivative, Weighted-Average Floor Price | $ / Barrels		22.05
Derivative, Weighted-Average Ceiling Price | $ / Barrels		27.30
OPIS Normal Butane Mont Belvieu | NGL Swaps Contract Second Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		37
Derivative, Swap Type, Weighted-Average Contract Price | $ / Barrels		30.87
OPIS Normal Butane Mont Belvieu | NGL Swaps Contract Third Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		37
Derivative, Swap Type, Weighted-Average Contract Price | $ / Barrels		30.87
OPIS Normal Butane Mont Belvieu | NGL Swaps Contract Fourth Quarter, 2021 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		36
Derivative, Swap Type, Weighted-Average Contract Price | $ / Barrels		30.87
OPIS Normal Butane Mont Belvieu | NGL Swaps Contract, 2022 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		0
Derivative, Swap Type, Weighted-Average Contract Price | $ / Barrels		0
OPIS Normal Butane Mont Belvieu | NGL Swaps Contracts [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume		110
Subsequent Event [Member] | NYMEX Oil Collar Contract, 2022 [Member]
Derivative Financial Instruments
Derivative, Nonmonetary Notional Amount, Volume	180
Derivative, Weighted-Average Floor Price | $ / Barrels	50
Derivative, Weighted-Average Ceiling Price | $ / Barrels	65

Derivative Financial Instrume_4

Derivative Financial Instruments Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair value of derivative assets and liabilities
Derivative, fair value, net	$ (405,000)	$ (168,200)
Derivative assets, current	20,859	31,203
Derivative assets, noncurrent	13,567	23,150
Total derivative assets	34,426	54,353
Derivative liabilities, current	371,802	200,189
Derivatives liabilities, noncurrent	67,595	22,331
Total derivative liabilities	(439,397)	(222,520)
Derivative asset, amounts not offset in the accompanying balance sheets	(34,238)	(53,598)
Derivative liabilities, amounts not offset in the accompanying balance sheets	34,238	53,598
Derivative asset, fair value, net amounts	188	755
Derivative liabilities, fair value, net amounts	(405,159)	(168,922)
Not Designated as Hedging Instrument [Member]
Fair value of derivative assets and liabilities
Derivative assets, current	20,859	31,203
Derivative assets, noncurrent	13,567	23,150
Derivative liabilities, current	371,802	200,189
Derivatives liabilities, noncurrent	67,595	22,331
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Not Designated as Hedging Instrument [Member]
Fair value of derivative assets and liabilities
Total derivative assets	34,426	54,353
Total derivative liabilities	$ 439,397	$ 222,520

Derivative Financial Instrume_5

Derivative Financial Instruments Gains and Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Derivative Instruments, (Gain) Loss [Line Items]
Derivative settlement (gain) loss	$ 107,885	$ (73,437)
Net derivative (gain) loss	344,689	(545,340)
Oil Contracts [Member]
Derivative Instruments, (Gain) Loss [Line Items]
Derivative settlement (gain) loss	56,329	(53,582)
Net derivative (gain) loss	265,815	(542,540)
Gas Contracts [Member]
Derivative Instruments, (Gain) Loss [Line Items]
Derivative settlement (gain) loss	40,448	(14,625)
Net derivative (gain) loss	48,922	6,728
NGL Contracts [Member]
Derivative Instruments, (Gain) Loss [Line Items]
Derivative settlement (gain) loss	11,108	(5,230)
Net derivative (gain) loss	$ 29,952	$ (9,528)

Credit Facility and Derivative

Credit Facility and Derivative Counterparties (Details)	Mar. 31, 2021
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Percentage of proved property secured for credit facility borrowing	85.00%

Fair Value (Details)

Fair Value (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)
Assets
Derivative Assets, Fair Value, Gross Asset	$ 34,426		$ 54,353
Liabilities
Derivative Liability, Fair Value, Gross Liability	(439,397)		$ (222,520)
Oil and Gas Property [Abstract]
Property, Plant, and Equipment, Fair Value Disclosure	0
Impairment of proved oil and gas properties and related support equipment	0	$ 956,700
Abandonment and impairment of unproved properties	$ 8,800	$ 33,100
1.50% Senior Secured Convertible Notes Due 2021 [Member]
Debt Instrument, Fair Value Disclosure [Abstract]
Senior Notes, interest rate, stated percentage	1.50%		1.50%
Senior Notes, Principal amount	$ 65,485		$ 65,485
Long-term Debt, Fair Value	$ 63,864		$ 61,449
10.0% Senior Secured Notes due 2025 [Member]
Debt Instrument, Fair Value Disclosure [Abstract]
Senior Notes, interest rate, stated percentage	10.00%		10.00%
Senior Notes, Principal amount	$ 446,675		$ 446,675
Long-term Debt, Fair Value	$ 502,858		$ 482,887
6.125% Senior Unsecured Notes due 2022 [Member]
Debt Instrument, Fair Value Disclosure [Abstract]
Senior Notes, interest rate, stated percentage	6.125%		6.125%
Senior Notes, Principal amount	$ 212,403		$ 212,403
Long-term Debt, Fair Value	$ 209,633		$ 205,379
5.0% Senior Unsecured Notes due 2024 [Member]
Debt Instrument, Fair Value Disclosure [Abstract]
Senior Notes, interest rate, stated percentage	5.00%		5.00%
Senior Notes, Principal amount	$ 277,034		$ 277,034
Long-term Debt, Fair Value	$ 261,936		$ 240,072
5.625% Senior Unsecured Notes due 2025 [Member]
Debt Instrument, Fair Value Disclosure [Abstract]
Senior Notes, interest rate, stated percentage	5.625%		5.625%
Senior Notes, Principal amount	$ 349,118		$ 349,118
Long-term Debt, Fair Value	$ 323,007		$ 289,401
6.75% Senior Unsecured Notes due 2026 [Member]
Debt Instrument, Fair Value Disclosure [Abstract]
Senior Notes, interest rate, stated percentage	6.75%		6.75%
Senior Notes, Principal amount	$ 419,235		$ 419,235
Long-term Debt, Fair Value	$ 387,373		$ 342,385
6.625% Senior Unsecured Notes due 2027 [Member]
Debt Instrument, Fair Value Disclosure [Abstract]
Senior Notes, interest rate, stated percentage	6.625%		6.625%
Senior Notes, Principal amount	$ 416,791		$ 416,791
Long-term Debt, Fair Value	384,323		331,220
Fair Value, Nonrecurring [Member] | Measurement Input, Discount Rate [Member] | Oil and Gas Properties
Oil and Gas Property [Abstract]
Fair Value Assumptions, Measurement Input		0.11
Not Designated as Hedging Instrument [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets
Derivative Assets, Fair Value, Gross Asset	0		0
Liabilities
Derivative Liability, Fair Value, Gross Liability	0		0
Not Designated as Hedging Instrument [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets
Derivative Assets, Fair Value, Gross Asset	34,426		54,353
Liabilities
Derivative Liability, Fair Value, Gross Liability	439,397		222,520
Not Designated as Hedging Instrument [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets
Derivative Assets, Fair Value, Gross Asset	0		0
Liabilities
Derivative Liability, Fair Value, Gross Liability	$ 0		$ 0