Carrizo Oil & Gas (CRZO) 10-Q 7 Nov 18 2018 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Nov. 02, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Entity Registrant Name	CARRIZO OIL & GAS INC
Entity Central Index Key	1,040,593
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		91,625,532

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 2,415,000	$ 9,540,000
Accounts receivable, net	128,780,000	107,441,000
Derivative assets, current	10,258,000	0
Other current assets	9,636,000	5,897,000
Total current assets	151,089,000	122,878,000
Oil and gas properties, full cost method
Proved properties, net	2,124,767,000	1,965,347,000
Unproved properties, not being amortized	579,275,000	660,287,000
Other property and equipment, net	10,885,000	10,176,000
Total property and equipment, net	2,714,927,000	2,635,810,000
Deposit For Acquisition Of Oil And Gas Properties	21,500,000	0
Other assets	23,482,000	19,616,000
Total Assets	2,910,998,000	2,778,304,000
Current liabilities
Accounts payable	147,670,000	74,558,000
Revenues and royalties payable	52,975,000	52,154,000
Accrued capital expenditures	117,556,000	119,452,000
Accrued interest	23,748,000	28,362,000
Derivative liabilities	162,895,000	57,121,000
Other current liabilities	50,918,000	41,175,000
Total current liabilities	555,762,000	372,822,000
Long-term debt	1,327,689,000	1,629,209,000
Asset retirement obligations	17,071,000	23,497,000
Derivative liabilities, noncurrent	102,103,000	112,332,000
Deferred income tax liabilities, noncurrent	4,699,000	3,635,000
Other liabilities	8,703,000	51,650,000
Liabilities	2,016,027,000	2,193,145,000
Preferred stock, $0.01 par value, 10,000,000 shares authorized; 200,000 issued and outstanding as of September 30, 2018 and 250,000 issued and outstanding as of December 31, 2017	173,629,000	214,262,000
Shareholders’ equity
Common stock, $0.01 par value, 180,000,000 shares authorized; 91,619,733 issued and outstanding as of September 30, 2018 and 81,454,621 issued and outstanding as of December 31, 2017	916,000	815,000
Additional paid-in capital	2,132,253,000	1,926,056,000
Accumulated deficit	(1,411,827,000)	(1,555,974,000)
Total shareholders’ equity	721,342,000	370,897,000
Total Liabilities and Shareholders’ Equity	$ 2,910,998,000	$ 2,778,304,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	180,000,000	180,000,000
Common stock, shares issued (in shares)	91,619,733	81,454,621
Common stock, shares outstanding (in shares)	91,619,733	81,454,621
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	10,000,000	10,000,000
Preferred Stock, Shares Issued	200,000	250,000
Preferred Stock, Shares Outstanding	200,000	250,000

Consolidated Statements Of Oper

Consolidated Statements Of Operations (Unaudited) - USD ($) shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Crude oil revenues	$ 254,525,000	$ 152,101,000	$ 679,242,000	$ 422,999,000
Natural gas liquids revenues	33,798,000	12,467,000	71,969,000	27,678,000
Natural gas revenues	15,052,000	16,711,000	41,417,000	48,440,000
Total revenues	303,375,000	181,279,000	792,628,000	499,117,000
Costs and Expenses
Lease operating	41,022,000	34,874,000	115,446,000	100,767,000
Production taxes	14,516,000	7,741,000	37,578,000	21,092,000
Ad valorem taxes	2,588,000	1,736,000	8,201,000	5,776,000
Depreciation, depletion and amortization	80,108,000	67,564,000	217,005,000	181,018,000
General and administrative, net	12,811,000	16,029,000	58,368,000	49,328,000
(Gain) loss on derivatives, net	55,388,000	24,377,000	152,698,000	(27,004,000)
Interest expense, net	15,406,000	20,673,000	46,522,000	62,350,000
Loss on extinguishment of debt	0	0	8,676,000	0
Other (income) expense, net	(690,000)	462,000	2,305,000	1,640,000
Total Costs and Expenses	221,149,000	173,456,000	646,799,000	394,967,000
Income Before Income Taxes	82,226,000	7,823,000	145,829,000	104,150,000
Income tax expense	(880,000)	0	(1,682,000)	0
Net Income (loss)	81,346,000	7,823,000	144,147,000	104,150,000
Dividends on preferred stock	(4,457,000)	(2,249,000)	(13,794,000)	(2,249,000)
Accretion on preferred stock	(771,000)	0	(2,264,000)	0
Loss on redemption of preferred stock	0	0	(7,133,000)	0
Net Income Attributable to Common Shareholders	$ 76,118,000	$ 5,574,000	$ 120,956,000	$ 101,901,000
Net Income Attributable to Common Shareholders Per Common Share
Income (loss) per share, basic (in dollars per share)	$ 0.88	$ 0.07	$ 1.45	$ 1.44
Income (loss) per share, diluted (in dollars per share)	$ 0.85	$ 0.07	$ 1.42	$ 1.43
Weighted Average Common Shares Outstanding
Basic (in shares)	86,727	81,053	83,461	70,728
Diluted (in shares)	89,039	81,138	85,221	71,147

Consolidated Statements Of Shar

Consolidated Statements Of Shareholders' Equity - 9 months ended Sep. 30, 2018 - USD ($)	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]
BALANCE at Dec. 31, 2017	$ 370,897,000	$ 815,000	$ 1,926,056,000	$ (1,555,974,000)
BALANCE, shares at Dec. 31, 2017		81,454,621
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	15,701,000		15,701,000
Issuance of common stock upon grants of restricted stock awards and vestings of restricted stock units and performance shares, net of forfeitures	(69,000)	$ 6,000	(75,000)
Issuance of common stock upon grants of restricted stock awards and vestings of restricted stock units and performance shares, net of forfeitures, shares		665,112
Sale of common stock, net of offering costs	$ 213,857,000	$ 95,000	213,762,000
Sale of common stock, net of offering costs, shares	9,500,000	9,500,000
Dividends on preferred stock	$ (13,794,000)		(13,794,000)
Accretion on preferred stock	(2,264,000)		(2,264,000)
Loss on redemption of preferred stock	(7,133,000)		(7,133,000)
Net Income (loss)	144,147,000			144,147,000
BALANCE at Sep. 30, 2018	$ 721,342,000	$ 916,000	$ 2,132,253,000	$ (1,411,827,000)
BALANCE, shares at Sep. 30, 2018		91,619,733

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Net income (loss)	$ 144,147	$ 104,150
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation, depletion and amortization	217,005	181,018
(Gain) loss on derivatives, net	152,698	(27,004)
Cash received (paid) for derivative settlements, net	(64,710)	7,714
Loss on extinguishment of debt	8,676	0
Stock-based compensation expense, net	13,786	8,462
Deferred income taxes	1,063	0
Non-cash interest expense, net	1,878	2,961
Other, net	4,100	4,249
Changes in components of working capital and other assets and liabilities-
Accounts receivable	(12,763)	(25,885)
Accounts payable	10,863	14,748
Accrued liabilities	(9,336)	11,970
Other assets and liabilities, net	(2,115)	(1,786)
Net cash provided by operating activities	465,292	280,597
Cash Flows From Investing Activities
Capital expenditures	(662,459)	(433,561)
Acquisitions of oil and gas properties	0	(692,006)
Deposit (paid for pending acquisition) received for pending divestiture of oil and gas properties	(21,500)
Proceeds from divestitures of oil and gas properties, net	377,693	18,212
Deposit for divestiture of oil and gas properties		6,200
Other, net	(2,687)	(3,804)
Net cash used in investing activities	(308,953)	(1,104,959)
Cash Flows From Financing Activities
Issuance of senior notes	0	250,000
Redemptions of senior notes and other long-term debt	(330,435)	0
Redemption of preferred stock	(50,030)	0
Borrowings under credit agreement	2,415,208	1,311,875
Repayments of borrowings under credit agreement	(2,396,671)	(1,183,275)
Payments of debt issuance costs and credit facility amendment fees	(627)	(8,964)
Sale of common stock, net of offering costs	213,857	222,378
Sale of preferred stock, net of issuance costs	0	236,404
Payments of dividends on preferred stock	(13,794)	(2,249)
Other, net	(972)	(909)
Net cash provided by (used in) financing activities	(163,464)	825,260
Net Increase (Decrease) in Cash and Cash Equivalents	(7,125)	898
Cash and Cash Equivalents, Beginning of Period	9,540	4,194
Cash and Cash Equivalents, End of Period	$ 2,415	$ 5,092

Nature Of Operations

Nature Of Operations	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature Of Operations	1. Basis of Presentation Nature of Operations Carrizo Oil & Gas, Inc. is a Houston-based energy company which, together with its subsidiaries (collectively, the “Company”), is actively engaged in the exploration, development, and production of crude oil, NGLs, and natural gas from resource plays located in the United States. The Company’s current operations are principally focused in proven, producing oil and gas plays in the Eagle Ford Shale in South Texas and the Permian Basin in West Texas. Consolidated Financial Statements The accompanying unaudited interim consolidated financial statements include the accounts of the Company after elimination of intercompany transactions and balances and have been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”) and therefore do not include all disclosures required for financial statements prepared in conformity with accounting principles generally accepted in the U.S. (“GAAP”). In the opinion of management, these financial statements include all adjustments (consisting of normal recurring accruals and adjustments) necessary to present fairly, in all material respects, the Company’s interim financial position, results of operations and cash flows. However, the results of operations for the periods presented are not necessarily indicative of the results of operations that may be expected for the full year. These financial statements and related notes included in this Quarterly Report on Form 10-Q should be read in conjunction with the Company’s audited Consolidated Financial Statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 (“ 2017 Annual Report”).

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Summary Of Significant Accounting Policies	2. Summary of Significant Accounting Policies Recently Adopted Accounting Standards Revenue From Contracts with Customers . Effective January 1, 2018, the Company adopted ASU No. 2014-09, Revenue From Contracts With Customers (Topic 606) (“ASC 606”) using the modified retrospective method and has applied the standard to all existing contracts. ASC 606 supersedes previous revenue recognition requirements in ASC 605 - Revenue Recognition (“ASC 605”) and includes a five-step revenue recognition model to depict the transfer of goods or services to customers in an amount that reflects the consideration in exchange for those goods or services. As a result of adopting ASC 606, the Company did not have a cumulative-effect adjustment in retained earnings. The comparative information for the three and nine months ended September 30, 2017 has not been recast and continues to be reported under the accounting standards in effect for that period. Additionally, adoption of ASC 606 did not impact net income attributable to common shareholders and the Company does not expect that it will do so in future periods. The tables below summarize the impact of adoption for the three and nine months ended September 30, 2018 : Three Months Ended September 30, 2018 Under ASC 606 Under ASC 605 Increase % Increase (In thousands) Revenues Crude oil $254,525 $254,382 $143 0.1 % Natural gas liquids 33,798 32,018 1,780 5.6 % Natural gas 15,052 14,280 772 5.4 % Total revenues 303,375 300,680 2,695 0.9 % Costs and Expenses Lease operating 41,022 38,327 2,695 7.0 % Income Before Income Taxes $82,226 $82,226 $— — % Nine Months Ended September 30, 2018 Under ASC 606 Under ASC 605 Increase % Increase (In thousands) Revenues Crude oil $679,242 $678,834 $408 0.1 % Natural gas liquids 71,969 68,253 3,716 5.4 % Natural gas 41,417 39,439 1,978 5.0 % Total revenues 792,628 786,526 6,102 0.8 % Costs and Expenses Lease operating 115,446 109,344 6,102 5.6 % Income Before Income Taxes $145,829 $145,829 $— — % Changes to crude oil, NGL, and natural gas revenues and lease operating expense are due to the conclusion that the Company controls the product throughout processing before transferring to the customer for certain natural gas processing arrangements. Therefore, any transportation, gathering, and processing fees incurred prior to transfer of control are included in lease operating expense. Business Combinations. In January 2017, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business (“ASU 2017-01”), which clarifies the definition of a business to assist entities with evaluating whether transactions should be accounted for as acquisitions (or divestitures) of assets or businesses. Effective January 1, 2018, the Company adopted ASU 2017-01 using the prospective method and will apply the clarified definition of a business to future acquisitions and divestitures. Statement of Cash Flows. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”), which is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. The guidance addresses eight specific cash flow issues for which current GAAP is either unclear or does not include specific guidance. Effective January 1, 2018, the Company adopted ASU 2016-15 using the retrospective approach as prescribed by ASU 2016-15. There were no changes to the statement of cash flows as a result of adoption. Recently Issued Accounting Pronouncements Leases. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (“ASU 2016-02”), which significantly changes accounting for leases by requiring that lessees recognize a right-of-use (“ROU”) asset and a related lease liability representing the obligation to make lease payments, for virtually all lease transactions. ASU 2016-02 does not apply to leases of mineral rights to explore for or use crude oil and natural gas. Additional disclosures about an entity’s lease transactions will also be required. ASU 2016-02 defines a lease as “a contract, or part of a contract, that conveys the right to control the use of identified property, plant or equipment (an identified asset) for a period of time in exchange for consideration.” ASU 2016-02 is effective for interim and annual periods beginning after December 15, 2018 with early adoption permitted. ASU 2016-02 requires companies to recognize and measure leases at the beginning of the earliest period presented in the financial statements using a modified retrospective approach. The Company is in the process of reviewing and determining the contracts to which ASU 2016-02 applies with the assistance of a third party consultant. These include contracts such as non-cancelable leases, drilling rig contracts, pipeline gathering, transportation and gas processing agreements, and contracts for the use of vehicles and well equipment. The Company continues to review current accounting policies, controls, processes, and disclosures that will change as a result of adopting the new standard. Based upon its initial assessment, the Company expects the adoption of ASU 2016-02 will result in: (i) an increase in assets and liabilities due to the required recognition of ROU assets and corresponding lease liabilities, (ii) increases in depreciation, depletion and amortization and interest expense, (iii) decreases in lease operating and general and administrative expense and (iv) additional disclosures, however, the full impact to the Company’s consolidated financial statements and related disclosures is still being evaluated. Currently, the Company plans to make certain elections allowing the Company not to reassess contracts that commenced prior to adoption, to continue applying its current accounting policy for land easements, and not to recognize ROU assets or lease liabilities for short-term leases. The Company plans to adopt the guidance on the effective date of January 1, 2019. As permitted by ASU No. 2018-11, Leases (Topic 842): Targeted Improvements, the Company does not expect to adjust comparative-period financial statements. Revenue Recognition The Company’s revenues are comprised solely of revenues from customers and include the sale of crude oil, NGLs, and natural gas. The Company believes that the disaggregation of revenue into these three major product types appropriately depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors based on its single geographic location. Crude oil, NGL, and natural gas revenues are recognized at a point in time when production is sold to a purchaser at a fixed or determinable price, delivery has occurred, control has transferred and collectability of the revenue is probable. The transaction price used to recognize revenue is a function of the contract billing terms. Revenue is invoiced by calendar month based on volumes at contractually based rates with payment typically required within 30 days of the end of the production month. At the end of each month when the performance obligation is satisfied, the variable consideration can be reasonably estimated and amounts due from customers are accrued in “Accounts receivable, net” in the consolidated balance sheets. As of September 30, 2018 and December 31, 2017 , receivables from contracts with customers were $100.2 million and $85.6 million , respectively. Taxes assessed by governmental authorities on crude oil, NGL, and natural gas sales are presented separately from such revenues in the consolidated statements of income. Crude oil sales. Crude oil production is primarily sold at the wellhead at an agreed upon index price, net of pricing differentials. Revenue is recognized when control transfers to the purchaser at the wellhead, net of transportation costs incurred by the purchaser. Natural gas and NGL sales. Natural gas is delivered to a midstream processing entity at the wellhead or the inlet of the midstream processing entity’s system. The midstream processing entity gathers and processes the natural gas and remits proceeds for the resulting sales of NGLs and residue gas. The Company evaluates whether it is the principal or agent in the transaction and has concluded it is the principal and the purchasers of the NGLs and residue gas are the customers. Revenue is recognized on a gross basis, with gathering, processing and transportation fees recognized as lease operating expense in the consolidated statements of income as the Company maintains control throughout processing. Transaction Price Allocated to Remaining Performance Obligations . The Company applied the practical expedient in ASC 606 exempting the disclosure of the transaction price allocated to remaining performance obligations if the variable consideration is allocated entirely to a wholly unsatisfied performance obligation. Each unit of product typically represents a separate performance obligation, therefore, future volumes are wholly unsatisfied and disclosure of the transaction price allocated to remaining performance obligations is not required. Net Income Attributable to Common Shareholders Per Common Share The following table summarizes the calculation of net income attributable to common shareholders per common share: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (In thousands, except per share amounts) Net Income $81,346 $7,823 $144,147 $104,150 Dividends on preferred stock (4,457 ) (2,249 ) (13,794 ) (2,249 ) Accretion on preferred stock (771 ) — (2,264 ) — Loss on redemption of preferred stock — — (7,133 ) — Net Income Attributable to Common Shareholders $76,118 $5,574 $120,956 $101,901 Basic weighted average common shares outstanding 86,727 81,053 83,461 70,728 Dilutive effect of restricted stock and performance shares 1,272 85 967 253 Dilutive effect of common stock warrants 1,040 — 793 166 Diluted weighted average common shares outstanding 89,039 81,138 85,221 71,147 Net Income Attributable to Common Shareholders Per Common Share Basic $0.88 $0.07 $1.45 $1.44 Diluted $0.85 $0.07 $1.42 $1.43 The computation of diluted net income attributable to common shareholders per common share excluded restricted stock, performance shares and common stock warrants that were anti-dilutive. The following table presents the weighted average anti-dilutive securities for the periods presented: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (In thousands) Anti-dilutive restricted stock and performance shares — 730 5 120 Anti-dilutive common stock warrants — 152 — — Total weighted average anti-dilutive securities — 882 5 120

Acquisitions and Divestitures

Acquisitions and Divestitures	9 Months Ended
	Sep. 30, 2018
Acquisitions and Divestitures [Abstract]
Acquisition and Divestiture Disclosures	3. Acquisitions and Divestitures of Oil and Gas Properties 2018 Acquisitions and Divestitures Devon Acquisition. On August 13, 2018, the Company entered into a purchase and sale agreement with Devon Energy Production Company, L.P. (“Devon”), a subsidiary of Devon Energy Corporation, to acquire oil and gas properties in the Delaware Basin in Reeves and Ward counties, Texas (the “Devon Properties”) for an agreed upon price of $215.0 million , with an effective date of April 1, 2018, subject to customary purchase price adjustments (the “Devon Acquisition”). The Company paid $21.5 million as a deposit on August 13, 2018 and $183.4 million upon initial closing on October 17, 2018, which included purchase price adjustments primarily related to the net cash flows from the effective date to the closing date, for an estimated aggregate purchase price of $204.9 million . The final purchase price remains subject to post-closing adjustments. Under one of the Company’s existing joint operating agreements covering acreage in the vicinity of the Devon Properties, the other party to the joint operating agreement has a right to purchase a 20% interest in certain of the acres within the Devon Properties acquired by the Company at a price based on the Company’s cost to acquire the Devon Properties. This right is exercisable for a 30-day period after the Company delivers a specified notice following the closing of the Devon Acquisition and, if not exercised, will expire in the fourth quarter of 2018. To the extent that the other party exercises its right to make such purchase, the Company’s interests in the Devon Properties will be reduced and the proceeds received will be recognized as a reduction of proved oil and gas properties. The Company funded the Devon Acquisition with net proceeds from the common stock offering completed on August 17, 2018, which, pending the closing of the Devon Acquisition, were used to temporarily repay a portion of the borrowings outstanding under the revolving credit facility. See “Note 9. Shareholders’ Equity and Stock-Based Compensation” for details regarding the common stock offering. The Devon Acquisition will be accounted for as a business combination. The Company has not completed its initial allocation of the purchase price to the assets acquired and liabilities assumed based on their estimated acquisition date fair values. The Company will disclose the allocation of the purchase price as well as other related disclosures in its Annual Report on Form 10-K for the year ended December 31, 2018. Delaware Basin Divestiture. On July 11, 2018, the Company closed on the divestiture of certain non-operated assets in the Delaware Basin for an agreed upon price of $30.0 million , with an effective date of May 1, 2018, subject to customary purchase price adjustments. The Company received $31.4 million upon closing on July 11, 2018 and paid $0.5 million upon post-closing on October 22, 2018, for aggregate net proceeds of $30.9 million . Eagle Ford Divestiture. On December 11, 2017, the Company entered into a purchase and sale agreement with EP Energy E&P Company, L.P. to sell a portion of its assets in the Eagle Ford Shale for an agreed upon price of $245.0 million , with an effective date of October 1, 2017, subject to adjustment and customary terms and conditions. The Company received $24.5 million as a deposit on December 11, 2017, $211.7 million upon closing on January 31, 2018, $10.0 million for leases that were not conveyed at closing on February 16, 2018, and paid $0.5 million upon post-closing on July 19, 2018, for aggregate net proceeds of $245.7 million . Niobrara Divestiture. On November 20, 2017, the Company entered into a purchase and sale agreement to sell substantially all of its assets in the Niobrara Formation for an agreed upon price of $140.0 million , with an effective date of October 1, 2017, subject to customary purchase price adjustments. The Company received $14.0 million as a deposit on November 20, 2017, $122.6 million upon closing on January 19, 2018, and paid $1.0 million upon post-closing on August 14, 2018, for aggregate net proceeds of $135.6 million . As part of this divestiture, the Company agreed to a contingent consideration arrangement (the “Contingent Niobrara Consideration”), which was determined to be an embedded derivative. As a result, the asset is recorded at fair value in the consolidated balance sheets with all gains and losses as a result of changes in the fair value between periods recognized in the consolidated statements of income in the period in which the changes occur. See “Note 10. Derivative Instruments” and “Note 11. Fair Value Measurements” for further details. The aggregate net proceeds for each of the 2018 divestitures discussed above were recognized as a reduction of proved oil and gas properties with no gain or loss recognized. 2017 Acquisitions and Divestitures ExL Acquisition. On June 28, 2017, the Company entered into a purchase and sale agreement with ExL Petroleum Management, LLC and ExL Petroleum Operating Inc. to acquire oil and gas properties located in the Delaware Basin in Reeves and Ward counties, Texas for an agreed upon price of $648.0 million , with an effective date of May 1, 2017, subject to customary purchase price adjustments (the “ExL Acquisition”). The Company paid $75.0 million as a deposit on June 28, 2017, $601.0 million upon closing on August 10, 2017, and $3.8 million upon post-closing on December 8, 2017 for aggregate cash consideration of $679.8 million , which included purchase price adjustments primarily related to the net cash flows from the effective date to the closing date. As part of the ExL Acquisition, the Company agreed to a contingent consideration arrangement (the “Contingent ExL Consideration”), which was determined to be an embedded derivative. As a result, the liability is recorded at fair value in the consolidated balance sheets with all gains and losses as a result of changes in the fair value between periods recognized in the consolidated statements of income in the period in which the changes occur. See “Note 10. Derivative Instruments” and “Note 11. Fair Value Measurements” for further details. The ExL Acquisition was accounted for as a business combination, therefore, the purchase price was allocated to the assets acquired and the liabilities assumed based on their estimated acquisition date fair values based on then currently available information. A combination of a discounted cash flow model and market data was used by a third-party valuation specialist in determining the fair value of the oil and gas properties. Significant inputs into the calculation included forward oil and gas price curves, estimated volumes of oil and gas reserves, expectations for timing and amount of future development and operating costs, future plugging and abandonment costs and a risk adjusted discount rate. The fair value of the Contingent ExL Consideration was determined by a third-party valuation specialist using a Monte Carlo simulation. Significant inputs into the calculation included forward oil and gas price curves, volatility factors, and a risk adjusted discount rate. See “Note 11. Fair Value Measurements” for further details. The following table presents the final allocation of the purchase price to the assets acquired and liabilities assumed as of the acquisition date. Purchase Price Allocation (In thousands) Assets Other current assets $106 Oil and gas properties Proved properties 294,754 Unproved properties 443,194 Total oil and gas properties $737,948 Total assets acquired $738,054 Liabilities Revenues and royalties payable $5,785 Asset retirement obligations 153 Contingent ExL Consideration 52,300 Total liabilities assumed $58,238 Net Assets Acquired $679,816 The results of operations for the ExL Acquisition have been included in the Company’s consolidated statements of income since the August 10, 2017 closing date, including total revenues and net income attributable to common shareholders for the three and nine months ended September 30, 2018 and 2017 as shown in the table below: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (In thousands) Total revenues $71,525 $14,016 $167,764 $14,016 Net Income Attributable to Common Shareholders $57,466 $11,393 $134,317 $11,393 Pro Forma Operating Results (Unaudited). The following unaudited pro forma financial information presents a summary of the Company’s consolidated results of operations for the three and nine months ended September 30, 2017, assuming the ExL Acquisition had been completed as of January 1, 2016, including adjustments to reflect the fair values assigned to the assets acquired and liabilities assumed. The pro forma financial information does not purport to represent what the actual results of operations would have been had the transactions been completed as of the date assumed, nor is this information necessarily indicative of future consolidated results of operations. The Company believes the assumptions used provide a reasonable basis for reflecting the significant pro forma effects directly attributable to the ExL Acquisition. Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (In thousands, except per share amounts) Total revenues $189,499 $534,607 Net Income Attributable to Common Shareholders $14,654 $115,053 Net Income Attributable to Common Shareholders Per Common Share Basic $0.18 $1.63 Diluted $0.18 $1.62 Marcellus Divestiture. On October 5, 2017, the Company entered into a purchase and sale agreement with BKV Chelsea, LLC, a subsidiary of Kalnin Ventures LLC, to sell substantially all of its assets in the Marcellus Shale for an agreed upon price of $84.0 million . The Company received $6.3 million into escrow as a deposit on October 5, 2017 and $67.6 million upon closing on November 21, 2017, for aggregate net proceeds of $73.9 million . As part of this divestiture, the Company agreed to a contingent consideration arrangement (the “Contingent Marcellus Consideration”), which was determined to be an embedded derivative. As a result, the asset is recorded at fair value in the consolidated balance sheets with all gains and losses as a result of changes in the fair value between periods recognized in the consolidated statements of income in the period in which the changes occur. See “Note 10. Derivative Instruments” and “Note 11. Fair Value Measurements” for further details. Effective August 2008, the Company’s wholly-owned subsidiary, Carrizo (Marcellus) LLC, entered into a joint venture with ACP II Marcellus LLC (“ACP II”), an affiliate of Avista Capital Partners, LP, a private equity fund (Avista Capital Partners, LP, together with its affiliates, “Avista”). There have been no revenues, expenses, or operating cash flows in the Avista Marcellus joint venture during the years ended December 31, 2015, 2016 and 2017 or during the nine months ended September 30, 2018 . The Avista Marcellus joint venture agreements terminated during the third quarter of 2018 in connection with the sale of the remaining immaterial assets. Steven A. Webster, Chairman of the Company’s Board of Directors, serves as Co-Managing Partner and President of Avista Capital Holdings, LP. ACP II’s Board of Managers has the sole authority for determining whether, when and to what extent any cash distributions will be declared and paid to members of ACP II. Mr. Webster is not a member of ACP II’s Board of Managers. The terms of the Avista Marcellus joint venture were approved by a special committee of the Company’s independent directors. Utica Divestiture . On August 31, 2017, the Company entered into a purchase and sale agreement to sell substantially all of its assets in the Utica Shale for an agreed upon price of $62.0 million . The Company received $6.2 million as a deposit on August 31, 2017, $54.4 million upon closing on November 15, 2017, and $2.5 million upon post-closing on December 28, 2017, for aggregate net proceeds of $63.1 million . As part of this divestiture, the Company agreed to a contingent consideration arrangement (the “Contingent Utica Consideration”), which was determined to be an embedded derivative. As a result, the asset is recorded at fair value in the consolidated balance sheets with all gains and losses as a result of changes in the fair value between periods recognized in the consolidated statements of income in the period in which the changes occur. See “Note 10. Derivative Instruments” and “Note 11. Fair Value Measurements” for further details. Delaware Basin Divestiture. During the first quarter of 2017, the Company sold a small undeveloped acreage position in the Delaware Basin for aggregate net proceeds of $15.3 million . The aggregate net proceeds for each of the 2017 divestitures discussed above were recognized as a reduction of proved oil and gas properties with no gain or loss recognized. 2016 Acquisitions and Divestitures Sanchez Acquisition. On October 24, 2016, the Company entered into a purchase and sale agreement with Sanchez Energy Corporation and SN Cotulla Assets, LLC, a subsidiary of Sanchez Energy Corporation to acquire oil and gas properties located in the Eagle Ford Shale for an agreed upon price of $181.0 million , with an effective date of June 1, 2016, subject to customary purchase price adjustments. The Company paid $10.0 million as a deposit on October 24, 2016, $143.5 million upon initial closing on December 14, 2016, and $7.0 million and $9.8 million on January 9, 2017 and April 13, 2017, respectively, for leases that were not conveyed to the Company at the time of initial closing, for aggregate cash consideration of $170.3 million , which included purchase price adjustments primarily related to the net cash flows from the effect date to the closing date. The Company did not have any material divestitures in 2016.

Property And Equipment, Net

Property And Equipment, Net	9 Months Ended
	Sep. 30, 2018
Property, Plant and Equipment [Abstract]
Property And Equipment, Net	4. Property and Equipment, Net As of September 30, 2018 and December 31, 2017 , total property and equipment, net consisted of the following: September 30, December 31, (In thousands) Oil and gas properties, full cost method Proved properties $5,988,301 $5,615,153 Accumulated depreciation, depletion and amortization and impairments (3,863,534 ) (3,649,806 ) Proved properties, net 2,124,767 1,965,347 Unproved properties, not being amortized Unevaluated leasehold and seismic costs 516,537 612,589 Capitalized interest 62,738 47,698 Total unproved properties, not being amortized 579,275 660,287 Other property and equipment 28,134 25,625 Accumulated depreciation (17,249 ) (15,449 ) Other property and equipment, net 10,885 10,176 Total property and equipment, net $2,714,927 $2,635,810 Average depreciation, depletion and amortization (“DD&A”) per Boe of proved properties was $13.29 and $13.04 for the three months ended September 30, 2018 and 2017 , respectively, and $13.57 and $12.73 for the nine months ended September 30, 2018 and 2017 , respectively. The Company capitalized internal costs of employee compensation and benefits, including stock-based compensation, directly associated with acquisition, exploration and development activities totaling $2.9 million and $3.3 million for the three months ended September 30, 2018 and 2017 , respectively, and $15.6 million and $10.6 million for the nine months ended September 30, 2018 and 2017 , respectively. Unproved properties, not being amortized, include unevaluated leasehold and seismic costs associated with specific unevaluated properties and related capitalized interest. The Company capitalized interest costs associated with its unproved properties totaling $8.5 million for the three months ended September 30, 2018 and 2017 and $27.6 million and $16.2 million for the nine months ended September 30, 2018 and 2017 , respectively.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	5. Income Taxes The Company’s estimated annual effective income tax rates are used to allocate expected annual income tax expense or benefit to interim periods. The rates are the ratio of estimated annual income tax expense or benefit to estimated annual income or loss before income taxes by taxing jurisdiction, excluding significant unusual or infrequent items, the tax effects of statutory rate changes, certain changes in the assessment of the realizability of deferred tax assets, and excess tax benefits or deficiencies related to the vesting of stock-based compensation awards, which are recognized as discrete items in the interim period in which they occur. The Company’s income tax expense differs from the income tax expense computed by applying the U.S. federal statutory corporate income tax rate of 21% for the three and nine months ended September 30, 2018 and 35% for the three and nine months ended September 30, 2017, to income before income taxes as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (In thousands) Income before income taxes $82,226 $7,823 $145,829 $104,150 Income tax expense at the U.S. federal statutory rate (17,267 ) (2,738 ) (30,624 ) (36,452 ) State income tax expense, net of U.S. federal income tax benefit (881 ) (247 ) (1,687 ) (1,974 ) Tax deficiencies related to stock-based compensation (10 ) (273 ) (2,552 ) (3,029 ) Decrease in valuation allowance due to current period activity 17,400 3,253 33,849 41,570 Other (122 ) 5 (668 ) (115 ) Income tax expense ($880 ) $— ($1,682 ) $— Tax Cuts and Jobs Act On December 22, 2017, the U.S. Congress enacted the Tax Cuts and Jobs Act (the “Act”) which made significant changes to U.S. federal income tax law, including lowering the U.S. federal statutory corporate income tax rate to 21% from 35% beginning January 1, 2018. Due to the uncertainty regarding the application of ASC 740 in the period of enactment of the Act, the SEC issued Staff Accounting Bulletin 118 which allowed the Company to provide a provisional estimate of the impacts of the Act in earnings for the year ended December 31, 2017 and also provided a one-year measurement period in which the Company would record additional impacts from the enactment of the Act as they are identified. In August 2018, the Internal Revenue Service issued Notice 2018-68, Guidance on the Application of Section 162(m) (“Notice 2018-68”), which provides initial guidance on the application of Section 162(m), as amended. Notice 2018-68 provided guidance regarding the group of covered employees subject to Section 162(m)’s deduction limit under the Act and the scope of transition relief available under the Act. The Company is currently evaluating the impact of Notice 2018-68, but as of September 30, 2018 , has not made any changes to the provisional estimate recorded in earnings for the year ended December 31, 2017. While the Company has made a reasonable estimate of the effects on its existing deferred tax balances, it has not completed its accounting for the tax effects of the enactment of the Act and will continue to monitor provisions with discrete rate impacts and additional guidance provided within the one year measurement period. Deferred Tax Asset Valuation Allowance The deferred tax asset valuation allowance was $299.1 million and $333.0 million as of September 30, 2018 and December 31, 2017, respectively. Decreases in the valuation allowance for the three months and nine months ended September 30, 2018 and 2017 were based primarily on the pre-tax income recorded during those periods. Throughout 2017 and the first nine months of 2018, the Company maintained a full valuation allowance against its deferred tax assets based on its conclusion, considering all available evidence (both positive and negative), that it was more likely than not that the deferred tax assets would not be realized. The Company intends to maintain a full valuation allowance against its deferred tax assets until there is sufficient evidence to support the reversal of such valuation allowance.

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Debt	6. Long-Term Debt Long-term debt consisted of the following as of September 30, 2018 and December 31, 2017 : September 30, December 31, (In thousands) Senior Secured Revolving Credit Facility due 2022 $309,837 $291,300 7.50% Senior Notes due 2020 130,000 450,000 Unamortized premium for 7.50% Senior Notes 124 579 Unamortized debt issuance costs for 7.50% Senior Notes (980 ) (4,492 ) 6.25% Senior Notes due 2023 650,000 650,000 Unamortized debt issuance costs for 6.25% Senior Notes (7,219 ) (8,208 ) 8.25% Senior Notes due 2025 250,000 250,000 Unamortized debt issuance costs for 8.25% Senior Notes (4,073 ) (4,395 ) Other long-term debt due 2028 — 4,425 Long-term debt $1,327,689 $1,629,209 Senior Secured Revolving Credit Facility The Company has a senior secured revolving credit facility with a syndicate of banks that, as of September 30, 2018 , had a borrowing base of $1.0 billion , with an elected commitment amount of $900.0 million , and borrowings outstanding of $309.8 million at a weighted average interest rate of 3.87% . The credit agreement governing the revolving credit facility provides for interest-only payments until May 4, 2022 (subject to a springing maturity date of June 15, 2020 if the 7.50% Senior Notes due 2020 (the “ 7.50% Senior Notes”) have not been redeemed or refinanced on or prior to such time), when the credit agreement matures and any outstanding borrowings are due. See “Note 14. Subsequent Events” for details regarding the maturity date of the credit agreement upon redemption of the remaining $130.0 million outstanding aggregate principal amount of its 7.50% Senior Notes. The borrowing base under the credit agreement is subject to regular redeterminations in the spring and fall of each year, as well as special redeterminations described in the credit agreement, which in each case may reduce the amount of the borrowing base. The amount the Company is able to borrow with respect to the borrowing base is subject to compliance with the financial covenants and other provisions of the credit agreement. The capitalized terms which are not defined in this description of the revolving credit facility, shall have the meaning given to such terms in the credit agreement. On January 31, 2018, as a result of the Eagle Ford divestiture, the Company’s borrowing base under the senior secured revolving credit facility was reduced from $900.0 million to $830.0 million , however, the elected commitment amount remained unchanged at $800.0 million . See “Note 3. Acquisitions and Divestitures of Oil and Gas Properties” for details of the Eagle Ford divestiture. On May 4, 2018, the Company entered into the twelfth amendment to its credit agreement governing the revolving credit facility to, among other things, (i) establish the borrowing base at $1.0 billion , with an elected commitment amount of $900.0 million , until the next redetermination thereof, (ii) reduce the applicable margins for Eurodollar loans from 2.00% - 3.00% to 1.50% - 2.50% and base rate loans from 1.00% - 2.00% to 0.50% - 1.50% , each depending on level of facility usage, (iii) amend the covenant limiting payment of dividends and distributions on equity to increase the Company’s ability to make dividends and distributions on its equity interests and (iv) amend certain other provisions, in each case as set forth therein. On October 29, 2018, the Company entered into the thirteenth amendment to its credit agreement governing the revolving credit facility. See “Note 14. Subsequent Events” for further details of the thirteenth amendment. The obligations of the Company under the credit agreement are guaranteed by the Company’s material subsidiaries and are secured by liens on substantially all of the Company’s assets, including a mortgage lien on oil and gas properties having at least 90% of the total value of the oil and gas properties included in the Company’s reserve report used in its most recent redetermination. Borrowings outstanding under the credit agreement bear interest at the Company’s option at either (i) a base rate for a base rate loan plus the margin set forth in the table below, where the base rate is defined as the greatest of the prime rate, the federal funds rate plus 0.50% and the adjusted LIBO rate plus 1.00% , or (ii) an adjusted LIBO rate for a Eurodollar loan plus the margin set forth in the table below. The Company also incurs commitment fees at rates as set forth in the table below on the unused portion of lender commitments, which are included in “Interest expense, net” in the consolidated statements of income. Ratio of Outstanding Borrowings to Lender Commitments Applicable Margin for Base Rate Loans Applicable Margin for Eurodollar Loans Commitment Fee Less than 25% 0.50% 1.50% 0.375% Greater than or equal to 25% but less than 50% 0.75% 1.75% 0.375% Greater than or equal to 50% but less than 75% 1.00% 2.00% 0.500% Greater than or equal to 75% but less than 90% 1.25% 2.25% 0.500% Greater than or equal to 90% 1.50% 2.50% 0.500% The Company is subject to certain covenants under the terms of the credit agreement, which include the maintenance of the following financial covenants determined as of the last day of each quarter: (1) a ratio of Total Debt to EBITDA of not more than 4.00 to 1.00 and (2) a Current Ratio of not less than 1.00 to 1.00. As defined in the credit agreement, Total Debt excludes debt premiums and debt issuance costs and is net of cash and cash equivalents, EBITDA will be calculated based on the last four fiscal quarters after giving pro forma effect to EBITDA for material acquisitions and divestitures of oil and gas properties, and the Current Ratio includes an add back of the unused portion of lender commitments. As of September 30, 2018 , the ratio of Total Debt to EBITDA was 1.95 to 1.00 and the Current Ratio was 1.84 to 1.00. Because the financial covenants are determined as of the last day of each quarter, the ratios can fluctuate significantly period to period as the level of borrowings outstanding under the credit agreement are impacted by the timing of cash flows from operations, capital expenditures, acquisitions and divestitures of oil and gas properties and securities offerings. The credit agreement also places restrictions on the Company and certain of its subsidiaries with respect to additional indebtedness, liens, dividends and other payments to shareholders, repurchases or redemptions of the Company’s common stock, redemptions of senior notes, investments, acquisitions and divestitures of oil and gas properties, mergers, transactions with affiliates, hedging transactions and other matters. The credit agreement is subject to customary events of default, including in connection with a change in control. If an event of default occurs and is continuing, the lenders may elect to accelerate amounts due under the credit agreement (except in the case of a bankruptcy event of default, in which case such amounts will automatically become due and payable). Redemptions of 7.50% Senior Notes During the first quarter of 2018, the Company redeemed $320.0 million of the outstanding aggregate principal amount of its 7.50% Senior Notes at a price equal to 101.875% of par. Upon the redemptions, the Company paid $336.9 million , which included redemption premiums of $6.0 million and accrued and unpaid interest of $10.9 million . The redemptions were funded primarily from the net proceeds received from the divestitures in Eagle Ford and Niobrara in the first quarter of 2018. See “Note 3. Acquisitions and Divestitures of Oil and Gas Properties” for further details of these divestitures. As a result of the redemptions, the Company recorded a loss on extinguishment of debt of $8.7 million , which included the redemption premiums of $6.0 million and the write-off of associated unamortized premiums and debt issuance costs of $2.7 million . See “Note 14. Subsequent Events” for details of the notice of conditional redemption for the remaining $130.0 million outstanding aggregate principal amount of its 7.50% Senior Notes. Redemption of Other Long-Term Debt On May 3, 2018, the Company redeemed the remaining $4.4 million outstanding aggregate principal amount of its 4.375% Convertible Senior Notes due 2028 at a price equal to 100% of par. Upon the redemption, the Company paid $4.5 million , which included accrued and unpaid interest of $0.1 million . Issuance of 8.25% Senior Notes On July 14, 2017, the Company closed a public offering of $250.0 million aggregate principal amount of 8.25% Senior Notes due 2025 (the “ 8.25% Senior Notes”). The Company used the proceeds of $245.4 million , net of underwriting discounts and commissions and offering costs, to fund a portion of the ExL Acquisition and for general corporate purposes. See “Note 3. Acquisitions and Divestitures of Oil and Gas Properties” for further details of the ExL Acquisition.

Commitments And Contingencies

Commitments And Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	7. Commitments and Contingencies From time to time, the Company is party to certain legal actions and claims arising in the ordinary course of business. While the outcome of these events cannot be predicted with certainty, management does not currently expect these matters to have a materially adverse effect on the financial position or results of operations of the Company. The results of operations and financial position of the Company continue to be affected from time to time in varying degrees by domestic and foreign political developments as well as legislation and regulations pertaining to restrictions on oil and gas production, imports and exports, tax changes, environmental regulations and cancellation of contract rights. Both the likelihood and overall effect of such occurrences on the Company vary greatly and are not predictable.

Preferred Stock

Preferred Stock	9 Months Ended
	Sep. 30, 2018
Preferred Stock [Abstract]
Preferred Stock	8. Preferred Stock and Common Stock Warrants On August 10, 2017, the Company closed on the issuance and sale in a private placement of (i) $250.0 million initial liquidation preference ( 250,000 shares) of 8.875% redeemable preferred stock, par value $0.01 per share (the “Preferred Stock”) and (ii) warrants for 2,750,000 shares of the Company’s common stock, with a term of ten years and an exercise price of $16.08 per share, exercisable only on a net share settlement basis (the “Warrants”), for a cash purchase price equal to $970.00 per share of Preferred Stock, to certain funds managed or sub-advised by GSO Capital Partners LP and its affiliates (the “GSO Funds”). The closing of the private placement occurred on August 10, 2017, contemporaneously with the closing of the ExL Acquisition. The Company used the proceeds of approximately $236.4 million, net of issuance costs, to fund a portion of the ExL Acquisition and for general corporate purposes. The Preferred Stock has a liquidation preference of $1,000.00 per share and bears an annual cumulative dividend rate of 8.875% , payable on March 15, June 15, September 15 and December 15 of any given year. The Company may elect to pay all or a portion of the Preferred Stock dividends in shares of its common stock in decreasing percentages as follows with respect to any preferred stock dividend declared by the Company’s Board of Directors and paid in respect of a quarter ending: Period Percentage On or after December 15, 2018 and on or prior to September 15, 2019 75 % On or after December 15, 2019 and on or prior to September 15, 2020 50 % If the Company fails to satisfy the Preferred Stock dividend on the applicable dividend payment date, then the unpaid dividend will be added to the liquidation preference until paid. The Preferred Stock outstanding is not mandatorily redeemable, but can be redeemed at the Company’s option and, in certain circumstances, at the option of the holders of the Preferred Stock. On or prior to August 10, 2018, the Company had the right to redeem up to 50,000 shares of Preferred Stock, in cash, at $1,000.00 per share, plus accrued and unpaid dividends in an amount not to exceed the sum of the cash proceeds of divestitures of oil and gas properties and related assets, the sale or issuance of the Company’s common stock and the sale of any of the Company’s wholly owned subsidiaries. In addition, at any time on or prior to August 10, 2020, the Company may redeem all or part of the Preferred Stock in cash at a redemption premium of 104.4375% , plus accrued and unpaid dividends and the present value on the redemption date of all quarterly dividends that would be payable from the redemption date through August 10, 2020. After August 10, 2020, the Company may redeem all or part of the Preferred Stock in cash at redemption premiums, as presented in the table below, plus accrued but unpaid dividends. Period Percentage After August 10, 2020 but on or prior to August 10, 2021 104.4375 % After August 10, 2021 but on or prior to August 10, 2022 102.21875 % After August 10, 2022 100 % The holders of the Preferred Stock have the option to cause the Company to redeem the Preferred Stock under the following conditions: • Upon the Company’s failure to pay a quarterly dividend within three months of the applicable payment date; • On or after August 10, 2024, if the Preferred Shares remain outstanding; or • Upon the occurrence of certain changes of control. For the first two conditions described above, the Company has the option to settle any such redemption in cash or shares of its common stock and the holders of the Preferred Stock may elect to revoke or reduce the redemption if the Company elects to settle in shares of common stock. The Preferred Stock are non-voting shares except as required by the Company’s articles of incorporation or bylaws. However, so long as the GSO Funds beneficially own more than 50% of the Preferred Stock, the consent of the holders of the Preferred Stock will be required prior to issuing stock senior to or on parity with the Preferred Stock, incurring indebtedness subject to a leverage ratio, agreeing to certain restrictions on dividends on, or redemption of, the Preferred Stock and declaring or paying dividends on the Company’s common stock in excess of $15.0 million per year subject to a leverage ratio. Additionally, if the Company does not redeem the Preferred Stock before August 10, 2024, in connection with a change of control, or failure to pay a quarterly dividend within three months of the applicable payment date, the holders of the Preferred Stock are entitled to additional rights including: • Increasing the dividend rate to 12.0% per annum until August 10, 2024 and thereafter to the greater of 12.0% per annum and the one-month LIBOR plus 10.0% ; • Electing up to two directors to the Company’s Board of Directors; and • Requiring approval by the holders of the Preferred Stock to incur indebtedness subject to a leverage ratio, declaring or paying dividends on the Company’s common stock in excess of $15.0 million per year or issuing equity of the Company’s subsidiaries to third parties. The Preferred Stock is presented as temporary equity in the consolidated balance sheets with the issuance date fair value accreted to the initial liquidation preference using the effective interest method. The table below presents the reconciliation of changes in the carrying amount of Preferred Stock for the nine months ended September 30, 2018 : Carrying Amount of Preferred Stock (In thousands) December 31, 2017 $214,262 Redemption of Preferred Stock (42,897 ) Accretion on Preferred Stock 2,264 September 30, 2018 $173,629 Loss on Redemption of Preferred Stock During the first quarter of 2018, the Company redeemed 50,000 shares of Preferred Stock, representing 20% of the issued and outstanding Preferred Stock, for $50.5 million , consisting of the $50.0 million redemption price and $0.5 million accrued and unpaid dividends. The Company recognized a $7.1 million loss on the redemption due to the excess of the $50.0 million redemption price over the $42.9 million redemption date carrying value of the Preferred Stock.

Shareholders' Equity and Stock

Shareholders' Equity and Stock Incentive Plans	9 Months Ended
	Sep. 30, 2018
Shareholders' Equity and Stock Incentive Plans [Abstract]
Shareholders' Equity and Share-based Payments	9. Shareholders’ Equity and Stock-Based Compensation Sales of Common Stock On August 17, 2018, the Company completed a public offering of 9.5 million shares of its common stock at a price per share of $22.55 . The Company used the proceeds of $213.9 million , net of offering costs, to fund the Devon Acquisition and for general corporate purposes. Pending the closing of the Devon Acquisition, the Company used the net proceeds to temporarily repay a portion of the borrowings outstanding under the revolving credit facility. See “Note 3. Acquisitions and Divestitures of Oil and Gas Properties” for further details of the Devon Acquisition. On July 3, 2017, the Company completed a public offering of 15.6 million shares of its common stock at a price per share of $14.28 . The Company used the proceeds of $222.4 million , net of offering costs, to fund a portion of the ExL Acquisition and for general corporate purposes. See “Note 3. Acquisitions and Divestitures of Oil and Gas Properties” for further details of the ExL Acquisition. Stock-Based Compensation The Company grants equity-based incentive awards under the 2017 Incentive Plan of Carrizo Oil & Gas, Inc. (the “2017 Incentive Plan”) and the Carrizo Oil & Gas, Inc. Cash-Settled Stock Appreciation Rights Plan (“Cash SAR Plan”). The 2017 Incentive Plan replaced the Incentive Plan of Carrizo Oil & Gas, Inc., as amended and restated effective May 15, 2014 (the “Prior Incentive Plan”) and, from the effective date of the 2017 Incentive Plan, no further awards may be granted under the Prior Incentive Plan. However, awards previously granted under the Prior Incentive Plan will remain outstanding in accordance with their terms. Under the 2017 Incentive Plan, the Company may grant restricted stock awards and units, stock appreciation rights that can be settled in cash or shares of common stock, performance shares, and stock options to employees, independent contractors, and non-employee directors. Under the Cash SAR Plan, the Company may grant stock appreciation rights that may only be settled in cash to employees and independent contractors. The 2017 Incentive Plan provides that up to 2,675,000 shares of the Company’s common stock, plus the shares remaining available for awards under the Prior Incentive Plan at the effective date of the 2017 Incentive Plan, may be granted (the “Maximum Share Limit”). Each restricted stock award and unit and performance share granted under the 2017 Incentive Plan counts as 1.35 shares against the Maximum Share Limit. Each stock option and stock appreciation right to be settled in shares of common stock granted under the 2017 Incentive Plan counts as 1.00 share against the Maximum Share Limit. Stock appreciation rights to be settled in cash granted under the 2017 Incentive Plan and stock appreciation rights granted under the Cash SAR Plan (collectively, “Cash SARs”) do not count against the Maximum Share Limit. Restricted stock awards and units, performance shares, and Cash SARs activity during the nine months ended September 30, 2018 is presented below. The Company has not granted stock appreciation rights to be settled in shares of common stock and has no outstanding stock options. As of September 30, 2018 , there were 296,654 shares of common stock available for grant under the 2017 Incentive Plan. Restricted Stock Awards and Units The table below summarizes restricted stock award and unit activity for the nine months ended September 30, 2018 : Restricted Stock Awards and Units Weighted Average Grant Date Fair Value Unvested restricted stock awards and units, beginning of period 1,482,655 $28.07 Granted 1,391,422 $15.07 Vested (615,762 ) $31.44 Forfeited (23,880 ) $18.51 Unvested restricted stock awards and units, end of period 2,234,435 $19.14 During the nine months ended September 30, 2018 , the Company granted 1,391,422 restricted stock awards and units primarily consisting of 1,343,412 restricted stock units to employees and independent contractors as part of its annual grant of long-term equity incentive awards during the first quarter of 2018. These restricted stock units had a grant date fair value of $19.7 million and vest ratably over an approximate three -year period. During the third quarter of 2018, the Company granted 33,536 restricted stock units to its non-employee directors, which had a grant date fair value of $0.9 million and will vest on the earlier of the date of the 2019 Annual Meeting of Shareholders and June 30, 2019. As of September 30, 2018 , unrecognized compensation costs related to unvested restricted stock awards and units were $26.8 million and will be recognized over a weighted average period of 2.0 years. Cash SARs The table below summarizes the Cash SAR activity for the nine months ended September 30, 2018 : Cash SARs Weighted Average Exercise Prices Weighted Average Remaining Life (In years) Aggregate Intrinsic Value (In millions) Aggregate Intrinsic Value of Exercises (In millions) Outstanding, beginning of period 714,238 $27.12 Granted 616,686 $14.67 Exercised — $— $— Forfeited — $— Expired — $— Outstanding, end of period 1,330,924 $21.35 4.6 $6.5 Vested, end of period 543,018 $27.18 Vested and exercisable, end of period — $27.18 2.8 $— During the nine months ended September 30, 2018 , the Company granted 616,686 Cash SARs to certain employees and independent contractors, all of which occurred in the first quarter of 2018 as part of the Company’s annual grant of long-term equity incentive awards. These Cash SARs vest ratably over an approximate three -year period and expire approximately seven years from the grant date. The grant date fair value of the Cash SARs, calculated using the Black-Scholes-Merton option pricing model, was $4.9 million . The following table summarizes the assumptions used to calculate the grant date fair value of the Cash SARs granted during the nine months ended September 30, 2018 : Grant Date Fair Value Assumptions Expected term (in years) 6.0 Expected volatility 54.3 % Risk-free interest rate 2.8 % Dividend yield — % The liability for Cash SARs as of September 30, 2018 was $7.9 million , all of which was classified as “Other current liabilities,” in the consolidated balance sheets. As of December 31, 2017 , the liability for Cash SARs was $4.4 million , all of which was classified as “Other liabilities” in the consolidated balance sheets. Unrecognized compensation costs related to unvested Cash SARs were $8.7 million as of September 30, 2018 , and will be recognized over a weighted average period of 2.4 years. Performance Shares The table below summarizes performance share activity for the nine months ended September 30, 2018 : Target Performance Shares (1) Weighted Average Grant Date Fair Value Unvested performance shares, beginning of period 144,955 $47.14 Granted 93,771 $19.09 Vested at end of performance period (49,458 ) $65.51 Did not vest at end of performance period (7,059 ) $65.51 Forfeited — $— Unvested performance shares, end of period 182,209 $27.01 (1) The number of performance shares that vest may vary from the number of target performance shares granted depending on the Company ’ s final TSR ranking for the approximate three -year performance period. During the nine months ended September 30, 2018 , the Company granted 93,771 target performance shares to certain employees and independent contractors, all of which occurred in the first quarter of 2018 as part of the Company’s annual grant of long-term equity incentive awards. Each performance share represents the right to receive one share of common stock, however, the number of performance shares that vest ranges from zero to 200% of the target performance shares granted based on the total shareholder return (“TSR”) of the Company’s common stock relative to the TSR achieved by a specified industry peer group over an approximate three -year performance period, the last day of which is also the vesting date. During the first quarter of 2018, as a result of the Company’s final TSR ranking during the performance period, a multiplier of 88% was applied to the 56,517 target performance shares that were granted in 2015, resulting in the vesting of 49,458 shares and 7,059 shares that did not vest. The grant date fair value of the performance shares, calculated using a Monte Carlo simulation, was $1.8 million . The following table summarizes the assumptions used to calculate the grant date fair value of the performance shares granted during the nine months ended September 30, 2018 : Grant Date Fair Value Assumptions Number of simulations 500,000 Expected term (in years) 3.0 Expected volatility 61.5 % Risk-free interest rate 2.4 % Dividend yield — % As of September 30, 2018 , unrecognized compensation costs related to unvested performance shares were $2.5 million and will be recognized over a weighted average period of 2.0 years. Stock-Based Compensation Expense, Net Stock-based compensation expense associated with restricted stock awards and units, Cash SARs and performance shares, net of amounts capitalized, is included in “General and administrative, net” in the consolidated statements of income. The Company recognized the following stock-based compensation expense, net for the three and nine months ended September 30, 2018 and 2017 : Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (In thousands) Restricted stock awards and units $4,487 $5,311 $14,291 $16,184 Cash SARs (868 ) 429 3,505 (7,040 ) Performance shares 411 581 1,374 1,861 4,030 6,321 19,170 11,005 Less: amounts capitalized to oil and gas properties (968 ) (1,455 ) (5,384 ) (2,543 ) Total stock-based compensation expense, net $3,062 $4,866 $13,786 $8,462

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	10. Derivative Instruments Commodity Derivative Instruments The Company uses commodity derivative instruments to mitigate the effects of commodity price volatility for a portion of its forecasted sales of production and achieve a more predictable level of cash flow. Since the Company derives a significant portion of its revenues from sales of crude oil, crude oil price volatility represents the Company’s most significant commodity price risk. While the use of commodity derivative instruments limits or partially reduces the downside risk of adverse commodity price movements, such use also limits the upside from favorable commodity price movements. The Company does not enter into commodity derivative instruments for speculative purposes. The Company’s commodity derivative instruments, which settle on a monthly basis over the term of the contract for contracted volumes, consist of over-the-counter price swaps, three-way collars, sold call options and basis swaps, each of which is described below. Price swaps are settled based on differences between a fixed price and the settlement price of a referenced index. If the settlement price of the referenced index is below the fixed price, the Company receives the difference from the counterparty. If the referenced settlement price is above the fixed price, the Company pays the difference to the counterparty. Three-way collars consist of a purchased put option (floor price), a sold call option (ceiling price) and a sold put option (sub-floor price) and are settled based on differences between the floor or ceiling prices and the settlement price of a referenced index or the difference between the floor price and sub-floor price. If the settlement price of the referenced index is below the sub-floor price, the Company receives the difference between the floor price and sub-floor price from the counterparty. If the settlement price of the referenced index is between the floor price and sub-floor price, the Company receives the difference between the floor price and the settlement price of the referenced index from the counterparty. If the settlement price of the referenced index is between the floor price and ceiling price, no payments are due to or from either party. If the settlement price of the referenced index is above the ceiling price, the Company pays the difference to the counterparty. Sold call options are settled based on differences between the ceiling price and the settlement price of a referenced index. If the settlement price of the referenced index is above the ceiling price, the Company pays the difference to the counterparty. If the settlement price of the referenced index is below the ceiling price, no payments are due to or from either party. Premiums from the sale of call options have been used to enhance the fixed price of certain contemporaneously executed price swaps. Purchased call options executed contemporaneously with sold call options in order to increase the ceiling price of existing sold call options have been presented on a net basis in the table below. Basis swaps are settled based on differences between a fixed price differential and the differential between the settlement prices of two referenced indexes. If the differential between the settlement prices of the two referenced indexes is greater than the fixed price differential, the Company receives the difference from the counterparty. If the differential between the settlement prices of the two referenced indexes is less than the fixed price differential, the Company pays the difference to the counterparty. The referenced index of the Company’s price swaps, three-way collars and sold call options is U.S. New York Mercantile Exchange (“NYMEX”) West Texas Intermediate (“WTI”) for crude oil, NYMEX Henry Hub for natural gas and OPIS Mont Belvieu Non-TET (“OPIS”) for NGL products, as applicable. The prices received by the Company for the sale of its production generally vary from these referenced index prices due to adjustments for delivery location (basis) and other factors. The referenced indexes of the Company’s basis swaps, which are used to mitigate location price risk for a portion of its production, are Argus WTI Cushing (“WTI Cushing”) and the applicable index price of the Company’s crude oil sales contracts is Argus WTI Midland (“WTI Midland”) for its Delaware Basin crude oil production and Argus Light Louisiana Sweet (“LLS”) for its Eagle Ford crude oil production. The Company has incurred premiums on certain of its commodity derivative instruments in order to obtain a higher fixed price, higher floor price and/or higher ceiling price. Payment of these premiums are deferred until the applicable contracts settle on a monthly basis over the term of the contract or, in some cases, during the final 12 months of the contract and are referred to as deferred premium obligations. As of September 30, 2018 , the Company had the following outstanding commodity derivative instruments at weighted average contract volumes and prices: Commodity Period Type of Contract Index Volumes (Bbls per day) Fixed Price ($ per Bbl) Sub-Floor Price ($ per Bbl) Floor Price ($ per Bbl) Ceiling Price ($ per Bbl) Fixed Price Differential ($ per Bbl) Crude oil 4Q18 Price Swaps NYMEX WTI 6,000 $49.55 — — — — Crude oil 4Q18 Three-Way Collars NYMEX WTI 24,000 — $39.38 $49.06 $60.14 — Crude oil 4Q18 Basis Swaps LLS-WTI Cushing 18,000 — — — — $5.11 Crude oil 4Q18 Basis Swaps WTI Midland-WTI Cushing 6,000 — — — — ($0.10 ) Crude oil 4Q18 Sold Call Options NYMEX WTI 3,388 — — — $71.33 — Crude oil 2019 Three-Way Collars NYMEX WTI 21,000 — $40.71 $49.80 $67.80 — Crude oil 2019 Basis Swaps LLS-WTI Cushing 3,000 — — — — $4.57 Crude oil 2019 Basis Swaps WTI Midland-WTI Cushing 7,389 — — — — ($4.82 ) Crude oil 2019 Sold Call Options NYMEX WTI 3,875 — — — $73.66 — Crude oil 2020 Basis Swaps WTI Midland-WTI Cushing 13,000 — — — — ($1.27 ) Crude oil 2020 Sold Call Options NYMEX WTI 4,575 — — — $75.98 — Crude oil 2021 Basis Swaps WTI Midland-WTI Cushing 6,000 — — — — $0.03 Commodity Period Type of Contract Index Volumes (Bbls per day) Fixed Price ($ per Bbl) Sub-Floor Price ($ per Bbl) Floor Price ($ per Bbl) Ceiling Price ($ per Bbl) Fixed Price Differential ($ per Bbl) NGLs 4Q18 Price Swaps OPIS-Ethane 2,200 $12.01 — — — — NGLs 4Q18 Price Swaps OPIS-Propane 1,500 $34.23 — — — — NGLs 4Q18 Price Swaps OPIS-Butane 200 $38.85 — — — — NGLs 4Q18 Price Swaps OPIS-Isobutane 600 $38.98 — — — — NGLs 4Q18 Price Swaps OPIS-Natural Gasoline 600 $55.23 — — — — Commodity Period Type of Contract Index Volumes (MMBtu per day) Fixed Price ($ per MMBtu) Sub-Floor Price ($ per MMBtu) Floor Price ($ per MMBtu) Ceiling Price ($ per MMBtu) Fixed Price Differential ($ per MMBtu) Natural gas 4Q18 Price Swaps NYMEX Henry Hub 25,000 $3.01 — — — — Natural gas 4Q18 Sold Call Options NYMEX Henry Hub 33,000 — — — $3.25 — Natural gas 2019 Sold Call Options NYMEX Henry Hub 33,000 — — — $3.25 — Natural gas 2020 Sold Call Options NYMEX Henry Hub 33,000 — — — $3.50 — The Company typically has numerous commodity derivative instruments outstanding with a counterparty that were executed at various dates, for various contract types, commodities and time periods often resulting in both commodity derivative asset and liability positions with that counterparty. The Company nets its commodity derivative instrument fair values executed with the same counterparty, along with any deferred premium obligations, to a single asset or liability pursuant to International Swap Dealers Association Master Agreements (“ISDAs”), which provide for net settlement over the term of the contract and in the event of default or termination of the contract. Counterparties to the Company’s commodity derivative instruments who are also lenders under the Company’s credit agreement (“Lender Counterparty”) allow the Company to satisfy any need for margin obligations associated with commodity derivative instruments where the Company is in a net liability position with the Lender Counterparty with the collateral securing the credit agreement, thus eliminating the need for independent collateral posting. Counterparties to the Company’s commodity derivative instruments who are not lenders under the Company’s credit agreement (“Non-Lender Counterparty”) can require commodity derivative instruments to be novated to a Lender Counterparty if the Company’s net liability position exceeds the Company’s unsecured credit limit with the Non-Lender Counterparty and therefore do not require the posting of cash collateral. Because each Lender Counterparty has an investment grade credit rating and the Company has obtained a guaranty from each Non-Lender Counterparty’s parent company which has an investment grade credit rating, the Company believes it does not have significant credit risk and accordingly does not currently require its counterparties to post collateral to support the net asset positions of its commodity derivative instruments. Although the Company does not currently anticipate nonperformance from its counterparties, it continually monitors the credit ratings of each Lender Counterparty and each Non-Lender Counterparty’s parent company. The Company executes its derivative instruments with seventeen counterparties to minimize its credit exposure to any individual counterparty. Contingent Consideration Arrangements The purchase and sale agreements of the ExL Acquisition and divestitures of the Company’s assets in the Niobrara, Marcellus and Utica, included contingent consideration arrangements that entitle the Company to receive or require the Company to pay specified amounts if commodity prices exceed specified thresholds, which are summarized in the table below. See “Note 3. Acquisitions and Divestitures of Oil and Gas Properties” for details of these acquisitions and divestitures. Contingent Consideration Arrangements Years Threshold (1) Contingent Receipt (Payment) - Annual Contingent Receipt (Payment) - Aggregate Limit (In thousands) Contingent ExL Consideration 2018 $50.00 ($50,000 ) 2019 50.00 (50,000 ) 2020 50.00 (50,000 ) 2021 50.00 (50,000 ) ($125,000 ) Contingent Niobrara Consideration 2018 $55.00 $5,000 2019 55.00 5,000 2020 60.00 5,000 — Contingent Marcellus Consideration 2018 $3.13 $3,000 2019 3.18 3,000 2020 3.30 3,000 $7,500 Contingent Utica Consideration 2018 $50.00 $5,000 2019 53.00 5,000 2020 56.00 5,000 — (1) The price used to determine whether the specified threshold for each year has been met for the Contingent ExL Consideration, Contingent Niobrara Consideration and Contingent Utica Consideration is the average daily closing spot price per barrel of WTI crude oil as measured by the U.S. Energy Information Administration. The price used to determine whether the specified threshold for each year has been met for the Marcellus Contingent Consideration is the average monthly settlement price per MMBtu of Henry Hub natural gas for the next calendar month, as determined on the last business day preceding each calendar month as measured by the CME Group Inc. Derivative Assets and Liabilities Commodity derivative instruments and contingent consideration arrangements are recorded in the consolidated balance sheets as either an asset or liability measured at fair value. As of September 30, 2018, the Company had $9.8 million classified as current derivative assets and $49.2 million classified as current derivative liabilities, representing the first cash receipts and payments, expected to occur in January 2019, from settlement of contingent consideration assets and liabilities. The deferred premium obligations associated with the Company’s commodity derivative instruments are recorded in the period in which they are incurred and are netted with the commodity derivative instrument asset or liability fair values pursuant to the netting provisions of the ISDAs described above. The derivative instrument asset and liability fair values recorded in the consolidated balance sheets as of September 30, 2018 and December 31, 2017 are summarized below: September 30, 2018 Gross Amounts Recognized Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets (In thousands) Commodity derivative instruments $19,408 ($18,985 ) $423 Contingent Niobrara Consideration 4,920 — 4,920 Contingent Utica Consideration 4,915 — 4,915 Derivative assets $29,243 ($18,985 ) $10,258 Commodity derivative instruments 12,028 (12,028 ) — Contingent Niobrara Consideration 6,755 — 6,755 Contingent Marcellus Consideration 1,315 — 1,315 Contingent Utica Consideration 7,300 — 7,300 Other assets $27,398 ($12,028 ) $15,370 Commodity derivative instruments ($123,611 ) $9,876 ($113,735 ) Deferred premium obligations (9,109 ) 9,109 — Contingent ExL Consideration (49,160 ) — (49,160 ) Derivative liabilities-current ($181,880 ) $18,985 ($162,895 ) Commodity derivative instruments (45,532 ) 6,314 (39,218 ) Deferred premium obligations (5,714 ) 5,714 — Contingent ExL Consideration (62,885 ) — (62,885 ) Derivative liabilities-non current ($114,131 ) $12,028 ($102,103 ) December 31, 2017 Gross Amounts Recognized Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets (In thousands) Commodity derivative instruments $4,869 ($4,869 ) $— Derivative assets $4,869 ($4,869 ) $— Commodity derivative instruments 9,505 (9,505 ) — Contingent Marcellus Consideration 2,205 — 2,205 Contingent Utica Consideration 7,985 — 7,985 Other assets $19,695 ($9,505 ) $10,190 Commodity derivative instruments ($52,671 ) ($4,450 ) ($57,121 ) Deferred premium obligations (9,319 ) 9,319 — Derivative liabilities-current ($61,990 ) $4,869 ($57,121 ) Commodity derivative instruments (24,609 ) (2,098 ) (26,707 ) Deferred premium obligations (11,603 ) 11,603 — Contingent ExL Consideration (85,625 ) — (85,625 ) Derivative liabilities-non current ($121,837 ) $9,505 ($112,332 ) See “Note 11. Fair Value Measurements” for additional information regarding the fair value of the Company’s derivative instruments. (Gain) Loss on Derivatives, Net The Company has elected not to meet the criteria to qualify its commodity derivative instruments for hedge accounting treatment. Therefore, all gains and losses as a result of changes in the fair value of the Company’s commodity derivative instruments, as well as its contingent consideration arrangements, are recognized as “(Gain) loss on derivatives, net” in the consolidated statements of income in the period in which the changes occur. Deferred premium obligations associated with the Company’s commodity derivative instruments are recognized as “(Gain) loss on derivatives, net” in the consolidated statements of income in the period in which the deferred premium obligations are incurred. The net (gain) loss on derivatives in the consolidated statements of income for the three and nine months ended September 30, 2018 and 2017 are summarized below: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (In thousands) (Gain) Loss on Derivatives, Net Crude oil $43,664 $8,409 $126,612 ($39,754 ) NGL 5,086 — 9,885 — Natural gas (192 ) (2,183 ) (3,084 ) (12,902 ) Deferred premium obligations — 10,151 — 17,652 Contingent ExL Consideration 9,990 8,000 26,420 8,000 Contingent Niobrara Consideration (1,705 ) — (3,795 ) — Contingent Marcellus Consideration 215 — 890 — Contingent Utica Consideration (1,670 ) — (4,230 ) — (Gain) Loss on Derivatives, Net $55,388 $24,377 $152,698 ($27,004 ) Cash Received (Paid) for Derivative Settlements, Net Cash flows are impacted to the extent that settlements of commodity derivative instruments, including deferred premium obligations, and contingent consideration arrangements result in cash received or paid during the period and are recognized as “Cash received (paid) for derivative settlements, net” in the consolidated statements of cash flows. Cash received or paid in settlement of contingent consideration assets or liabilities, respectively, are classified as cash flows from financing activities up to the divestiture or acquisition date fair value with any excess classified as cash flows from operating activities. For the three and nine months ended September 30, 2018 and 2017 , there were no settlements of contingent consideration arrangements. The net cash received (paid) for derivative settlements in the consolidated statements of cash flows for the three and nine months ended September 30, 2018 and 2017 are summarized below: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Cash Flows from Operating Activities (In thousands) Cash Received (Paid) for Derivative Settlements, Net Crude oil ($21,261 ) $6,500 ($54,594 ) $9,941 NGL (2,641 ) — (3,829 ) — Natural gas 245 522 785 (731 ) Deferred premium obligations (2,605 ) (566 ) (7,072 ) (1,496 ) Cash Received (Paid) for Derivative Settlements, Net ($26,262 ) $6,456 ($64,710 ) $7,714

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	11. Fair Value Measurements Accounting guidelines for measuring fair value establish a three-level valuation hierarchy for disclosure of fair value measurements. The valuation hierarchy categorizes assets and liabilities measured at fair value into one of three different levels depending on the observability of the inputs employed in the measurement. The three levels are defined as follows: Level 1 – Observable inputs such as quoted prices in active markets at the measurement date for identical, unrestricted assets or liabilities. Level 2 – Other inputs that are observable directly or indirectly such as quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability. Level 3 – Unobservable inputs for which there is little or no market data and which the Company makes its own assumptions about how market participants would price the assets and liabilities. Assets and Liabilities Measured at Fair Value on a Recurring Basis The following tables summarize the Company’s derivative instrument assets and liabilities measured at fair value on a recurring basis as of September 30, 2018 and December 31, 2017 : September 30, 2018 Level 1 Level 2 Level 3 (In thousands) Assets Commodity derivative instruments $— $423 $— Contingent Niobrara Consideration — — 11,675 Contingent Marcellus Consideration — — 1,315 Contingent Utica Consideration — — 12,215 Liabilities Commodity derivative instruments $— ($152,953 ) $— Contingent ExL Consideration — — (112,045 ) December 31, 2017 Level 1 Level 2 Level 3 (In thousands) Assets Commodity derivative instruments $— $— $— Contingent Niobrara Consideration — — — Contingent Marcellus Consideration — — 2,205 Contingent Utica Consideration — — 7,985 Liabilities Commodity derivative instruments $— ($83,828 ) $— Contingent ExL Consideration — — (85,625 ) The asset and liability fair values reported in the consolidated balance sheets are as of the balance sheet date and subsequently change as a result of changes in commodity prices, market conditions and other factors. Commodity derivative instruments. The fair value of the Company’s commodity derivative instruments is based on a third-party industry-standard pricing model which uses contract terms and prices and assumptions and inputs that are substantially observable in active markets throughout the full term of the instruments including forward oil and gas price curves, discount rates and volatility factors, and are therefore designated as Level 2 within the valuation hierarchy. The fair values are also compared to the values provided by the counterparties for reasonableness and are adjusted for the counterparties’ credit quality for commodity derivative assets and the Company’s credit quality for commodity derivative liabilities. The Company had no transfers into Level 1 and no transfers into or out of Level 2 for the nine months ended September 30, 2018 and 2017 . Contingent consideration arrangements. The fair values of the contingent consideration arrangements were determined by a third-party valuation specialist using Monte Carlo simulations including significant inputs such as forward oil and gas price curves, volatility factors, and risk adjusted discount rates, which include adjustments for the counterparties’ credit quality for contingent consideration assets and the Company’s credit quality for the contingent consideration liabilities. As some of these assumptions are not observable throughout the full term of the contingent consideration arrangements, the contingent consideration arrangements were designated as Level 3 within the valuation hierarchy. The Company reviewed the valuations, including the related inputs, and analyzed changes in fair value measurements between periods. The following table presents the reconciliation of changes in the fair values of the contingent consideration arrangements, which were designated as Level 3 within the valuation hierarchy, for the nine months ended September 30, 2018 and 2017: Contingent Consideration Arrangements Assets Liability (In thousands) December 31, 2017 $10,190 ($85,625 ) Recognition of divestiture date fair value 7,880 — Gain (loss) on changes in fair value, net (1) 7,135 (26,420 ) Transfers into (out of) Level 3 — — September 30, 2018 $25,205 ($112,045 ) Contingent Consideration Arrangements Assets Liability (In thousands) December 31, 2016 $— $— Recognition of acquisition date fair value — (52,300 ) Loss on change in fair value (1) — (8,000 ) Transfers into (out of) Level 3 — — September 30, 2017 $— ($60,300 ) (1) Recognized as “(Gain) loss on derivatives, net” in the consolidated statements of income. See “Note 10. Derivative Instruments” for additional information regarding the contingent consideration arrangements. Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis The fair value measurements of asset retirement obligations are measured as of the date a well is drilled or when production equipment and facilities are installed using a discounted cash flow model based on inputs that are not observable in the market and therefore are designated as Level 3 within the valuation hierarchy. Significant inputs to the fair value measurement of asset retirement obligations include estimates of the costs of plugging and abandoning oil and gas wells, removing production equipment and facilities and restoring the surface of the land as well as estimates of the economic lives of the oil and gas wells and future inflation rates. The fair value measurements of assets acquired and liabilities assumed, other than contingent consideration which is discussed above, are measured as of the acquisition date by a third-party valuation specialist using a discounted cash flow model based on inputs that are not observable in the market and are therefore designated as Level 3 inputs. Significant inputs to the valuation of acquired oil and gas properties include forward oil and gas price curves, estimated volumes of oil and gas reserves, expectations for timing and amount of future development and operating costs, future plugging and abandonment costs, and a risk adjusted discount rate. See “Note 3. Acquisitions and Divestitures of Oil and Gas Properties” for details of assets acquired and liabilities assumed as of the acquisition date for the ExL Acquisition. Fair Value of Other Financial Instruments The Company’s other financial instruments consist of cash and cash equivalents, receivables, payables, and long-term debt. The carrying amounts of cash and cash equivalents, receivables, and payables approximate fair value due to the highly liquid or short-term nature of these instruments. The carrying amount of long-term debt associated with borrowings outstanding under the Company’s revolving credit facility approximates fair value as borrowings bear interest at variable rates. The following table presents the carrying amounts of the Company’s senior notes and other long-term debt, net of unamortized premiums and debt issuance costs with the fair values measured using quoted secondary market trading prices which are designated as Level 1 within the valuation hierarchy. September 30, 2018 December 31, 2017 Carrying Amount Fair Value Carrying Amount Fair Value (In thousands) 7.50% Senior Notes due 2020 $129,144 $130,000 $446,087 $459,518 6.25% Senior Notes due 2023 642,781 664,625 641,792 674,375 8.25% Senior Notes due 2025 245,927 268,750 245,605 274,375 Other long-term debt due 2028 — — 4,425 4,445

Condensed Consolidating Financi

Condensed Consolidating Financial Information	9 Months Ended
	Sep. 30, 2018
Condensed Consolidating Financial Information [Abstract]
Condensed Consolidating Financial Information	12. Condensed Consolidating Financial Information The rules of the SEC require that condensed consolidating financial information be provided for a subsidiary that has guaranteed the debt of a registrant issued in a public offering, where the guarantee is full, unconditional and joint and several and where the voting interest of the subsidiary is 100% owned by the registrant. The Company is, therefore, presenting condensed consolidating financial information on a parent company, combined guarantor subsidiaries, combined non-guarantor subsidiaries and consolidated basis and should be read in conjunction with the consolidated financial statements. The financial information may not necessarily be indicative of results of operations, cash flows, or financial position had such guarantor subsidiaries operated as independent entities. CARRIZO OIL & GAS, INC. CONDENSED CONSOLIDATING BALANCE SHEETS (In thousands) (Unaudited) September 30, 2018 Parent Company Combined Guarantor Subsidiaries Combined Non- Guarantor Subsidiaries Eliminations Consolidated Assets Total current assets $3,114,698 $133,308 $— ($3,096,917 ) $151,089 Total property and equipment, net 6,570 2,709,162 3,028 (3,833 ) 2,714,927 Investment in subsidiaries (576,826 ) — — 576,826 — Other assets 29,611 15,371 — — 44,982 Total Assets $2,574,053 $2,857,841 $3,028 ($2,523,924 ) $2,910,998 Liabilities and Shareholders’ Equity Current liabilities $305,096 $3,347,575 $3,028 ($3,099,937 ) $555,762 Long-term liabilities 1,357,294 87,092 — 15,879 1,460,265 Preferred stock 173,629 — — — 173,629 Total shareholders’ equity 738,034 (576,826 ) — 560,134 721,342 Total Liabilities and Shareholders’ Equity $2,574,053 $2,857,841 $3,028 ($2,523,924 ) $2,910,998 December 31, 2017 Parent Company Combined Guarantor Subsidiaries Combined Non- Guarantor Subsidiaries Eliminations Consolidated Assets Total current assets $3,441,633 $105,533 $— ($3,424,288 ) $122,878 Total property and equipment, net 5,953 2,630,707 3,028 (3,878 ) 2,635,810 Investment in subsidiaries (999,793 ) — — 999,793 — Other assets 9,270 10,346 — — 19,616 Total Assets $2,457,063 $2,746,586 $3,028 ($2,428,373 ) $2,778,304 Liabilities and Shareholders’ Equity Current liabilities $165,701 $3,631,401 $3,028 ($3,427,308 ) $372,822 Long-term liabilities 1,689,466 114,978 — 15,879 1,820,323 Preferred stock 214,262 — — — 214,262 Total shareholders’ equity 387,634 (999,793 ) — 983,056 370,897 Total Liabilities and Shareholders’ Equity $2,457,063 $2,746,586 $3,028 ($2,428,373 ) $2,778,304 CARRIZO OIL & GAS, INC. CONDENSED CONSOLIDATING STATEMENTS OF INCOME (In thousands) (Unaudited) Three Months Ended September 30, 2018 Parent Company Combined Guarantor Subsidiaries Combined Non- Guarantor Subsidiaries Eliminations Consolidated Total revenues $38 $303,337 $— $— $303,375 Total costs and expenses 85,242 135,920 — (13 ) 221,149 Income (loss) before income taxes (85,204 ) 167,417 — 13 82,226 Income tax expense — (880 ) — — (880 ) Equity in income of subsidiaries 166,537 — — (166,537 ) — Net income $81,333 $166,537 $— ($166,524 ) $81,346 Dividends on preferred stock (4,457 ) — — — (4,457 ) Accretion on preferred stock (771 ) — — — (771 ) Loss on redemption of preferred stock — — — — — Net income attributable to common shareholders $76,105 $166,537 $— ($166,524 ) $76,118 Three Months Ended September 30, 2017 Parent Company Combined Guarantor Subsidiaries Combined Non- Guarantor Subsidiaries Eliminations Consolidated Total revenues $35 $181,244 $— $— $181,279 Total costs and expenses 54,061 119,366 — 29 173,456 Income (loss) before income taxes (54,026 ) 61,878 — (29 ) 7,823 Income tax expense — — — — — Equity in income of subsidiaries 61,878 — — (61,878 ) — Net income $7,852 $61,878 $— ($61,907 ) $7,823 Dividends on preferred stock (2,249 ) — — — (2,249 ) Accretion on preferred stock — — — — — Loss on redemption of preferred stock — — — — — Net income attributable to common shareholders $5,603 $61,878 $— ($61,907 ) $5,574 CARRIZO OIL & GAS, INC. CONDENSED CONSOLIDATING STATEMENTS OF INCOME (In thousands) (Unaudited) Nine Months Ended September 30, 2018 Parent Company Combined Guarantor Subsidiaries Combined Non- Guarantor Subsidiaries Eliminations Consolidated Total revenues $77 $792,551 $— $— $792,628 Total costs and expenses 278,942 367,902 — (45 ) 646,799 Income (loss) before income taxes (278,865 ) 424,649 — 45 145,829 Income tax expense — (1,682 ) — — (1,682 ) Equity in income of subsidiaries 422,967 — — (422,967 ) — Net income $144,102 $422,967 $— ($422,922 ) $144,147 Dividends on preferred stock (13,794 ) — — — (13,794 ) Accretion on preferred stock (2,264 ) — — — (2,264 ) Loss on redemption of preferred stock (7,133 ) — — — (7,133 ) Net income attributable to common shareholders $120,911 $422,967 $— ($422,922 ) $120,956 Nine Months Ended September 30, 2017 Parent Company Combined Guarantor Subsidiaries Combined Non- Guarantor Subsidiaries Eliminations Consolidated Total revenues $291 $498,826 $— $— $499,117 Total costs and expenses 80,660 314,237 — 70 394,967 Income (loss) before income taxes (80,369 ) 184,589 — (70 ) 104,150 Income tax expense — — — — — Equity in income of subsidiaries 184,589 — — (184,589 ) — Net income $104,220 $184,589 $— ($184,659 ) $104,150 Dividends on preferred stock (2,249 ) — — — (2,249 ) Accretion on preferred stock — — — — — Loss on redemption of preferred stock — — — — — Net income attributable to common shareholders $101,971 $184,589 $— ($184,659 ) $101,901 CARRIZO OIL & GAS, INC. CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS (In thousands) (Unaudited) Nine Months Ended September 30, 2018 Parent Company Combined Guarantor Subsidiaries Combined Non- Guarantor Subsidiaries Eliminations Consolidated Net cash provided by (used in) operating activities ($218,926 ) $684,218 $— $— $465,292 Net cash provided by (used in) investing activities 375,265 (284,076 ) — (400,142 ) (308,953 ) Net cash used in financing activities (163,464 ) (400,142 ) — 400,142 (163,464 ) Net decrease in cash and cash equivalents (7,125 ) — — — (7,125 ) Cash and cash equivalents, beginning of period 9,540 — — — 9,540 Cash and cash equivalents, end of period $2,415 $— $— $— $2,415 Nine Months Ended September 30, 2017 Parent Company Combined Guarantor Subsidiaries Combined Non- Guarantor Subsidiaries Eliminations Consolidated Net cash provided by (used in) operating activities ($95,529 ) $376,126 $— $— $280,597 Net cash used in investing activities (728,833 ) (1,102,155 ) — 726,029 (1,104,959 ) Net cash provided by financing activities 825,260 726,029 — (726,029 ) 825,260 Net increase in cash and cash equivalents 898 — — — 898 Cash and cash equivalents, beginning of period 4,194 — — — 4,194 Cash and cash equivalents, end of period $5,092 $— $— $— $5,092

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	9 Months Ended
	Sep. 30, 2018
Supplemental Cash Flow Elements [Abstract]
Cash Flow, Supplemental Disclosures	13. Supplemental Cash Flow Information Supplemental cash flow disclosures and non-cash investing activities are presented below: Nine Months Ended September 30, 2018 2017 (In thousands) Supplemental cash flow disclosures: Cash paid for interest, net of amounts capitalized $44,644 $59,389 Non-cash investing activities: Increase in capital expenditure payables and accruals $61,893 $98,829 Fair value of contingent consideration (assets) liabilities on date of (divestiture) acquisition (7,880 ) 52,300 Stock-based compensation expense capitalized to oil and gas properties 5,384 2,543 Asset retirement obligations capitalized to oil and gas properties 1,127 2,761

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events Commodity Derivative Instruments In October 2018, the Company entered into the following commodity derivative instruments at weighted average contract volumes and prices: Commodity Period Type of Contract Index Volumes (Bbls per day) Fixed Price ($ per Bbl) Sub-Floor Price ($ per Bbl) Floor Price ($ per Bbl) Ceiling Price ($ per Bbl) Fixed Price Differential ($ per Bbl) Crude oil 2019 Three-Way Collars NYMEX WTI 6,000 — $45.00 $55.00 $93.01 — Crude oil 2019 Basis Swaps LLS-WTI Cushing 1,000 $5.78 — — — — Redemption of 7.50% Senior Notes Due 2020 On October 18, 2018, the Company delivered a notice of conditional redemption to the trustee for its 7.50% Senior Notes to call for redemption on November 19, 2018, the remaining $130.0 million outstanding aggregate principal amount of 7.50% Senior Notes at a redemption price of 100% of par, plus accrued and unpaid interest. The Company’s redemption obligation was conditioned on and subject to there being made available to the Company under its revolving credit facility a commitment amount of at least $1.1 billion as of November 19, 2018, which was satisfied on October 29, 2018 in connection with the amendment to the credit agreement discussed below, therefore, the Company’s redemption obligation is no longer conditional. As a result of the redemption, the Company expects to record a loss on extinguishment of debt of approximately $0.8 million , which is solely attributable to the write-off of unamortized premium and debt issuance costs. Upon redemption of the 7.50% Senior Notes, the May 4, 2022 maturity date of the credit agreement will no longer be subject to a springing maturity date of June 15, 2020. Thirteenth Amendment to the Credit Agreement On October 29, 2018, the Company entered into the thirteenth amendment to its credit agreement governing its revolving credit facility to, among other things, (i) establish the borrowing base at $1.3 billion , with an elected commitment amount of $1.1 billion , until the next redetermination thereof, (ii) reduce the applicable margins for Eurodollar loans from 1.50% - 2.50% to 1.25% - 2.25% and base rate loans from 0.50% - 1.50% to 0.25% - 1.25% , each depending on the level of facility usage and each subject to an increase of 0.25% for any period during which the ratio of Total Debt to EBITDA exceeds 3.00 to 1.00, (iii) amend the definition of Capital Leases, and (iv) amend certain other definitions and provisions.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policy)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
New Accounting Pronouncements	Recently Adopted Accounting Standards Revenue From Contracts with Customers . Effective January 1, 2018, the Company adopted ASU No. 2014-09, Revenue From Contracts With Customers (Topic 606) (“ASC 606”) using the modified retrospective method and has applied the standard to all existing contracts. ASC 606 supersedes previous revenue recognition requirements in ASC 605 - Revenue Recognition (“ASC 605”) and includes a five-step revenue recognition model to depict the transfer of goods or services to customers in an amount that reflects the consideration in exchange for those goods or services. As a result of adopting ASC 606, the Company did not have a cumulative-effect adjustment in retained earnings. The comparative information for the three and nine months ended September 30, 2017 has not been recast and continues to be reported under the accounting standards in effect for that period. Additionally, adoption of ASC 606 did not impact net income attributable to common shareholders and the Company does not expect that it will do so in future periods. The tables below summarize the impact of adoption for the three and nine months ended September 30, 2018 : Three Months Ended September 30, 2018 Under ASC 606 Under ASC 605 Increase % Increase (In thousands) Revenues Crude oil $254,525 $254,382 $143 0.1 % Natural gas liquids 33,798 32,018 1,780 5.6 % Natural gas 15,052 14,280 772 5.4 % Total revenues 303,375 300,680 2,695 0.9 % Costs and Expenses Lease operating 41,022 38,327 2,695 7.0 % Income Before Income Taxes $82,226 $82,226 $— — % Nine Months Ended September 30, 2018 Under ASC 606 Under ASC 605 Increase % Increase (In thousands) Revenues Crude oil $679,242 $678,834 $408 0.1 % Natural gas liquids 71,969 68,253 3,716 5.4 % Natural gas 41,417 39,439 1,978 5.0 % Total revenues 792,628 786,526 6,102 0.8 % Costs and Expenses Lease operating 115,446 109,344 6,102 5.6 % Income Before Income Taxes $145,829 $145,829 $— — % Changes to crude oil, NGL, and natural gas revenues and lease operating expense are due to the conclusion that the Company controls the product throughout processing before transferring to the customer for certain natural gas processing arrangements. Therefore, any transportation, gathering, and processing fees incurred prior to transfer of control are included in lease operating expense. Business Combinations. In January 2017, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business (“ASU 2017-01”), which clarifies the definition of a business to assist entities with evaluating whether transactions should be accounted for as acquisitions (or divestitures) of assets or businesses. Effective January 1, 2018, the Company adopted ASU 2017-01 using the prospective method and will apply the clarified definition of a business to future acquisitions and divestitures. Statement of Cash Flows. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”), which is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. The guidance addresses eight specific cash flow issues for which current GAAP is either unclear or does not include specific guidance. Effective January 1, 2018, the Company adopted ASU 2016-15 using the retrospective approach as prescribed by ASU 2016-15. There were no changes to the statement of cash flows as a result of adoption. Recently Issued Accounting Pronouncements Leases. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (“ASU 2016-02”), which significantly changes accounting for leases by requiring that lessees recognize a right-of-use (“ROU”) asset and a related lease liability representing the obligation to make lease payments, for virtually all lease transactions. ASU 2016-02 does not apply to leases of mineral rights to explore for or use crude oil and natural gas. Additional disclosures about an entity’s lease transactions will also be required. ASU 2016-02 defines a lease as “a contract, or part of a contract, that conveys the right to control the use of identified property, plant or equipment (an identified asset) for a period of time in exchange for consideration.” ASU 2016-02 is effective for interim and annual periods beginning after December 15, 2018 with early adoption permitted. ASU 2016-02 requires companies to recognize and measure leases at the beginning of the earliest period presented in the financial statements using a modified retrospective approach. The Company is in the process of reviewing and determining the contracts to which ASU 2016-02 applies with the assistance of a third party consultant. These include contracts such as non-cancelable leases, drilling rig contracts, pipeline gathering, transportation and gas processing agreements, and contracts for the use of vehicles and well equipment. The Company continues to review current accounting policies, controls, processes, and disclosures that will change as a result of adopting the new standard. Based upon its initial assessment, the Company expects the adoption of ASU 2016-02 will result in: (i) an increase in assets and liabilities due to the required recognition of ROU assets and corresponding lease liabilities, (ii) increases in depreciation, depletion and amortization and interest expense, (iii) decreases in lease operating and general and administrative expense and (iv) additional disclosures, however, the full impact to the Company’s consolidated financial statements and related disclosures is still being evaluated. Currently, the Company plans to make certain elections allowing the Company not to reassess contracts that commenced prior to adoption, to continue applying its current accounting policy for land easements, and not to recognize ROU assets or lease liabilities for short-term leases. The Company plans to adopt the guidance on the effective date of January 1, 2019. As permitted by ASU No. 2018-11, Leases (Topic 842): Targeted Improvements, the Company does not expect to adjust comparative-period financial statements. Revenue Recognition The Company’s revenues are comprised solely of revenues from customers and include the sale of crude oil, NGLs, and natural gas. The Company believes that the disaggregation of revenue into these three major product types appropriately depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors based on its single geographic location. Crude oil, NGL, and natural gas revenues are recognized at a point in time when production is sold to a purchaser at a fixed or determinable price, delivery has occurred, control has transferred and collectability of the revenue is probable. The transaction price used to recognize revenue is a function of the contract billing terms. Revenue is invoiced by calendar month based on volumes at contractually based rates with payment typically required within 30 days of the end of the production month. At the end of each month when the performance obligation is satisfied, the variable consideration can be reasonably estimated and amounts due from customers are accrued in “Accounts receivable, net” in the consolidated balance sheets. As of September 30, 2018 and December 31, 2017 , receivables from contracts with customers were $100.2 million and $85.6 million , respectively. Taxes assessed by governmental authorities on crude oil, NGL, and natural gas sales are presented separately from such revenues in the consolidated statements of income. Crude oil sales. Crude oil production is primarily sold at the wellhead at an agreed upon index price, net of pricing differentials. Revenue is recognized when control transfers to the purchaser at the wellhead, net of transportation costs incurred by the purchaser. Natural gas and NGL sales. Natural gas is delivered to a midstream processing entity at the wellhead or the inlet of the midstream processing entity’s system. The midstream processing entity gathers and processes the natural gas and remits proceeds for the resulting sales of NGLs and residue gas. The Company evaluates whether it is the principal or agent in the transaction and has concluded it is the principal and the purchasers of the NGLs and residue gas are the customers. Revenue is recognized on a gross basis, with gathering, processing and transportation fees recognized as lease operating expense in the consolidated statements of income as the Company maintains control throughout processing. Transaction Price Allocated to Remaining Performance Obligations . The Company applied the practical expedient in ASC 606 exempting the disclosure of the transaction price allocated to remaining performance obligations if the variable consideration is allocated entirely to a wholly unsatisfied performance obligation. Each unit of product typically represents a separate performance obligation, therefore, future volumes are wholly unsatisfied and disclosure of the transaction price allocated to remaining performance obligations is not required.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block]	The tables below summarize the impact of adoption for the three and nine months ended September 30, 2018 : Three Months Ended September 30, 2018 Under ASC 606 Under ASC 605 Increase % Increase (In thousands) Revenues Crude oil $254,525 $254,382 $143 0.1 % Natural gas liquids 33,798 32,018 1,780 5.6 % Natural gas 15,052 14,280 772 5.4 % Total revenues 303,375 300,680 2,695 0.9 % Costs and Expenses Lease operating 41,022 38,327 2,695 7.0 % Income Before Income Taxes $82,226 $82,226 $— — % Nine Months Ended September 30, 2018 Under ASC 606 Under ASC 605 Increase % Increase (In thousands) Revenues Crude oil $679,242 $678,834 $408 0.1 % Natural gas liquids 71,969 68,253 3,716 5.4 % Natural gas 41,417 39,439 1,978 5.0 % Total revenues 792,628 786,526 6,102 0.8 % Costs and Expenses Lease operating 115,446 109,344 6,102 5.6 % Income Before Income Taxes $145,829 $145,829 $— — %
Schedule of Supplemental Net Income Per Common Share	Net Income Attributable to Common Shareholders Per Common Share The following table summarizes the calculation of net income attributable to common shareholders per common share: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (In thousands, except per share amounts) Net Income $81,346 $7,823 $144,147 $104,150 Dividends on preferred stock (4,457 ) (2,249 ) (13,794 ) (2,249 ) Accretion on preferred stock (771 ) — (2,264 ) — Loss on redemption of preferred stock — — (7,133 ) — Net Income Attributable to Common Shareholders $76,118 $5,574 $120,956 $101,901 Basic weighted average common shares outstanding 86,727 81,053 83,461 70,728 Dilutive effect of restricted stock and performance shares 1,272 85 967 253 Dilutive effect of common stock warrants 1,040 — 793 166 Diluted weighted average common shares outstanding 89,039 81,138 85,221 71,147 Net Income Attributable to Common Shareholders Per Common Share Basic $0.88 $0.07 $1.45 $1.44 Diluted $0.85 $0.07 $1.42 $1.43
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	The computation of diluted net income attributable to common shareholders per common share excluded restricted stock, performance shares and common stock warrants that were anti-dilutive. The following table presents the weighted average anti-dilutive securities for the periods presented: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (In thousands) Anti-dilutive restricted stock and performance shares — 730 5 120 Anti-dilutive common stock warrants — 152 — — Total weighted average anti-dilutive securities — 882 5 120

Acquisitions and Divestitures (

Acquisitions and Divestitures (Tables)	9 Months Ended
	Sep. 30, 2018
Business Acquisition [Line Items]
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual	The results of operations for the ExL Acquisition have been included in the Company’s consolidated statements of income since the August 10, 2017 closing date, including total revenues and net income attributable to common shareholders for the three and nine months ended September 30, 2018 and 2017 as shown in the table below: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (In thousands) Total revenues $71,525 $14,016 $167,764 $14,016 Net Income Attributable to Common Shareholders $57,466 $11,393 $134,317 $11,393
Business Acquisition, Pro Forma Information [Table Text Block]	Pro Forma Operating Results (Unaudited). The following unaudited pro forma financial information presents a summary of the Company’s consolidated results of operations for the three and nine months ended September 30, 2017, assuming the ExL Acquisition had been completed as of January 1, 2016, including adjustments to reflect the fair values assigned to the assets acquired and liabilities assumed. The pro forma financial information does not purport to represent what the actual results of operations would have been had the transactions been completed as of the date assumed, nor is this information necessarily indicative of future consolidated results of operations. The Company believes the assumptions used provide a reasonable basis for reflecting the significant pro forma effects directly attributable to the ExL Acquisition. Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (In thousands, except per share amounts) Total revenues $189,499 $534,607 Net Income Attributable to Common Shareholders $14,654 $115,053 Net Income Attributable to Common Shareholders Per Common Share Basic $0.18 $1.63 Diluted $0.18 $1.62
ExL Acquisition
Business Acquisition [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following table presents the final allocation of the purchase price to the assets acquired and liabilities assumed as of the acquisition date. Purchase Price Allocation (In thousands) Assets Other current assets $106 Oil and gas properties Proved properties 294,754 Unproved properties 443,194 Total oil and gas properties $737,948 Total assets acquired $738,054 Liabilities Revenues and royalties payable $5,785 Asset retirement obligations 153 Contingent ExL Consideration 52,300 Total liabilities assumed $58,238 Net Assets Acquired $679,816

Property And Equipment, Net (Ta

Property And Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2018
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	As of September 30, 2018 and December 31, 2017 , total property and equipment, net consisted of the following: September 30, December 31, (In thousands) Oil and gas properties, full cost method Proved properties $5,988,301 $5,615,153 Accumulated depreciation, depletion and amortization and impairments (3,863,534 ) (3,649,806 ) Proved properties, net 2,124,767 1,965,347 Unproved properties, not being amortized Unevaluated leasehold and seismic costs 516,537 612,589 Capitalized interest 62,738 47,698 Total unproved properties, not being amortized 579,275 660,287 Other property and equipment 28,134 25,625 Accumulated depreciation (17,249 ) (15,449 ) Other property and equipment, net 10,885 10,176 Total property and equipment, net $2,714,927 $2,635,810

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Schedule Of Effective Income Tax Rate Reconciliation	The Company’s income tax expense differs from the income tax expense computed by applying the U.S. federal statutory corporate income tax rate of 21% for the three and nine months ended September 30, 2018 and 35% for the three and nine months ended September 30, 2017, to income before income taxes as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (In thousands) Income before income taxes $82,226 $7,823 $145,829 $104,150 Income tax expense at the U.S. federal statutory rate (17,267 ) (2,738 ) (30,624 ) (36,452 ) State income tax expense, net of U.S. federal income tax benefit (881 ) (247 ) (1,687 ) (1,974 ) Tax deficiencies related to stock-based compensation (10 ) (273 ) (2,552 ) (3,029 ) Decrease in valuation allowance due to current period activity 17,400 3,253 33,849 41,570 Other (122 ) 5 (668 ) (115 ) Income tax expense ($880 ) $— ($1,682 ) $—

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	Long-term debt consisted of the following as of September 30, 2018 and December 31, 2017 : September 30, December 31, (In thousands) Senior Secured Revolving Credit Facility due 2022 $309,837 $291,300 7.50% Senior Notes due 2020 130,000 450,000 Unamortized premium for 7.50% Senior Notes 124 579 Unamortized debt issuance costs for 7.50% Senior Notes (980 ) (4,492 ) 6.25% Senior Notes due 2023 650,000 650,000 Unamortized debt issuance costs for 6.25% Senior Notes (7,219 ) (8,208 ) 8.25% Senior Notes due 2025 250,000 250,000 Unamortized debt issuance costs for 8.25% Senior Notes (4,073 ) (4,395 ) Other long-term debt due 2028 — 4,425 Long-term debt $1,327,689 $1,629,209
Interest and Commitment Fee Rates	Borrowings outstanding under the credit agreement bear interest at the Company’s option at either (i) a base rate for a base rate loan plus the margin set forth in the table below, where the base rate is defined as the greatest of the prime rate, the federal funds rate plus 0.50% and the adjusted LIBO rate plus 1.00% , or (ii) an adjusted LIBO rate for a Eurodollar loan plus the margin set forth in the table below. The Company also incurs commitment fees at rates as set forth in the table below on the unused portion of lender commitments, which are included in “Interest expense, net” in the consolidated statements of income. Ratio of Outstanding Borrowings to Lender Commitments Applicable Margin for Base Rate Loans Applicable Margin for Eurodollar Loans Commitment Fee Less than 25% 0.50% 1.50% 0.375% Greater than or equal to 25% but less than 50% 0.75% 1.75% 0.375% Greater than or equal to 50% but less than 75% 1.00% 2.00% 0.500% Greater than or equal to 75% but less than 90% 1.25% 2.25% 0.500% Greater than or equal to 90% 1.50% 2.50% 0.500%

Preferred Stock (Tables)

Preferred Stock (Tables)	9 Months Ended
	Sep. 30, 2018
Preferred Stock Disclosure [Abstract]
Schedule of Preferred Stock Dividends Paid in Common Stock	The Company may elect to pay all or a portion of the Preferred Stock dividends in shares of its common stock in decreasing percentages as follows with respect to any preferred stock dividend declared by the Company’s Board of Directors and paid in respect of a quarter ending: Period Percentage On or after December 15, 2018 and on or prior to September 15, 2019 75 % On or after December 15, 2019 and on or prior to September 15, 2020 50 %
Schedule of Preferred Stock Redemption Premiums	After August 10, 2020, the Company may redeem all or part of the Preferred Stock in cash at redemption premiums, as presented in the table below, plus accrued but unpaid dividends. Period Percentage After August 10, 2020 but on or prior to August 10, 2021 104.4375 % After August 10, 2021 but on or prior to August 10, 2022 102.21875 % After August 10, 2022 100 %
Temporary Equity [Table Text Block]	The table below presents the reconciliation of changes in the carrying amount of Preferred Stock for the nine months ended September 30, 2018 : Carrying Amount of Preferred Stock (In thousands) December 31, 2017 $214,262 Redemption of Preferred Stock (42,897 ) Accretion on Preferred Stock 2,264 September 30, 2018 $173,629

Shareholders' Equity and Stoc_2

Shareholders' Equity and Stock Incentive Plans (Tables)	9 Months Ended
	Sep. 30, 2018
Shareholders' Equity and Stock Incentive Plans [Abstract]
Schedule of Restricted Stock Awards and Restricted Stock Units Activity	The table below summarizes restricted stock award and unit activity for the nine months ended September 30, 2018 : Restricted Stock Awards and Units Weighted Average Grant Date Fair Value Unvested restricted stock awards and units, beginning of period 1,482,655 $28.07 Granted 1,391,422 $15.07 Vested (615,762 ) $31.44 Forfeited (23,880 ) $18.51 Unvested restricted stock awards and units, end of period 2,234,435 $19.14
Schedule of Stock Appreciation Rights Award Activity	The table below summarizes the Cash SAR activity for the nine months ended September 30, 2018 : Cash SARs Weighted Average Exercise Prices Weighted Average Remaining Life (In years) Aggregate Intrinsic Value (In millions) Aggregate Intrinsic Value of Exercises (In millions) Outstanding, beginning of period 714,238 $27.12 Granted 616,686 $14.67 Exercised — $— $— Forfeited — $— Expired — $— Outstanding, end of period 1,330,924 $21.35 4.6 $6.5 Vested, end of period 543,018 $27.18 Vested and exercisable, end of period — $27.18 2.8 $—
Schedule of Stock Appreciation Rights Valuation Assumptions	The following table summarizes the assumptions used to calculate the grant date fair value of the Cash SARs granted during the nine months ended September 30, 2018 : Grant Date Fair Value Assumptions Expected term (in years) 6.0 Expected volatility 54.3 % Risk-free interest rate 2.8 % Dividend yield — %
Schedule of Performance Shares Award Unvested Activity	The table below summarizes performance share activity for the nine months ended September 30, 2018 : Target Performance Shares (1) Weighted Average Grant Date Fair Value Unvested performance shares, beginning of period 144,955 $47.14 Granted 93,771 $19.09 Vested at end of performance period (49,458 ) $65.51 Did not vest at end of performance period (7,059 ) $65.51 Forfeited — $— Unvested performance shares, end of period 182,209 $27.01
Schedule of Performance Share Award Valuation Assumptions	following table summarizes the assumptions used to calculate the grant date fair value of the performance shares granted during the nine months ended September 30, 2018 : Grant Date Fair Value Assumptions Number of simulations 500,000 Expected term (in years) 3.0 Expected volatility 61.5 % Risk-free interest rate 2.4 % Dividend yield — %
Schedule of Stock-based Compensation, net	The Company recognized the following stock-based compensation expense, net for the three and nine months ended September 30, 2018 and 2017 : Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (In thousands) Restricted stock awards and units $4,487 $5,311 $14,291 $16,184 Cash SARs (868 ) 429 3,505 (7,040 ) Performance shares 411 581 1,374 1,861 4,030 6,321 19,170 11,005 Less: amounts capitalized to oil and gas properties (968 ) (1,455 ) (5,384 ) (2,543 ) Total stock-based compensation expense, net $3,062 $4,866 $13,786 $8,462

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2018
Derivative [Line Items]
Schedule of Contingent Consideration	The purchase and sale agreements of the ExL Acquisition and divestitures of the Company’s assets in the Niobrara, Marcellus and Utica, included contingent consideration arrangements that entitle the Company to receive or require the Company to pay specified amounts if commodity prices exceed specified thresholds, which are summarized in the table below. See “Note 3. Acquisitions and Divestitures of Oil and Gas Properties” for details of these acquisitions and divestitures. Contingent Consideration Arrangements Years Threshold (1) Contingent Receipt (Payment) - Annual Contingent Receipt (Payment) - Aggregate Limit (In thousands) Contingent ExL Consideration 2018 $50.00 ($50,000 ) 2019 50.00 (50,000 ) 2020 50.00 (50,000 ) 2021 50.00 (50,000 ) ($125,000 ) Contingent Niobrara Consideration 2018 $55.00 $5,000 2019 55.00 5,000 2020 60.00 5,000 — Contingent Marcellus Consideration 2018 $3.13 $3,000 2019 3.18 3,000 2020 3.30 3,000 $7,500 Contingent Utica Consideration 2018 $50.00 $5,000 2019 53.00 5,000 2020 56.00 5,000 — (1) The price used to determine whether the specified threshold for each year has been met for the Contingent ExL Consideration, Contingent Niobrara Consideration and Contingent Utica Consideration is the average daily closing spot price per barrel of WTI crude oil as measured by the U.S. Energy Information Administration. The price used to determine whether the specified threshold for each year has been met for the Marcellus Contingent Consideration is the average monthly settlement price per MMBtu of Henry Hub natural gas for the next calendar month, as determined on the last business day preceding each calendar month as measured by the CME Group Inc.
Schedule of Derivative Instrument Fair Value Assets and Liabilities	The derivative instrument asset and liability fair values recorded in the consolidated balance sheets as of September 30, 2018 and December 31, 2017 are summarized below: September 30, 2018 Gross Amounts Recognized Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets (In thousands) Commodity derivative instruments $19,408 ($18,985 ) $423 Contingent Niobrara Consideration 4,920 — 4,920 Contingent Utica Consideration 4,915 — 4,915 Derivative assets $29,243 ($18,985 ) $10,258 Commodity derivative instruments 12,028 (12,028 ) — Contingent Niobrara Consideration 6,755 — 6,755 Contingent Marcellus Consideration 1,315 — 1,315 Contingent Utica Consideration 7,300 — 7,300 Other assets $27,398 ($12,028 ) $15,370 Commodity derivative instruments ($123,611 ) $9,876 ($113,735 ) Deferred premium obligations (9,109 ) 9,109 — Contingent ExL Consideration (49,160 ) — (49,160 ) Derivative liabilities-current ($181,880 ) $18,985 ($162,895 ) Commodity derivative instruments (45,532 ) 6,314 (39,218 ) Deferred premium obligations (5,714 ) 5,714 — Contingent ExL Consideration (62,885 ) — (62,885 ) Derivative liabilities-non current ($114,131 ) $12,028 ($102,103 ) December 31, 2017 Gross Amounts Recognized Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets (In thousands) Commodity derivative instruments $4,869 ($4,869 ) $— Derivative assets $4,869 ($4,869 ) $— Commodity derivative instruments 9,505 (9,505 ) — Contingent Marcellus Consideration 2,205 — 2,205 Contingent Utica Consideration 7,985 — 7,985 Other assets $19,695 ($9,505 ) $10,190 Commodity derivative instruments ($52,671 ) ($4,450 ) ($57,121 ) Deferred premium obligations (9,319 ) 9,319 — Derivative liabilities-current ($61,990 ) $4,869 ($57,121 ) Commodity derivative instruments (24,609 ) (2,098 ) (26,707 ) Deferred premium obligations (11,603 ) 11,603 — Contingent ExL Consideration (85,625 ) — (85,625 ) Derivative liabilities-non current ($121,837 ) $9,505 ($112,332 )
Schedule of (Gain) Loss on Derivative Instruments	The net (gain) loss on derivatives in the consolidated statements of income for the three and nine months ended September 30, 2018 and 2017 are summarized below: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (In thousands) (Gain) Loss on Derivatives, Net Crude oil $43,664 $8,409 $126,612 ($39,754 ) NGL 5,086 — 9,885 — Natural gas (192 ) (2,183 ) (3,084 ) (12,902 ) Deferred premium obligations — 10,151 — 17,652 Contingent ExL Consideration 9,990 8,000 26,420 8,000 Contingent Niobrara Consideration (1,705 ) — (3,795 ) — Contingent Marcellus Consideration 215 — 890 — Contingent Utica Consideration (1,670 ) — (4,230 ) — (Gain) Loss on Derivatives, Net $55,388 $24,377 $152,698 ($27,004 )
Schedule of Cash Received for Derivatives	The net cash received (paid) for derivative settlements in the consolidated statements of cash flows for the three and nine months ended September 30, 2018 and 2017 are summarized below: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Cash Flows from Operating Activities (In thousands) Cash Received (Paid) for Derivative Settlements, Net Crude oil ($21,261 ) $6,500 ($54,594 ) $9,941 NGL (2,641 ) — (3,829 ) — Natural gas 245 522 785 (731 ) Deferred premium obligations (2,605 ) (566 ) (7,072 ) (1,496 ) Cash Received (Paid) for Derivative Settlements, Net ($26,262 ) $6,456 ($64,710 ) $7,714
Crude Oil
Derivative [Line Items]
Schedule of Derivative Instruments	As of September 30, 2018 , the Company had the following outstanding commodity derivative instruments at weighted average contract volumes and prices: Commodity Period Type of Contract Index Volumes (Bbls per day) Fixed Price ($ per Bbl) Sub-Floor Price ($ per Bbl) Floor Price ($ per Bbl) Ceiling Price ($ per Bbl) Fixed Price Differential ($ per Bbl) Crude oil 4Q18 Price Swaps NYMEX WTI 6,000 $49.55 — — — — Crude oil 4Q18 Three-Way Collars NYMEX WTI 24,000 — $39.38 $49.06 $60.14 — Crude oil 4Q18 Basis Swaps LLS-WTI Cushing 18,000 — — — — $5.11 Crude oil 4Q18 Basis Swaps WTI Midland-WTI Cushing 6,000 — — — — ($0.10 ) Crude oil 4Q18 Sold Call Options NYMEX WTI 3,388 — — — $71.33 — Crude oil 2019 Three-Way Collars NYMEX WTI 21,000 — $40.71 $49.80 $67.80 — Crude oil 2019 Basis Swaps LLS-WTI Cushing 3,000 — — — — $4.57 Crude oil 2019 Basis Swaps WTI Midland-WTI Cushing 7,389 — — — — ($4.82 ) Crude oil 2019 Sold Call Options NYMEX WTI 3,875 — — — $73.66 — Crude oil 2020 Basis Swaps WTI Midland-WTI Cushing 13,000 — — — — ($1.27 ) Crude oil 2020 Sold Call Options NYMEX WTI 4,575 — — — $75.98 — Crude oil 2021 Basis Swaps WTI Midland-WTI Cushing 6,000 — — — — $0.03 In October 2018, the Company entered into the following commodity derivative instruments at weighted average contract volumes and prices: Commodity Period Type of Contract Index Volumes (Bbls per day) Fixed Price ($ per Bbl) Sub-Floor Price ($ per Bbl) Floor Price ($ per Bbl) Ceiling Price ($ per Bbl) Fixed Price Differential ($ per Bbl) Crude oil 2019 Three-Way Collars NYMEX WTI 6,000 — $45.00 $55.00 $93.01 — Crude oil 2019 Basis Swaps LLS-WTI Cushing 1,000 $5.78 — — — —
Natural Gas Liquids
Derivative [Line Items]
Schedule of Derivative Instruments	Commodity Period Type of Contract Index Volumes (Bbls per day) Fixed Price ($ per Bbl) Sub-Floor Price ($ per Bbl) Floor Price ($ per Bbl) Ceiling Price ($ per Bbl) Fixed Price Differential ($ per Bbl) NGLs 4Q18 Price Swaps OPIS-Ethane 2,200 $12.01 — — — — NGLs 4Q18 Price Swaps OPIS-Propane 1,500 $34.23 — — — — NGLs 4Q18 Price Swaps OPIS-Butane 200 $38.85 — — — — NGLs 4Q18 Price Swaps OPIS-Isobutane 600 $38.98 — — — — NGLs 4Q18 Price Swaps OPIS-Natural Gasoline 600 $55.23 — — — —
Natural Gas
Derivative [Line Items]
Schedule of Derivative Instruments	Commodity Period Type of Contract Index Volumes (MMBtu per day) Fixed Price ($ per MMBtu) Sub-Floor Price ($ per MMBtu) Floor Price ($ per MMBtu) Ceiling Price ($ per MMBtu) Fixed Price Differential ($ per MMBtu) Natural gas 4Q18 Price Swaps NYMEX Henry Hub 25,000 $3.01 — — — — Natural gas 4Q18 Sold Call Options NYMEX Henry Hub 33,000 — — — $3.25 — Natural gas 2019 Sold Call Options NYMEX Henry Hub 33,000 — — — $3.25 — Natural gas 2020 Sold Call Options NYMEX Henry Hub 33,000 — — — $3.50 —

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following tables summarize the Company’s derivative instrument assets and liabilities measured at fair value on a recurring basis as of September 30, 2018 and December 31, 2017 : September 30, 2018 Level 1 Level 2 Level 3 (In thousands) Assets Commodity derivative instruments $— $423 $— Contingent Niobrara Consideration — — 11,675 Contingent Marcellus Consideration — — 1,315 Contingent Utica Consideration — — 12,215 Liabilities Commodity derivative instruments $— ($152,953 ) $— Contingent ExL Consideration — — (112,045 ) December 31, 2017 Level 1 Level 2 Level 3 (In thousands) Assets Commodity derivative instruments $— $— $— Contingent Niobrara Consideration — — — Contingent Marcellus Consideration — — 2,205 Contingent Utica Consideration — — 7,985 Liabilities Commodity derivative instruments $— ($83,828 ) $— Contingent ExL Consideration — — (85,625 )
Fair Value, Assets and Liabilities Measured on Recurring Basis, Level 3 Reconciliation	Contingent Consideration Arrangements Assets Liability (In thousands) December 31, 2017 $10,190 ($85,625 ) Recognition of divestiture date fair value 7,880 — Gain (loss) on changes in fair value, net (1) 7,135 (26,420 ) Transfers into (out of) Level 3 — — September 30, 2018 $25,205 ($112,045 ) Contingent Consideration Arrangements Assets Liability (In thousands) December 31, 2016 $— $— Recognition of acquisition date fair value — (52,300 ) Loss on change in fair value (1) — (8,000 ) Transfers into (out of) Level 3 — — September 30, 2017 $— ($60,300 )
Schedule of Carrying Value and Fair Value of Debt Instruments	The following table presents the carrying amounts of the Company’s senior notes and other long-term debt, net of unamortized premiums and debt issuance costs with the fair values measured using quoted secondary market trading prices which are designated as Level 1 within the valuation hierarchy. September 30, 2018 December 31, 2017 Carrying Amount Fair Value Carrying Amount Fair Value (In thousands) 7.50% Senior Notes due 2020 $129,144 $130,000 $446,087 $459,518 6.25% Senior Notes due 2023 642,781 664,625 641,792 674,375 8.25% Senior Notes due 2025 245,927 268,750 245,605 274,375 Other long-term debt due 2028 — — 4,425 4,445

Condensed Consolidating Finan_2

Condensed Consolidating Financial Information (Tables)	9 Months Ended
	Sep. 30, 2018
Condensed Consolidating Financial Information [Abstract]
Schedule Of Condensed Consolidating Balance Sheets	CARRIZO OIL & GAS, INC. CONDENSED CONSOLIDATING BALANCE SHEETS (In thousands) (Unaudited) September 30, 2018 Parent Company Combined Guarantor Subsidiaries Combined Non- Guarantor Subsidiaries Eliminations Consolidated Assets Total current assets $3,114,698 $133,308 $— ($3,096,917 ) $151,089 Total property and equipment, net 6,570 2,709,162 3,028 (3,833 ) 2,714,927 Investment in subsidiaries (576,826 ) — — 576,826 — Other assets 29,611 15,371 — — 44,982 Total Assets $2,574,053 $2,857,841 $3,028 ($2,523,924 ) $2,910,998 Liabilities and Shareholders’ Equity Current liabilities $305,096 $3,347,575 $3,028 ($3,099,937 ) $555,762 Long-term liabilities 1,357,294 87,092 — 15,879 1,460,265 Preferred stock 173,629 — — — 173,629 Total shareholders’ equity 738,034 (576,826 ) — 560,134 721,342 Total Liabilities and Shareholders’ Equity $2,574,053 $2,857,841 $3,028 ($2,523,924 ) $2,910,998 December 31, 2017 Parent Company Combined Guarantor Subsidiaries Combined Non- Guarantor Subsidiaries Eliminations Consolidated Assets Total current assets $3,441,633 $105,533 $— ($3,424,288 ) $122,878 Total property and equipment, net 5,953 2,630,707 3,028 (3,878 ) 2,635,810 Investment in subsidiaries (999,793 ) — — 999,793 — Other assets 9,270 10,346 — — 19,616 Total Assets $2,457,063 $2,746,586 $3,028 ($2,428,373 ) $2,778,304 Liabilities and Shareholders’ Equity Current liabilities $165,701 $3,631,401 $3,028 ($3,427,308 ) $372,822 Long-term liabilities 1,689,466 114,978 — 15,879 1,820,323 Preferred stock 214,262 — — — 214,262 Total shareholders’ equity 387,634 (999,793 ) — 983,056 370,897 Total Liabilities and Shareholders’ Equity $2,457,063 $2,746,586 $3,028 ($2,428,373 ) $2,778,304
Schedule Of Condensed Consolidating Statements Of Operations	CARRIZO OIL & GAS, INC. CONDENSED CONSOLIDATING STATEMENTS OF INCOME (In thousands) (Unaudited) Three Months Ended September 30, 2018 Parent Company Combined Guarantor Subsidiaries Combined Non- Guarantor Subsidiaries Eliminations Consolidated Total revenues $38 $303,337 $— $— $303,375 Total costs and expenses 85,242 135,920 — (13 ) 221,149 Income (loss) before income taxes (85,204 ) 167,417 — 13 82,226 Income tax expense — (880 ) — — (880 ) Equity in income of subsidiaries 166,537 — — (166,537 ) — Net income $81,333 $166,537 $— ($166,524 ) $81,346 Dividends on preferred stock (4,457 ) — — — (4,457 ) Accretion on preferred stock (771 ) — — — (771 ) Loss on redemption of preferred stock — — — — — Net income attributable to common shareholders $76,105 $166,537 $— ($166,524 ) $76,118 Three Months Ended September 30, 2017 Parent Company Combined Guarantor Subsidiaries Combined Non- Guarantor Subsidiaries Eliminations Consolidated Total revenues $35 $181,244 $— $— $181,279 Total costs and expenses 54,061 119,366 — 29 173,456 Income (loss) before income taxes (54,026 ) 61,878 — (29 ) 7,823 Income tax expense — — — — — Equity in income of subsidiaries 61,878 — — (61,878 ) — Net income $7,852 $61,878 $— ($61,907 ) $7,823 Dividends on preferred stock (2,249 ) — — — (2,249 ) Accretion on preferred stock — — — — — Loss on redemption of preferred stock — — — — — Net income attributable to common shareholders $5,603 $61,878 $— ($61,907 ) $5,574 CARRIZO OIL & GAS, INC. CONDENSED CONSOLIDATING STATEMENTS OF INCOME (In thousands) (Unaudited) Nine Months Ended September 30, 2018 Parent Company Combined Guarantor Subsidiaries Combined Non- Guarantor Subsidiaries Eliminations Consolidated Total revenues $77 $792,551 $— $— $792,628 Total costs and expenses 278,942 367,902 — (45 ) 646,799 Income (loss) before income taxes (278,865 ) 424,649 — 45 145,829 Income tax expense — (1,682 ) — — (1,682 ) Equity in income of subsidiaries 422,967 — — (422,967 ) — Net income $144,102 $422,967 $— ($422,922 ) $144,147 Dividends on preferred stock (13,794 ) — — — (13,794 ) Accretion on preferred stock (2,264 ) — — — (2,264 ) Loss on redemption of preferred stock (7,133 ) — — — (7,133 ) Net income attributable to common shareholders $120,911 $422,967 $— ($422,922 ) $120,956 Nine Months Ended September 30, 2017 Parent Company Combined Guarantor Subsidiaries Combined Non- Guarantor Subsidiaries Eliminations Consolidated Total revenues $291 $498,826 $— $— $499,117 Total costs and expenses 80,660 314,237 — 70 394,967 Income (loss) before income taxes (80,369 ) 184,589 — (70 ) 104,150 Income tax expense — — — — — Equity in income of subsidiaries 184,589 — — (184,589 ) — Net income $104,220 $184,589 $— ($184,659 ) $104,150 Dividends on preferred stock (2,249 ) — — — (2,249 ) Accretion on preferred stock — — — — — Loss on redemption of preferred stock — — — — — Net income attributable to common shareholders $101,971 $184,589 $— ($184,659 ) $101,901
Schedule Of Condensed Consolidating Statements Of Cash Flows	CARRIZO OIL & GAS, INC. CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS (In thousands) (Unaudited) Nine Months Ended September 30, 2018 Parent Company Combined Guarantor Subsidiaries Combined Non- Guarantor Subsidiaries Eliminations Consolidated Net cash provided by (used in) operating activities ($218,926 ) $684,218 $— $— $465,292 Net cash provided by (used in) investing activities 375,265 (284,076 ) — (400,142 ) (308,953 ) Net cash used in financing activities (163,464 ) (400,142 ) — 400,142 (163,464 ) Net decrease in cash and cash equivalents (7,125 ) — — — (7,125 ) Cash and cash equivalents, beginning of period 9,540 — — — 9,540 Cash and cash equivalents, end of period $2,415 $— $— $— $2,415 Nine Months Ended September 30, 2017 Parent Company Combined Guarantor Subsidiaries Combined Non- Guarantor Subsidiaries Eliminations Consolidated Net cash provided by (used in) operating activities ($95,529 ) $376,126 $— $— $280,597 Net cash used in investing activities (728,833 ) (1,102,155 ) — 726,029 (1,104,959 ) Net cash provided by financing activities 825,260 726,029 — (726,029 ) 825,260 Net increase in cash and cash equivalents 898 — — — 898 Cash and cash equivalents, beginning of period 4,194 — — — 4,194 Cash and cash equivalents, end of period $5,092 $— $— $— $5,092

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	9 Months Ended
	Sep. 30, 2018
Supplemental Cash Flow Elements [Abstract]
Schedule of Cash Flow, Supplemental Disclosures	Supplemental cash flow disclosures and non-cash investing activities are presented below: Nine Months Ended September 30, 2018 2017 (In thousands) Supplemental cash flow disclosures: Cash paid for interest, net of amounts capitalized $44,644 $59,389 Non-cash investing activities: Increase in capital expenditure payables and accruals $61,893 $98,829 Fair value of contingent consideration (assets) liabilities on date of (divestiture) acquisition (7,880 ) 52,300 Stock-based compensation expense capitalized to oil and gas properties 5,384 2,543 Asset retirement obligations capitalized to oil and gas properties 1,127 2,761

Subsequent Events (Tables)

Subsequent Events (Tables)	9 Months Ended
	Sep. 30, 2018
Crude Oil
Derivative [Line Items]
Schedule of Derivative Instruments	As of September 30, 2018 , the Company had the following outstanding commodity derivative instruments at weighted average contract volumes and prices: Commodity Period Type of Contract Index Volumes (Bbls per day) Fixed Price ($ per Bbl) Sub-Floor Price ($ per Bbl) Floor Price ($ per Bbl) Ceiling Price ($ per Bbl) Fixed Price Differential ($ per Bbl) Crude oil 4Q18 Price Swaps NYMEX WTI 6,000 $49.55 — — — — Crude oil 4Q18 Three-Way Collars NYMEX WTI 24,000 — $39.38 $49.06 $60.14 — Crude oil 4Q18 Basis Swaps LLS-WTI Cushing 18,000 — — — — $5.11 Crude oil 4Q18 Basis Swaps WTI Midland-WTI Cushing 6,000 — — — — ($0.10 ) Crude oil 4Q18 Sold Call Options NYMEX WTI 3,388 — — — $71.33 — Crude oil 2019 Three-Way Collars NYMEX WTI 21,000 — $40.71 $49.80 $67.80 — Crude oil 2019 Basis Swaps LLS-WTI Cushing 3,000 — — — — $4.57 Crude oil 2019 Basis Swaps WTI Midland-WTI Cushing 7,389 — — — — ($4.82 ) Crude oil 2019 Sold Call Options NYMEX WTI 3,875 — — — $73.66 — Crude oil 2020 Basis Swaps WTI Midland-WTI Cushing 13,000 — — — — ($1.27 ) Crude oil 2020 Sold Call Options NYMEX WTI 4,575 — — — $75.98 — Crude oil 2021 Basis Swaps WTI Midland-WTI Cushing 6,000 — — — — $0.03 In October 2018, the Company entered into the following commodity derivative instruments at weighted average contract volumes and prices: Commodity Period Type of Contract Index Volumes (Bbls per day) Fixed Price ($ per Bbl) Sub-Floor Price ($ per Bbl) Floor Price ($ per Bbl) Ceiling Price ($ per Bbl) Fixed Price Differential ($ per Bbl) Crude oil 2019 Three-Way Collars NYMEX WTI 6,000 — $45.00 $55.00 $93.01 — Crude oil 2019 Basis Swaps LLS-WTI Cushing 1,000 $5.78 — — — —

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Summary Of Significant Accounting Policies [Line Items]
Accrued Fees and Other Revenue Receivable	$ 100.2	$ 85.6

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Schedule of Impact of Adoption) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Crude oil revenues	$ 254,525	$ 152,101	$ 679,242	$ 422,999
Natural gas liquids revenues	33,798	12,467	71,969	27,678
Natural gas revenues	15,052	16,711	41,417	48,440
Oil and Gas Sales Revenue	303,375	181,279	792,628	499,117
Lease operating	41,022	34,874	115,446	100,767
Income before income taxes	82,226	$ 7,823	145,829	$ 104,150
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Crude oil revenues	254,382		678,834
Natural gas liquids revenues	32,018		68,253
Natural gas revenues	14,280		39,439
Oil and Gas Sales Revenue	300,680		786,526
Lease operating	38,327		109,344
Income before income taxes	82,226		145,829
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Crude oil revenues	143		408
Natural gas liquids revenues	1,780		3,716
Natural gas revenues	772		1,978
Oil and Gas Sales Revenue	2,695		6,102
Lease operating	2,695		6,102
Income before income taxes	$ 0		$ 0
Crude Oil
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent Difference Between Revenue Guidance In Effect Before And After Topic 606	0.10%		0.10%
Natural Gas Liquids
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent Difference Between Revenue Guidance In Effect Before And After Topic 606	5.60%		5.40%
Natural Gas
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent Difference Between Revenue Guidance In Effect Before And After Topic 606	5.40%		5.00%
Total Oil and Gas
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent Difference Between Revenue Guidance In Effect Before And After Topic 606	0.90%		0.80%
Lease Operating Expense
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent Difference Between Revenue Guidance In Effect Before And After Topic 606	7.00%		5.60%
Income Before Income Taxes
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent Difference Between Revenue Guidance In Effect Before And After Topic 606	0.00%		0.00%

Summary of Significant Accoun_6

Summary of Significant Accounting Policies (Schedule of Earnings Per Share Reconciliation) (Details) - USD ($) $ / shares in Units, shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income (loss)	$ 81,346,000	$ 7,823,000	$ 144,147,000	$ 104,150,000
Dividends on preferred stock	(4,457,000)	(2,249,000)	(13,794,000)	(2,249,000)
Accretion on preferred stock	(771,000)	0	(2,264,000)	0
Loss on redemption of preferred stock	0	0	(7,133,000)	0
Net Income Attributable to Common Shareholders	$ 76,118,000	$ 5,574,000	$ 120,956,000	$ 101,901,000
Basic weighted average common shares outstanding	86,727	81,053	83,461	70,728
Dilutive effect of restricted stock and performance shares	1,272	85	967	253
Dilutive effect of common stock warrants	1,040	0	793	166
Diluted weighted average common shares outstanding	89,039	81,138	85,221	71,147
Net Income (Loss) - basic (in dollars per share)	$ 0.88	$ 0.07	$ 1.45	$ 1.44
Net Income (Loss) - diluted (in dollars per share)	$ 0.85	$ 0.07	$ 1.42	$ 1.43

Summary of Significant Accoun_7

Summary of Significant Accounting Policies (Schedule of Antidilutive Shares Excluded from Earnings Per Share) (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	882	5	120
Restricted Stock and Performance Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	730	5	120
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	152	0	0

Acquisitions and Divestitures_2

Acquisitions and Divestitures (Narrative) (Details) - USD ($) $ in Thousands

1 Months Ended

3 Months Ended

6 Months Ended

7 Months Ended

9 Months Ended

12 Months Ended

Feb. 28, 2018

Jan. 31, 2018

Apr. 30, 2017

Jan. 31, 2017

Dec. 31, 2018

Sep. 30, 2018

Mar. 31, 2018

Dec. 31, 2017

Sep. 30, 2017

Jun. 30, 2017

Mar. 31, 2017

Dec. 31, 2016

Mar. 31, 2018

Apr. 30, 2017

Sep. 30, 2018

Sep. 30, 2017

Dec. 31, 2018

Sep. 30, 2018

Dec. 31, 2017

Aug. 13, 2018

Jul. 11, 2018

Dec. 11, 2017

Nov. 20, 2017

Oct. 05, 2017

Aug. 31, 2017

Business Acquisition [Line Items]

Deposit For Acquisition Of Oil And Gas Properties

$ 21,500

Payments to Acquire Oil and Gas Property

0

$ 692,006

Proceeds from divestitures of oil and gas properties, net

$ 15,300

$ 377,693

$ 18,212

Devon Acquisition

Business Acquisition [Line Items]

Agreed upon Purchase Price of Oil and Gas Property and Equipment

$ 215,000

Deposit For Acquisition Of Oil And Gas Properties

21,500

Interest Available To Joint Operating Partner

20.00%

Devon Acquisition | Subsequent Event [Member]

Business Acquisition [Line Items]

Payments to Acquire Oil and Gas Property

$ 183,400

$ 204,900

Delaware Basin Divestiture

Business Acquisition [Line Items]

Sale Price of Oil and Gas Property and Equipment

$ 30,000

Proceeds from divestitures of oil and gas properties, net

31,400

Delaware Basin Divestiture | Subsequent Event [Member]

Business Acquisition [Line Items]

Proceeds from divestitures of oil and gas properties, net

$ 30,900

Cash Paid for Post-Closing Adjustments to Divestitures

$ 500

Eagle Ford Shale Divestiture

Business Acquisition [Line Items]

Sale Price of Oil and Gas Property and Equipment

$ 245,000

Proceeds from divestitures of oil and gas properties, net

$ 245,700

Cash Paid for Post-Closing Adjustments to Divestitures

(500)

Niobrara Divestiture

Business Acquisition [Line Items]

Sale Price of Oil and Gas Property and Equipment

$ 140,000

Proceeds from divestitures of oil and gas properties, net

$ 122,600

$ 14,000

$ 135,550

Cash Paid for Post-Closing Adjustments to Divestitures

$ (1,000)

ExL Acquisition

Business Acquisition [Line Items]

Agreed upon Purchase Price of Oil and Gas Property and Equipment

$ 648,000

Payments to Acquire Oil and Gas Property

3,800

601,000

$ 75,000

$ 679,800

Marcellus Shale Divestiture

Business Acquisition [Line Items]

Sale Price of Oil and Gas Property and Equipment

$ 84,000

Proceeds from divestitures of oil and gas properties, net

73,900

Utica Shale Divestiture

Business Acquisition [Line Items]

Sale Price of Oil and Gas Property and Equipment

$ 62,000

Proceeds from divestitures of oil and gas properties, net

$ 63,100

Sanchez Acquisition

Business Acquisition [Line Items]

Agreed upon Purchase Price of Oil and Gas Property and Equipment

$ 181,000

Deposit For Acquisition Of Oil And Gas Properties

10,000

Payments to Acquire Oil and Gas Property

$ 9,800

$ 7,000

$ 143,500

$ 170,300

Deposit Received Prior To Closing [Member] | Eagle Ford Shale Divestiture

Business Acquisition [Line Items]

Proceeds from divestitures of oil and gas properties, net

24,500

Deposit Received Prior To Closing [Member] | Marcellus Shale Divestiture

Business Acquisition [Line Items]

Proceeds from divestitures of oil and gas properties, net

6,300

Deposit Received Prior To Closing [Member] | Utica Shale Divestiture

Business Acquisition [Line Items]

Proceeds from divestitures of oil and gas properties, net

$ 6,200

Cash Received At Closing [Member] | Eagle Ford Shale Divestiture

Business Acquisition [Line Items]

Proceeds from divestitures of oil and gas properties, net

$ 211,700

Cash Received At Closing [Member] | Marcellus Shale Divestiture

Business Acquisition [Line Items]

Proceeds from divestitures of oil and gas properties, net

67,600

Cash Received At Closing [Member] | Utica Shale Divestiture

Business Acquisition [Line Items]

Proceeds from divestitures of oil and gas properties, net

54,400

Cash Received Post Closing [Member] | Eagle Ford Shale Divestiture

Business Acquisition [Line Items]

Proceeds from divestitures of oil and gas properties, net

$ 10,000

Cash Received Post Closing [Member] | Utica Shale Divestiture

Business Acquisition [Line Items]

Proceeds from divestitures of oil and gas properties, net

$ 2,500

Acquisitions (Schedule of Consi

Acquisitions (Schedule of Consideration Paid for Assets Acquired and Liabilities Assumed) (Table) (Details) $ in Thousands	Aug. 10, 2017USD ($)
Acquisitions - Schedule of Consideration Paid for the Transactions of Assets Acquired and Liabilities Assumed [Abstract]
Business Combination, Current Assets	$ 106
Business Combination, Proved Oil and Gas Properties	294,754
Business Combination, Unproved Oil and Gas Properties	443,194
Business Combination, Oil and Gas Properties	737,948
Business Combination, Assets	738,054
Business Combination, Current Liabilities	5,785
Business Combination, Noncurrent Liabilities	153
Business Combination, Contingent Consideration, Liability	52,300
Business Combination, Liabilities	58,238
Business Combination, Assets Acquired and Liabilities Assumed, Net	$ 679,816

Acquisitions and Divestitures A

Acquisitions and Divestitures Acquisitions (Revenue and Income of Acquiree Since Acquisition Date) (Details) - ExL Acquisition - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Business Acquisition [Line Items]
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual	$ 71,525	$ 14,016	$ 167,764	$ 14,016
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual	$ 57,466	$ 11,393	$ 134,317	$ 11,393

Acquisitions (Pro Forma Informa

Acquisitions (Pro Forma Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Revenue	$ 189,499	$ 534,607
Business Acquisition, Pro Forma Net Income (Loss)	$ 14,654	$ 115,053
Business Acquisition, Pro Forma Earnings Per Share, Basic	$ 0.18	$ 1.63
Business Acquisition, Pro Forma Earnings Per Share, Diluted	$ 0.18	$ 1.62

Property and Equipment, Net (Na

Property and Equipment, Net (Narrative) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)$ / Boe	Sep. 30, 2017USD ($)$ / Boe	Sep. 30, 2018USD ($)$ / Boe	Sep. 30, 2017USD ($)$ / Boe
Property, Plant and Equipment [Line Items]
Average depreciation, depletion and amortization, per Boe | $ / Boe	13.29	13.04	13.57	12.73
Internal costs capitalized, Oil and Gas producing activities	$ 2,900,000	$ 3,300,000	$ 15,600,000	$ 10,600,000
Capitalized interest	$ 8,500,000	$ 8,500,000	$ 27,600,000	$ 16,200,000

Property And Equipment, Net (Sc

Property And Equipment, Net (Schedule Of Property And Equipment) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Proved properties	$ 5,988,301	$ 5,615,153
Accumulated depreciation, depletion and amortization and impairments	(3,863,534)	(3,649,806)
Proved properties, net	2,124,767	1,965,347
Unproved properties, not being amortized
Unevaluated leasehold and seismic costs	516,537	612,589
Capitalized interest	62,738	47,698
Total unproved properties, not being amortized	579,275	660,287
Other property and equipment	28,134	25,625
Accumulated depreciation	(17,249)	(15,449)
Other property and equipment, net	10,885	10,176
Total property and equipment, net	$ 2,714,927	$ 2,635,810

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Income Taxes [Line Items]
U.S. federal statutory corporate pretax rate			21.00%	35.00%
State and Local Income Taxes	$ 881	$ 247	$ 1,687	$ 1,974
Deferred Tax Assets, Valuation Allowance	299,089		299,089		$ 333,029
Change in Deferred Tax Assets Valuation Allowance	$ (17,400)	$ (3,253)	$ (33,849)	$ (41,570)

Income Taxes (Schedule Of Effec

Income Taxes (Schedule Of Effective Income Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income before income taxes	$ 82,226	$ 7,823	$ 145,829	$ 104,150
Income tax expense at the U.S. federal statutory rate	(17,267)	(2,738)	(30,624)	(36,452)
State income tax expense, net of U.S. federal income tax benefit	(881)	(247)	(1,687)	(1,974)
Tax deficiencies related to stock-based compensation	(10)	(273)	(2,552)	(3,029)
Decrease in valuation allowance due to current period activity	17,400	3,253	33,849	41,570
Other	(122)	5	(668)	(115)
Income tax expense	$ (880)	$ 0	$ (1,682)	$ 0

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) $ in Thousands	1 Months Ended	2 Months Ended		3 Months Ended				9 Months Ended
	May 31, 2018USD ($)	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)Rate	Sep. 30, 2017USD ($)	Nov. 19, 2018	Oct. 29, 2018USD ($)	May 04, 2018USD ($)	May 03, 2018	Jan. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Jul. 14, 2017USD ($)
Debt Instrument [Line Items]
Debt Instrument, Repurchased Face Amount						$ 320,000
Cash paid for debt redemption						336,900
Redemption Premium						6,000
Accrued interest paid associated with redemption of debt						10,900
Loss on extinguishment of debt					$ 0		$ 0	$ 8,676	$ 0
Write off of Deferred Debt Issuance Cost						$ 2,700
Redemption price, percentage of principal amount						101.875%
Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity					1,000,000			1,000,000				$ 1,000,000		$ 830,000	$ 900,000
Line of Credit Facility, Elected Borrowing Capacity					900,000			900,000				$ 900,000		$ 800,000
Line of credit facility amount outstanding					$ 309,837			$ 309,837							291,300
Debt, Weighted Average Interest Rate					3.87%			3.87%
Ratio of total debt to EBITDA								1.95
Current Ratio					1.84			1.84
Pre-Tax SEC PV10 Reserve Value Percentage | Rate								90.00%
Federal funds rate plus percentage					0.50%			0.50%
Adjusted LIBO rate plus percentage					1.00%			1.00%
Senior Secured Revolving Credit Facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Margin for eurodollar loans			2.50%			3.00%
Ratio of total debt to EBITDA								4
Margin for base rate loans			1.50%			2.00%
Senior Secured Revolving Credit Facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
Margin for eurodollar loans			1.50%			2.00%
Current Ratio					1			1
Margin for base rate loans			0.50%			1.00%
7.50% Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage					7.50%			7.50%
Long term debt					$ 130,000			$ 130,000							450,000
8.25% Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage																8.25%
Debt Instrument, Face Amount																$ 250,000
Proceeds from Issuance of Debt							$ 245,400
Long term debt					250,000			250,000							250,000
Other Long Term Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage													4.375%
Cash paid for debt redemption	$ 4,500
Accrued interest paid associated with redemption of debt	$ 100
Redemption price, percentage of principal amount													100.00%
Long term debt					$ 0			$ 0							$ 4,425
Less than 25 percent [Member] | Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Margin for eurodollar loans					1.50%
Line of Credit Facility, Commitment Fee Percentage					0.375%
Margin for base rate loans					0.50%
Greater than or equal to 90 percent [Member] | Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Margin for eurodollar loans					2.50%
Line of Credit Facility, Commitment Fee Percentage					0.50%
Margin for base rate loans					1.50%
Subsequent Event [Member] | Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity											$ 1,300,000
Line of Credit Facility, Elected Borrowing Capacity											$ 1,100,000
Subsequent Event [Member] | 7.50% Senior Notes [Member]
Debt Instrument [Line Items]
Loss on extinguishment of debt				$ 800
Redemption price, percentage of principal amount										100.00%
Subsequent Event [Member] | Less than 25 percent [Member] | Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Margin for eurodollar loans		1.25%
Margin for base rate loans		0.25%
Subsequent Event [Member] | Greater than or equal to 90 percent [Member] | Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Margin for eurodollar loans		2.25%
Margin for base rate loans		1.25%

Long-Term Debt (Schedule of Lon

Long-Term Debt (Schedule of Long-Term Debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Long-term debt	$ 1,327,689	$ 1,629,209
Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility amount outstanding	309,837	291,300
7.50% Senior Notes [Member]
Debt Instrument [Line Items]
Long term debt	130,000	450,000
Debt instrument, unamortized premium	124	579
Unamortized Debt Issuance Expense	(980)	(4,492)
6.25% Senior Notes [Member]
Debt Instrument [Line Items]
Long term debt	650,000	650,000
Unamortized Debt Issuance Expense	(7,219)	(8,208)
8.25% Senior Notes [Member]
Debt Instrument [Line Items]
Long term debt	250,000	250,000
Unamortized Debt Issuance Expense	(4,073)	(4,395)
Other Long Term Debt [Member]
Debt Instrument [Line Items]
Long term debt	$ 0	$ 4,425

Long-Term Debt (Interest and Co

Long-Term Debt (Interest and Commitment Fee Rates) (Details) - Senior Secured Revolving Credit Facility [Member]	2 Months Ended	3 Months Ended
	Jun. 30, 2018	Sep. 30, 2018	Mar. 31, 2018
Less than 25 percent [Member]
Interest and Commitment Fee Rates [Line Items]
Margin for base rate loans		0.50%
Margin for eurodollar loans		1.50%
Line of Credit Facility, Commitment Fee Percentage		0.375%
Greater than or equal to 25 percent but less than 50 percent [Member]
Interest and Commitment Fee Rates [Line Items]
Margin for base rate loans		0.75%
Margin for eurodollar loans		1.75%
Line of Credit Facility, Commitment Fee Percentage		0.375%
Greater than or equal to 50 percent but less than 75 percent [Member]
Interest and Commitment Fee Rates [Line Items]
Margin for base rate loans		1.00%
Margin for eurodollar loans		2.00%
Line of Credit Facility, Commitment Fee Percentage		0.50%
Greater than or equal to 75 percent but less than 90 percent [Member]
Interest and Commitment Fee Rates [Line Items]
Margin for base rate loans		1.25%
Margin for eurodollar loans		2.25%
Line of Credit Facility, Commitment Fee Percentage		0.50%
Greater than or equal to 90 percent [Member]
Interest and Commitment Fee Rates [Line Items]
Margin for base rate loans		1.50%
Margin for eurodollar loans		2.50%
Line of Credit Facility, Commitment Fee Percentage		0.50%
Minimum [Member]
Interest and Commitment Fee Rates [Line Items]
Margin for base rate loans	0.50%		1.00%
Margin for eurodollar loans	1.50%		2.00%
Maximum [Member]
Interest and Commitment Fee Rates [Line Items]
Margin for base rate loans	1.50%		2.00%
Margin for eurodollar loans	2.50%		3.00%

Preferred Stock (Narrative) (De

Preferred Stock (Narrative) (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jan. 24, 2018	Dec. 31, 2017	Aug. 10, 2017
Preferred Stock Disclosure [Line Items]
Preferred Stock, Par Value								$ 250,000,000
Preferred Stock, Shares Issued	200,000			200,000			250,000	250,000
Preferred Stock, Dividend Rate, Percentage	8.875%
Preferred Stock, Par or Stated Value Per Share	$ 0.01			$ 0.01			$ 0.01	$ 0.01
Issuance of warrants to purchase Common Stock			2,750,000
Class of Warrant or Right, Term			10 years
Class of Warrant or Right, Exercise Price of Warrants or Rights								16.08
Cash purchase price per share of Preferred Stock								970
Sale of preferred stock, net of issuance costs				$ 0	$ 236,404,000
Temporary Equity, Liquidation Preference Per Share								$ 1,000
Maximum Preferred Stock Shares Redeemable Within the First Year								50,000
Preferred Stock Shares Redeemed						50,000
Preferred Stock, Percentage Redeemed						20.00%
Payments for Repurchase of Redeemable Preferred Stock		$ 50,500,000
Redemption Price of Preferred Stock				50,030,000
Loss on redemption of preferred stock	$ 0		$ 0	7,133,000	0
Redemption of Preferred Stock				(42,897,000)
Payments Of Accrued Dividends Upon Redemption Of Preferred Stock				$ 500,000
Preferred Stock, Redemption Premium, Percentage				104.4375%
Preferred Stock, Percent of Ownership to be Able to Vote			50.00%
Preferred Stock, Prohibited Distributions			$ 15,000,000
Dividends on preferred stock				$ (13,794,000)	(2,249,000)
Accretion on preferred stock	$ (771,000)		$ 0	$ (2,264,000)	$ 0
On or before the seventh anniversary of the Preferred Stock Issuance Date [Domain]
Preferred Stock Disclosure [Line Items]
Preferred Stock, Dividend Rate, Percentage			12.00%
After August 10, 2024 [Domain]
Preferred Stock Disclosure [Line Items]
Preferred Stock, Dividend Rate, Percentage			12.00%
Libor Rate to Calculate Preferred Stock Dividend Rate			10.00%

Preferred Stock (Schedule of Di

Preferred Stock (Schedule of Dividends Paid in Common Stock) (Details)	Sep. 30, 2018Rate
Preferred Stock Dividend Paid in Common Stock Second Year [Member]
Schedule of Preferred Stock Dividend Paid in Common Stock [Line Items]
Percent of Dividend Payable in Common Stock	75.00%
Preferred Stock Dividend Paid in Common Stock Third Year [Member]
Schedule of Preferred Stock Dividend Paid in Common Stock [Line Items]
Percent of Dividend Payable in Common Stock	50.00%

Preferred Stock (Schedule of Pr

Preferred Stock (Schedule of Preferred Stock Redemption Premiums) (Details)	9 Months Ended
	Sep. 30, 2018
Schedule of Preferred Stock Redemption Premiums [Line Items]
Preferred Stock, Redemption Premium, Percentage	104.4375%
Preferred Stock Redemption Fourth Year [Member]
Schedule of Preferred Stock Redemption Premiums [Line Items]
Preferred Stock, Redemption Premium, Percentage	104.4375%
Preferred Stock Redemption Fifth Year [Member] [Member]
Schedule of Preferred Stock Redemption Premiums [Line Items]
Preferred Stock, Redemption Premium, Percentage	102.21875%
Preferred Stock Redemption Sixth Year [Member]
Schedule of Preferred Stock Redemption Premiums [Line Items]
Preferred Stock, Redemption Premium, Percentage	100.00%

Preferred Stock (Schedule of _2

Preferred Stock (Schedule of Preferred Stock Activity) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Schedule of Preferred Stock Activity [Abstract]
Preferred stock, $0.01 par value, 10,000,000 shares authorized; 200,000 issued and outstanding as of September 30, 2018 and 250,000 issued and outstanding as of December 31, 2017	$ 173,629,000		$ 173,629,000		$ 214,262,000
Redemption of Preferred Stock			(42,897,000)
Accretion on preferred stock	$ (771,000)	$ 0	$ (2,264,000)	$ 0

Shareholders' Equity and Stoc_3

Shareholders' Equity and Stock Incentive Plans (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Mar. 31, 2018	Sep. 30, 2018	Sep. 30, 2017	Aug. 17, 2018	Dec. 31, 2017	Jul. 03, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Sale of common stock, net of offering costs, shares			9,500,000	15,600,000
Sale of Stock, Price Per Share					$ 22.55		$ 14.28
Sale of common stock, net of offering costs			$ 213,857	$ 222,378
Number of Shares Available for Grant	2,675,000		2,675,000
Shares Of Common Stock Per Performance Shares Earned			1
Common stock, shares authorized (in shares)	180,000,000		180,000,000			180,000,000
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ratio of stock based compensation shares to common shares			1
Restricted Stock Awards And Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ratio of stock based compensation shares to common shares			1.35
Granted Shares/Units	33,536		1,391,422
Fair Value of Shares Issued	$ 900
Nonvested Awards, Compensation Cost Not yet Recognized	26,800		$ 26,800
Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition			2 years
Equity Instruments Other than Options, Vested in Period			615,762
Forfeited Shares/Units			(23,880)
Restricted Stock Awards And Units [Member] | Annual Grant of Long-Term Equity Incentive Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted Shares/Units		1,343,412
Fair Value of Shares Issued		$ 19,700
Vesting period, in years		3 years
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair Value of Shares Issued			$ 4,900
Vesting period, in years			3 years
Expiration period after date of grant, in years			7 years
Nonvested Awards, Compensation Cost Not yet Recognized	8,700		$ 8,700
Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition			2 years 4 months 24 days
Liability For Cash Stock Appreciation Rights			$ 7,900
SARs, Granted			616,686
Stock Appreciation Rights (SARs) [Member] | Other Noncurrent Liabilities [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Liability For Cash Stock Appreciation Rights				$ 4,400
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted Shares/Units			93,771
Fair Value of Shares Issued		$ 1,800
Vesting period, in years			3 years
Nonvested Awards, Compensation Cost Not yet Recognized	$ 2,500		$ 2,500
Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition			2 years
Vesting percentage of target performance shares granted		88.00%
Performance shares vested per TSR ranking		56,517
Equity Instruments Other than Options, Vested in Period		49,458	49,458
Unearned Shares due to Market Condition			7,059
Forfeited Shares/Units			0
Performance Shares [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award Vesting Rights Percentage Range			200.00%
Performance Shares [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award Vesting Rights Percentage Range			0.00%
2017 Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares Available for Grant	296,654		296,654

Shareholders' Equity and Stoc_4

Shareholders' Equity and Stock Incentive Plans (Summary of Restricted Stock Award and Unit Activity) (Details) - Restricted Stock Awards And Units [Member] - $ / shares	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Restricted Stock Awards and Units [Abstract]
Unvested Shares/Units, Beginning of Period		1,482,655
Granted Shares/Units	33,536	1,391,422
Vested Shares/Units		(615,762)
Forfeited Shares/Units		(23,880)
Unvested Shares/Units, End of Period	2,234,435	2,234,435
Weighted Average Grant Date Fair Value [Abstract]
Grant Date Fair Value, Beginning of Period (USD per share)		$ 28.07
Granted, Grant Date Fair Value (USD per share)		15.07
Vested, Grant Date Fair Value (USD per share)		31.44
Forfeited, Grant Date Fair Value (USD per share)		18.51
Grant Date Fair Value, End of Period (USD per share)	$ 19.14	$ 19.14

Shareholders' Equity and Stoc_5

Shareholders' Equity and Stock Incentive Plans (Summary of SARs Activity) (Details) - Stock Appreciation Rights (SARs) [Member] $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2018USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
SARs, Outstanding, Beginning of period | shares	714,238
SARs, Granted | shares	616,686
SARs, Exercised | shares	0
SARs, Forfeitures | shares	0
SARs, Expirations | shares	0
SARs, Outstanding, End of period | shares	1,330,924
SARs, Vested, End of Period | shares	543,018
SARs, Exercisable, End of Period | shares	0
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Weighted Average Exercise Price [Roll Forward]
Weighted Average Exercise Prices, Outstanding, Beginning of Period | $ / shares	$ 27.12
Weighted Average Exercise Prices, Granted | $ / shares	14.67
Weighted Average Exercise Prices, Exercised | $ / shares	0
Weighted Average Exercise Prices, Forfeitures | $ / shares	0
Weighted Average Exercise Prices, Expired | $ / shares	0
Weighted Average Exercise Prices, Outstanding, End of Period | $ / shares	21.35
Weighted Average Exercise Prices, Vested, End of Period | $ / shares	27.18
Weighted Average Exercise Prices, Exercisable, End of Period | $ / shares	$ 27.18
Cash paid at exercises, Stock Appreciation Rights | $	$ 0
Weighted Average Remaining Life, Outstanding, End of Period	4 years 6 months 29 days
Weighted Average Remaining Life, Exercisable, End of Period	2 years 9 months 11 days
Aggregate Intrinsic Value, Outstanding, End of Period | $	$ 6.5
Aggregate Intrinsic Value, Exercisable, End of Period | $	$ 0

Shareholders' Equity and Stoc_6

Shareholders' Equity and Stock Incentive Plans (Summary of SARs Fair Value Assumptions) (Details) - Stock Appreciation Rights (SARs) [Member]	9 Months Ended
	Sep. 30, 2018Rate
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected Term	6 years
Expected Volatility Rate	54.30%
Risk-free Interest Rate	2.80%
Dividend Yield	0.00%

Shareholders' Equity and Stoc_7

Shareholders' Equity and Stock Incentive Plans (Summary of Performance Share Award Activity) (Details) - Performance Shares [Member] - $ / shares	3 Months Ended	9 Months Ended
	Mar. 31, 2018	Sep. 30, 2018
Performance Share Awards
Unvested Shares/Units, Beginning of Period	144,955	144,955
Granted Shares/Units		93,771
Vested Shares/Units	(49,458)	(49,458)
Forfeited Shares/Units		0
Unearned Shares due to Market Condition		7,059
Unvested Shares/Units, End of Period		182,209
Weighted Average Grant Date Fair Value [Abstract]
Grant Date Fair Value, Beginning of Period (USD per share)	$ 47.14	$ 47.14
Granted, Grant Date Fair Value (USD per share)		19.09
Vested, Grant Date Fair Value (USD per share)		65.51
Forfeited, Grant Date Fair Value (USD per share)		0
Unearned Shares due to Market Condition, Weighted Average Grant Date Fair Value		65.51
Grant Date Fair Value, End of Period (USD per share)		$ 27.01

Shareholders' Equity and Stoc_8

Shareholders' Equity and Stock Incentive Plans (Summary of Performance Share Awards Fair Value Assumptions) (Details) - Performance Shares [Member]	9 Months Ended
	Sep. 30, 2018Rate
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of simulations performed	500,000
Expected Term	3 years
Expected Volatility Rate	61.50%
Risk-free Interest Rate	2.40%
Dividend Yield	0.00%

Shareholders' Equity and Stoc_9

Shareholders' Equity and Stock Incentive Plans (Schedule of Share-Based Compensation Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated Share-based Compensation Expense	$ 4,030	$ 6,321	$ 19,170	$ 11,005
Less: amounts capitalized	(968)	(1,455)	(5,384)	(2,543)
Share-based Compensation Arrangement, Compensation Cost	3,062	4,866	13,786	8,462
Restricted Stock Awards And Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated Share-based Compensation Expense	4,487	5,311	14,291	16,184
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated Share-based Compensation Expense	(868)	429	3,505	(7,040)
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated Share-based Compensation Expense	$ 411	$ 581	$ 1,374	$ 1,861

Derivative Instruments (Narrati

Derivative Instruments (Narrative) (Details) $ in Thousands	Sep. 30, 2018USD ($)
Current Derivative Assets [Member]
Derivative [Line Items]
Contingent Consideration, Current Asset	$ 9,835
Derivative Liabilities Current [Member]
Derivative [Line Items]
Derivative Liability, Contingent Payment, Gross Liability	$ (49,160)

Derivative Instruments (Schedul

Derivative Instruments (Schedule of Crude Oil Derivative Positions) (Details) - Crude Oil	Sep. 30, 2018bbl / d$ / bbls
Q4 2018 | Fixed Price Swaps
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	6,000
Weighted Average Fixed Price ($/Bbl)	49.55
Q4 2018 | Three-way Collars
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	24,000
Weighted Average Sub-Floor Price ($/Bbl)	39.38
Weighted Average Floor Price ($/Bbl)	49.06
Weighted Average Ceiling Price ($/Bbl)	60.14
Q4 2018 | Basis Swaps | LLS-Cushing WTI Price Differential
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	18,000
Weighted Average Fixed Price ($/Bbl)	5.11
Q4 2018 | Basis Swaps | Midland WTI-Cushing WTI Price Differential
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	6,000
Weighted Average Fixed Price ($/Bbl)	0.10
Q4 2018 | Call Option
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	3,388
Weighted Average Ceiling Price ($/Bbl)	71.33
FY 2019 | Three-way Collars
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	21,000
Weighted Average Sub-Floor Price ($/Bbl)	40.71
Weighted Average Floor Price ($/Bbl)	49.80
Weighted Average Ceiling Price ($/Bbl)	67.80
FY 2019 | Basis Swaps | LLS-Cushing WTI Price Differential
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	3,000
Weighted Average Fixed Price ($/Bbl)	4.57
FY 2019 | Basis Swaps | Midland WTI-Cushing WTI Price Differential
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	7,389
Weighted Average Fixed Price ($/Bbl)	4.82
FY 2019 | Call Option
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	3,875
Weighted Average Ceiling Price ($/Bbl)	73.66
FY 2020 | Basis Swaps | Midland WTI-Cushing WTI Price Differential
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	13,000
Weighted Average Fixed Price ($/Bbl)	1.27
FY 2020 | Call Option
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	4,575
Weighted Average Ceiling Price ($/Bbl)	75.98
FY 2021 | Basis Swaps | Midland WTI-Cushing WTI Price Differential
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	6,000
Weighted Average Fixed Price ($/Bbl)	0.03

Derivative Instruments (Sched_2

Derivative Instruments (Schedule of NGL Derivative Positions) (Details) - Q4 2018 - Natural Gas Liquids - Fixed Price Swaps	Sep. 30, 2018bbl / d$ / bbls
OPIS Purity Ethane Mont Belvieu Non-TET
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	2,200
Weighted Average Fixed Price ($/Bbl) | $ / bbls	12.01
OPIS Propane Mont Belvieu Non-TET
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	1,500
Weighted Average Fixed Price ($/Bbl) | $ / bbls	34.23
OPIS Normal Butane Mont Belvieu Non-TET
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	200
Weighted Average Fixed Price ($/Bbl) | $ / bbls	38.85
OPIS Isobutane Mont Belvieu Non-TET
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	600
Weighted Average Fixed Price ($/Bbl) | $ / bbls	38.98
OPIS Natural Gasoline Mont Belvieu Non-TET
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	600
Weighted Average Fixed Price ($/Bbl) | $ / bbls	55.23

Derivative Instruments (Sched_3

Derivative Instruments (Schedule of Natural Gas Derivative Positions) (Details) - Natural Gas	Sep. 30, 2018MMBTU / d$ / MMBTU
Q4 2018 | Fixed Price Swaps
Derivative [Line Items]
Derivative, Volumes (in MMBtu/d) | MMBTU / d	25,000
Weighted Average Fixed Price ($/MMBtu) | $ / MMBTU	3.01
Q4 2018 | Call Option
Derivative [Line Items]
Derivative, Volumes (in MMBtu/d) | MMBTU / d	33,000
Weighted Average Ceiling Price ($/MMBtu) | $ / MMBTU	3.25
FY 2019 | Call Option
Derivative [Line Items]
Derivative, Volumes (in MMBtu/d) | MMBTU / d	33,000
Weighted Average Ceiling Price ($/MMBtu) | $ / MMBTU	3.25
FY 2020 | Call Option
Derivative [Line Items]
Derivative, Volumes (in MMBtu/d) | MMBTU / d	33,000
Weighted Average Ceiling Price ($/MMBtu) | $ / MMBTU	3.50

Derivative Instruments (Sched_4

Derivative Instruments (Schedule of Contingent Consideration) (Details) $ in Thousands	3 Months Ended
	Sep. 30, 2018USD ($)$ / bbls$ / MMBTU
ExL Acquisition
Embedded Derivative [Line Items]
Contingent Consideration, Range of Outcomes, Value, High	$ (125,000)
ExL Acquisition | FY 2018 [Member]
Embedded Derivative [Line Items]
Threshold Price per Bbl for Additional Payments for Acquisition | $ / bbls	50
Potential Additional Annual Payments for Acquisition	$ (50,000)
ExL Acquisition | FY 2019 [Member]
Embedded Derivative [Line Items]
Threshold Price per Bbl for Additional Payments for Acquisition | $ / bbls	50
Potential Additional Annual Payments for Acquisition	$ (50,000)
ExL Acquisition | FY 2020 [Member]
Embedded Derivative [Line Items]
Threshold Price per Bbl for Additional Payments for Acquisition | $ / bbls	50
Potential Additional Annual Payments for Acquisition	$ (50,000)
ExL Acquisition | FY 2021 [Member]
Embedded Derivative [Line Items]
Threshold Price per Bbl for Additional Payments for Acquisition | $ / bbls	50
Potential Additional Annual Payments for Acquisition	$ (50,000)
Niobrara Divestiture | FY 2018 [Member]
Embedded Derivative [Line Items]
Threshold Price Per Bbl For Additional Proceeds From Divestiture | $ / bbls	55
Potential Additional Annual Proceeds From Divestiture	$ 5,000
Niobrara Divestiture | FY 2019 [Member]
Embedded Derivative [Line Items]
Threshold Price Per Bbl For Additional Proceeds From Divestiture | $ / bbls	55
Potential Additional Annual Proceeds From Divestiture	$ 5,000
Niobrara Divestiture | FY 2020 [Member]
Embedded Derivative [Line Items]
Threshold Price Per Bbl For Additional Proceeds From Divestiture | $ / bbls	60
Potential Additional Annual Proceeds From Divestiture	$ 5,000
Marcellus Shale Divestiture
Embedded Derivative [Line Items]
Contingent Consideration, Range of Outcomes, Value, High	$ (7,500)
Marcellus Shale Divestiture | FY 2018 [Member]
Embedded Derivative [Line Items]
Threshold Price per MMBtu for Additional Payments from Divestiture | $ / MMBTU	3.13
Potential Additional Annual Proceeds From Divestiture	$ 3,000
Marcellus Shale Divestiture | FY 2019 [Member]
Embedded Derivative [Line Items]
Threshold Price per MMBtu for Additional Payments from Divestiture | $ / MMBTU	3.18
Potential Additional Annual Proceeds From Divestiture	$ 3,000
Marcellus Shale Divestiture | FY 2020 [Member]
Embedded Derivative [Line Items]
Threshold Price per MMBtu for Additional Payments from Divestiture | $ / MMBTU	3.30
Potential Additional Annual Proceeds From Divestiture	$ 3,000
Utica Shale Divestiture | FY 2018 [Member]
Embedded Derivative [Line Items]
Threshold Price Per Bbl For Additional Proceeds From Divestiture | $ / bbls	50
Potential Additional Annual Proceeds From Divestiture	$ 5,000
Utica Shale Divestiture | FY 2019 [Member]
Embedded Derivative [Line Items]
Threshold Price Per Bbl For Additional Proceeds From Divestiture | $ / bbls	53
Potential Additional Annual Proceeds From Divestiture	$ 5,000
Utica Shale Divestiture | FY 2020 [Member]
Embedded Derivative [Line Items]
Threshold Price Per Bbl For Additional Proceeds From Divestiture | $ / bbls	56
Potential Additional Annual Proceeds From Divestiture	$ 5,000

Derivative Instruments (Sched_5

Derivative Instruments (Schedule of Derivative Instruments in Statement of Financial Position) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Aug. 10, 2017
Derivatives, Fair Value [Line Items]
Derivative assets, current	$ 10,258	$ 0
Business Combination, Contingent Consideration, Liability			$ 52,300
Derivative liabilities, current	(162,895)	(57,121)
Derivative liabilities, noncurrent	(102,103)	(112,332)
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	19,408	4,869
Derivative Asset, Gross Asset	29,243	4,869
Derivative Asset, Fair Value, Gross Liability	(18,985)	(4,869)
Derivative Asset, Gross Liability	(18,985)	(4,869)
Derivative, Fair Value, Net	423	0
Derivative assets, current	10,258	0
Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	12,028	9,505
Derivative Asset, Gross Asset	27,398	19,695
Derivative Asset, Fair Value, Gross Liability	(12,028)	(9,505)
Derivative Asset, Gross Liability	(12,028)	(9,505)
Derivative, Fair Value, Net	0	0
Derivative assets, noncurrent	15,370	10,190
Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net	(113,735)	(57,121)
Derivative Deferred Premium, Net	0	0
Derivative Liability, Fair Value, Gross Liability	(123,611)	(52,671)
Derivative Liability, Deferred Premiums, Gross Liability	(9,109)	(9,319)
Derivative Liability, Contingent Payment, Gross Liability	(49,160)
Derivative Liability, Gross Liability	(181,880)	(61,990)
Derivative Liability, Fair Value, Gross Asset	9,876	(4,450)
Derivative Liability, Deferred Premiums, Gross Asset	9,109	(9,319)
Derivative Liability, Gross Asset	18,985	4,869
Business Combination, Contingent Consideration, Liability	(49,160)
Derivative liabilities, current	(162,895)	(57,121)
Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net	(39,218)	(26,707)
Derivative Deferred Premium, Net	0	0
Derivative Liability, Fair Value, Gross Liability	(45,532)	(24,609)
Derivative Liability, Deferred Premiums, Gross Liability	(5,714)	(11,603)
Derivative Liability, Contingent Payment, Gross Liability	(62,885)	(85,625)
Derivative Liability, Gross Liability	(114,131)	(121,837)
Derivative Liability, Fair Value, Gross Asset	6,314	(2,098)
Derivative Liability, Deferred Premiums, Gross Asset	(5,714)	(11,603)
Derivative Liability, Contingent Payment, Gross Asset		0
Derivative Liability, Gross Asset	12,028	9,505
Business Combination, Contingent Consideration, Liability	(62,885)	(85,625)
Derivative liabilities, noncurrent	(102,103)	(112,332)
Niobrara Divestiture
Derivatives, Fair Value [Line Items]
Contingent Consideration, Current Asset	4,920
Contingent Consideration, Noncurrent Asset	6,755
Marcellus Shale Divestiture
Derivatives, Fair Value [Line Items]
Contingent Consideration, Noncurrent Asset	1,315	2,205
Utica Shale Divestiture
Derivatives, Fair Value [Line Items]
Contingent Consideration, Current Asset	4,915
Contingent Consideration, Noncurrent Asset	$ 7,300	$ 7,985

Derivative Instruments (Sched_6

Derivative Instruments (Schedule of (Gain) Loss on Derivative Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Derivative Instruments, Gain (Loss), Commodity [Line Items]
(Gain) loss on derivatives, net	$ 55,388	$ 24,377	$ 152,698	$ (27,004)
Crude Oil
Derivative Instruments, Gain (Loss), Commodity [Line Items]
(Gain) loss on derivatives, net	43,664	8,409	126,612	(39,754)
Natural Gas Liquids
Derivative Instruments, Gain (Loss), Commodity [Line Items]
(Gain) loss on derivatives, net	5,086	0	9,885	0
Natural Gas
Derivative Instruments, Gain (Loss), Commodity [Line Items]
(Gain) loss on derivatives, net	(192)	(2,183)	(3,084)	(12,902)
Deferred Premiums on Derivative Instruments
Derivative Instruments, Gain (Loss), Commodity [Line Items]
(Gain) loss on derivatives, net	0	10,151	0	17,652
ExL Acquisition
Derivative Instruments, Gain (Loss), Commodity [Line Items]
Gain (Loss) on Embedded Derivative, Net	9,990	8,000	26,420	8,000
Niobrara Divestiture
Derivative Instruments, Gain (Loss), Commodity [Line Items]
Gain (Loss) on Embedded Derivative, Net	(1,705)	0	(3,795)	0
Marcellus Shale Divestiture
Derivative Instruments, Gain (Loss), Commodity [Line Items]
Gain (Loss) on Embedded Derivative, Net	215	0	890	0
Utica Shale Divestiture
Derivative Instruments, Gain (Loss), Commodity [Line Items]
Gain (Loss) on Embedded Derivative, Net	$ (1,670)	$ 0	$ (4,230)	$ 0

Derivative Instruments (Sched_7

Derivative Instruments (Schedule of Cash Received for Derivative Settlements) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Schedule Of Cash Received For Derivatives [Line Items]
Cash received (paid) for derivative settlements, net	$ (26,262)	$ 6,456	$ (64,710)	$ 7,714
Crude Oil
Schedule Of Cash Received For Derivatives [Line Items]
Cash received (paid) for derivative settlements, net	(21,261)	6,500	(54,594)	9,941
Natural Gas Liquids
Schedule Of Cash Received For Derivatives [Line Items]
Cash received (paid) for derivative settlements, net	(2,641)	0	(3,829)	0
Natural Gas
Schedule Of Cash Received For Derivatives [Line Items]
Cash received (paid) for derivative settlements, net	245	522	785	(731)
Deferred Premiums on Derivative Instruments
Schedule Of Cash Received For Derivatives [Line Items]
Cash received (paid) for derivative settlements, net	$ (2,605)	$ (566)	$ (7,072)	$ (1,496)

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($)	Sep. 30, 2018	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount	$ 0	$ 0
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	0	0
Fair Value, Assets, Level 3 Transfers	$ 0	$ 0

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Assets and Liabilities Measured on Recurring Basis) (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	$ 0	$ 0
Derivative Liability	0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	423	0
Derivative Liability	(152,953)	(83,828)
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0	0
Derivative Liability	0	0
Niobrara Divestiture | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0	0
Niobrara Divestiture | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0	0
Niobrara Divestiture | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	11,675	0
Marcellus Shale Divestiture | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0	0
Marcellus Shale Divestiture | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0	0
Marcellus Shale Divestiture | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	1,315	2,205
Utica Shale Divestiture | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0	0
Utica Shale Divestiture | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0	0
Utica Shale Divestiture | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	12,215	7,985
ExL Acquisition | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	0	0
ExL Acquisition | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	0	0
ExL Acquisition | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	$ (112,045)	$ (85,625)

Fair Value Measurements (Sche_2

Fair Value Measurements (Schedule of Assets and Liabilities, Level 3 Reconciliation) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Contingent Consideration, Fair Value, Asset Value	$ 25,205	$ 0	$ 10,190	$ 0
Fair Value, Asset, Issuances	7,880	0
Fair Value, Asset, Gain (Loss) Included in Earnings	7,135	0
Fair Value, Asset Transfers Into Level 3	0	0
Contingent Consideration, Fair Value, Liability Value	(112,045)	(60,300)	$ (85,625)	$ 0
Fair Value, Liability, Issuances	0	(52,300)
Fair Value, Liability, Gain (Loss) Included in Earnings	(26,420)	(8,000)
Fair Value, Liability, Transfers Into Level 3	$ 0	$ 0

Fair Value Measurements (Sche_3

Fair Value Measurements (Schedule of Carrying Value and Fair Value of Debt Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
7.50% Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	$ 130,000	$ 450,000
7.50% Senior Notes [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	129,144	446,087
7.50% Senior Notes [Member] | Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	130,000	459,518
6.25% Senior Notes [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	642,781	641,792
6.25% Senior Notes [Member] | Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	664,625	674,375
8.25% Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	250,000	250,000
8.25% Senior Notes [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	245,927	245,605
8.25% Senior Notes [Member] | Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	268,750	274,375
Other Long Term Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	0	4,425
Other Long Term Debt [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	0	4,425
Other Long Term Debt [Member] | Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	$ 0	$ 4,445

Condensed Consolidating Finan_3

Condensed Consolidating Financial Information (Narrative) (Details)	Sep. 30, 2018
Condensed Consolidating Financial Information [Abstract]
Voting interest of the subsidiary owned by the registrant	100.00%

Condensed Consolidating Finan_4

Condensed Consolidating Financial Information (Schedule Of Condensed Consolidating Balance Sheet) (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Condensed Balance Sheet Statements, Captions [Line Items]
Total current assets	$ 151,089,000	$ 122,878,000
Total property and equipment, net	2,714,927,000	2,635,810,000
Investment in subsidiaries	0	0
Other assets	44,982,000	19,616,000
Total Assets	2,910,998,000	2,778,304,000
Current liabilities	555,762,000	372,822,000
Long-term liabilities	1,460,265,000	1,820,323,000
Preferred Stock	173,629,000	214,262,000
Total shareholders’ equity	721,342,000	370,897,000
Total Liabilities and Shareholders’ Equity	2,910,998,000	2,778,304,000
Eliminations [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Total current assets	(3,096,917,000)	(3,424,288,000)
Total property and equipment, net	(3,833,000)	(3,878,000)
Investment in subsidiaries	576,826,000	999,793,000
Other assets	0	0
Total Assets	(2,523,924,000)	(2,428,373,000)
Current liabilities	(3,099,937,000)	(3,427,308,000)
Long-term liabilities	15,879,000	15,879,000
Preferred Stock	0	0
Total shareholders’ equity	560,134,000	983,056,000
Total Liabilities and Shareholders’ Equity	(2,523,924,000)	(2,428,373,000)
Parent Company [Member] | Reportable Legal Entities [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Total current assets	3,114,698,000	3,441,633,000
Total property and equipment, net	6,570,000	5,953,000
Investment in subsidiaries	(576,826,000)	(999,793,000)
Other assets	29,611,000	9,270,000
Total Assets	2,574,053,000	2,457,063,000
Current liabilities	305,096,000	165,701,000
Long-term liabilities	1,357,294,000	1,689,466,000
Preferred Stock	173,629,000	214,262,000
Total shareholders’ equity	738,034,000	387,634,000
Total Liabilities and Shareholders’ Equity	2,574,053,000	2,457,063,000
Combined Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Total current assets	133,308,000	105,533,000
Total property and equipment, net	2,709,162,000	2,630,707,000
Investment in subsidiaries	0	0
Other assets	15,371,000	10,346,000
Total Assets	2,857,841,000	2,746,586,000
Current liabilities	3,347,575,000	3,631,401,000
Long-term liabilities	87,092,000	114,978,000
Preferred Stock	0	0
Total shareholders’ equity	(576,826,000)	(999,793,000)
Total Liabilities and Shareholders’ Equity	2,857,841,000	2,746,586,000
Combined Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Total current assets	0	0
Total property and equipment, net	3,028,000	3,028,000
Investment in subsidiaries	0	0
Other assets	0	0
Total Assets	3,028,000	3,028,000
Current liabilities	3,028,000	3,028,000
Long-term liabilities	0	0
Preferred Stock	0	0
Total shareholders’ equity	0	0
Total Liabilities and Shareholders’ Equity	$ 3,028,000	$ 3,028,000

Condensed Consolidating Finan_5

Condensed Consolidating Financial Information (Schedule Of Condensed Consolidating Statement Of Operations) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Condensed Income Statements, Captions [Line Items]
Total revenues	$ 303,375,000	$ 181,279,000	$ 792,628,000	$ 499,117,000
Total costs and expenses	221,149,000	173,456,000	646,799,000	394,967,000
Income (loss) before income taxes	82,226,000	7,823,000	145,829,000	104,150,000
Income tax (expense) benefit	(880,000)	0	(1,682,000)	0
Equity (deficit) in income of subsidiaries	0	0	0	0
Net Income (loss)	81,346,000	7,823,000	144,147,000	104,150,000
Dividends on preferred stock	(4,457,000)	(2,249,000)	(13,794,000)	(2,249,000)
Accretion on preferred stock	(771,000)	0	(2,264,000)	0
Loss on redemption of preferred stock	0	0	(7,133,000)	0
Net Income Attributable to Common Shareholders	76,118,000	5,574,000	120,956,000	101,901,000
Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Total revenues	0	0	0	0
Total costs and expenses	(13,000)	29,000	(45,000)	70,000
Income (loss) before income taxes	13,000	(29,000)	45,000	(70,000)
Income tax (expense) benefit	0	0	0	0
Equity (deficit) in income of subsidiaries	(166,537,000)	(61,878,000)	(422,967,000)	(184,589,000)
Net Income (loss)	(166,524,000)	(61,907,000)	(422,922,000)	(184,659,000)
Dividends on preferred stock	0	0	0	0
Accretion on preferred stock	0	0	0	0
Loss on redemption of preferred stock	0	0	0	0
Net Income Attributable to Common Shareholders	(166,524,000)	(61,907,000)	(422,922,000)	(184,659,000)
Parent Company [Member] | Reportable Legal Entities [Member]
Condensed Income Statements, Captions [Line Items]
Total revenues	38,000	35,000	77,000	291,000
Total costs and expenses	85,242,000	54,061,000	278,942,000	80,660,000
Income (loss) before income taxes	(85,204,000)	(54,026,000)	(278,865,000)	(80,369,000)
Income tax (expense) benefit	0	0	0	0
Equity (deficit) in income of subsidiaries	166,537,000	61,878,000	422,967,000	184,589,000
Net Income (loss)	81,333,000	7,852,000	144,102,000	104,220,000
Dividends on preferred stock	(4,457,000)	(2,249,000)	(13,794,000)	(2,249,000)
Accretion on preferred stock	(771,000)	0	(2,264,000)	0
Loss on redemption of preferred stock	0	0	(7,133,000)	0
Net Income Attributable to Common Shareholders	76,105,000	5,603,000	120,911,000	101,971,000
Combined Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Condensed Income Statements, Captions [Line Items]
Total revenues	303,337,000	181,244,000	792,551,000	498,826,000
Total costs and expenses	135,920,000	119,366,000	367,902,000	314,237,000
Income (loss) before income taxes	167,417,000	61,878,000	424,649,000	184,589,000
Income tax (expense) benefit	(880,000)	0	(1,682,000)	0
Equity (deficit) in income of subsidiaries	0	0	0	0
Net Income (loss)	166,537,000	61,878,000	422,967,000	184,589,000
Dividends on preferred stock	0	0	0	0
Accretion on preferred stock	0	0	0	0
Loss on redemption of preferred stock	0	0	0	0
Net Income Attributable to Common Shareholders	166,537,000	61,878,000	422,967,000	184,589,000
Combined Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Condensed Income Statements, Captions [Line Items]
Total revenues	0	0	0	0
Total costs and expenses	0	0	0	0
Income (loss) before income taxes	0	0	0	0
Income tax (expense) benefit	0	0	0	0
Equity (deficit) in income of subsidiaries	0	0	0	0
Net Income (loss)	0	0	0	0
Dividends on preferred stock	0	0	0	0
Accretion on preferred stock	0	0	0	0
Loss on redemption of preferred stock	0	0	0	0
Net Income Attributable to Common Shareholders	$ 0	$ 0	$ 0	$ 0

Condensed Consolidating Finan_6

Condensed Consolidating Financial Information (Schedule Of Condensed Consolidating Statement Of Cash Flows) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ 465,292	$ 280,597
Net cash provided by (used in) investing activities	(308,953)	(1,104,959)
Net cash provided by (used in) financing activities	(163,464)	825,260
Net Increase (Decrease) in Cash and Cash Equivalents	(7,125)	898
Cash and Cash Equivalents, Beginning of Period	9,540	4,194
Cash and Cash Equivalents, End of Period	2,415	5,092
Eliminations [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	0	0
Net cash provided by (used in) investing activities	(400,142)	726,029
Net cash provided by (used in) financing activities	400,142	(726,029)
Net Increase (Decrease) in Cash and Cash Equivalents	0	0
Cash and Cash Equivalents, Beginning of Period	0	0
Cash and Cash Equivalents, End of Period	0	0
Parent Company [Member] | Reportable Legal Entities [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(218,926)	(95,529)
Net cash provided by (used in) investing activities	375,265	(728,833)
Net cash provided by (used in) financing activities	(163,464)	825,260
Net Increase (Decrease) in Cash and Cash Equivalents	(7,125)	898
Cash and Cash Equivalents, Beginning of Period	9,540	4,194
Cash and Cash Equivalents, End of Period	2,415	5,092
Combined Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	684,218	376,126
Net cash provided by (used in) investing activities	(284,076)	(1,102,155)
Net cash provided by (used in) financing activities	(400,142)	726,029
Net Increase (Decrease) in Cash and Cash Equivalents	0	0
Cash and Cash Equivalents, Beginning of Period	0	0
Cash and Cash Equivalents, End of Period	0	0
Combined Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	0	0
Net cash provided by (used in) investing activities	0	0
Net cash provided by (used in) financing activities	0	0
Net Increase (Decrease) in Cash and Cash Equivalents	0	0
Cash and Cash Equivalents, Beginning of Period	0	0
Cash and Cash Equivalents, End of Period	$ 0	$ 0

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information (Supplemental Cash Flow Disclosures) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Supplemental Cash Flow Elements [Abstract]
Interest Paid, Net			$ 44,644	$ 59,389
Change in capital expenditure payables and accruals			61,893	98,829
Divestiture date fair value of contingent consideration arrangement	$ (7,880)		(7,880)
Acquisition date fair value of contingent consideration arrangement		$ 52,300		52,300
Share-based Compensation, Capitalized Amount	968	1,455	5,384	2,543
Capitalized Costs, Asset Retirement Costs	$ 1,127	$ 2,761	$ 1,127	$ 2,761

Subsequent Events (Narrative) (

Subsequent Events (Narrative) (Details) - USD ($) $ in Thousands

2 Months Ended

3 Months Ended

9 Months Ended

Dec. 31, 2018

Jun. 30, 2018

Dec. 31, 2018

Sep. 30, 2018

Mar. 31, 2018

Sep. 30, 2017

Sep. 30, 2018

Sep. 30, 2017

Nov. 19, 2018

Oct. 29, 2018

May 04, 2018

May 03, 2018

Jan. 31, 2018

Dec. 31, 2017

Subsequent Event [Line Items]

Redemption price, percentage of principal amount

101.875%

Gain (Loss) on Extinguishment of Debt

$ 0

$ 0

$ (8,676)

$ 0

7.50% Senior Notes [Member]

Subsequent Event [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

7.50%

7.50%

Other Long Term Debt [Member]

Subsequent Event [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

4.375%

Redemption price, percentage of principal amount

100.00%

Senior Secured Revolving Credit Facility [Member]

Subsequent Event [Line Items]

Line of Credit Facility, Current Borrowing Capacity

$ 1,000,000

$ 1,000,000

$ 1,000,000

$ 830,000

$ 900,000

Line of Credit Facility, Elected Borrowing Capacity

$ 900,000

$ 900,000

$ 900,000

$ 800,000

Senior Secured Revolving Credit Facility [Member] | Maximum [Member]

Subsequent Event [Line Items]

Margin for eurodollar loans

2.50%

3.00%

Margin for base rate loans

1.50%

2.00%

Senior Secured Revolving Credit Facility [Member] | Minimum [Member]

Subsequent Event [Line Items]

Margin for eurodollar loans

1.50%

2.00%

Margin for base rate loans

0.50%

1.00%

Senior Secured Revolving Credit Facility [Member] | Less than 25 percent [Member]

Subsequent Event [Line Items]

Margin for eurodollar loans

1.50%

Margin for base rate loans

0.50%

Senior Secured Revolving Credit Facility [Member] | Greater than or equal to 90 percent [Member]

Subsequent Event [Line Items]

Margin for eurodollar loans

2.50%

Margin for base rate loans

1.50%

Subsequent Event [Member]

Subsequent Event [Line Items]

Required Commitment Amount for Senior Note Redemption

$ 1,100,000

Subsequent Event [Member] | 7.50% Senior Notes [Member]

Subsequent Event [Line Items]

Debt Instrument, Face amount to be repurchased

$ 130,000

Redemption price, percentage of principal amount

100.00%

Gain (Loss) on Extinguishment of Debt

$ (800)

Subsequent Event [Member] | Senior Secured Revolving Credit Facility [Member]

Subsequent Event [Line Items]

Line of Credit Facility, Current Borrowing Capacity

$ 1,300,000

Line of Credit Facility, Elected Borrowing Capacity

$ 1,100,000

Increase To Margin For Eurodollar And Base Rate Loans

0.25%

Ratio of Total Debt to EBITDA to increase interest rate

3

Subsequent Event [Member] | Senior Secured Revolving Credit Facility [Member] | Less than 25 percent [Member]

Subsequent Event [Line Items]

Margin for eurodollar loans

1.25%

Margin for base rate loans

0.25%

Subsequent Event [Member] | Senior Secured Revolving Credit Facility [Member] | Greater than or equal to 90 percent [Member]

Subsequent Event [Line Items]

Margin for eurodollar loans

2.25%

Margin for base rate loans

1.25%

Subsequent Events, Derivative I

Subsequent Events, Derivative Instruments (Schedule of Crude Oil Derivative Positions) (Details) - FY 2019 - Crude Oil	Oct. 29, 2018bbl / d$ / bbls	Oct. 04, 2018bbl / d$ / bbls	Sep. 30, 2018bbl / d$ / bbls
Three-way Collars
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d			21,000
Weighted Average Sub-Floor Price ($/Bbl)			40.71
Weighted Average Floor Price ($/Bbl)			49.80
Weighted Average Ceiling Price ($/Bbl)			67.80
Subsequent Event [Member] | Three-way Collars
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d		6,000
Weighted Average Sub-Floor Price ($/Bbl)		45
Weighted Average Floor Price ($/Bbl)		55
Weighted Average Ceiling Price ($/Bbl)		93.01
LLS-Cushing WTI Price Differential | Basis Swaps
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d			3,000
Weighted Average Fixed Price ($/Bbl)			4.57
LLS-Cushing WTI Price Differential | Subsequent Event [Member] | Basis Swaps
Derivative [Line Items]
Derivative, Volumes (in Bbl/d) | bbl / d	1,000
Weighted Average Fixed Price ($/Bbl)	5.78