Alta Mesa Resources (AMRWW) 10-Q 21 May 18 2018 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 30, 2018
Entity Registrant Name	Alta Mesa Resources, Inc. /DE
Entity Central Index Key	1,690,769
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Trading Symbol	AMR
Entity Filer Category	Non-accelerated Filer
Common Class A [Member]
Entity Common Stock, Shares Outstanding		170,931,140
Common Class C [Member]
Entity Common Stock, Shares Outstanding		213,402,398

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Mar. 31, 2018	Dec. 31, 2017
OTHER ASSETS
Intangible assets, net	$ 468,913,000
CURRENT LIABILITIES
Asset retirement obligations	622,000
LONG-TERM LIABILITIES
Asset retirement obligations, net of current portion	6,033,000
Successor [Member]
CURRENT ASSETS
Cash and cash equivalents	261,063,000
Short-term restricted cash	1,295,000
Accounts receivable, net of allowance of $65 and $415, respectively	109,825,000
Other receivables	225,000
Receivables due from related party	7,892,000
Note receivable due from related party	1,578,000
Prepaid expenses and other current assets	5,903,000
Total current assets	387,781,000
PROPERTY, PLANT, AND EQUIPMENT
Oil and natural gas properties, successful efforts method, net	2,389,522,000
Other property, plant and equipment, net	322,122,000
Total property, plant, and equipment, net	2,711,644,000
OTHER ASSETS
Deferred financing costs, net	1,007,000
Notes receivable due from related party	11,039,000
Goodwill	650,663,000
Intangible assets, net	468,913,000
Deposits and other long-term assets	8,630,000
Deferred tax asset	3,813,000
Derivative financial instruments	49,000
Total other assets	1,144,114,000
TOTAL ASSETS	4,243,539,000
CURRENT LIABILITIES
Accounts payable and accrued liabilities	159,110,000
Advances from non-operators	1,312,000
Advances from related party	40,498,000
Asset retirement obligations	622,000
Derivative financial instruments	26,401,000
Total current liabilities	227,943,000
LONG-TERM LIABILITIES
Asset retirement obligations, net of current portion	6,033,000
Long-term debt, net	584,815,000
Derivative financial instruments	2,916,000
Other long-term liabilities	1,934,000
Total long-term liabilities	595,698,000
TOTAL LIABILITIES	823,641,000
Commitments and Contingencies (Note 13)
Additional paid in capital	1,402,888,000
Retained earnings (accumulated deficit)	(21,349,000)
Total stockholders' equity/partners' capital	1,381,577,000
Non-controlling interest	2,038,321,000
Total equity	3,419,898,000
TOTAL LIABILITIES, PARTNERS' CAPITAL AND STOCKHOLDERS' EQUITY	4,243,539,000
Successor [Member] | Common Class A [Member]
LONG-TERM LIABILITIES
Common stock	17,000
Successor [Member] | Common Class C [Member]
LONG-TERM LIABILITIES
Common stock	$ 21,000
Predecessor [Member]
CURRENT ASSETS
Cash and cash equivalents		$ 3,660,000
Short-term restricted cash		1,269,000
Accounts receivable, net of allowance of $65 and $415, respectively		76,161,000
Other receivables		1,388,000
Receivables due from related party		790,000
Prepaid expenses and other current assets		2,932,000
Current assets - discontinued operations		5,195,000
Derivative financial instruments		216,000
Total current assets		91,611,000
PROPERTY, PLANT, AND EQUIPMENT
Oil and natural gas properties, successful efforts method, net		920,563,000
Other property, plant and equipment, net		6,207,000
Total property, plant, and equipment, net		926,770,000
OTHER ASSETS
Deferred financing costs, net		1,787,000
Notes receivable due from related party		12,369,000
Intangible assets, net		0
Deposits and other long-term assets		9,067,000
Noncurrent assets - discontinued operations		43,785,000
Derivative financial instruments		8,000
Total other assets		67,016,000
TOTAL ASSETS		1,085,397,000
CURRENT LIABILITIES
Accounts payable and accrued liabilities		170,489,000
Accounts payable - affiliate		5,476,000
Advances from non-operators		5,502,000
Advances from related party		23,390,000
Asset retirement obligations		69,000
Current liabilities - discontinued operations		15,419,000
Derivative financial instruments		19,303,000
Total current liabilities		239,648,000
LONG-TERM LIABILITIES
Asset retirement obligations, net of current portion		10,400,000
Long-term debt, net		607,440,000
Non-current liabilities - discontinued operations		66,862,000
Derivative financial instruments		1,114,000
Other long-term liabilities		5,488,000
Total long-term liabilities		691,304,000
TOTAL LIABILITIES		930,952,000
Commitments and Contingencies (Note 13)
PARTNERS' CAPITAL		154,445,000
Total stockholders' equity/partners' capital		154,445,000
Total equity		154,445,000
TOTAL LIABILITIES, PARTNERS' CAPITAL AND STOCKHOLDERS' EQUITY		$ 1,085,397,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Successor [Member]
Allowance for doubtful accounts	$ 65
Preferred stock, par value	$ 0.0001
Preferred stock, shares authorized	1,000,000
Common stock, par value	$ 0.0001
Predecessor [Member]
Allowance for doubtful accounts		$ 415
Preferred stock, par value		$ 0.0001
Preferred stock, shares authorized		1,000,000
Common stock, par value		$ 0.0001
Preferred Class A [Member]
Preferred stock, par value	$ 0.0001
Preferred Class A [Member] | Successor [Member]
Preferred stock, shares issued	3
Preferred stock, shares outstanding	3
Preferred Class A [Member] | Predecessor [Member]
Preferred stock, shares issued		3
Preferred stock, shares outstanding		3
Preferred Class B [Member]
Preferred stock, par value	$ 0.0001
Preferred Class B [Member] | Successor [Member]
Preferred stock, shares issued	1
Preferred stock, shares outstanding	1
Preferred Class B [Member] | Predecessor [Member]
Preferred stock, shares issued		1
Preferred stock, shares outstanding		1
Common Class A [Member] | Successor [Member]
Common stock, shares authorized	1,200,000,000
Common stock, shares issued	169,371,730
Common stock, shares outstanding	169,371,730
Common Class A [Member] | Predecessor [Member]
Common stock, shares authorized		1,200,000,000
Common stock, shares issued		169,371,730
Common stock, shares outstanding		169,371,730
Common Class C [Member] | Successor [Member]
Common stock, shares authorized	280,000,000
Common stock, shares issued	213,402,398
Common stock, shares outstanding	213,402,398
Common Class C [Member] | Predecessor [Member]
Common stock, shares authorized		280,000,000
Common stock, shares issued		213,402,398
Common stock, shares outstanding		213,402,398

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended
	Feb. 08, 2018	Mar. 31, 2018	Mar. 31, 2017
Successor [Member]
OPERATING REVENUES AND OTHER
Gain on sale of assets and other		$ 5,979
Gain (loss) on derivative contracts		(22,646)
Total operating revenues and other		45,870
OPERATING EXPENSES
Lease operating expense		8,317
Marketing and transportation expense		1,021
Plant operating expense		587
Product expense		8,220
Gathering and processing expense		2,338
Production taxes		1,415
Workover expense		1,245
Exploration expense		4,955
Depreciation, depletion, and amortization expense		15,577
Accretion expense		102
General and administrative expense		34,557
Total operating expenses		78,334
INCOME (LOSS) FROM OPERATIONS		(32,464)
OTHER INCOME (EXPENSE)
Interest expense		(5,444)
Interest income and other		546
Total other income (expense)		(4,898)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES		(37,362)
Income tax provision (benefit)		(3,813)
Deferred income tax benefit		(3,813)
INCOME (LOSS) FROM CONTINUING OPERATIONS		(33,549)
NET INCOME (LOSS)		(33,549)
Net loss attributable to noncontrolling interest		(20,314)
NET LOSS (LOSS) ATTRIBUTABLE TO ALTA MESA RESOURCES, INC.		$ (13,235)
NET INCOME (LOSS) PER COMMON SHARE:
Basic and Diluted		$ (0.08)
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Basic and Diluted		169,371,730
Successor [Member] | Oil Revenue [Member]
OPERATING REVENUES AND OTHER
Total operating revenues and other		$ 40,278
Successor [Member] | Natural Gas [Member]
OPERATING REVENUES AND OTHER
Total operating revenues and other		5,210
Successor [Member] | Natural Gas Liquids [Member]
OPERATING REVENUES AND OTHER
Total operating revenues and other		4,714
Successor [Member] | Product Sales [Member]
OPERATING REVENUES AND OTHER
Total operating revenues and other		8,369
Successor [Member] | Gathering And Processing [Member]
OPERATING REVENUES AND OTHER
Total operating revenues and other		3,411
Successor [Member] | Other Revenues [Member]
OPERATING REVENUES AND OTHER
Total operating revenues and other		555
Successor [Member] | Oil and Gas [Member]
OPERATING REVENUES AND OTHER
Total operating revenues and other		$ 62,537
Predecessor [Member]
OPERATING REVENUES AND OTHER
Gain (loss) on derivative contracts	$ 7,298		$ 30,242
Total operating revenues and other	47,434		95,079
OPERATING EXPENSES
Lease operating expense	4,485		11,010
Marketing and transportation expense	3,725		5,662
Production taxes	953		1,266
Workover expense	423		588
Exploration expense	3,633		5,047
Depreciation, depletion, and amortization expense	11,784		18,978
Impairment expense			1,188
Accretion expense	39		96
General and administrative expense	24,352		9,736
Total operating expenses	49,394		53,571
INCOME (LOSS) FROM OPERATIONS	(1,960)		41,508
OTHER INCOME (EXPENSE)
Interest expense	(5,511)		(12,042)
Interest income and other	172		249
Total other income (expense)	(5,339)		(11,793)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	(7,299)		29,715
Income tax provision (benefit)			285
INCOME (LOSS) FROM CONTINUING OPERATIONS	(7,299)		29,430
Loss from discontinued operations, net of tax	(7,593)		(4,515)
NET INCOME (LOSS)	(14,892)		24,915
NET LOSS (LOSS) ATTRIBUTABLE TO ALTA MESA RESOURCES, INC.	(14,892)		24,915
Predecessor [Member] | Oil Revenue [Member]
OPERATING REVENUES AND OTHER
Total operating revenues and other	30,972		46,940
Predecessor [Member] | Natural Gas [Member]
OPERATING REVENUES AND OTHER
Total operating revenues and other	4,276		9,591
Predecessor [Member] | Natural Gas Liquids [Member]
OPERATING REVENUES AND OTHER
Total operating revenues and other	4,000		7,072
Predecessor [Member] | Other Revenues [Member]
OPERATING REVENUES AND OTHER
Total operating revenues and other	888		1,234
Predecessor [Member] | Oil and Gas [Member]
OPERATING REVENUES AND OTHER
Total operating revenues and other	$ 40,136		$ 64,837

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended
	Feb. 08, 2018	Mar. 31, 2018	Mar. 31, 2017
Successor [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)		$ (33,549)
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Depreciation, depletion, and amortization expense		15,577
Accretion expense		102
Amortization of debt premium		(820)
Equity based compensation expense		3,466
Expired leases		4,189
(Gain) loss on derivative contracts		22,646
Settlements of derivative contracts		(4,610)
Interest on notes receivable due from related party		(162)
Deferred tax provision (benefit)		(3,813)
Changes in assets and liabilities:
Accounts receivable		(3,189)
Other receivables		997
Receivables due from related party		(2,067)
Prepaid expenses and other non-current assets		(2,194)
Advances from related party		(7,008)
Settlement of asset retirement obligation		(166)
Accounts payable, accrued liabilities, and other liabilities		(75,960)
NET CASH (USED IN) PROVIDED BY OPERATING ACTIVITIES		(86,561)
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures for property, plant and equipment		(133,055)
Acquisitions of Alta Mesa and Kingfisher, net of cash acquired		(796,826)
Proceeds withdrawn from Trust Account		1,042,742
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES		112,861
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from long-term debt		9,000
Repayments of long-term debt		(134,065)
Additions to deferred financing costs		(1,007)
Proceeds from issuance of Class A shares		400,000
Repayment of sponsor note		(2,000)
Repayment of deferred underwriting compensation		(36,225)
Redemption of Class A common shares		(33)
NET CASH PROVIDED BY FINANCING ACTIVITIES		235,670
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH		261,970
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, end of period		262,358
Predecessor [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (14,892)		$ 24,915
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Depreciation, depletion, and amortization expense	12,414		24,804
Impairment expense	5,560		1,220
Accretion expense	140		572
Amortization of deferred financing costs	171		962
Dry hole expense	(45)
Expired leases	1,250		3,333
(Gain) loss on derivative contracts	(7,298)		(30,242)
Settlements of derivative contracts	(1,661)		(1,970)
Interest converted into debt	103		298
Interest on notes receivable due from related party	(85)		(200)
Loss on sale of assets and other	1,923
Changes in assets and liabilities:
Accounts receivable	(20,895)		(5,374)
Other receivables	(9,887)		7,494
Receivables due from related party	(117)		139
Prepaid expenses and other non-current assets	9,970		(9,543)
Advances from related party	24,116		(29,791)
Settlement of asset retirement obligation	(63)		(2,394)
Accounts payable, accrued liabilities, and other liabilities	25,815		11,837
NET CASH (USED IN) PROVIDED BY OPERATING ACTIVITIES	26,519		(3,940)
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures for property, plant and equipment	(38,096)		(60,589)
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	(38,096)		(60,589)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from long-term debt	60,000		55,065
Repayments of long-term debt	(43,000)
Additions to deferred financing costs			(64)
Capital distributions	(68)
Capital contributions			7,875
NET CASH PROVIDED BY FINANCING ACTIVITIES	16,932		62,876
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	5,355		(1,653)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, beginning of period	4,990	$ 10,345	7,618
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, end of period	$ 10,345		$ 5,965

Consolidated Statement Of Stock

Consolidated Statement Of Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]Common Class A [Member]	Common Stock [Member]Common Class B [Member]	Common Stock [Member]Common Class C [Member]	Paid-In Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Total Equity Before Noncontrolling Interest [Member]	Noncontrolling Interests [Member]	Common Class C [Member]	Total
Shares, Outstanding | Successor [Member]	169,372		213,402
Class C common shares issued in connection with the closing of the Business Combination, shares								213,402,398
Balance (Successor [Member]) at Mar. 31, 2018	$ 17		$ 21	$ 1,402,888	$ (21,349)	$ 1,381,577	$ 2,038,321		$ 3,419,898
Balance, shares (Successor [Member]) at Mar. 31, 2018	169,372		213,402
Shares, Outstanding | Successor [Member]	3,862	25,875
Balance (Successor [Member]) at Feb. 08, 2018		$ 3		3,106	(8,114)	(5,005)			(5,005)
Shares, Outstanding | Successor [Member]	169,372		213,402
Conversion of common shares from Class B to Class A at closing of Business Combination | Successor [Member]	$ 3	$ (3)
Conversion of common shares from Class B to Class A at closing of Business Combination, shares | Successor [Member]	25,875	(25,875)
Class A common shares released from possible redemption | Successor [Member]	$ 10			996,374		996,384			996,384
Class A common shares released from possible redemption, share | Successor [Member]	99,638
Sale of Class A common shares | Successor [Member]	$ 4			399,996		400,000			400,000
Sale of Class A common sharest, shares | Successor [Member]	40,000
Class A common shares redeemed | Successor [Member]				(33)		(33)			(33)
Class A common shares redeemed, shares | Successor [Member]	(3)
Class C common shares issued in connection with the closing of the Business Combination | Successor [Member]			$ 21	(21)
Class C common shares issued in connection with the closing of the Business Combination, shares | Successor [Member]			213,402
Noncontrolling interest in SRII Opco issued in the Business Combination | Successor [Member]							2,058,635		2,058,635
Balance (Successor [Member]) at Feb. 09, 2018	$ 17		$ 21	1,399,422	(8,114)	1,391,346	2,058,635		3,449,981
Balance, shares (Successor [Member]) at Feb. 09, 2018	169,372		213,402
Balance (Successor [Member]) at Feb. 08, 2018		$ 3		3,106	(8,114)	(5,005)			(5,005)
Shares, Outstanding | Successor [Member]	169,372		213,402
Noncontrolling interest in SRII Opco issued in the Business Combination | Successor [Member]									2,058,635
Balance (Successor [Member]) at Mar. 31, 2018	$ 17		$ 21	1,402,888	(21,349)	1,381,577	2,038,321		3,419,898
Balance, shares (Successor [Member]) at Mar. 31, 2018	169,372		213,402
Shares, Outstanding | Successor [Member]	169,372		213,402
Balance (Successor [Member]) at Feb. 09, 2018	$ 17		$ 21	1,399,422	(8,114)	1,391,346	2,058,635		3,449,981
Shares, Outstanding | Successor [Member]	169,372		213,402
Equity based compensation | Successor [Member]				3,466		3,466			3,466
Net loss | Successor [Member]					(13,235)	(13,235)	(20,314)		(33,549)
Balance (Successor [Member]) at Mar. 31, 2018	$ 17		$ 21	$ 1,402,888	$ (21,349)	$ 1,381,577	$ 2,038,321		$ 3,419,898
Balance, shares (Successor [Member]) at Mar. 31, 2018	169,372		213,402
Shares, Outstanding | Successor [Member]	169,372		213,402

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Partners' Capital - 2 months ended Feb. 28, 2018 - Predecessor [Member] $ in Thousands	USD ($)
BALANCE, BEGINNING at Dec. 31, 2017	$ 154,445
DISTRIBUTION OF NON-STACK ASSETS (NET LIABILITY)	33,102
NET LOSS	(14,892)
BALANCE, ENDING at Feb. 28, 2018	$ 172,655

Description Of Business

Description Of Business	3 Months Ended
	Mar. 31, 2018
Description Of Business [Abstract]
Description Of Business	NOTE 1 — DESCRIPTION OF BUSINESS  Alta Mesa Resources, Inc. (together with its consolidated subsidiaries, (“AMR,” “we,” “us,” “our,” or the “Company,”) was originally incorporated in Delaware in November 2016 as a special purpose acquisition company under the name Silver Run Acquisition Corporation II for the purpose of effecting a merger, capital stock exchange, asset acquisition, stock purchase, reorganization or similar business combination involving the Company and one or more businesses.  On March 29, 2017, we consummated our initial public offering (“IPO”) generating net proceeds of approximately $1.0 billion. Simultaneously with the closing of our IPO, we completed the private sale of 15,133,333 warrants (the “Private Placement Warrants”) to Silver Run Sponsor II, LLC (the “Sponsor”) generating gross proceeds to us of $22,700,000 . A total of $1.035 billion (which includes approximately $36.2 million in deferred underwriting commissions to the underwriters of the IPO), representing $1.0143 billion of the proceeds from the IPO after deducting upfront underwriting commissions of $20.7 million, and the proceeds of the sale of the Private Placement Warrants were placed in the Trust Account (the “Trust Account”) to be used to fund an initial business combination.  On February 9, 2018 (the “Closing Date”), we consummated the transactions contemplated by the Contribution Agreement (“AM Contribution Agreement”), dated August 16, 2017, with Alta Mesa Holdings, LP (“Alta Mesa”), High Mesa Holdings, LP (the “AM Contributor”), High Mesa Holdings GP, LLC, the sole general partner of the AM Contributor, Alta Mesa Holdings GP, LLC, Alta Mesa’s sole general partner (“Alta Mesa GP”), and, solely for certain provisions therein, the equity owners of the AM Contributor. Simultaneous with the execution of the AM Contribution Agreement, we entered into (i) a Contribution Agreement (the “KFM Contribution Agreement”) with KFM Holdco, LLC, a Delaware limited liability company (the “KFM Contributor”), Kingfisher Midstream, LLC, a Delaware limited liability company (“Kingfisher”), and, solely for certain provisions therein, the equity owners of the KFM Contributor; and (ii) a Contribution Agreement (the “Riverstone Contribution Agreement” and, together with the AM Contribution Agreement and the KFM Contribution Agreement, the “Contribution Agreements”) with Riverstone VI Alta Mesa Holdings, L.P., a Delaware limited partnership (the “Riverstone Contributor” and together with the AM Contributor and the KFM Contributor, the “Contributors”).  Pursuant to the Contribution Agreements, SRII Opco, LP, our newly formed subsidiary (“SRII Opco”) acquired (a) (i) all of the limited partner interests in Alta Mesa and (ii) 100% of the economic interests and 90% of the voting interests in Alta Mesa GP, (with (i) and (ii) collectively, the “AM Contribution”) and (b) 100% of the economic interests in Kingfisher (the “Kingfisher Contribution”). The acquisition of Alta Mesa and Kingfisher pursuant to the Contribution Agreements is referred to herein as the “Business Combination” and the transactions contemplated by the Contribution Agreements are referred to herein as the “Transactions.” SRII Opco GP, LLC, a Delaware limited liability company (“SRII Opco GP”), the sole general partner of SRII Opco, is a wholly owned subsidiary of AMR. As a result of the Business Combination, our only significant asset is our ownership of an approximate 44.2% partnership interest in SRII Opco. SRII Opco owns all of the economic interests in each of Alta Mesa and Kingfisher.  In connection with the closing of the Business Combination, the Company changed its name from “Silver Run Acquisition Corporation II” to “Alta Mesa Resources, Inc.” and continued the listing of its Class A Common Stock and public warrants (which were originally sold as part of the units issued in our initial public offering) on NASDAQ under the symbols “AMR” and “AMRWW,” respectively.  Alta Mesa is an independent exploration and production company engaged primarily in the acquisition, exploration, development, and production of unconventional oil and natural gas properties in the eastern portion of the Anadarko Basin commonly referred to as the STACK. Kingfisher owns and operates midstream oil and gas assets in the STACK and its operations are primarily comprised of crude oil gathering, natural gas gathering and processing of products. The STACK is an acronym describing both its location – Sooner Trend Anadarko Basin Canadian and Kingfisher County – and the multiple, stacked productive formations present in the area. In connection with the closing of the Business Combination, Alta Mesa distributed the remainder of its non-STACK assets to the AM Contributor and completed its transition from a diversified asset base composed of a portfolio of conventional assets to an oil and liquids-rich resource play in the STACK with an extensive inventory of drilling opportunities.

Summary Of Significant Accounti

Summary Of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Summary Of Significant Accounting Policies [Abstract]
Summary Of Significant Accounting Policies	NOTE 2 — SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES  Basis of Presentation . As a result of the Business Combination, the Company is the acquirer for accounting purposes and Alta Mesa and Kingfisher are the acquirees. Alta Mesa is our accounting predecessor. The Company’s financial statement presentation reflects Alta Mesa as the “Predecessor” for periods prior to the Business Combination. The Company is the “Successor” for periods after the Business Combination, which includes consolidation of Alta Mesa and Kingfisher concurrent with the Business Combination on February 9, 2018. The Business Combination was accounted for as a business combination using the acquisition method of accounting, and the Successor financial statements reflect a new basis of accounting that is based on the fair value of Alta Mesa and Kingfisher’s net assets acquired. Refer to Note 4 — Business Combination (Successor) for further information related to the Business Combination. As a result of the application of the acquisition method of accounting resulting from the Business Combination, the financial statements and certain footnote presentations separate the Company’s presentations into two distinct periods, the period before the consummation of the Transactions and the period on or after that date, to indicate that the financial statements presented are those of different entities and reflect the application of the different basis of accounting between the periods presented. The Successor period presented herein is from February 9, 2018 to March 31, 2018 (“Successor Period”) and the Predecessor periods presented herein are from January 1, 2018 to February 8, 2018 (“2018 Predecessor Period”) and the three months ended March 31, 2017 (“2017 Predecessor Period”).  Prior to the Business Combination, Alta Mesa distributed its non-STACK assets to the AM Contributor. The distribution of its remaining non-STACK assets in 2018 and the sale of its Weeks Island field during the fourth quarter of 2017 (collectively, the “non-STACK assets”) were part of Alta Mesa’s overall strategic shift to operate only in the eastern Anadarko Basin. As a result of the strategic shift, Alta Mesa classified the Predecessor assets and liabilities and operating results directly related to non-STACK assets as discontinued operations within the consolidated financial statements. See Note 6 — Discontinued Operations (Predecessor) for further discussion.  Principles of Consolidation and Reporting . The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Certain reclassifications of prior period consolidated financial statements have been made to conform to current reporting practices. The consolidated financial statements include the accounts of the Company and its subsidiaries, including SRII Opco, after eliminating all significant intercompany transactions and balances. The Company’s interests in oil and natural gas exploration and production ventures and partnerships are proportionately consolidated. Noncontrolling interests represent third-party ownership interests in SRII Opco and are presented as a component of equity. See Note 15—Stockholders' Equity and Partners’ Capital for further discussion of noncontrolling interest.  The consolidated financial statements included herein are unaudited, and in the opinion of management, the information furnished reflects all material adjustments, consisting of normal recurring adjustments, necessary for a fair presentation of consolidated financial position and of the results of operations for the interim periods presented. The consolidated results of operations for interim periods are not necessarily indicative of results to be expected for a full year.  Use of Estimates . The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period.  Reserve estimates significantly impact depreciation, depletion, and amortization expense and potential impairments of oil and natural gas properties and are subject to change based on changes in oil and natural gas prices and trends and changes in estimated reserve quantities. We analyze estimates, including those related to oil and natural gas reserves, oil and natural gas revenues, product and gathering and compression sales, the value of oil and natural gas properties, the value of pipeline equipment, bad debts, goodwill, intangible assets, asset retirement obligations, derivative contracts, accounting for business combinations, federal and state taxes, share-based compensation and contingencies and litigation. We base our estimates on historical experience and various other assumptions that are believed to be reasonable under the circumstances. We review estimates and underlying assumptions on a regular basis. Actual results may differ from these estimates.  Cash and Cash Equivalents . We consider all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. The Company maintains cash balances at financial institutions in the United States of America, which at times exceed federally insured amounts. The Federal Deposit Insurance Corporation provides insurance up to $250,000 per depositor. We monitor the financial condition of the financial institutions and have experienced no losses associated with these accounts.  Restricted Cash. The Company classifies cash balances as restricted cash when cash is restricted as to withdrawal or usage. As of March 31, 2018, and December 31, 2017, the restricted cash represents cash received by the Company from production sold where the final division of ownership of the production is in dispute or there is unclaimed property for pooling orders in Oklahoma.  The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets and the consolidated statements of cash flows (in thousands):      Successor Predecessor  March 31, December 31,  2018 2017   Cash and cash equivalents $ 261,063 $ 3,660  Short-term restricted cash 1,295 1,269  Cash of discontinued operations — 61  Total cash, cash equivalents and restricted cash $ 262,358 $ 4,990  A ccounts Receivable . Our receivables arise primarily from the sale of oil, natural gas and natural gas liquids and joint interest owner receivables for properties in which we serve as the operator, and valid claims against nonaffiliated customers for services rendered. This concentration of customers may impact our overall credit risk, either positively or negatively, in that these entities may be similarly affected by changes in economic or other conditions affecting the oil and natural gas industry. Accounts receivable are generally not collateralized. We may have the ability to withhold future revenue disbursements to recover non-payment of joint interest billings on properties of which we are the operator. Accounts receivable from joint interest owners are stated at amounts due, net of an allowance for doubtful accounts.  Accounts receivable consisted of the following (in thousands):     Successor Predecessor  March 31, December 31,  2018 2017  Oil, natural gas and natural gas liquids sales $ 39,067 $ 26,916  Joint interest billings 33,197 13,821  Pooling interest (1) 37,626 35,839  Allowance for doubtful accounts (65) (415)  Total accounts receivable, net $ 109,825 $ 76,161 _________________ (1) Pooling interest relates to Oklahoma’s forced pooling process which requires the Company to offer mineral interest owners the option to participate in the drilling of proposed wells. The pooling interest listed above represent costs of unbilled interests on wells which the Company incurred before the pooling process was completed. Depending upon the outcome of the pooling process, these costs may be billed to potential working interest owners or added to oil and gas properties.  Allowance for Doubtful Accounts . We routinely assess the recoverability of all material trade and other receivables to determine their collectability. We accrue a reserve when, based on the judgment of management, it is probable that a receivable will not be collected and the amount of the reserve can be reasonably estimated.  Property, Plant and Equipment . Oil and natural gas producing activities are accounted for using the successful efforts method of accounting. Under the successful efforts meth od, lease acquisition costs and all development costs, including unsuccessful development wells, are capitalized. In conjunction with acquisition accounting, property, plant and equipment was measured at fair value as of the acquisition date, which also impacted how value was assigned between the categories within property, plant, and equipment. See Note 4 — Business Combination (Successor) for discussion.  Unproved Properties — Acquisition costs associated with the acquisition of leases are recorded as unproved properties and capitalized as incurred. These consist of costs incurred in obtaining a mineral interest or right in a property, such as a lease, in addition to options to lease, broker fees, recording fees and other similar costs related to activities in acquiring properties. Unproved properties are classified as unproved until proved reserves are discovered, at which time related costs are transferred to the proved oil and natural gas properties.  Exploration Expense — Exploration expenses, other than exploration drilling costs, are charged to expense as incurred. These expenses include seismic expenditures and other geological and geophysical costs, expired leases, delay rentals, gain or loss on settlement of asset retirement obligations and lease rentals. The costs of drilling exploratory wells and exploratory-type stratigraphic wells are initially capitalized, or “suspended” on the balance sheet pending determination of whether the well has discovered proved commercial reserves. If the exploratory well is determined to be unsuccessful, the cost of the well is transferred to expense. Exploratory well drilling costs may continue to be capitalized if the reserve quantity is sufficient to justify completion as a producing well and sufficient progress in assessing the reserves and the economic and operating viability of the project is being made. Assessments of such capitalized costs are made quarterly.  Proved Oil and Natural Gas Properties — Costs incurred to obtain access to the proved reserves and to provide facilities for extracting, treating, gathering, and storing oil and natural gas are capitalized. All costs incurred to drill and equip successful exploratory wells, development wells, development-type stratigraphic test wells, and service wells, including unsuccessful development wells, are capitalized.  Impairment — The capitalized costs of proved oil and natural gas properties are reviewed quarterly for impairment following the guidance provided in Account Standards Codification (“ASC”) 360-10-35, Property, Plant and Equipment, Subsequent Measurement , or whenever events or changes in circumstances indicate that the carrying amount of a long-lived asset or asset group exceeds its fair value and is not recoverable. The determination of recoverability is based on comparing the estimated undiscounted future net cash flows at a producing field level to the carrying value of the assets. If the future undiscounted cash flows, based on estimates of anticipated production from proved and risk-adjusted unproved reserves and future crude oil and natural gas prices and operating costs, are lower than the carrying cost, the carrying cost of the asset or group of assets is reduced to fair value. For our proved oil and natural gas properties, we estimate fair value by discounting the projected future cash flows at an appropriate risk-adjusted discount rate.  Our evaluation of the Company’s proved properties resulted in no impairment expense in the Successor Period and the 2018 Predecessor Period. For the 2017 Predecessor Period, our evaluation of the Company’s proved properties resulted in an impairment expense of $1.2 million.  Unproved properties are assessed at least annually to determine whether they have been impaired. Individually significant properties are assessed for impairment on a property-by-property basis, while individually insignificant unproved properties may be assessed in the aggregate. If unproved properties are found to be impaired, an impairment allowance is provided and a loss is recognized in the consolidated statements of operations. No impairment expense was recognized in the Successor Period, the 2018 Predecessor Period, and the 2017 Predecessor Period.  Management evaluates whether the carrying value of all other long-lived assets has been impaired when circumstances indicate the carrying value of those assets may not be recoverable. This evaluation is based on undiscounted cash flow projections. The carrying amount is not recoverable if it exceeds the sum of undiscounted cash flows expected to result from the use and eventual disposition of the assets. Management considers various factors when determining if these assets should be evaluated for impairment.  If the carrying value is not recoverable on an undiscounted basis, the impairment loss is measured as the excess of the asset’s carrying value over its fair value. Management assesses the fair value of long-lived assets using commonly accepted techniques, and may use more than one method, including, but not limited to, recent third party comparable sales, internally developed discounted cash flow analysis and analysis from outside advisors. Significant changes in market conditions resulting from events such as the condition of an asset or a change in management’s intent to utilize the asset would generally require management to reassess the cash flows related to the long-lived assets. The Company did not record any impairment expense related to other long-lived assets for the Successor Period, the 2018 Predecessor Period and the 2017 Predecessor Period, respectively.  Other Property, Plant and Equipment — Other property, plant and equipment such as plant equipment, salt water disposal system, office furniture and equipment, buildings, vehicles, are recorded at cost, or fair value, if impaired. Maintenance, repairs and minor renewals are expensed as incurred. Plant and equipment include costs incurred to build a cryogenic processing facility along with gathering pipelines, including right of ways, crude oil gathering system, and compressors.  Depreciation, Depletion and Amortization — Depreciation, depletion, and amortization (“DD&A”) of capitalized costs of proved oil and natural gas properties is computed using the unit-of-production method based upon estimated proved reserves. Assets are grouped for DD&A on the basis of reasonable aggregation of properties with a common geological structural feature or stratigraphic condition, such as a reservoir or field. The reserve base used to calculate DD&A for leasehold acquisition costs and the cost to acquire proved properties is total proved reserves. The reserve base used to calculate DD&A for lease and well equipment costs, which include development costs and successful exploration drilling costs, includes only proved developed reserves. Our midstream assets are depreciated on the straight-line method based on their expected useful lives. The Company uses estimated lives of 35 years for its processing plant and pipelines.  DD&A expense related to oil and natural gas properties was $10.8 million, $11.2 million and $18.3 million for the Successor Period, the 2018 Predecessor Period and the 2017 Predecessor Period, respectively. DD&A expense related to our midstream assets was $1.1 million in the Successor Period. There was no such DD&A expense for midstream assets for the 2018 and 2017 Predecessor Period.  Leasehold improvements to offices are depreciated using the straight-line method over the life of the lease. Other property and equipment is depreciated using the straight-line method over periods ranging from three to seven years. For the Successor Period, depreciation expense was immaterial. Depreciation expense for non-oil, natural gas, and midstream properties was $0.2 million, $0.6 million and $0.7 million for the Successor Period, the 2018 Predecessor Period and the 2017 Predecessor Period, respectively.  Intangible Assets (Successor) . In connection with the acquisition of Kingfisher, the Company recorded the estimated fair value of acquired customer contracts and relationships as intangible assets, which were valued using the income approach, and are presented as Intangible Assets, net in the accompanying consolidated balance sheet of the Successor. These intangible assets have definite lives and are subject to amortization utilizing an accelerated attrition method over their economic lives, currently ranging between 10 years and 15 years. We assess intangible assets for impairment together with related underlying long-lived assets whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. An impairment is recognized in the consolidated statements of income if the carrying amount of an intangible asset is not recoverable and its carrying amount exceeds its fair value. As a result of the Business Combination, we determined all the Company’s intangible assets relate to the midstream reporting unit, and concluded that there was no impairment after evaluating the intangible assets for impairment as of March 31, 2018.  Goodwill (Successor). Goodwill represents the excess of the purchase price of an entity over the estimated fair value of the assets acquired and liabilities assumed, and it is presented as Goodwill in the accompanying consolidated balance sheet of the Successor. Under ASC 350, Intangibles – Goodwill and Other (“ASC 350”), goodwill is not amortized but is subject to periodic impairment testing. ASC 350 requires that an entity assign its goodwill to reporting units and test each reporting unit’s goodwill for impairment at least on an annual basis and between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount . In our evaluation of goodwill for impairment, performed annually during the third quarter, we first assess qualitative factors to determine whether the existence of events or circumstances led to a determination that it was more likely than not that the fair value of a reporting unit is less than its carrying amount. If, after assessing the totality of events or circumstances, we determine it is more likely than not that the fair value of a reporting unit is less than its carrying amount, we are required to perform the quantitative goodwill impairment test. As a result of the Business Combination, we acquired goodwill during the Successor Period. There was no goodwill prior to the Business Combination. We determined that all of the Company’s goodwill relates to the midstream reporting unit and did not identify any significant events or circumstances that would require us to perform an impairment test as of March 31, 2018. As such, there was no impairment recognized during the Successor Period.  Bond Premium on Senior Unsecured Notes . In connection with the Business Combination, the Company estimated the fair value of Alta Mesa’s $500 million senior unsecured notes at $533.6 million as of the acquisition date. The amount in excess of the principal amount was recorded as a bond premium, which is being amortized over the term of the notes using the straight-line method, which approximates the effective interest method.  Asset Retirement Obligations . We recognize liabilities for the future costs of dismantlement and abandonment of our wells, facilities, and other tangible long-lived assets along with an associated increase in the carrying amount of the related long-lived asset. The fair values of new asset retirement obligations are estimated using expected future costs discounted to present value. The cost of the tangible asset, including the asset retirement cost, is depleted over the useful life of the asset. Accretion expense is recognized as the discounted liability is accreted to its expected settlement value. Asset retirement obligations are subject to revision primarily for changes to the estimated timing and cost of abandonment.  Asset retirement obligations for the Company’s midstream processing and pipeline facilities generally become firm at the time the facilities are permanently shut down and dismantled. These obligations may include the costs of asset disposal and additional soil remediation. However, these sites have indeterminate lives based on plans for continued operations and as such, the fair value of the conditional legal obligations cannot be measured due to the uncertainty associated with the future settlement dates of such obligations.  Derivative Financial Instruments . We use derivative contracts to hedge the effects of fluctuations in the prices of oil, natural gas and natural gas liquids. We account for such derivative instruments in accordance with ASC 815, Derivatives and Hedging (“ASC 815”), which establishes accounting and disclosure requirements for derivative instruments and requires them to be measured at fair value and recorded as assets or liabilities in the consolidated balance sheets (see Note 7 — Fair Value Disclosures for information on fair value).  Under ASC 815, hedge accounting is used to defer recognition of unrealized changes in the fair value of such financial instruments, for those contracts which qualify as fair value or cash flow hedges, as defined in the guidance. Historically, we have not designated any of our derivative contracts as fair value or cash flow hedges. Accordingly, the changes in fair value of the contracts are included in gain (loss) on derivative contracts in the consolidated statement of operations. Gains or losses from the settlement of matured derivatives contracts are also included in gain (loss) on derivatives contracts in the consolidated statement of operations. Cash flows from settlements of derivative contracts are classified as operating cash flows.  Income Taxes (Successor) . Income taxes and uncertain tax positions are accounted for in accordance with ASC 740, Accounting for Income Taxes (“ASC 740”). Deferred income taxes are provided for the differences between the bases of assets and liabilities for financial reporting and income tax purposes. Tax positions meeting the more-likely-than-not recognition threshold are measured pursuant to the guidance set forth in ASC 740. We assess the ability to realize our deferred tax assets on a quarterly basis. A valuation allowance is established to reduce deferred tax assets to the amount expected to be realized when it is determined that it is more likely than not that some or all of the deferred tax assets are not realizable.  The Company is also subject to the Texas margin tax, which is considered a state income tax, and is included in “Income tax provision (benefit)” on the consolidated statements of operations. The Company records state income tax (current and deferred) based on taxable income, as defined under the rules for the margin tax.  We have considered our exposure under the standard at both the federal and state tax levels. We did not record any liabilities for uncertain tax positions as of the Successor Period and December 31, 2017. We record income tax, related interest, and penalties, if any, as a component of income tax expense. We did not incur any material interest or penalties on income taxes for the 2018 Predecessor Period and the 2017 Predecessor Period.  Alta Mesa’s tax returns for the years ended December 31, 2014 forward remain open for examination. None of the Company’s federal or state tax returns are currently under examination by the relevant authorities.  Income Taxes (Predecessor) . Alta Mesa has historically elected under the provisions of the Internal Revenue Code of 1986, as amended, to be treated as individual partnerships for tax purposes. Accordingly, items of income, expense, gains and losses of the Predecessor flowed through to the partners and were taxed at the partner level. Accordingly, no tax provision for federal income taxes is included in the consolidated financial statements of the Predecessor.  Predecessor net income (loss) for financial statement purposes differed significantly from taxable income (loss) reported to limited partners as a result of differences between the tax bases and financial reporting bases of assets and liabilities and the taxable income allocation requirements under Alta Mesa’s amended and restated partnership agreement. As a result, the aggregate difference in the basis of net assets for financial and tax reporting purposes could not be readily determined as Alta Mesa does not have access to information about each unitholder’s tax attributes in Alta Mesa. However, with respect to Alta Mesa, the Predecessor’s book basis in its net assets exceeded Alta Mesa’s net tax basis by $333.2 million at December 31, 2017.  We follow guidance issued by the FASB in accounting for uncertainty in income taxes. This guidance clarifies the accounting for income taxes by prescribing the minimum recognition threshold an income tax position is required to meet before being recognized in the consolidated financial statements and applies to all income tax positions. Each income tax position is assessed using a two-step process. A determination is first made as to whether it is more likely than not that the income tax position will be sustained, based upon technical merits, upon examination by the taxing authorities. If the income tax position is expected to meet the more likely than not criteria, the benefit recorded in the consolidated financial statements equals the largest amount that is greater than 50% likely to be realized upon its ultimate settlement.  Revenue Recognition . We recognize oil, natural gas and natural gas liquids revenues when products are delivered at a fixed or determinable price, title has transferred and collectability is reasonably assured. We use the sales method of accounting for recognition of natural gas imbalances.  Gathering and processing revenues are generated by charging fees on a per unit basis for gathering crude oil and natural gas and processing natural gas. The Company recognizes revenue when services have been rendered, the prices are fixed or determinable and collectability is reasonably assured. In addition, revenue from sales of crude oil, natural gas and NGLS is recognized when title passes to the customer, which is when risk of ownership passes to the customer and physical delivery occurs, the price of the product is fixed or determinable and collectability is reasonably assured.  Equity Based Compensation (Successor) . The Company recognizes compensation related to all stock-based awards, including stock options, in the financial statements based on their estimated grant-date fair value. The Company grants various types of stock-based awards including stock options and restricted stock. The fair value of stock option awards is determined using the Black-Scholes option pricing model. Service-based restricted stock awards are valued using the market price of the Company’s common stock on the grant date. Compensation cost is recognized ratably over the applicable vesting period. See Note 16 — Equity Based Compensation for additional information regarding the Company’s equity based compensation (Successor).  Fair Value of Financial Instruments . The fair values of cash, accounts receivable and current liabilities approximate book value due to their short-term nature. The fair value estimate of long-term debt under our senior secured revolving credit facilities is not considered to be materially different from carrying value due to market rates of interest. Derivative financial instruments are carried at fair value. For further information on fair values of financial instruments see Note 7 — Fair Value Disclosures and Note 11 — Long-Term Debt, Net .  Acquisitions . Acquisitions are accounted for as purchases using the acquisition method of accounting. Accordingly, the results of operations are included in our consolidated statements of operations from the closing date of the acquisitions, except in the case of our acquisition of Alta Mesa, as that entity was deemed to be our Predecessor for accounting purposes . Purchase prices are allocated to acquired assets and assumed liabilities based on their estimated fair values at the time of the acquisition.  Earnings (Loss) Per Share . Basic earnings (loss) per share is calculated by dividing earnings (loss) available to common shareholders by the weighted average shares-basic during each period.  The Company uses the "if-converted" method to determine the potential dilutive effect of exchanges of outstanding SRII Opco Common Units and corresponding shares of its outstanding Class C common stock, and the treasury stock method to determine the potential dilutive effect of its outstanding warrants, restricted stock, and stock options.  The following table reflects the allocation of net income to common stockholders and EPS computations for the periods indicated based on a weighted average number of common stock outstanding for the period:      Successor  February 9, 2018 Through March 31, 2018  (in thousands, except share and per share data)   Net loss attributable to common stock $ (13,235)   Weighted average common shares outstanding (Basic) 169,371,730  Effect of Dilutive Securities:  Warrants, Class C Common Stock, restricted stock, and stock options —  Weighted average common shares outstanding (Diluted) 169,371,730   Net income (loss) per common share  Basic and diluted $ (0.08)  During the Successor Period, approximately 63.2 million of warrants, 213.4 million shares of Class C Common Stock and 6.1 million of stock options, restricted stock and restricted stock units were excluded from the calculation of diluted earnings per share as their effect would have been anti-dilutive.  Segment Reporting (Successor) . The Company (Predecessor) operated in only one industry segment which is the exploration and production of oil and natural gas. All of its operations are conducted in one geographic area of the United States and all of its revenues are derived from customers located in the United States. The Company (Successor) reports financial results under two reportable segments: (1) Exploration & Production and (2) Midstream. See Note 20 — Business Segment Information for financial information about our segments.  Recent Accounting Pronouncements  In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU 2014-09”), which seeks to provide a single, comprehensive revenue recognition model for all contracts with customers concerning the recognition, measurement and disclosure of revenue from those contracts. The revenue standard contains principles that an entity will apply to determine the measurement of revenue and timing of when it is recognized. Subsequent to the issuance of ASU 2014-09, the FASB issued various clarifications and interpretive guidance to assist entities with implementation efforts, including guidance pertaining to the presentation of revenues on a gross basis (revenues presented separately from associated expenses) versus a net basis. ASU 2014-09 and related interpretive guidance will be effective for interim and annual periods beginning after December 15, 2017, except for emerging growth companies that elect to use the extended transition period for complying with any new or revised financial accounting standards pursuant to Section 7(a)(2)(b) of the Securities Act. The standard allows for either full retrospective adoption, meaning the standard is applied to all periods presented in the financial statements, or modified retrospective adoption, meaning the standard is applied only to the most current period presented. AMR is an emerging growth company. As an emerging growth company, we have elected to use the extended transition period a

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	3 Months Ended
	Mar. 31, 2018
Supplemental Cash Flow Information [Abstract]
Supplemental Cash Flow Information	NOTE 3 — SUPPLEMENTAL CASH FLOW INFORMATION  Supplemental cash flow disclosures and non-cash investing and financing activities are presented below (in thousands):      Successor Predecessor  February 9, 2018 January 1, 2018 Three  Through Through Months Ended  March 31, 2018 February 8, 2018 March 31, 2017   Supplemental cash flow information:  Cash paid for interest $ 1,092 $ 1,145 $ 1,162  Non-cash investing and financing activities:  Change in asset retirement obligations 421 — 296  Change in accruals or liabilities for capital expenditures (36,866) 4,712 21,111  Distribution of non-STACK assets (net liability) — 33,102 —  Equity issued in Business Combination 2,058,635 — —

Business Combination

Business Combination	3 Months Ended
	Mar. 31, 2018
Business Combination [Abstract]
Business Combination	NOTE 4 — BUSINESS COMBINATION (Successor)  As discussed in Note 1, on February 9, 2018, we consummated the Transactions contemplated by the AM Contribution Agreement and Kingfisher Contribution Agreement.  Pursuant to the AM Contribution Agreement and Kingfisher Contribution Agreement, SRII Opco acquired (a) (i) all of the limited partner interests in Alta Mesa and (ii) 100% of the economic interests and 90% of the voting interests in Alta Mesa and (b) 100% of the economic interests in Kingfisher.  At the closing of the Business Combination, · The Company issued 40,000,000 shares of Class A Common Stock and warrants to purchase 13,333,333 shares of Class A Common Stock to Riverstone VI SR II Holdings, L.P. (“ Fund VI Holdings ”) pursuant to the terms of that certain Forward Purchase Agreement, dated as of March 17, 2017 (the “ Forward Purchase Agreement ”) for cash proceeds of $400 million to us; · The Company contributed $1,406 million in cash (the proceeds of the Forward Purchase Agreement and the net proceeds (after redemptions) of the Trust Account) to SRII Opco, in exchange for (i) 169,371,730 of the common units (approximately 44.2% ) representing limited partner interests (the “ SRII Opco Common Units ”) in SRII Opco issued to us and (ii) 62,966,666 warrants to purchase SRII Opco Common Units (“ SRII Opco Warrants ”) issued to us; · The Company caused SRII Opco to issue 213,402,398 SRII Opco Common Units (approximately 55.8% ) to the Contributors in exchange for the ownership interests in Alta Mesa, Alta Mesa GP and Kingfisher contributed to SRII Opco by the Contributors; · The Company agreed to cause SRII Opco to issue up to 59,871,031 SRII Opco Common Units to the AM Contributor and the KFM Contributor if the earn-out consideration provided for in the Contribution Agreements is earned by the AM Contributor or the KFM Contributor pursuant to the terms of the Contribution Agreements ; · The Company issued to each of the Contributors a number of shares of Class C common stock, par value $0.0001 per share (the “ Class C Common Stock ”), equal to the number of the SRII Opco Common Units received by such Contributor at the closing; · SRII Opco distributed to the KFM Contributor cash in the amount of approximately $814.8 million in partial payment for the ownership interests in Kingfisher contributed by the KFM Contributor; and · SRII Opco entered into an amended and restated voting agreement with the owners of the remaining 10% voting interests in Alta Mesa GP whereby such other owners agreed to vote their interests in Alta Mesa GP as directed by SRII Opco . Holders of AMR’s Class C Common Stock, together with holders of Class A Common Stock, voting as a single class, have the right to vote on all matters properly submitted to a vote of the stockholders, but holders of Class C Common Stock are not entitled to any dividends or liquidating distributions from us. After a specified period of time after Closing, the Contributors will generally have the right to cause SRII Opco to redeem all or a portion of their SRII Opco Common Units in exchange for shares of our Class A Common Stock or, at SRII Opco’s option, an equivalent amount of cash. However, we may, at our option, effect a direct exchange of cash or Class A Common Stock for such SRII Opco Common Units in lieu of such a redemption by SRII Opco. Upon the future redemption or exchange of SRII Opco Common Units held by a Contributor, a corresponding number of shares of Class C Common Stock will be cancelled.  Pursuant to the AM Contribution Agreement and the KFM Contribution Agreement, for a period of seven years following the closing, the Alta Mesa Contributor and the Kingfisher Contributor may be entitled to receive additional SRII Opco Common Units (and acquire a corresponding number of shares of AMR’s Class C Common Stock) as earn-out consideration if the 20 -day volume-weighted average price (“20-Day VWAP”) of AMR’s Class A Common Stock equals or exceeds the following prices (each such payment, an “Earn-Out Payment”):      Earn-Out Consideration Payable to Earn-Out Consideration Payable to  20-Day VWAP AM Contributor KFM Contributor  $ 14.00 10,714,285 SRII Opco Common Units 7,142,857 SRII Opco Common Units  $ 16.00 9,375,000 SRII Opco Common Units 6,250,000 SRII Opco Common Units  $ 18.00 13,888,889 SRII Opco Common Units —  $ 20.00 12,500,000 SRII Opco Common Units —   Neither the AM Contributor nor the KFM Contributor will be entitled to receive a particular Earn-Out Payment on more than one occasion and, if, on a particular date, the 20-Day VWAP entitles the AM Contributor or the KFM Contributor to more than one Earn-Out Payment (each of which has not been previously paid), the AM Contributor and/or the KFM Contributor will be entitled to receive each such Earn-Out Payment. The AM Contributor and the KFM Contributor will be entitled to the earn-out consideration described above in connection with certain liquidity events of the Company, including a merger or sale of all or substantially all of our assets, if the consideration paid to holders of Class A Common Stock in connection with such liquidity event is greater than any of the above-specified 20-Day VWAP hurdles.  We also contributed $560 million in net cash to Alta Mesa at the closing. Our source for these funds was from the sale of our securities to investors in a public offering and in private placements. Alta Mesa used a portion of the amount to repay its outstanding balance under its Alta Mesa Credit Facility described in Note 11 .  Pursuant to the Contribution Agreements, the AM Contributor and KFM Contributor delivered a final closing statement. Subsequent to quarter end, it was determined that the AM Contributor would receive a positive adjustment amount and be issued 1,197,934 additional SRII Opco Common Units and an equivalent number of shares of our Class C Common Stock and the KFM Contributor would remit back to the Company a negative adjustment of $5.0 million in cash and 89,680 SRII Opco Common Units and an equivalent number of shares of our Class C Common Stock.  The Business Combination has been accounted for using the acquisition method. The acquisition method of accounting is based on FASB ASC 805, Business Combination (“ASC 805”), and uses the fair value concepts defined in FASB ASC 820, Fair Value Measurements ("ASC 820"). ASC 805 requires, among other things, that the assets acquired and liabilities assumed be recognized at their fair values as of the acquisition date by the Company.  Preliminary Estimated Purchase Price for Alta Mesa  The preliminary estimated purchase price consideration for Alta Mesa is as follows (in thousands):      At February 9,  2018  Preliminary Purchase Consideration: (1)  SRII Opco Common Units ( 158,402,398 valued at $7.90 per unit) (2) $ 1,251,782  Estimated fair value of contingent earn-out purchase consideration (3) 284,109  Settlement of preexisting working capital (4) 5,476  Total purchase price consideration $ 1,541,367 _________________ (1) The preliminary purchase price consideration is for 100% of the limited partner interests in Alta Mesa and 100% of the economic interests and 90% of the voting interests in AMH GP. The preliminary purchase price consideration does not include the effects of the final closing statement adjustments, which adjustments were determined subsequent to March 31, 2018. (2) At closing , the Riverstone Contributor received consideration of 20,000,000 SRII Opco Common Units and the AM Contributor received consideration of 138,402,398 SRII Opco Common Units. The estimated fair value of an SRII Opco Common Unit was $7.90 per unit and reflects discounts for holding requirements and liquidity. (3) For a period of seven years following Closing, the AM Contributor will be entitled to receive earn- out consideration to be paid in the form of SRII Opco Common Units (and a corresponding number of shares of Class C Common Stock) if the 20 -day VWAP of our Class A Common Stock equals or exceeds the specified prices pursuant to the AM Contribution Agreement. Pursuant to ASC 805 and ASC 480, Distinguishing Liabilities from Equity (“ASC 480”), we have determined that the fair value of the earn-out consideration was approximately $284.1 million, which was classified as equity. The fair value of the contingent equity earn-out consideration was determined using the Monte Carlo simulation valuation method based on Level 3 inputs using the fair value hierarchy. The key inputs included the listed market price for Class A Common Stock, market volatility of a peer group of companies similar to the Company (due to the lack of trading activity in the Class A Common Stock), no dividend yield, an expected life of each earn-out threshold based on the remaining contractual term of the contingent liability earn-out period and a risk-free rate based on U.S. dollars overnight indexed swaps with a maturity equivalent to the earn-out’s expected life. (4) Settlement of preexisting working capital between Alta Mesa and Kingfisher. Preliminary Estimated Purchase Price Allocation for Alta Mesa  The following table summarizes the allocation of the preliminary estimate of the purchase consideration to the assets acquired and liabilities assumed in connection with the acquisition of Alta Mesa in the Business Combination. The allocation is as follows (in thousands):      At February 9,  2018  Estimated Fair Value of Assets Acquired (1)  Cash, cash equivalents and short term restricted cash $ 10,345  Accounts Receivable 101,745  Other Receivables 1,222  Receivables due from related party 907  Prepaid expenses and other current assets 1,405  Derivative financial instruments 352  Property and equipment: (2)  Oil and natural gas properties, successful efforts 2,314,858  Other property and equipment, net 43,318  Notes receivable due from related party 12,454  Deposits and other long-term assets 10,286  Total fair value of assets acquired 2,496,892  Estimated Fair Value of Liabilities Assumed (1)  Accounts payable and accrued liabilities 210,867  Advances from non-operators 6,803  Advances from related party 47,506  Asset retirement obligations 5,998  Derivative financial instruments 11,585  Long-term debt (3) 667,700  Other long-term liabilities 5,066  Total fair value of liabilities assumed 955,525  Total consideration and fair value $ 1,541,367 _________________ (1) The preliminary purchase price is allocated based on Alta Mesa’s STACK Assets. (2) The fair value measurements of oil and natural gas properties and asset retirement obligations are based on inputs that are not observable in the market and therefore represent Level 3 inputs. The fair values of oil and natural gas properties and asset retirement obligations were measured using valuation techniques that convert future cash flows to a single discounted amount. Significant inputs to the valuation of oil and natural gas properties include, but are not limited to recoverable reserves, production rates, future operating and development costs, future commodity prices, appropriate risk-adjusted discounts rates, and other relevant data. These inputs required significant judgments and estimates by management at the time of the valuation and are the most sensitive and may be subject to change. (3) Represents the approximate fair value of Alta Mesa’s $500 million aggregate principal amount of the 7.875% senior unsecured notes due December 15, 2024 using Level 1 inputs as of the acquisition date of approximately $533.6 million, and outstanding borrowings under the Alta Mesa Credit Facility (described in Note 11) of $134 .0 million as of the acquisition date.  Preliminary Estimated Purchase Price for Kingfisher  The estimated purchase consideration paid for Kingfisher is as follows (in thousands):      At February 9,  2018  Preliminary Purchase Consideration:  Cash (1) $ 814,820  SRII Opco Common Units ( 55,000,000 valued at $7.90 per unit) (2) 434,640  Estimated fair value of contingent earn-out purchase consideration (3) 88,105  Settlement of preexisting working capital (4) (5,476)  Total purchase price consideration $ 1,332,089 _________________ (1) The cash consideration after estimated adjustments to net working capital, debt, transaction expenses, capital expenditures and banking fees was $814.8 million. (2) At closing, KFM Contributor received consideration of 55,000,000 SRII Opco Common Units. At closing, the estimated fair value of an SRII Opco Common Unit was assumed to be $7.90 per unit and reflects discounts for holding requirements and liquidity. (3) Pursuant to ASC 805 and ASC 480, the Kingfisher earn-out consideration has been valued at fair value as of the Closing Date and has been classified in stockholders’ equity. The fair value of the contingent equity earn-out consideration was determined using the Monte Carlo simulation valuation method based on Level 3 inputs using the fair value hierarchy. The key inputs included the quoted market price for the Company’s Class A Common Stock, market volatility of a peer group of companies similar to the Company (due to the lack of trading activity in the Company’s Class A Common Stock), no dividend yield, an expected life of each earn-out threshold based on the remaining contractual term of the contingent liability earn-out period and a risk-free rate based on U.S. Dollars overnight indexed swaps with a maturity equivalent to the earn-out’s expected life. (4) Settlement of preexisting working capital between Alta Mesa and Kingfisher.  Preliminary Estimated Purchase Price Allocation for Kingfisher The following table summarizes the allocation of the preliminary estimate of the purchase consideration to the assets acquired and liabilities assumed in connection with the acquisition of Kingfisher in the Business Combination. The allocation is as follows (in thousands):      At February 9,  2018  Estimated Fair Value of Assets Acquired  Cash and cash equivalents $ 7,648  Accounts Receivable 4,334  Prepaid expenses 550  Property, plant and equipment: (1)  Pipeline 272,442  Other property, plant and equipment 519  Intangible assets (2) 472,432  Goodwill (3) 650,663  Total fair value of assets acquired 1,408,588  Estimated Fair Value of Liabilities Assumed  Accounts payable and accrued liabilities 33,499  Long-term debt 43,000  Total fair value of liabilities assumed 76,499  Total consideration and fair value $ 1,332,089 _________________ (1) The fair value measurements of crude oil, natural gas and NGL gathering, processing and storage assets are based on inputs that are not observable in the market and therefore represent Level 3 inputs. The fair values of gathering, processing and storage assets were measured using valuation techniques that convert future cash flows to a single discounted amount. These valuations required significant judgments and estimates made by management based on assumptions believed to be reasonable at the time of the valuation, but which are inherently uncertain. The estimates and assumptions are sensitive and may be subject to change. (2) The identifiable intangible assets acquired are primarily related to customer relationships held by Kingfisher prior to Closing. The intangible assets acquired were based upon the estimated fair value as of the acquisition date. The intangible assets have definite lives and are subject to amortization over their economic lives, currently ranging from approximately 10 - 15 years. (3) Goodwill is measured as the excess of the total purchase consideration over the net acquisition date fair value of the assets acquired and liabilities assumed. Goodwill will not be amortized but will be tested for impairment at least annually or whenever certain indicators of impairment are present. If, in the future, it is determined that goodwill is impaired, an impairment charge would be recorded at that time. The factors that make up the goodwill reflected in the preliminary purchase price allocation include expected synergies, including future cost efficiencies with continual flow of activity of Alta Mesa production into the Kingfisher processing facility as the basin expands, as well as other benefits that are expected to be generated.  Unaudited Pro Forma Operating Results  The following unaudited pro forma combined financial information has been prepared as if the Business Combination and other related transactions had taken place on January 1, 2017. The unaudited pro forma consolidated financial information has been prepared using the acquisition method of accounting in accordance with GAAP.  The information reflects pro forma adjustments based on available information and certain assumptions that the Company believes are reasonable, including depletion of Alta Mesa’s fair-valued proved oil and gas properties, and the estimated tax impacts of the pro forma adjustments. Additionally, pro forma earnings for the 2018 Predecessor Period and the 2017 Predecessor Period, were adjusted to exclude $65.2 million of transaction-related costs incurred by Alta Mesa. These costs are not included as they are directly related to the Business Combination and are nonrecurring.  The pro forma combined financial information has been included for comparative purposes and is not necessarily indicative of the results that might have actually occurred had the Business Combination taken place on January 1, 2017; furthermore, the financial information is not intended to be a projection of future results.     Three Months Ended Three Months Ended  March 31, 2018 March 31, 2017  (in thousands)  Total operating revenues $ 112,037 $ 75,452  Net income (loss) (12,100) 25,265  Net income (loss) attributable to Alta Mesa Resources, Inc. (5,281) 8,218   Basic and diluted net income (loss) per share $ (0.03) $ 0.05

Property And Equipment

Property And Equipment	3 Months Ended
	Mar. 31, 2018
Property And Equipment [Abstract]
Property And Equipment	NOTE 5 — PROPERTY, PLANT AND EQUIPMENT  Property and equipment consists of the following (in thousands):    Successor Predecessor  March 31, December 31,  2018 2017    OIL AND NATURAL GAS PROPERTIES  Unproved properties $ 899,465 $ 84,590  Accumulated impairment of unproved properties — —  Unproved properties, net 899,465 84,590  Proved oil and natural gas properties 1,500,830 1,092,095  Accumulated depreciation, depletion, amortization and impairment (10,773) (256,122)  Proved oil and natural gas properties, net 1,490,057 835,973  TOTAL OIL AND NATURAL GAS PROPERTIES, net 2,389,522 920,563  OTHER PROPERTY AND EQUIPMENT  Land 4,954 2,912  Salt water disposal system 42,113 —  Plant and equipment 275,361 —  Office furniture and equipment, vehicles 979 20,008  Accumulated depreciation (1,285) (16,713)  OTHER PROPERTY AND EQUIPMENT, net 322,122 6,207  TOTAL PROPERTY, PLANT AND EQUIPMENT, net $ 2,711,644 $ 926,770

Discontinued Operations

Discontinued Operations	3 Months Ended
	Mar. 31, 2018
Discontinued Operations [Abstract]
Discontinued Operations	NOTE 6 — DISCONTINUED OPERATIONS (Predecessor)  As discussed in Note 1, Alta Mesa distributed the remainder of its non-STACK assets and related liabilities to the AM Contributor in connection with the closing of the Business Combination. The distribution of Alta Mesa’s remaining non-STACK assets and related liabilities during the first quarter of 2018 and the sale of Alta Mesa’s Weeks Island field during the fourth quarter of 2017 were part of Alta Mesa’s overall strategic shift to operate only in the eastern Anadarko Basin. As a result, the Predecessor’s non-STACK assets and liabilities have been presented as discontinued operations in the consolidated balance sheets. The operating results directly related to non-STACK assets and liabilities have been segregated and presented as discontinued operations within the consolidated financial statements in the 2018 Predecessor Period and the 2017 Predecessor Period. Prior to the Business Combination, Alta Mesa had notes payable to its founder (“Founder Notes”) that bear simple interest at 10% . In connection with the Transactions described in Note 1, the Founder Notes were converted into equity interest in the AM Contributor immediately prior to the closing of the Business Combination as they were considered part of the non-STACK asset distribution. The balance of the Founder Notes at the time of conversion was approximately $28.3 million including accrued interest. Interest on the Founder Notes was $0.1 million for the 2018 Predecessor Period and $0.3 million for the 2017 Predecessor Period.  The assets and liabilities directly related to the non-STACK assets have been reclassified to assets and liabilities associated with discontinued operations as follows (in thousands):     Predecessor  December 31,  2017   Assets associated with discontinued operations:  Current assets  Cash $ 61  Accounts receivable 4,980  Other receivables 154  Total current assets 5,195  Noncurrent assets  Investments in LLC - Cost 9,000  Proved oil and natural gas properties, net 15,408  Unproved properties, net 15,504  Land 2,706  Other long-term assets 1,167  Total noncurrent assets 43,785  Total assets associated with discontinued operations $ 48,980   Liabilities associated with discontinued operations:  Current liabilities  Accounts payable and accrued liabilities $ 7,882  Asset retirement obligations 7,537  Total current liabilities 15,419  Noncurrent liabilities  Asset retirement obligations, net of current 37,049  Founder's note 28,166  Other long-term liabilities 1,647  Total noncurrent liabilities 66,862  Total liabilities associated with discontinued operations $ 82,281  The results of operations of the non-STACK assets and other items directly related to the sale of the non-STACK assets have been reclassified in discontinued operations as follows (in thousands):     Predecessor  January 1, 2018 Three  Through Months Ended  February 8, 2018 March 31, 2017   Loss from Discontinued Operations  Operating revenues and other:  Oil $ 1,617 $ 12,405  Natural gas 1,023 3,094  Natural gas liquids 236 547  Other revenues 16 116  Total operating revenues 2,892 16,162  Loss on sale of assets (1,923) —  Total operating revenues and other 969 16,162  Operating expenses:  Lease operating expenses 1,770 7,960  Marketing and transportation 83 381  Production and ad valorem taxes 167 1,802  Workover expense 127 795  Exploration expense — 3,095  Depreciation, depletion and amortization expense 630 5,826  Impairment 5,560 32  Accretion 101 476  General and administrative expense 21 12  Total operating expenses 8,459 20,379  Interest expense (103) (298)  Loss from discontinued operations, net of state income taxes $ (7,593) $ (4,515)  The total operating and investing cash flows of the non-STACK assets are as follows (in thousands):      Predecessor  January 1, 2018 Three  Through Months Ended  February 8, 2018 March 31, 2017   Total operating cash flows of discontinued operations $ (6,838) $ 738  Total investing cash flows of discontinued operations (570) (910)

Fair Value Disclosures

Fair Value Disclosures	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Disclosures	NOTE 7 — FAIR VALUE DISCLOSURES  W e follow ASC 820, which provides a hierarchy of fair value measurements, based on the inputs to the fair value estimation process. It requires disclosure of fair values classified according to defined “levels,” which are based on the reliability of the evidence used to determine fair value, with Level 1 being the most reliable and Level 3 the least reliable. Level 1 evidence consists of observable inputs, such as quoted prices in an active market. Level 2 inputs typically correlate the fair value of the asset or liability to a similar, but not identical item which is actively traded. Level 3 inputs include at least some unobservable inputs, such as valuation models developed using the best information available in the circumstances. The fair value of cash, accounts receivable, other current assets, and current liabilities approximate book value due to their short-term nature. The estimate of fair value of long-term debt under our senior secured revolving credit facility is not considered to be materially different from carrying value due to market rates of interest. In connection with the Business Combination, we recorded the fair value of Alta Mesa’s $500 million unsecured senior notes at $533.6 million as of the acquisition date. We have estimated the fair value of the senior notes to be $520.6 million at March 31, 2018. This estimation is based on the most recent trading values of the senior notes at or near the reporting date, which is a Level 1 determination. See Note 11 — Long-Term Debt, Net for information on long-term debt.  We utilize the modified Black-Scholes and the Turnbull Wakeman option pricing models to estimate the fair values of oil, natural gas and natural gas liquids derivative contracts. Inputs to these models include observable inputs from the New York Mercantile Exchange (“NYMEX”) for futures contracts, and inputs derived from NYMEX observable inputs, such as implied volatility of oil, natural gas and natural gas liquids prices. We have classified the fair values of all our oil, natural gas and natural gas liquids derivative contracts as Level 2.  Oil and natural gas properties are subject to impairment testing and potential impairment write down. Oil and natural gas properties with a carrying amount of $3.3 million were written down to their fair value of $2.1 million, resulting in an impairment charge of $1.2 million for the 2017 Predecessor Period. S ignificant Level 3 assumptions used in the calculation of estimated discounted cash flows in the impairment analysis included our estimate of future oil and natural gas prices, production costs, development expenditures, estimated timing of production of proved reserves, appropriate risk-adjusted discount rates, and other relevant data.  New additions to asset retirement obligations result from estimations for new or acquired properties, and fair values for them are categorized as Level 3. Such estimations are based on present value techniques that utilize company-specific information for such inputs as cost and timing of plugging and abandonment of wells and facilities. We recorded $0.4 million, zero and $0.3 million in additions to asset retirement obligations measured at fair value during the Successor Period, the 2018 Predecessor Period, and the 2017 Predecessor Period, respectively.  The following table presents information about our financial assets and liabilities measured at fair value on a recurring basis as of March 31, 2018 and December 31, 2017, and indicates the fair value hierarchy of the valuation techniques we utilized to determine such fair value:      Level 1 Level 2 Level 3 Total  (in thousands)  At March 31, 2018: (Successor)  Financial Assets:  Derivative contracts for oil and natural gas — $ 4,481 — $ 4,481  Financial Liabilities:  Derivative contracts for oil and natural gas — $ 33,749 — $ 33,749  At December 31, 2017: (Predecessor)  Financial Assets:  Derivative contracts for oil and natural gas — $ 4,416 — $ 4,416  Financial Liabilities:  Derivative contracts for oil and natural gas — $ 24,609 — $ 24,609 The amounts above are presented on a gross basis. Presentation on our consolidated balance sheets utilizes netting of assets and liabilities with the same counterparty where master netting agreements are in place. For additional information on derivative contracts, see Note 8 — Derivative Financial Instruments . 

Derivative Financial Instrument

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2018
Derivative Financial Instruments [Abstract]
Derivative Financial Instruments	NOTE 8 — DERIVATIVE FINANCIAL INSTRUMENTS  We account for our derivative contracts under the provisions of ASC 815. We have entered into forward-swap contracts and collar contracts to reduce our exposure to price risk in the spot market for oil, natural gas and natural gas liquids. From time to time, we also utilize financial basis swap contracts, which address the price differential between market-wide benchmark prices and other benchmark pricing referenced in certain of our oil, natural gas and natural gas liquids sales contracts. Substantially all of our hedging agreements are executed by affiliates of our lenders under the Alta Mesa Credit Facility described in Note 11, and are collateralized by the security interests of the respective affiliated lenders in certain of our assets under the Alta Mesa Credit Facility. The contracts settle monthly and are scheduled to coincide with oil production equivalent to barrels (Bbl) per month, natural gas production equivalent to volumes in millions of British thermal units (MMBtu) per month, and natural gas liquids production to volumes in gallons (Gal) per month . The contracts represent agreements between us and the counterparties to exchange cash based on a designated price, or in the case of financial basis hedging contracts, based on a designated price differential between various benchmark prices. Cash settlement occurs monthly. No derivative contracts have been entered into for trading or speculative purposes.  From time to time, we enter into interest rate swap agreements with financial institutions to mitigate the risk of loss due to changes in interest rates.  We have not designated any of our derivative contracts as fair value or cash flow hedges. Accordingly, we use mark-to-market accounting, recognizing changes in the fair value of derivative contracts in the consolidated statements of operations at each reporting date.  Derivative contracts are subject to master netting arrangements and are presented on a net basis in the consolidated balance sheets. This netting can cause derivative assets to be ultimately presented in a liability account on the consolidated balance sheets. Likewise, derivative liabilities could be presented in a derivative asset account.  The following table summarizes the fair value and classification of our derivative instruments, none of which have been designated as hedging instruments under ASC 815:  Fair Values of Derivative Contracts:     Successor  March 31, 2018  Net Fair  Gross Gross amounts Value of Assets  Fair Value offset against assets presented in  Balance sheet location of Assets in the Balance Sheet the Balance Sheet   (in thousands)  Derivative financial instruments, current assets $ 1,539 $ (1,539) $ —  Derivative financial instruments, long-term assets 2,942 (2,893) 49  Total $ 4,481 $ (4,432) $ 49      Net Fair  Gross Gross amounts Value of Liabilities  Fair Value offset against liabilities presented in  Balance sheet location of Liabilities in the Balance Sheet the Balance Sheet   (in thousands)  Derivative financial instruments, current liabilities $ 27,940 $ (1,539) $ 26,401  Derivative financial instruments, long-term liabilities 5,809 (2,893) 2,916  Total $ 33,749 $ (4,432) $ 29,317      Predecessor  December 31, 2017  Net Fair  Gross Gross amounts Value of Assets  Fair Value offset against assets presented in  Balance sheet location of Assets in the Balance Sheet the Balance Sheet  (in thousands)  Derivative financial instruments, current assets $ 1,406 $ (1,190) $ 216  Derivative financial instruments, long-term assets 3,010 (3,002) 8  Total $ 4,416 $ (4,192) $ 224      Net Fair  Gross Gross amounts Value of Liabilities  Fair Value offset against liabilities presented in  Balance sheet location of Liabilities in the Balance Sheet the Balance Sheet  (in thousands)  Derivative financial instruments, current liabilities $ 20,493 $ (1,190) $ 19,303  Derivative financial instruments, long-term liabilities 4,116 (3,002) 1,114  Total $ 24,609 $ (4,192) $ 20,417  The following table summarizes the effect of our derivative instruments in the consolidated statements of operations:      Successor Predecessor  Derivatives not February 9, 2018 January 1, 2018 Three  designated as hedging Through Through Months Ended  instruments under ASC 815 March 31, 2018 February 8, 2018 March 31, 2017  (in thousands)  Gain (loss) on derivative contracts  Oil commodity contracts $ (22,579) $ 5,431 $ 26,085   Natural gas commodity contracts (67) 1,867 3,899   Natural gas liquids commodity contracts — — 258  Total gain (loss) on derivative contracts $ (22,646) $ 7,298 $ 30,242  Although our counterparties provide no collateral, the master derivative agreements with each counterparty effectively allow us, so long as we are not a defaulting party, after a default or the occurrence of a termination event, to set-off an unpaid hedging agreement receivable against the interest of the counterparty in any outstanding balance under the Alta Mesa Credit Facility described in Note 11— Long Term Debt, net.  If a counterparty were to default in payment of an obligation under the master derivative agreements, we could be exposed to commodity price fluctuations, and the protection intended by the hedge could be lost. The value of our derivative financial instruments would be impacted.  We had the following open derivative contracts for crude oil at March 31, 2018:  OIL DERIVATIVE CONTRACTS       Volume Weighted Range  Period and Type of Contract in Bbls Average High Low  2018  Price Swap Contracts 1,832,000 $ 53.22 $ 61.26 $ 50.27  Collar Contracts  Short Call Options 1,559,000 61.09 64.60 60.50  Long Put Options 1,559,000 51.18 60.00 50.00  Short Put Options 1,559,000 41.48 52.50 40.00  2019  Collar Contracts  Short Call Options 1,788,500 61.84 65.35 56.50  Long Put Options 1,971,000 50.00 50.00 50.00  Short Put Options 1,971,000 38.43 40.00 37.50  2020  Collar Contracts  Short Call Options 183,000 60.20 60.20 60.20  Long Put Options 549,000 50.67 51.00 50.00  Short Put Options 549,000 40.00 40.00 40.00  We had the following open derivative contracts for natural gas at March 31, 2018:  NATURAL GAS DERIVATIVE CONTRACTS      Volume in Weighted Range  Period and Type of Contract MMBtu Average High Low  2018  Price Swap Contracts 4,280,000 $ 2.80 $ 2.85 $ 2.75  Collar Contracts  Short Call Options 1,985,000 3.30 3.75 3.14  Long Put Options 1,680,000 2.82 2.90 2.75  Short Put Options 610,000 2.40 2.40 2.40  2019  Collar Contracts  Short Call Options 1,350,000 3.47 3.75 3.30  Long Put Options 900,000 2.90 2.90 2.90  Short Put Options 900,000 2.40 2.40 2.40  In those instances where contracts are identical as to time period, volume and strike price, and counterparty, but opposite as to direction (long and short), the volumes and average prices have been netted in the two tables above. Prices stated in the table above for oil may settle against either the NYMEX index or may reflect a mix of positions settling on various combinations of these benchmarks.  We had the following open financial basis swaps at March 31, 2018:  NATURAL GAS BASIS SWAP DERIVATIVE CONTRACTS      Weighted  Average Spread  Volume in MMBtu (1) Reference Price 1 (1) Reference Price 2 (1) Period ($ per MMBtu)  152,500 WAHA NYMEX Henry Hub Nov '18 — Dec '18 $ (1.05)  225,000 WAHA NYMEX Henry Hub Jan '19 — Mar '19 (1.05) _________________ (1) Represents short swaps that fix the basis differentials between WAHA and NYMEX Henry Hub.  OIL BASIS SWAP DERIVATIVE CONTRACTS      Weighted  Average Spread  Volume in Bbl (1) Reference Price 1 (1) Reference Price 2 (1) Period ($ per Bbl)  1,104,000 CMA Oil WTI July '18 — Dec '18 $ (0.54) _________________ (1) Represents basis swaps for the NYMEX CMA (Calendar Monthly Average) Roll that reconcile the trade month versus the delivery month for physical contract pricing.

Intangible Assets

Intangible Assets	3 Months Ended
	Mar. 31, 2018
Intangible Assets [Abstract]
Intangible Assets	NOTE 9 — INTANGIBLE ASSETS  Our intangible assets with finite lives include customer relationships within the midstream segment. Intangible assets consist of the following as of March 31, 2018 (in thousands):      March 31, 2018  Customer Relationships $ 472,432  Accumulated amortization (3,519)  Intangibles, net $ 468,913  Weighted average amortization (years) 12  Amortization expense was $3.5 million for the Successor Period. There was no amortization expense for the 2018 Predecessor Period and the 2017 Predecessor Period. Estimated amortization expense for each of the subsequent five years and thereafter is as follows (in thousands):     Fiscal Year: March 31, 2018  Remainder of 2018 $ 15,839  2019 35,170  2020 42,002  2021 41,222  2022 40,562  Thereafter 294,118  Total amortization $ 468,913  There were no intangible assets at December 31, 2017.

Asset Retirement Obligations

Asset Retirement Obligations	3 Months Ended
	Mar. 31, 2018
Asset Retirement Obligations [Abstract]
Asset Retirement Obligations	NOTE 10 — ASSET RETIREMENT OBLIGATIONS  A summary of the changes in asset retirement obligations is included in the table below (in thousands):    2018   Balance, as of January 1 (Predecessor) $ 10,469  Liabilities settled (63)  Revisions to estimates 63  Accretion expense 39  Balance, as of February 8 (Predecessor) 10,508   Balance, as of February 9 (Successor) $ —  Liabilities assumed from Business Combination 5,998  Liabilities incurred 421  Liabilities settled (166)  Revisions to estimates 300  Accretion expense 102  Balance, as of March 31 (Successor) 6,655  Less: Current portion 622  Long-term portion $ 6,033

Long Term Debt, Net

Long Term Debt, Net	3 Months Ended
	Mar. 31, 2018
Long Term Debt, Net [Abstract]
Long Term Debt, Net	NOTE 11 — LONG-TERM DEBT, NET  Long-term debt, net consists of the following (in thousands):     Successor Predecessor  March 31, December 31,  2018 2017   Alta Mesa senior secured revolving credit facility $ — $ 117,065  Kingfisher secured revolving credit facility 52,000 —  7.875% senior unsecured notes due 2024 500,000 500,000  Unamortized premium on senior unsecured notes 32,815 —  Unamortized deferred financing costs — (9,625)  Total long-term debt, net $ 584,815 $ 607,440  Alta Mesa Senior Secured Revolving Credit Facility . In connection with the consummation of the Business Combination, all indebtedness under the Alta Mesa senior secured revolving credit facility was repaid in full. On February 9, 2018 and in connection with the closing of the AM Contribution Agreement (as described in Note 1 — Description of Business ), Alta Mesa entered into the Eighth Amended and Restated Credit Agreement with Wells Fargo Bank, National Association, as the administrative agent (the “Alta Mesa Credit Facility”). The Alta Mesa Credit Facility is for an aggregate maximum credit amount of $1.0 billion with an initial $350.0 million borrowing base. In April 2018, the borrowing base was increased to $400.0 million until the next scheduled redetermination in October 2018. The Alta Mesa Credit Facility does not permit Alta Mesa to borrow funds if at the time of such borrowing it is not in compliance with the financial covenants set forth in the Alta Mesa Credit Facility. As of March 31, 2018, Alta Mesa has no borrowings under the Alta Mesa Credit Facility and has $13.6 million of outstanding letters of credit reimbursement obligations.  The principal amounts borrowed are payable on the maturity date of February 9, 2023. Alta Mesa has a choice of borrowing in Eurodollars or at the reference rate, with such borrowings bearing interest, payable quarterly for reference rate loans and one month, three month or six month periods for Eurodollar loans. Eurodollar loans bear interest at a rate per annum equal to the rate at the LIBOR, plus an applicable margin ranging from 2.00% and 3.00% . Reference rate loans bear interest at a rate per annum equal to the greater of (i) the agent bank’s reference rate, (ii) the federal funds effective rate plus 50 basis points and (iii) the rate for one month Eurodollar loans plus 1% , plus a margin ranging from 1.00% to 2.00% . The next scheduled redetermination of the borrowing base is in October 2018. The borrowing base may be reduced in connection with the next redetermination of its borrowing base. The amounts outstanding under Alta Mesa Credit Facility are secured by first priority liens on substantially all of Alta Mesa’s and its material operating subsidiaries’ oil and natural gas properties and associated assets and all of the equity of our material operating subsidiaries that are guarantors of the Alta Mesa Credit Facility. Additionally, SRII Opco and Alta Mesa GP have pledged their respective limited partner interests in Alta Mesa as security for its obligations. If an event of default occurs under the Alta Mesa Credit Facility, the administrative agent will have the right to proceed against the pledged capital stock and take control of substantially all of Alta Mesa’s assets and its material operating subsidiaries that are guarantors.  The Alta Mesa Credit Facility contains restrictive covenants that may limit Alta Mesa’s ability to, among other things, incur additional indebtedness, sell assets, guaranty or make loans to others, make investments, enter into mergers, make certain payments and distributions, enter into or be party to hedge agreements, amend organizational documents, incur liens and engage in certain other transactions without the prior consent of the lenders. The Alta Mesa Credit Facility permits Alta Mesa to make distributions to any parent entity (i) to pay for reimbursement of third party costs and expenses that are general and administrative expenses incurred in the ordinary course of business by such parent entity or (ii) in order to permit such parent entity to (x) make permitted tax distributions and (y) pay the obligations under the Tax Receivable Agreement. See Note 17 — Income Taxes for further information regarding the Tax Receivable Agreement. In addition, Alta Mesa can make restricted payments, so long as certain conditions are met, to any direct or indirect parent for the sole purpose of making a loan or capital contribution to Kingfisher in an amount up to $300 million until August 9, 2018.  The Alta Mesa Credit Facility also requires Alta Mesa to maintain the following two financial ratios: · a current ratio, tested quarterly, commencing within the fiscal quarter ending June 30, 2018, of Alta Mesa’s consolidated current assets to its consolidated current liabilities of not less than 1.0 to 1.0 as of the end of each fiscal quarter; and · a leverage ratio, tested quarterly, commencing with the fiscal quarter ending June 30, 2018, of Alta Mesa’s consolidated debt (other than obligations under hedge agreements) as of the end of such fiscal quarter to Alta Mesa’s consolidated earnings before interest, taxes, depreciation, depletion, amortization and exploration expenses (“EBITDAX”) annualized by multiplying EBITDAX for the period of (A) the fiscal quarter ending June 30, 2018 times 4, (B) the two fiscal quarter periods ending September 30, 2018 times 2, (C) the three fiscal quarter periods ending December 31, 2018 times 4/3rds and (D) for each fiscal quarter on or after March 31, 2019, EBITDAX times 4/4ths, of not greater than 4.0 to 1.0.  Alta Mesa will be required to maintain financial ratios commencing on the fiscal quarter ending June 30, 2018.  Senior Secured Revolving Credit Facility (Predecessor) . As of December 31, 2017, Alta Mesa had $117.1 million outstanding. At the date of the Business Combination, the outstanding balance under the credit facility was paid off.  Kingfisher Senior Secured Revolving Credit Facility . On August 8, 2017, Kingfisher entered into a $200 million revolving credit facility with a syndicate of lenders (the “Kingfisher Credit Facility”). The Kingfisher Credit Facility has a four -year term, with repayment due at maturity on August 8, 2021 . ABN AMRO Capital USA LLC acts as agent, initial letter of credit issuer, bookrunner and lead arranger. The Kingfisher Credit Facility includes a letter of credit sublimit of $20 million for the issuance of letters of credit. Kingfisher has the option to increase its borrowing capacity under its revolving credit facility by an amount not to exceed $50 million (for a total commitment of $250 million subject to certain conditions). Kingfisher’s revolving credit facility is available to fund capital expenditures, working capital, general corporate purposes and to finance approved acquisitions.  The Kingfisher Credit Facility is secured by substantially all of Kingfisher’s real property interests, pledged equity and intangibles. The applicable margins are dependent upon the Kingfisher’s leverage ratio, with the highest margins for Eurodollar Loans and Base Rate loans being 3.25% and 2.25% , respectively. The Kingfisher Credit Facility is subject to commitment fees ranging from 0.50% to 0.375% based on the leverage grid. Additionally the Kingfisher Credit Facility is subject to customary affirmative and negative covenants and events of default relating to Kingfisher.  As of March 31, 2018, the outstanding balance of the Kingfisher Credit Facility was $52.0 million.  Senior Unsecured Notes . Alta Mesa has $500 million in aggregate principal amount of 7.875% senior unsecured notes (the “senior notes”) due December 15, 2024 which were issued at par by Alta Mesa and its wholly owned subsidiary Alta Mesa Finance Services Corp. (collectively, the “Issuers”) during the fourth quarter of 2016. The senior notes were issued in a private placement but were exchanged for substantially identical registered senior notes in November 2017 .  The senior notes will mature on December 15, 2024, and interest is payable semi-annually on June 15 and December 15 of each year, beginning June 15, 2017. At any time prior to December 15, 2019, Alta Mesa may, from time to time, redeem up to 35% of the aggregate principal amount of the senior notes in an amount of cash not greater than the net cash proceeds from certain equity offerings at the redemption price of 107.875% of the principal amount, plus accrued and unpaid interest, if any, to the date of redemption, if at least 65% of the aggregate principal amount of the senior notes remains outstanding after such redemption and the redemption occurs within 120 days of the closing date of such equity offering. At any time prior to December 15, 2019, Alta Mesa may, on any one or more occasions, redeem all or part of the senior notes for cash at a redemption price equal to 100% of their principal amount of the senior notes redeemed plus an applicable make-whole premium and accrued and unpaid interest, if any, to the date of redemption. Upon the occurrence of certain kinds of change of control, each holder of the senior notes may require Alta Mesa to repurchase all or a portion of the senior notes for cash at a price equal to 101% of the aggregate principal amount of the senior notes, plus accrued and unpaid interest, if any, to the date of repurchase. On and after December 15, 2019, Alta Mesa may redeem the senior notes, in whole or in part, at redemption prices (expressed as percentages of principal amount) equal to 105.906% for the twelve-month period beginning on December 15, 2019, 103.938% for the twelve-month period beginning on December 15, 2020, 101.969% for the twelve-month period beginning on December 15, 2021 and 100.000% beginning on December 15, 2022, plus accrued and unpaid interest, if any, to the date of redemption.  The senior notes are fully and unconditionally guaranteed on a senior unsecured basis by each of Alta Mesa’s material subsidiaries, subject to certain customary release provisions. Accordingly, they will rank equal in right of payment to all of Alta Mesa existing and future senior indebtedness; senior in right of payment to all of Alta Mesa existing and future indebtedness that is expressly subordinated to the senior notes or the respective guarantees; effectively subordinated to all of Alta Mesa existing and future secured indebtedness to the extent of the value of the collateral securing such indebtedness, including amounts outstanding under the Alta Mesa Credit Facility; and structurally subordinated to all existing and future indebtedness and obligations of any of Alta Mesa subsidiaries that do not guarantee the senior notes.  The senior notes contain certain covenants limiting the Issuers’ ability and the ability of the Restricted Subsidiaries (as defined in the indenture governing the senior notes) to, under certain circumstances, prepay subordinated indebtedness, pay distributions, redeem stock or make certain restricted investments; incur indebtedness; create liens on the Issuers’ assets to secure debt; restrict dividends, distributions or other payments; enter into transactions with affiliates; designate subsidiaries as unrestricted subsidiaries; sell or otherwise transfer or dispose of assets, including equity interests of restricted subsidiaries; effect a consolidation or merger; and change Alta Mesa’s line of business.  Under the terms of the indenture for the senior notes, if Issuers experience certain specific change of control events, unless the Issuers have previously or concurrently exercised their right to redeem all of the senior notes under the optional redemption provision, such holder has the right to require Alta Mesa to purchase such holder’s senior notes at 101% of the principal amount plus accrued and unpaid interest to the date of purchase. The closing of the Business Combination did not constitute a change of control under the indenture governing the senior notes because certain existing owners of Alta Mesa and SRII Opco entered into an amended and restated voting agreement with respect to the voting interests in Alta Mesa GP. See Note 4 — Business Combination (Successor) to the consolidated financial statements for further detail.  The indenture contains customary events of default, including: · default in any payment of interest on the senior notes when due, continued for 30 days; · default in the payment of principal of or premium, if any, on the senior notes when due; · failure by the Issuers or any subsidiary guarantor to comply with its obligations under the indenture; · default under any mortgage, indenture or instrument under which there may be issued or by which there may be secured or evidenced any indebtedness for money borrowed by the Issuers or restricted subsidiaries; · certain events of bankruptcy, insolvency or reorganization of the Issuers or restricted subsidiaries; and · failure by the Issuers or certain subsidiaries that would constitute a payment of final judgment aggregating in excess of $20.0 million.  The Alta Mesa Credit Facility and the senior notes contain customary events of default. If an event of default occurs and is continuing, the holders of such indebtedness may elect to declare all the funds borrowed to be immediately due and payable with accrued and unpaid interest. Borrowings under other debt instruments that contain cross-acceleration or cross-default provisions may also be accelerated and become due and payable.  A s of March 31, 2018, we were in compliance with the indentures governing the senior notes.  Bond Premium (Successor) . As discussed in Note 6 , the fair value of the Alta Mesa senior notes as of the acquisition date was $533.6 million. The bond premium of $33.6 million is being amortized over the respective term of the Alta Mesa senior notes. The bond premium amortization recorded in the Successor Period was $0.8 million. The unamortized bond premium related to the senior notes are netted with long-term debt on the consolidated balance sheet as of March 31, 2018.  Maturities (Successor) . Future maturities of long-term debt, excluding unamortized bond premium, at March 31, 2018 are as follows:      (in thousands)  2019 $ —  2020 —  2021 52,000  2022 —  2023 500,000  Thereafter —  $ 552,000  Deferred financing costs . As of December 31, 2017, Alta Mesa had $11.4 million of unamortized deferred financing costs. As a result of the Business Combination, the 2018 Predecessor Period deferred financing costs have been adjusted to a fair value of zero at February 9, 2018. During the Successor Period, we incurred new deferred financing costs related to Alta Mesa’s Credit Facility of $1.0 million. Amortization expense of zero , $0.2 million and $1.0 million is included in interest expense on the consolidated statements of operations for the Successor Period, the 2018 Predecessor Period and the 2017 Predecessor Period, respectively.

Accounts Payable And Accrued Li

Accounts Payable And Accrued Liabilities	3 Months Ended
	Mar. 31, 2018
Accounts Payable And Accrued Liabilities [Abstract]
Accounts Payable And Accrued Liabilities	NOTE 12 — ACCOUNTS PAYABLE AND ACCRUED LIABILITIES  The following provides the details of accounts payable and accrued liabilities (in thousands):      Successor Predecessor  March 31, December 31,  2018 2017   Capital expenditures $ 50,117 $ 48,771  Revenues and royalties payable 31,861 29,514  Operating expenses/taxes 23,138 14,632  Interest 12,355 2,587  Derivative settlement payable 2,826 2,106  Other 540 4,301  Total accrued liabilities 120,837 101,911  Accounts payable 38,273 68,578  Accounts payable and accrued liabilities $ 159,110 $ 170,489

Commitments And Contingencies

Commitments And Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies [Abstract]
Commitments And Contingencies	NOTE 13 — COMMITMENTS AND CONTINGENCIES  Contingencies  Environmental claims. Various landowners have sued Alta Mesa in lawsuits concerning several fields in which Alta Mesa has or historically had operations. The lawsuits seek injunctive relief and other relief, including unspecified amounts in both actual and punitive damages for alleged breaches of mineral leases and alleged failure to restore the plaintiffs’ lands from alleged contamination and otherwise from its oil and natural gas operations. We are unable to express an opinion with respect to the likelihood of an unfavorable outcome of the various environmental claims or to estimate the amount or range of potential loss should the outcome be unfavorable. Therefore, we have not provided any material amounts for these claims in our condensed consolidated financial statements at March 31, 2018.  Title/lease disputes. Title and lease disputes may arise in the normal course of our operations. These disputes are usually small but could result in an increase or decrease in reserves and/or other forms of settlement, such as cash, once a final resolution to the title dispute is made.  Litigation (Predecessor). On April 13, 2005, Henry Sarpy and several other plaintiffs (collectively, “Plaintiffs”) filed a petition against Exxon, Extex, The Meridian Resource Corporation (“TMRC,” a former subsidiary of Alta Mesa), and the State of Louisiana for contamination of their land in the New Sarpy and/or Good Hope Field in St. Charles Parish. Plaintiffs claimed they are owners of land upon which oil field waste pits containing dangerous and contaminating substances are located. Plaintiffs alleged that they discovered in May 2004 that their property is contaminated with oil field wastes greater than represented by Exxon. The property was originally owned by Exxon and was sold to TMRC. TMRC subsequently sold the property to Extex. On April 14, 2015, TMRC entered into a Memorandum of Understanding with Exxon to settle the claims in this ongoing matter. On July 10, 2015, the settlement and comprised agreements were finalized and signed by the Plaintiffs and Exxon. On July 28, 2015, the State of Louisiana issued a letter of no objection to the settlement. In connection with the Business Combination, the liability was included in the distribution of our non-STACK assets to the AM contributor.  On January 25, 2017, Bollenbach Enterprises Limited Partnership filed a class action petition in Kingfisher County, Oklahoma against Alta Mesa and Oklahoma Energy Acquisitions, LP and Alta Mesa Services, LP, each a wholly owned subsidiary of Alta Mesa, (collectively, the “AMH Parties”) claiming royalty underpayment or non-payment of royalty. The suit alleges that the AMH Parties made improper post production deductions for midstream services that resulted in underpayment of royalties on natural gas and/or constituents of the gas stream produced from wells. The case was moved to federal court and stayed by the court pending the parties’ efforts to settle the case. In June 2017, the court administratively closed the case following mediation. As of December 31, 2017, Alta Mesa accrued approximately $4.7 million in accounts payable and accrued liabilities in its consolidated balance sheets and in general and administrative expense in its consolidated statements of operations in connection with this litigation. On March 12, 2018, the Class settlement was approved by the Court. During January 2018, approximately $4.7 million was paid to fund the settlement.  On March 1, 2017, Mustang Gas Products, LLC (“Mustang”) filed suit in the District Court of Kingfisher County, Oklahoma, against Oklahoma Energy Acquisitions, LP, and eight other entities, including certain of our affiliates and subsidiaries. Mustang alleges that (1) Mustang is a party to gas purchase agreements with Oklahoma Energy containing gas dedication covenants that burden land, leases and wells in Kingfisher County, Oklahoma, and (2) Oklahoma Energy, in concert with the other defendants, has wrongfully diverted gas sales to us in contravention of these agreements. Mustang asserts claims for declaratory judgment, anticipatory repudiation and breach of contract against Oklahoma Energy only. Mustang also claims tortious interference with contract, conspiracy, and unjust enrichment/constructive trust against all defendants. While we may incur costs or losses in connection with this litigation, we have not accrued a loss contingency because we are currently unable to determine the scope or merit of Mustang’s claim or to reasonably estimate an amount or range of such costs or losses. We believe that the allegations contained in this lawsuit are without merit and intend to vigorously defend ourselves.  Other contingencies. We are subject to legal proceedings, claims and liabilities arising in the ordinary course of business. The outcomes cannot be reasonably estimated; however, in the opinion of management, such litigation and claims will be resolved without material adverse effect on our financial position, results of operations or cash flows. Accruals for losses associated with litigation are made when losses are deemed probable and can be reasonably estimated.  Performance appreciation rights. In the third quarter of 2014, Alta Mesa adopted the Alta Mesa Holdings, LP Amended and Restated Performance Appreciation Rights Plan (the “Plan”), effective September 24, 2014. The Plan was intended to provide incentive compensation to key employees and consultants who make significant contributions to Alta Mesa. Under the Plan, participants were granted performance appreciation rights (“PARs”) with a stipulated initial designated value. The Business Combination described in Note 4 resulted in the accelerated vesting and payment of all outstanding PARs. The value of the PARs that vested upon closing of the Business Combination was approximately $10.6 million and was recorded in general and administrative expense in the 2018 Successor Period . Following the closing of the Business Combination, the Plan was terminated. Nonqualified Deferred Compensation : In 2013, Alta Mesa established a nonqualified deferred compensation plan, the Alta Mesa Holdings, L.P. Supplemental Executive Retirement Plan (the “Retirement Plan”). The Retirement Plan was intended to provide additional flexibility and tax planning advantages to our senior executives and other key highly compensated employees. In connection with Business Combination, we terminated the Retirement Plan resulting in approximately $9.4 million being recorded in general and administrative expense in the Successor Period.  Commitments  Office and Equipment Leases. We lease office space, as well as certain field equipment such as compressors, under long-term operating lease agreements. The lease for our main office will expire in 2022. Any initial rent-free months are amortized over the life of the lease. Equipment leases are generally for two years or less. Total rent expense, net of sublease income, including office space and compressors, were approximately $ 1.5 million, $ 1.1 million, and $ 2.6 million for the Successor Period, the 2018 Predecessor Period, and the 2017 Predecessor Period, respectively .  At March 31, 2018, the future minimum base rentals for non-cancelable operating leases are as follows :      (in thousands)  Remainder of 2018 $ 1,284  2019 1,545  2020 1,593  2021 1,620  2022 839  Thereafter 368  $ 7,249  Firm transportation contracts . The Company has entered into certain firm transportation contracts that extend through 2036. At March 31, 2018, the future minimum commitments related to these contracts are as follows:    (in thousands)  Remainder of 2018 $ 9,702  2019 10,976  2020 7,876  2021 7,876  2022 7,876  Thereafter 84,742  $ 129,048

Significant Risks And Uncertain

Significant Risks And Uncertainties	3 Months Ended
	Mar. 31, 2018
Significant Risks And Uncertainties [Abstract]
Significant Risks And Uncertainties	NOTE 14 — SIGNIFICANT RISKS AND UNCERTAINTIES  Our business makes us vulnerable to changes in wellhead prices of oil and natural gas. Historically, world-wide oil and natural gas prices and markets have been volatile, and may continue to be volatile in the future. Prices for oil and natural gas can fluctuate widely in response to relatively minor changes in the global and regional supply of and demand for oil and natural gas, as well as market uncertainty, economic conditions and a variety of additional factors. The duration and magnitude of changes in oil and natural gas prices cannot be predicted. Declines in oil and/or natural gas prices, or any other unfavorable market conditions could have a material adverse effect on our financial condition and on the carrying value of our proved oil and natural gas reserves. Low prices may also reduce our cash available for distribution, acquisitions and for servicing our indebtedness. We mitigate some of this vulnerability by entering into oil, natural gas and natural gas liquids price derivative contracts. See Note 8 — Derivative Financial Instruments for further details on derivatives.

Shareholders' Equity And Partne

Shareholders' Equity And Partners' Capital	3 Months Ended
	Mar. 31, 2018
Shareholders' Equity And Partners' Capital [Abstract]
Shareholders' Equity And Partners' Capital	NOTE 15 — SHAREHOLDERS’ EQUITY AND PARTNERS’ CAPITAL  Redeemable Preferred Stock and S hareholders’ Equity (Successor)  Class A Common Stock . Holders of our Class A Common Stock are entitled to one vote for each share held on all matters to be voted on by our stockholders. Holders of the Class A Common Stock and holders of the Class C Common Stock will vote together as a single class on all matters submitted to a vote of our stockholders, except as required by law. Unless specified in our certificate of incorporation (including any certificate of designation of preferred stock) or the Bylaws, or as required by applicable provisions of the Delaware General Corporation Law or applicable stock exchange rules, the affirmative vote of a majority of our shares of common stock that are voted is required to approve any such matter voted on by our stockholders. There is no cumulative voting with respect to the election of directors, with the result that the holders of more than 50% of the shares voted for the election of directors can elect all of the directors (subject to the right of the holders of our Series A Preferred Stock and Series B Preferred Stock to nominate and elect up to seven directors). Subject to the rights of the holders of any outstanding series of preferred stock, our stockholders are entitled to receive ratable dividends when, as and if declared by the board of directors out of funds legally available therefor.  In the event of a liquidation, dissolution or winding up of the Company, the holders of the Class A Common Stock are entitled to share ratably in all assets remaining available for distribution to them after payment of liabilities and after provision is made for each class of stock, if any, having preference over the Class A Common Stock. Our stockholders have no preemptive or other subscription rights. There are no sinking fund provisions applicable to the Class A Common Stock.  Class C Common Stock . In connection with the Business Combination, we issued 213,402,398 shares of Class C Common Stock to the Contributors which are outstanding as of March 31, 2018.  Holders of Class C Common Stock, together with holders of Class A Common Stock voting as a single class, will have the right to vote on all matters properly submitted to a vote of the stockholders. In addition, the holders of Class C Common Stock, voting as a separate class, will be entitled to approve any amendment, alteration or repeal of any provision of our certificate of incorporation that would alter or change the powers, preferences or relative, participating, optional or other or special rights of the Class C Common Stock. Holders of Class C Common Stock will not be entitled to any dividends from the Company and will not be entitled to receive any of our assets in the event of any voluntary or involuntary liquidation, dissolution or winding up of our affairs.  Shares of Class C Common Stock may be issued only to the Contributors, their respective successors and assigns, as well as any permitted transferees of the Contributors. A holder of Class C Common Stock may transfer shares of Class C Common Stock to any transferee (other than the Company) only if such holder also simultaneously transfers an equal number of such holder’s SRII Opco Common Units to such transferee in compliance with the amended and restated limited partnership agreement of SRII Opco. The Contributors generally have the right to cause SRII Opco to redeem all or a portion of their SRII Opco Common Units in exchange for shares of our Class A Common Stock or, at SRII Opco’s option, an equivalent amount of cash. The Company may, however, at its option, effect a direct exchange of cash or Class A Common Stock for such SRII Opco Common Units in lieu of such a redemption by SRII Opco. Upon the future redemption or exchange of SRII Opco Common Units held by a Contributor, a corresponding number of shares of Class C Common Stock will be cancelled.  Redeemable Series A Preferred Stock . As of March 31, 2018, Bayou City Energy Management LLC (“Bayou City”), HPS Investment Partners, LLC (“HPS”) and AM Equity Holdings, LP (“AM Management”) own the three outstanding shares of our Series A Preferred Stock, and may not transfer the Series A Preferred Stock or any rights, powers, preferences or privileges thereunder except to an affiliate. The holders of the Series A Preferred Stock are not entitled to vote on any matter on which stockholders generally are entitled to vote. In addition, the holders are not entitled to any dividends from the Company but will be entitled to receive, after payment or provision for debts and liabilities and prior to any distribution in respect of our Class A Common Stock or any other junior securities, liquidating distributions in an amount equal to $0.0001 per share of Series A Preferred Stock in the event of any voluntary or involuntary liquidation, dissolution or winding up of our affairs.  The Series A Preferred Stock is not convertible into any other security of the Company, but will be redeemable for the par value thereof by us upon the earlier to occur of (1) the fifth anniversary of the Closing Date, (2) the optional redemption of such Series A Preferred Stock at the election of the holder thereof or (3) upon a breach of the transfer restrictions described above. For so long as the Series A Preferred Stock remains outstanding, the holders of the Series A Preferred Stock will be entitled to nominate and elect directors to our board of directors for a period of five years following the closing of the Business Combination based on their and their affiliates’ beneficial ownership of Class A Common Stock.  Redeemable Series B Preferred Stock . As of March 31, 2018, the Riverstone Contributor owns the only outstanding share of our Series B Preferred Stock, and may not transfer the Series B Preferred Stock or any rights, powers, preferences or privileges thereunder except to an affiliate (as defined in the limited partnership agreement of SRII Opco). The holder of the Series B Preferred Stock is not entitled to vote on any matter on which stockholders generally are entitled to vote. In addition, the holder is not entitled to any dividends from the Company but will be entitled to receive, after payment or provision for debts and liabilities and prior to any distribution in respect of our Class A Common Stock or any other junior securities, liquidating distributions in an amount equal to $0.0001 per share of Series B Preferred Stock in the event of any voluntary or involuntary liquidation, dissolution or winding up of our affairs.  The Series B Preferred Stock is not convertible into any other security of the Company, but will be redeemable for the par value thereof by us upon the earlier to occur of (1) the fifth anniversary of the Closing Date, (2) the optional redemption of such Series B Preferred Stock at the election of the holder thereof or (3) upon a breach of the transfer restrictions described above. For so long as the Series B Preferred Stock remains outstanding, the holder of the Series B Preferred Stock will be entitled to nominate and elect directors to our board of directors for a period of five years following the closing of the Business Combination based on its and its affiliates’ beneficial ownership of Class A Common Stock.  Public Warrants . As of March 31, 2018, the Company had 62,966,666 warrants outstanding, consisting of 34,500,000 public warrants originally sold as part of the Units in the IPO (“Public Warrants”) and 13,333,333 Private Placement Warrants sold to the Company’s Sponsor in a private placement. Additionally, in connection with the Business Combination, we issued 15,133,333 Forward Purchase Warrants to Riverstone VI SR II Holdings, LP.  Each whole Public Warrant entitles the holder to purchase one whole share of our Class A Common Stock for $11.50 per share. The warrants become exercisable 12 months from February 9, 2018 and will expire February 9, 2023 or earlier upon redemption or liquidation. Pursuant to the warrant agreement, a warrant holder may exercise its Public Warrants only for a whole number of shares of Class A Common Stock. No fractional Public Warrants have been issued and only whole Public Warrants trade.  No Public Warrant will be exercisable and the Company will not be obligated to issue shares of Class A Common Stock upon exercise of a Public Warrant unless Class A Common Stock issuable upon such exercise has been registered, qualified or deemed to be exempt under the securities laws of the state of residence of the registered holder of the Public Warrants. In the event that the conditions in the two immediately preceding sentences are not satisfied with respect to a Public Warrant, the holder of such Public Warrant will not be entitled to exercise such Public Warrant and such Public Warrant may have no value and expire worthless.  Private Placement Warrants. As of March 31, 2018, 15,133,333 Private Placement Warrants remained outstanding. The Private Placement Warrants are identical to the public warrants underlying the Units sold in the Initial Public Offering.  Forward Purchase Warrants . The Forward Purchase Warrants have terms and provisions that are identical to those of the Private Placement Warrants, including as to exercise price, exercisability and exercise period, except the Forward Purchase Warrants are not subject to the lock-up that is applicable to the Private Placement Warrants. The Forward Purchase Warrants were sold in a private placement pursuant to a purchase agreement between us and our Sponsor and have the terms set forth in a warrant agreement between Continental Stock Transfer & Trust Company, as warrant agent, and the Company.  Noncontrolling Interest . The noncontrolling interest relates to SRII Opco Common Units that were originally issued to the Alta Mesa Contributor, the Kingfisher Contributor and the Riverstone Contributor in connection with the Business Combination and continue to be held by holders other than the Company. At the date of the Business Combination, the noncontrolling interest held 55.8 % (Alta Mesa Contributor 36.2% , Kingfisher Contributor 14.4% , and Riverstone Contributor 5.2% ) of the ownership in SRII Opco. The noncontrolling interest percentage is affected by various equity transactions such as Class C Common Stock conversions and Class A Common Stock activities.  The Company has consolidated the financial position, results of operations and cash flows of SRII Opco and reflected that portion retained by other holders of Common Units as a noncontrolling interest.  Management and Control . Alta Mesa’s amended and restated partnership agreement currently provides for interests to be divided into economic units held by the partners referred to as “LP Units” and non-economic general partner interests owned by Alta Mesa GP (as defined below) referred to as “GP Units”. Alta Mesa GP owns all the GP Units and SRII Opco owns all the LP Units.  Since Alta Mesa is a limited partnership, its operations and activities are managed by the board of directors (the “Board of Directors”) of its general partner, Alta Mesa GP. The limited liability company agreement of AMH GP provides for two classes of interests: (i) Class A Units, which hold 100% of the economic interests in Alta Mesa GP and (ii) Class B Units, which hold 100% of the voting interests in Alta Mesa GP.  SRII Opco is the sole owner of Alta Mesa’s Class A Units and owns 90% of the Class B Units. Harlan H. Chappelle, our Chief Executive Officer and a director, Michael Ellis, the founder, our Chief Operating Officer and a director and certain affiliates of Bayou City, and HPS, own an aggregate 10% of the Class B Units. Alta Mesa GP’s Board of Directors are selected by the Class B Members. Notwithstanding the foregoing, voting control of Alta Mesa GP is vested in SRII Opco pursuant to a voting agreement.  All distributions under Alta Mesa’s amended and restated partnership agreement are made to the limited partners pro rata when Alta Mesa GP so directs.

Equity Based Compensation

Equity Based Compensation	3 Months Ended
	Mar. 31, 2018
Equity Based Compensation [Abstract]
Equity Based Compensation	NOTE 16 — EQUITY BASED COMPENSATION (Successor)  Following the closing of the Business Combination, we adopted the Alta Mesa Resources , Inc. 2018 Long Term Incentive Plan (the “LTIP”) . A total of 50,000,000 shares of Class A Common Stock is reserved for issuance under the LTIP. The LTIP provides for the grant of stock options, including incentive stock options (“ISOs”), nonqualified stock options (“NSOs”), stock appreciation rights (“SARs”), restricted stock, dividend equivalents, restricted stock units (“RSUs”) and other stock-based awards in Class A Common Stock. Pursuant to the LTIP, certain grants of stock-based awards were deemed granted on February 9, 2018. During the Successor Period, the Company recognized non-cash stock-based compensation expense of $3.5 million resulting from stock option, restricted stock and RSUs awards, which is included in general and administrative expense in the accompanying consolidated statements of operations.. Historical amounts may not be representative of future amounts as the value of future awards may vary from historical amounts.  We recognize compensation expense on a straight-line basis for service based grants over the vesting period. The fair value of restricted stock awards is determined based on the estimated fair market value of our Class A Common Stock on the date of grant.  Stock options . Options that have been granted under the LTIP expire seven years from the grant date and have service-based vesting schedules of three years. The exercise for an option under the LTIP may not be below the fair value of the Company’s Class A Common Stock on the grant date. On the Closing Date , the Company granted 4,143,231 stock options to employees.  Information about outstanding stock options is summarized in the table below:     Successor  Stock Options Weighted Average Grant - Date Fair Value Weighted Average Remaining Term (in years) Aggregate Intrinsic Value (in thousands)  Outstanding as of February 9, 2018 $ — —  Granted 4,143,231 4.62 4.3  Exercised — — —  Forfeited or expired — — —  Outstanding as of March 31, 2018 4,143,231 4.62 4.3 $ 19,129  Exercisable as of March 31, 2018 — $ — — $ —  Compensation cost related to stock options is based on the grant-date fair value of the award, recognized ratably over the applicable vesting period. The Company estimates the fair value using the Black-Scholes option-pricing model. Expected volatilities are based on the re-levered asset volatility implied by a set of comparable companies. Expected term is based on the simplified method, and is estimated as the average of the weighted average vesting term and the time to expiration as of the grant date. The Company uses U.S. Treasury bond rates in effect at the grant date for its risk-free interest rates.  The following summarizes the assumptions used to determine the fair value of those options:    Successor  February 9, 2018  Through  March 31, 2018   Expected term (in years) 4.5  Expected stock volatility 64.5%  Dividend yield —  Risk-free interest rate 2.4%  As of March 31, 2018, there was $18.1 million of unrecognized compensation cost related to non-vested stock options. The Company expects to recognize that cost on a pro rata basis over a weighted average period of 2.8 years.  Restricted stock . On February 9, 2018, the Company granted 73,376 fully-vested restricted stock awards to certain of its directors and 1,160,094 restricted stock awards to employees, one third of which vest on each anniversary of the grant date over three years, subject to the employee’s continued service.  The following table provides information about restricted stock awards granted during the Successor Period:     Successor  Restricted Stock Awards Weighted Average Grant - Date Fair Value per share  Outstanding as of February 9, 2018 — $ —  Granted 1,233,470 8.94  Exercised — —  Forfeited or expired — —  Outstanding as of March 31, 2018 1,233,470 $ 8.94  Compensation cost for the service-based vesting restricted shares is based upon the grant-date market value of the award, recognized ratably over the applicable vesting period. Unrecognized compensation cost related to unvested restricted shares at March 31, 2018 was $9.8 million, which the Company expects to recognize over a weighted average period of 2.8 years.  Restricted stock units . On February 9, 2018, 0.7 million performance-based restricted stock units (“PSUs”) were deemed granted to key employees under the LTIP. For the PSUs, 20% vest on December 31, 2018, 30% vest on December 31, 2019 and 50% vest on December 31, 2020; provided that the actual number of PSUs that are deemed granted and may be earned is between 0% and 200% of the initial target, with the final number to be dependent upon achievement of certain performance goals and objectives. The performance criteria with respect to the PSUs that vest December 31, 2018 is based on our cumulative EBITDAX, as defined in the PSU grant agreement. The performance criteria for PSUs that vest in 2019 and 2020 have not yet been established and accordingly, those PSUs were not deemed granted as of March 31, 2018 for expense recognition purposes. During the restriction period, the RSUs may not be transferred or encumbered, and the recipient does not receive dividend equivalents or have voting rights until the unit vests.  The following summary provides information about RSUs granted during the Successor Period:    Successor  RSUs Weighted Average Grant - Date Fair Value per unit  Outstanding as of February 9, 2018 — $ —  Granted 718,163 8.94  Exercised — —  Forfeited or expired — —  Outstanding as of March 31, 2018 718,163 $ 8.94  As of March 31, 2018, there was $5.3 million of unrecognized compensation cost related to the unvested RSUs which we expect to recognize on a pro rata basis over a weighted average period of 0.8 years.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	NOTE 18 — RELATED PARTY TRANSACTIONS  Alta Mesa entered into a promissory note receivable with its affiliate Northwest Gas Processing, LLC, a Delaware limited liability company (“NWGP”), effective September 29, 2017, for approximately $1.5 million. The promissory note was issued by NWGP to Alta Mesa and bears interest (or paid-in-kind interest from time to time) on the principal balance at a rate of 8% per annum, with interest payable in quarterly installments beginning January 1, 2018 , and matures on February 28, 2019 . During the fourth quarter 2017, the $1.5 million promissory note was transferred from NWGP to High Mesa Services, LLC.  David Murrell, our Vice President of Land and Business Development, is the principal of David Murrell & Associates, which provides land consulting services to us. The primary employee of David Murrell & Associates is his spouse, Brigid Murrell. Services are provided at a pre-negotiated hourly rate based on actual time employed by us. Total expenditures under this arrangement were approximately $36,000 , $28,000 , and $43,000 for the Successor Period, the 2018 Predecessor Period, and the 2017 Predecessor Period, respectively. The contract may be terminated by either party without penalty upon 30 days’ notice. These amounts are recorded in general and administrative expense (“G&A”) on the consolidated statements of operations.  David McClure, our Vice President of Facilities and Midstream, and the son-in-law of our Chief Executive Officer, Harlan H. Chappelle, received total compensation of approximately $44,500 , $938,500 , and $67,500 for the Successor Period, the 2018 Predecessor Period, and the 2017 Predecessor Period, respectively. These amounts are recorded in G&A expense on the consolidated statements of operations.  David Pepper, one of our Landmen, and the cousin of our Vice President of Land and Business Development, David Murrell, received total compensation of $23,200 , $153,100 , and $38,700 for the Successor Period, the 2018 Predecessor Period, and the 2017 Predecessor Period, respectively . These amounts are recorded in G&A expense on the consolidated statements of operations.  On January 13, 2016, Alta Mesa’s wholly owned subsidiary Oklahoma Energy Acquisitions, LP (“Oklahoma Energy”) entered into a joint development agreement (the “joint development agreement”), with BCE-STACK Development LLC (“BCE”), a fund advised by Bayou City, to fund a portion of Alta Mesa’s drilling operations and to allow Alta Mesa to accelerate development of our STACK acreage. The drilling program initially called for the development of forty identified well locations, which developed in two tranches of twenty wells each. The parties subsequently agreed to add a third and fourth tranche of investment that will allow for the drilling of an additional forty wells. As of March 31, 2018, 67 joint wells have been drilled or spudded leaving 13 wells to be drilled under the joint development agreement.  Under the joint development agreement, as amended on December 31, 2016, BCE committed to fund 100% of Alta Mesa’s working interest share up to a maximum of an average of $3.2 million in drilling and completion costs per well for any tranche. We are responsible for any drilling and completion costs exceeding the aggregate limit of $64 million in any tranche. In exchange for the payment of drilling and completion costs, BCE receives 80% of our working interest in each wellbore, which BCE interest will be reduced to 20% of our initial working interest upon BCE achieving a 15% internal rate of return on the wells within a tranche and automatically further reduced to 12.5% of our initial interest upon BCE achieving a 25% internal rate of return. Following the completion of each joint well, we and BCE will each bear our respective proportionate working interest share of all subsequent costs and expenses related to such joint well. Mr. McMullen, our director, is founder and managing partner of BCE. The approximate dollar value of the amount involved in this transaction or Mr. McMullen’s interests in the transaction depends on a number of factors outside his control and is not known at this time. As of March 31, 2018 and December 31, 2017, we recorded $40.5 million and $23.4 million in advances from related party on our consolidated balance sheets, which represents net advances from BCE for their working interest share of the drilling and development cost as part of the joint development agreement. During the Successor Period, BCE advanced us approximately $39.5 million to drill additional wells under the joint development agreement. Management Services Agreement-High Mesa In connection with the Closing, we entered into a management services agreement (the “High Mesa Agreement”) with High Mesa with respect to our non-STACK assets that were distributed to High Mesa’s subsidiary in connection with the business combination. Under the High Mesa Agreement, during the 180-day period following the Closing (the “Initial Term”), we will provide certain administrative, management and operational services necessary to manage the business of High Mesa and its subsidiaries (the “Services”), in each case, subject to and in accordance with an approved budget. Thereafter, the High Mesa Agreement shall automatically renew for additional consecutive 180-day periods (each a “Renewal Term”), unless terminated by either party upon at least 90-days written notice to the other party prior to the end of the Initial Term or any Renewal Term. For a period of 60 days following the expiration of the term, we are obligated to assist High Mesa with the transition of the Services from Alta Mesa to a successor service provider. As compensation for the Services, including during any transition to a successor service provider, High Mesa will pay us each month (i) a management fee of $10,000 , (ii) an amount equal to our costs and expenses incurred in connection with providing the Services as provided for in the approved budget and (iii) an amount equal to our costs and expenses incurred in connection with any emergency. As of March 31, 2018 and December 31, 2017, approximately $7.9 million and $0.8 million, respectively, were due from High Mesa for reimbursement of expenses which is recorded in the receivables due from related party on the consolidated balance sheets.  We have a note receivable due from High Mesa Services, LLC (“HMS”), a subsidiary of High Mesa. The $ 8.5 million long-term note receivable, dated December 31, 2014, bears interest at 8% per annum, interest payable only in quarterly installments beginning January 1, 2015 , and matures on December 31, 2019 . As of March 31, 2018, and December 31, 2017, the balance of the note receivable amounted to $11.0 million and $10.8 million, respectively. The Company believes the promissory note to be fully collectible and accordingly has not recorded a reserve. Interest income on the note receivable from our affiliate amounted to approximately $0.1 million, $0.1 million and $0.2 million for the Successor Period, the 2018 Predecessor Period, and the 2017 Predecessor Period. Such amounts have been added to the balance of the note receivable.

Subsidiary Guarantors

Subsidiary Guarantors	3 Months Ended
	Mar. 31, 2018
Subsidiary Guarantors [Abstract]
Subsidiary Guarantors	NOTE 19 — SUBSIDIARY GUARANTORS  All of Alta Mesa’s material wholly owned subsidiaries are guarantors under the terms of its senior notes and credit facility. Our consolidated financial statements reflect the financial position of these subsidiary guarantors. As the parent company, we have no independent operations, assets, or liabilities. The guarantees are full and unconditional (except for customary release provisions) and joint and several. Those subsidiaries which are not wholly owned by Alta Mesa and are not guarantors of its senior notes or credit facility, are immaterial subsidiaries. There are restrictions on dividends, distributions, loans or other transfers of funds from the subsidiary guarantors to us.

Business Segment Information

Business Segment Information	3 Months Ended
	Mar. 31, 2018
Business Segment Information [Abstract]
Business Segment Information	NOTE 20 — BUSINESS SEGMENT INFORMATION  We disclose the results of our reportable segments in accordance with ASC 280, Segment Reporting . As a result of the Business Combination, the company has two reportable segments: (1) Exploration & Production and (2) Midstream . These segments represent the Company’s two operating units, each offering different products and services. Each segment is led by the Company’s Chief Operating Decision Maker (“CODM”). The CODM evaluates segment performance using operating income, which is defined as total operating and other revenue less total operating expenses. The Company’s corporate activities have been allocated to the supported business segments accordingly. The company had one reportable segment in the 2018 Predecessor Period and 2017 Predecessor period. For additional information regarding the Company’s reportable segments, see Note 2 — Summary of Significant Accounting Policies .      Successor  February 9, 2018 Through March 31, 2018  Exploration and  Production Midstream Eliminations Total  (in thousands)  Operating revenues from external customers $ 27,353 $ 18,517 $ — $ 45,870  Operating inter-segment revenues 6,737 4,562 (11,299) —  Total operating revenues 34,090 23,079 (11,299) 45,870   Operating income (loss) (29,921) (1,618) — (31,539)  Other income (expense) (4,650) (248) — (4,898)  Segment net income (loss) before tax $ (34,571) $ (1,866) $ — $ (36,437)  Corporate general and administrative expenses 925  Income (loss) from continuing operations before income taxes $ (37,362)  The following table summarizes our revenue by product line.     Successor  February 9, 2018 Through March 31, 2018  Exploration and  Production Midstream Eliminations Total  (in thousands)  Product line revenue:  Oil sales $ 40,278 $ — $ — $ 40,278  Natural gas sales 5,210 — — 5,210  Natural gas liquids sales 4,714 — — 4,714  Product sales — 15,106 (6,737) 8,369  Gathering and processing revenue — 7,973 (4,562) 3,411  Total product line revenue (1) $ 50,202 $ 23,079 $ (11,299) $ 61,982 _________________ (1) Total product line revenue excludes other revenue and gain (loss) on derivative contracts.  The following table summarizes total assets by segment:       Successor  March 31, 2018  Exploration and  Production Midstream Eliminations Total  (in thousands)  Total segment assets $ 2,828,379 $ 1,415,497 $ (4,092) $ 4,239,784  Corporate assets 3,755  Total assets $ 4,243,539

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	NOTE 21 — SUBSEQUENT EVENTS  Extended lease agreement . On April 1, 2018, Alta Mesa amended its lease agreement for the Corporate headquarters located in Houston, Texas. The amended lease agreement provides for additional expansion space and extends the original lease term through April 2028. As a result of the amendment, Alta Mesa has additional lease commitment obligations of approximately $17.6 million through 2028 .  Cimarron Express Pipeline . On May 10, 2018, a subsidiary of Kingfisher and Blueknight Energy Partners, L.P. (“Blueknight”), an unaffiliated third party, entered into definitive agreements for the purpose of constructing and operating a new crude oil pipeline serving STACK producers in central Oklahoma. The 65 -mile, 16 -inch crude oil pipeline, which will be owned by Cimarron Express Pipeline, LLC (“Cimarron Express”) and constructed and operated by an affiliate of Blueknight, will extend from northeastern Kingfisher County, Oklahoma, to Blueknight’s crude oil terminal in Cushing, Oklahoma. The receipt terminal for the newly constructed pipeline will be located at Kingfisher’s crude oil storage facility located in northeastern Kingfisher County, where it will have connectivity to Kingfisher’s crude oil gathering system and truck unloading facilities. The pipeline will provide direct market access at Cushing for producers and will have an initial capacity of 90,000 barrels per day, expandable to over 175,000 barrels per day. Cimarron Express is owned 50% by an affiliate of Kingfisher and 50% by an affiliate of Ergon, Inc. In connection with the transaction, Alta Mesa entered into a long-term acreage dedication and transportation agreement with Cimarron Express, which includes the dedication of the production from approximately 120,000 net acres in Kingfisher and Garfield counties in Oklahoma.

Summary Of Significant Accoun28

Summary Of Significant Accounting Policies (Policy)	3 Months Ended
	Mar. 31, 2018
Summary Of Significant Accounting Policies [Abstract]
Basis Of Presentation	Basis of Presentation . As a result of the Business Combination, the Company is the acquirer for accounting purposes and Alta Mesa and Kingfisher are the acquirees. Alta Mesa is our accounting predecessor. The Company’s financial statement presentation reflects Alta Mesa as the “Predecessor” for periods prior to the Business Combination. The Company is the “Successor” for periods after the Business Combination, which includes consolidation of Alta Mesa and Kingfisher concurrent with the Business Combination on February 9, 2018. The Business Combination was accounted for as a business combination using the acquisition method of accounting, and the Successor financial statements reflect a new basis of accounting that is based on the fair value of Alta Mesa and Kingfisher’s net assets acquired. Refer to Note 4 — Business Combination (Successor) for further information related to the Business Combination. As a result of the application of the acquisition method of accounting resulting from the Business Combination, the financial statements and certain footnote presentations separate the Company’s presentations into two distinct periods, the period before the consummation of the Transactions and the period on or after that date, to indicate that the financial statements presented are those of different entities and reflect the application of the different basis of accounting between the periods presented. The Successor period presented herein is from February 9, 2018 to March 31, 2018 (“Successor Period”) and the Predecessor periods presented herein are from January 1, 2018 to February 8, 2018 (“2018 Predecessor Period”) and the three months ended March 31, 2017 (“2017 Predecessor Period”).  Prior to the Business Combination, Alta Mesa distributed its non-STACK assets to the AM Contributor. The distribution of its remaining non-STACK assets in 2018 and the sale of its Weeks Island field during the fourth quarter of 2017 (collectively, the “non-STACK assets”) were part of Alta Mesa’s overall strategic shift to operate only in the eastern Anadarko Basin. As a result of the strategic shift, Alta Mesa classified the Predecessor assets and liabilities and operating results directly related to non-STACK assets as discontinued operations within the consolidated financial statements. See Note 6 — Discontinued Operations (Predecessor) for further discussion. 
Principles Of Consolidation And Reporting	Principles of Consolidation and Reporting . The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Certain reclassifications of prior period consolidated financial statements have been made to conform to current reporting practices. The consolidated financial statements include the accounts of the Company and its subsidiaries, including SRII Opco, after eliminating all significant intercompany transactions and balances. The Company’s interests in oil and natural gas exploration and production ventures and partnerships are proportionately consolidated. Noncontrolling interests represent third-party ownership interests in SRII Opco and are presented as a component of equity. See Note 15—Stockholders' Equity and Partners’ Capital for further discussion of noncontrolling interest.  The consolidated financial statements included herein are unaudited, and in the opinion of management, the information furnished reflects all material adjustments, consisting of normal recurring adjustments, necessary for a fair presentation of consolidated financial position and of the results of operations for the interim periods presented. The consolidated results of operations for interim periods are not necessarily indicative of results to be expected for a full year. 
Use Of Estimates	Use of Estimates . The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period.  Reserve estimates significantly impact depreciation, depletion, and amortization expense and potential impairments of oil and natural gas properties and are subject to change based on changes in oil and natural gas prices and trends and changes in estimated reserve quantities. We analyze estimates, including those related to oil and natural gas reserves, oil and natural gas revenues, product and gathering and compression sales, the value of oil and natural gas properties, the value of pipeline equipment, bad debts, goodwill, intangible assets, asset retirement obligations, derivative contracts, accounting for business combinations, federal and state taxes, share-based compensation and contingencies and litigation. We base our estimates on historical experience and various other assumptions that are believed to be reasonable under the circumstances. We review estimates and underlying assumptions on a regular basis. Actual results may differ from these estimates. 
Cash And Cash Equivalents	Cash and Cash Equivalents . We consider all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. The Company maintains cash balances at financial institutions in the United States of America, which at times exceed federally insured amounts. The Federal Deposit Insurance Corporation provides insurance up to $250,000 per depositor. We monitor the financial condition of the financial institutions and have experienced no losses associated with these accounts. 
Restricted Cash	Restricted Cash. The Company classifies cash balances as restricted cash when cash is restricted as to withdrawal or usage. As of March 31, 2018, and December 31, 2017, the restricted cash represents cash received by the Company from production sold where the final division of ownership of the production is in dispute or there is unclaimed property for pooling orders in Oklahoma.  The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets and the consolidated statements of cash flows (in thousands):      Successor Predecessor  March 31, December 31,  2018 2017   Cash and cash equivalents $ 261,063 $ 3,660  Short-term restricted cash 1,295 1,269  Cash of discontinued operations — 61  Total cash, cash equivalents and restricted cash $ 262,358 $ 4,990 
Accounts Receivable	A ccounts Receivable . Our receivables arise primarily from the sale of oil, natural gas and natural gas liquids and joint interest owner receivables for properties in which we serve as the operator, and valid claims against nonaffiliated customers for services rendered. This concentration of customers may impact our overall credit risk, either positively or negatively, in that these entities may be similarly affected by changes in economic or other conditions affecting the oil and natural gas industry. Accounts receivable are generally not collateralized. We may have the ability to withhold future revenue disbursements to recover non-payment of joint interest billings on properties of which we are the operator. Accounts receivable from joint interest owners are stated at amounts due, net of an allowance for doubtful accounts.  Accounts receivable consisted of the following (in thousands):     Successor Predecessor  March 31, December 31,  2018 2017  Oil, natural gas and natural gas liquids sales $ 39,067 $ 26,916  Joint interest billings 33,197 13,821  Pooling interest (1) 37,626 35,839  Allowance for doubtful accounts (65) (415)  Total accounts receivable, net $ 109,825 $ 76,161 _________________ (1) Pooling interest relates to Oklahoma’s forced pooling process which requires the Company to offer mineral interest owners the option to participate in the drilling of proposed wells. The pooling interest listed above represent costs of unbilled interests on wells which the Company incurred before the pooling process was completed. Depending upon the outcome of the pooling process, these costs may be billed to potential working interest owners or added to oil and gas properties.
Allowance For Doubtful Accounts	 Allowance for Doubtful Accounts . We routinely assess the recoverability of all material trade and other receivables to determine their collectability. We accrue a reserve when, based on the judgment of management, it is probable that a receivable will not be collected and the amount of the reserve can be reasonably estimated.
Property, Plant And Equipment	Property, Plant and Equipment . Oil and natural gas producing activities are accounted for using the successful efforts method of accounting. Under the successful efforts meth od, lease acquisition costs and all development costs, including unsuccessful development wells, are capitalized. In conjunction with acquisition accounting, property, plant and equipment was measured at fair value as of the acquisition date, which also impacted how value was assigned between the categories within property, plant, and equipment. See Note 4 — Business Combination (Successor) for discussion.  Unproved Properties — Acquisition costs associated with the acquisition of leases are recorded as unproved properties and capitalized as incurred. These consist of costs incurred in obtaining a mineral interest or right in a property, such as a lease, in addition to options to lease, broker fees, recording fees and other similar costs related to activities in acquiring properties. Unproved properties are classified as unproved until proved reserves are discovered, at which time related costs are transferred to the proved oil and natural gas properties.  Exploration Expense — Exploration expenses, other than exploration drilling costs, are charged to expense as incurred. These expenses include seismic expenditures and other geological and geophysical costs, expired leases, delay rentals, gain or loss on settlement of asset retirement obligations and lease rentals. The costs of drilling exploratory wells and exploratory-type stratigraphic wells are initially capitalized, or “suspended” on the balance sheet pending determination of whether the well has discovered proved commercial reserves. If the exploratory well is determined to be unsuccessful, the cost of the well is transferred to expense. Exploratory well drilling costs may continue to be capitalized if the reserve quantity is sufficient to justify completion as a producing well and sufficient progress in assessing the reserves and the economic and operating viability of the project is being made. Assessments of such capitalized costs are made quarterly.  Proved Oil and Natural Gas Properties — Costs incurred to obtain access to the proved reserves and to provide facilities for extracting, treating, gathering, and storing oil and natural gas are capitalized. All costs incurred to drill and equip successful exploratory wells, development wells, development-type stratigraphic test wells, and service wells, including unsuccessful development wells, are capitalized.  Impairment — The capitalized costs of proved oil and natural gas properties are reviewed quarterly for impairment following the guidance provided in Account Standards Codification (“ASC”) 360-10-35, Property, Plant and Equipment, Subsequent Measurement , or whenever events or changes in circumstances indicate that the carrying amount of a long-lived asset or asset group exceeds its fair value and is not recoverable. The determination of recoverability is based on comparing the estimated undiscounted future net cash flows at a producing field level to the carrying value of the assets. If the future undiscounted cash flows, based on estimates of anticipated production from proved and risk-adjusted unproved reserves and future crude oil and natural gas prices and operating costs, are lower than the carrying cost, the carrying cost of the asset or group of assets is reduced to fair value. For our proved oil and natural gas properties, we estimate fair value by discounting the projected future cash flows at an appropriate risk-adjusted discount rate.  Our evaluation of the Company’s proved properties resulted in no impairment expense in the Successor Period and the 2018 Predecessor Period. For the 2017 Predecessor Period, our evaluation of the Company’s proved properties resulted in an impairment expense of $1.2 million.  Unproved properties are assessed at least annually to determine whether they have been impaired. Individually significant properties are assessed for impairment on a property-by-property basis, while individually insignificant unproved properties may be assessed in the aggregate. If unproved properties are found to be impaired, an impairment allowance is provided and a loss is recognized in the consolidated statements of operations. No impairment expense was recognized in the Successor Period, the 2018 Predecessor Period, and the 2017 Predecessor Period.  Management evaluates whether the carrying value of all other long-lived assets has been impaired when circumstances indicate the carrying value of those assets may not be recoverable. This evaluation is based on undiscounted cash flow projections. The carrying amount is not recoverable if it exceeds the sum of undiscounted cash flows expected to result from the use and eventual disposition of the assets. Management considers various factors when determining if these assets should be evaluated for impairment.  If the carrying value is not recoverable on an undiscounted basis, the impairment loss is measured as the excess of the asset’s carrying value over its fair value. Management assesses the fair value of long-lived assets using commonly accepted techniques, and may use more than one method, including, but not limited to, recent third party comparable sales, internally developed discounted cash flow analysis and analysis from outside advisors. Significant changes in market conditions resulting from events such as the condition of an asset or a change in management’s intent to utilize the asset would generally require management to reassess the cash flows related to the long-lived assets. The Company did not record any impairment expense related to other long-lived assets for the Successor Period, the 2018 Predecessor Period and the 2017 Predecessor Period, respectively.  Other Property, Plant and Equipment — Other property, plant and equipment such as plant equipment, salt water disposal system, office furniture and equipment, buildings, vehicles, are recorded at cost, or fair value, if impaired. Maintenance, repairs and minor renewals are expensed as incurred. Plant and equipment include costs incurred to build a cryogenic processing facility along with gathering pipelines, including right of ways, crude oil gathering system, and compressors.  Depreciation, Depletion and Amortization — Depreciation, depletion, and amortization (“DD&A”) of capitalized costs of proved oil and natural gas properties is computed using the unit-of-production method based upon estimated proved reserves. Assets are grouped for DD&A on the basis of reasonable aggregation of properties with a common geological structural feature or stratigraphic condition, such as a reservoir or field. The reserve base used to calculate DD&A for leasehold acquisition costs and the cost to acquire proved properties is total proved reserves. The reserve base used to calculate DD&A for lease and well equipment costs, which include development costs and successful exploration drilling costs, includes only proved developed reserves. Our midstream assets are depreciated on the straight-line method based on their expected useful lives. The Company uses estimated lives of 35 years for its processing plant and pipelines.  DD&A expense related to oil and natural gas properties was $10.8 million, $11.2 million and $18.3 million for the Successor Period, the 2018 Predecessor Period and the 2017 Predecessor Period, respectively. DD&A expense related to our midstream assets was $1.1 million in the Successor Period. There was no such DD&A expense for midstream assets for the 2018 and 2017 Predecessor Period.  Leasehold improvements to offices are depreciated using the straight-line method over the life of the lease. Other property and equipment is depreciated using the straight-line method over periods ranging from three to seven years. For the Successor Period, depreciation expense was immaterial. Depreciation expense for non-oil, natural gas, and midstream properties was $0.2 million, $0.6 million and $0.7 million for the Successor Period, the 2018 Predecessor Period and the 2017 Predecessor Period, respectively. 
Intangible Assets	Intangible Assets (Successor) . In connection with the acquisition of Kingfisher, the Company recorded the estimated fair value of acquired customer contracts and relationships as intangible assets, which were valued using the income approach, and are presented as Intangible Assets, net in the accompanying consolidated balance sheet of the Successor. These intangible assets have definite lives and are subject to amortization utilizing an accelerated attrition method over their economic lives, currently ranging between 10 years and 15 years. We assess intangible assets for impairment together with related underlying long-lived assets whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. An impairment is recognized in the consolidated statements of income if the carrying amount of an intangible asset is not recoverable and its carrying amount exceeds its fair value. As a result of the Business Combination, we determined all the Company’s intangible assets relate to the midstream reporting unit, and concluded that there was no impairment after evaluating the intangible assets for impairment as of March 31, 2018. 
Goodwill	Goodwill (Successor). Goodwill represents the excess of the purchase price of an entity over the estimated fair value of the assets acquired and liabilities assumed, and it is presented as Goodwill in the accompanying consolidated balance sheet of the Successor. Under ASC 350, Intangibles – Goodwill and Other (“ASC 350”), goodwill is not amortized but is subject to periodic impairment testing. ASC 350 requires that an entity assign its goodwill to reporting units and test each reporting unit’s goodwill for impairment at least on an annual basis and between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount . In our evaluation of goodwill for impairment, performed annually during the third quarter, we first assess qualitative factors to determine whether the existence of events or circumstances led to a determination that it was more likely than not that the fair value of a reporting unit is less than its carrying amount. If, after assessing the totality of events or circumstances, we determine it is more likely than not that the fair value of a reporting unit is less than its carrying amount, we are required to perform the quantitative goodwill impairment test. As a result of the Business Combination, we acquired goodwill during the Successor Period. There was no goodwill prior to the Business Combination. We determined that all of the Company’s goodwill relates to the midstream reporting unit and did not identify any significant events or circumstances that would require us to perform an impairment test as of March 31, 2018. As such, there was no impairment recognized during the Successor Period. 
Bond Premium On Senior Unsecured Notes	Bond Premium on Senior Unsecured Notes . In connection with the Business Combination, the Company estimated the fair value of Alta Mesa’s $500 million senior unsecured notes at $533.6 million as of the acquisition date. The amount in excess of the principal amount was recorded as a bond premium, which is being amortized over the term of the notes using the straight-line method, which approximates the effective interest method. 
Asset Retirement Obligations	Asset Retirement Obligations . We recognize liabilities for the future costs of dismantlement and abandonment of our wells, facilities, and other tangible long-lived assets along with an associated increase in the carrying amount of the related long-lived asset. The fair values of new asset retirement obligations are estimated using expected future costs discounted to present value. The cost of the tangible asset, including the asset retirement cost, is depleted over the useful life of the asset. Accretion expense is recognized as the discounted liability is accreted to its expected settlement value. Asset retirement obligations are subject to revision primarily for changes to the estimated timing and cost of abandonment.  Asset retirement obligations for the Company’s midstream processing and pipeline facilities generally become firm at the time the facilities are permanently shut down and dismantled. These obligations may include the costs of asset disposal and additional soil remediation. However, these sites have indeterminate lives based on plans for continued operations and as such, the fair value of the conditional legal obligations cannot be measured due to the uncertainty associated with the future settlement dates of such obligations. 
Derivative Financial Instruments	Derivative Financial Instruments . We use derivative contracts to hedge the effects of fluctuations in the prices of oil, natural gas and natural gas liquids. We account for such derivative instruments in accordance with ASC 815, Derivatives and Hedging (“ASC 815”), which establishes accounting and disclosure requirements for derivative instruments and requires them to be measured at fair value and recorded as assets or liabilities in the consolidated balance sheets (see Note 7 — Fair Value Disclosures for information on fair value).  Under ASC 815, hedge accounting is used to defer recognition of unrealized changes in the fair value of such financial instruments, for those contracts which qualify as fair value or cash flow hedges, as defined in the guidance. Historically, we have not designated any of our derivative contracts as fair value or cash flow hedges. Accordingly, the changes in fair value of the contracts are included in gain (loss) on derivative contracts in the consolidated statement of operations. Gains or losses from the settlement of matured derivatives contracts are also included in gain (loss) on derivatives contracts in the consolidated statement of operations. Cash flows from settlements of derivative contracts are classified as operating cash flows. 
Income Taxes	Income Taxes (Successor) . Income taxes and uncertain tax positions are accounted for in accordance with ASC 740, Accounting for Income Taxes (“ASC 740”). Deferred income taxes are provided for the differences between the bases of assets and liabilities for financial reporting and income tax purposes. Tax positions meeting the more-likely-than-not recognition threshold are measured pursuant to the guidance set forth in ASC 740. We assess the ability to realize our deferred tax assets on a quarterly basis. A valuation allowance is established to reduce deferred tax assets to the amount expected to be realized when it is determined that it is more likely than not that some or all of the deferred tax assets are not realizable.  The Company is also subject to the Texas margin tax, which is considered a state income tax, and is included in “Income tax provision (benefit)” on the consolidated statements of operations. The Company records state income tax (current and deferred) based on taxable income, as defined under the rules for the margin tax.  We have considered our exposure under the standard at both the federal and state tax levels. We did not record any liabilities for uncertain tax positions as of the Successor Period and December 31, 2017. We record income tax, related interest, and penalties, if any, as a component of income tax expense. We did not incur any material interest or penalties on income taxes for the 2018 Predecessor Period and the 2017 Predecessor Period.  Alta Mesa’s tax returns for the years ended December 31, 2014 forward remain open for examination. None of the Company’s federal or state tax returns are currently under examination by the relevant authorities.  Income Taxes (Predecessor) . Alta Mesa has historically elected under the provisions of the Internal Revenue Code of 1986, as amended, to be treated as individual partnerships for tax purposes. Accordingly, items of income, expense, gains and losses of the Predecessor flowed through to the partners and were taxed at the partner level. Accordingly, no tax provision for federal income taxes is included in the consolidated financial statements of the Predecessor.  Predecessor net income (loss) for financial statement purposes differed significantly from taxable income (loss) reported to limited partners as a result of differences between the tax bases and financial reporting bases of assets and liabilities and the taxable income allocation requirements under Alta Mesa’s amended and restated partnership agreement. As a result, the aggregate difference in the basis of net assets for financial and tax reporting purposes could not be readily determined as Alta Mesa does not have access to information about each unitholder’s tax attributes in Alta Mesa. However, with respect to Alta Mesa, the Predecessor’s book basis in its net assets exceeded Alta Mesa’s net tax basis by $333.2 million at December 31, 2017.  We follow guidance issued by the FASB in accounting for uncertainty in income taxes. This guidance clarifies the accounting for income taxes by prescribing the minimum recognition threshold an income tax position is required to meet before being recognized in the consolidated financial statements and applies to all income tax positions. Each income tax position is assessed using a two-step process. A determination is first made as to whether it is more likely than not that the income tax position will be sustained, based upon technical merits, upon examination by the taxing authorities. If the income tax position is expected to meet the more likely than not criteria, the benefit recorded in the consolidated financial statements equals the largest amount that is greater than 50% likely to be realized upon its ultimate settlement. 
Revenue Recognition	Revenue Recognition . We recognize oil, natural gas and natural gas liquids revenues when products are delivered at a fixed or determinable price, title has transferred and collectability is reasonably assured. We use the sales method of accounting for recognition of natural gas imbalances.  Gathering and processing revenues are generated by charging fees on a per unit basis for gathering crude oil and natural gas and processing natural gas. The Company recognizes revenue when services have been rendered, the prices are fixed or determinable and collectability is reasonably assured. In addition, revenue from sales of crude oil, natural gas and NGLS is recognized when title passes to the customer, which is when risk of ownership passes to the customer and physical delivery occurs, the price of the product is fixed or determinable and collectability is reasonably assured. 
Equity Based Compensation (Successor)	Equity Based Compensation (Successor) . The Company recognizes compensation related to all stock-based awards, including stock options, in the financial statements based on their estimated grant-date fair value. The Company grants various types of stock-based awards including stock options and restricted stock. The fair value of stock option awards is determined using the Black-Scholes option pricing model. Service-based restricted stock awards are valued using the market price of the Company’s common stock on the grant date. Compensation cost is recognized ratably over the applicable vesting period. See Note 16 — Equity Based Compensation for additional information regarding the Company’s equity based compensation (Successor). 
Fair Value Of Financial Instruments	Fair Value of Financial Instruments . The fair values of cash, accounts receivable and current liabilities approximate book value due to their short-term nature. The fair value estimate of long-term debt under our senior secured revolving credit facilities is not considered to be materially different from carrying value due to market rates of interest. Derivative financial instruments are carried at fair value. For further information on fair values of financial instruments see Note 7 — Fair Value Disclosures and Note 11 — Long-Term Debt, Net . 
Acquisitions	Acquisitions . Acquisitions are accounted for as purchases using the acquisition method of accounting. Accordingly, the results of operations are included in our consolidated statements of operations from the closing date of the acquisitions, except in the case of our acquisition of Alta Mesa, as that entity was deemed to be our Predecessor for accounting purposes . Purchase prices are allocated to acquired assets and assumed liabilities based on their estimated fair values at the time of the acquisition. 
Earnings (Loss) Per Share	Earnings (Loss) Per Share . Basic earnings (loss) per share is calculated by dividing earnings (loss) available to common shareholders by the weighted average shares-basic during each period.  The Company uses the "if-converted" method to determine the potential dilutive effect of exchanges of outstanding SRII Opco Common Units and corresponding shares of its outstanding Class C common stock, and the treasury stock method to determine the potential dilutive effect of its outstanding warrants, restricted stock, and stock options.  The following table reflects the allocation of net income to common stockholders and EPS computations for the periods indicated based on a weighted average number of common stock outstanding for the period:      Successor  February 9, 2018 Through March 31, 2018  (in thousands, except share and per share data)   Net loss attributable to common stock $ (13,235)   Weighted average common shares outstanding (Basic) 169,371,730  Effect of Dilutive Securities:  Warrants, Class C Common Stock, restricted stock, and stock options —  Weighted average common shares outstanding (Diluted) 169,371,730   Net income (loss) per common share  Basic and diluted $ (0.08)  During the Successor Period, approximately 63.2 million of warrants, 213.4 million shares of Class C Common Stock and 6.1 million of stock options, restricted stock and restricted stock units were excluded from the calculation of diluted earnings per share as their effect would have been anti-dilutive.
Segment Reporting	Segment Reporting (Successor) . The Company (Predecessor) operated in only one industry segment which is the exploration and production of oil and natural gas. All of its operations are conducted in one geographic area of the United States and all of its revenues are derived from customers located in the United States. The Company (Successor) reports financial results under two reportable segments: (1) Exploration & Production and (2) Midstream. See Note 20 — Business Segment Information for financial information about our segments.
Recent Accounting Pronouncements	Recent Accounting Pronouncements  In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU 2014-09”), which seeks to provide a single, comprehensive revenue recognition model for all contracts with customers concerning the recognition, measurement and disclosure of revenue from those contracts. The revenue standard contains principles that an entity will apply to determine the measurement of revenue and timing of when it is recognized. Subsequent to the issuance of ASU 2014-09, the FASB issued various clarifications and interpretive guidance to assist entities with implementation efforts, including guidance pertaining to the presentation of revenues on a gross basis (revenues presented separately from associated expenses) versus a net basis. ASU 2014-09 and related interpretive guidance will be effective for interim and annual periods beginning after December 15, 2017, except for emerging growth companies that elect to use the extended transition period for complying with any new or revised financial accounting standards pursuant to Section 7(a)(2)(b) of the Securities Act. The standard allows for either full retrospective adoption, meaning the standard is applied to all periods presented in the financial statements, or modified retrospective adoption, meaning the standard is applied only to the most current period presented. AMR is an emerging growth company. As an emerging growth company, we have elected to use the extended transition period and as a result, we will be required to adopt the standard during the first quarter of 2019. We expect to adopt using the modified retrospective method with a cumulative adjustment to retained earnings as necessary. We will remain an emerging growth company for up to five years, although we will lose that status sooner if we have more than $1.07 billion of revenues at the end of any fiscal year, have more than $700.0 million in market value of our common stock held by non-affiliates measured as of June 30, or issue more than $1.0 billion of non-convertible debt over a three-year period. It is reasonably possible that we could cease to be an emerging growth company by December 31, 2018. If we lose our emerging growth status, we would adopt the standard in the fourth quarter of 2018.  We are in the process of assessing our contracts and evaluating the impact on the consolidated financial statements. We are continuing to evaluate the provisions of ASU 2014-09 as it relates to certain sales contracts, and in particular, as it relates to disclosure requirements. In addition, we are evaluating the impact, if any, on the presentation of our future revenues and expenses under the new gross-versus-net presentation guidance. We continue to evaluate the impact of these and other provisions of ASU 2014-09 on our accounting policies, changes to relevant business practices, internal controls, and consolidated financial statements.  In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (“ASU 2016-02”), which supersedes ASC 840 “Leases” and creates a new topic, ASC 842 “Leases.” The amendments in this update require, among other things, that lessees recognize the following for all leases (with the exception of short-term leases) at the commencement date: (i) a lease liability, which is a lessee's obligation to make lease payments arising from a lease, measured on a discounted basis; and (ii) a right-of-use asset, which is an asset that represents a lessee's right to use, or control the use of, a specified asset for the lease term. Lessees and lessors must apply a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. ASU 2016-02 also requires disclosures designed to provide information on the amount, timing, and uncertainty of cash flows arising from leases. In January 2018, the FASB issued ASU No. 2018-01, Land easement practical expedient for transition to Topic 842 (“ASU 2018-01”), which provides an optional transition practical expedient to not evaluate under Topic 842 existing or expired land easements that were not previously accounted for as leases under Topic 840, Leases . The standard will be effective for interim and annual periods beginning after December 15, 2018 for public companies and annual periods beginning after December 15, 2019 for all other entities, with earlier adoption permitted. In the normal course of business, we enter into operating lease agreements to support our exploration and development operations and lease assets such as drilling rigs, well equipment, compressors, office space and other assets.  At this time, we cannot reasonably estimate the financial impact ASU 2016-02 will have on our financial statements; however, the adoption and impletion of ASU 2016-02 is expected to have an impact on our consolidated balance sheets resulting in an increase in both the assets and liabilities relating to our operating lease activities greater than twelve months. The adoption is also expected to result in increase in depreciation, depletion and amortization expense, interest expense recorded on our consolidated statement of operations, and additional disclosures. As part of our assessment to date, we have formed an implementation work team and will complete our evaluation in 2018. As we continue to evaluate and implement the standard, we will provide additional information about the expected financial impact at a future date. As an emerging growth company, we have elected to use the extended transition period and as a result, we will be required to adopt the standard in 2020. It is reasonably possible that we could cease to be an emerging growth company by December 31, 2018. If we do lose our emerging growth status, we would adopt the standard on January 1, 2019.  In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows: 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 statements of cash flows. ASU 2016-15 is effective for fiscal years and interim periods within those fiscal years beginning after December 15, 2017 for public companies and for fiscal years beginning after December 15, 2018 for all other entities. As an emerging growth company we have elected to use the extended transition period and as a result, we will be required to adopt the standard in 2019. It is reasonably possible that we could cease to be an emerging growth company by December 31, 2018. If we lose our emerging growth status, we would adopt the standard in the fourth quarter of 2018. The adoption of this guidance will not impact our financial position or results of operations but could result in presentation changes on our consolidated statements of cash flows. In January 2017, the FASB issued ASU No. 2017-01, Clarifying the Definition of a Business (“ASU 2017-01”) , which provides guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. ASU 2017-01 requires entities to use a screen test to determine when an integrated set of assets and activities is not a business or if the integrated set of assets and activities needs to be further evaluated against the framework. ASU 2017-01 is effective for interim and annual periods after December 15, 2017 for public companies and annual periods beginning after December 15, 2018 for all other entities. The amendments should be applied prospectively on or after the effective date and disclosures are not required at transition. Early adoption is permitted for transactions for which the acquisition date occurs before the issuance date or effective date of the amendments, only when the transaction has not been reported in financial statements that have been issued or made available for issuance. The Company early adopted ASU 2017-01 in the fourth quarter of 2017. We do not expect the adoption of ASU 2017-01 to have a material impact on our consolidated financial statements; however these amendments could result in the recording of fewer business combinations in the future periods.  In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other, Simplifying the Test for Goodwill Impairment (ASU “2017-04”) , which provides guidance to simplify the subsequent measurement of goodwill by removing Step 2 from the goodwill impairment process. ASU 2017-04 is effective for goodwill impairment tests performed in annual or interim periods within those fiscal years beginning after December 15, 2019 for public companies and annual periods beginning after December 15, 2021 for all other entities. The amendments should be applied prospectively on or after the effective date and disclosures regarding the reason and change in accounting principle are required at transition. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company early adopted ASU 2017-01 in the first quarter of 2018.  In May 2017, the FASB issued ASU No. 2017-09, Compensation – Stock Compensation: Scope of Modification Accounting (“ASU 2017-09”), which provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting under Topic 718. ASU 2017-09 requires entities to account for the effects of a modification unless the fair value, vesting conditions, and classification of the modified award are all the same as the original award immediately before the original award is modified. ASU 2017-09 is effective prospectively for interim and annual reporting periods beginning after December 15, 2017. The Company adopted ASU 2017-09 in the first quarter of 2018; however, the adoption of ASU No. 2017-09 did not have a material impact on the Company's consolidated financial statements.

Summary Of Significant Accoun29

Summary Of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2018
Summary Of Significant Accounting Policies [Abstract]
Reconciliation Of Cash, Cash Equivalents And Restricted Cash	   Successor Predecessor  March 31, December 31,  2018 2017   Cash and cash equivalents $ 261,063 $ 3,660  Short-term restricted cash 1,295 1,269  Cash of discontinued operations — 61  Total cash, cash equivalents and restricted cash $ 262,358 $ 4,990 
Schedule Of Accounts Receivable	   Successor Predecessor  March 31, December 31,  2018 2017  Oil, natural gas and natural gas liquids sales $ 39,067 $ 26,916  Joint interest billings 33,197 13,821  Pooling interest (1) 37,626 35,839  Allowance for doubtful accounts (65) (415)  Total accounts receivable, net $ 109,825 $ 76,161 _________________ (1) Pooling interest relates to Oklahoma’s forced pooling process which requires the Company to offer mineral interest owners the option to participate in the drilling of proposed wells. The pooling interest listed above represent costs of unbilled interests on wells which the Company incurred before the pooling process was completed. Depending upon the outcome of the pooling process, these costs may be billed to potential working interest owners or added to oil and gas properties.
Schedule Of Earnings Per Share, Basic And Diluted	   Successor  February 9, 2018 Through March 31, 2018  (in thousands, except share and per share data)   Net loss attributable to common stock $ (13,235)   Weighted average common shares outstanding (Basic) 169,371,730  Effect of Dilutive Securities:  Warrants, Class C Common Stock, restricted stock, and stock options —  Weighted average common shares outstanding (Diluted) 169,371,730   Net income (loss) per common share  Basic and diluted $ (0.08) 

Supplemental Cash Flow Inform30

Supplemental Cash Flow Information (Tables)	3 Months Ended
	Mar. 31, 2018
Supplemental Cash Flow Information [Abstract]
Supplemental Disclosures To The Consolidated Statements Of Cash Flows	   Successor Predecessor  February 9, 2018 January 1, 2018 Three  Through Through Months Ended  March 31, 2018 February 8, 2018 March 31, 2017   Supplemental cash flow information:  Cash paid for interest $ 1,092 $ 1,145 $ 1,162  Non-cash investing and financing activities:  Change in asset retirement obligations 421 — 296  Change in accruals or liabilities for capital expenditures (36,866) 4,712 21,111  Distribution of non-STACK assets (net liability) — 33,102 —  Equity issued in Business Combination 2,058,635 — — 

Business Combination (Tables)

Business Combination (Tables)	3 Months Ended
	Mar. 31, 2018
Business Acquisition [Line Items]
Earn-out Consideration	   Earn-Out Consideration Payable to Earn-Out Consideration Payable to  20-Day VWAP AM Contributor KFM Contributor  $ 14.00 10,714,285 SRII Opco Common Units 7,142,857 SRII Opco Common Units  $ 16.00 9,375,000 SRII Opco Common Units 6,250,000 SRII Opco Common Units  $ 18.00 13,888,889 SRII Opco Common Units —  $ 20.00 12,500,000 SRII Opco Common Units — 
Summary Of Pro Forma Information	   Three Months Ended Three Months Ended  March 31, 2018 March 31, 2017  (in thousands)  Total operating revenues $ 112,037 $ 75,452  Net income (loss) (12,100) 25,265  Net income (loss) attributable to Alta Mesa Resources, Inc. (5,281) 8,218   Basic and diluted net income (loss) per share $ (0.03) $ 0.05 
Alta Mesa Holdings, LP [Member]
Business Acquisition [Line Items]
Purchase Consideration	   At February 9,  2018  Preliminary Purchase Consideration: (1)  SRII Opco Common Units ( 158,402,398 valued at $7.90 per unit) (2) $ 1,251,782  Estimated fair value of contingent earn-out purchase consideration (3) 284,109  Settlement of preexisting working capital (4) 5,476  Total purchase price consideration $ 1,541,367 _________________ (1) The preliminary purchase price consideration is for 100% of the limited partner interests in Alta Mesa and 100% of the economic interests and 90% of the voting interests in AMH GP. The preliminary purchase price consideration does not include the effects of the final closing statement adjustments, which adjustments were determined subsequent to March 31, 2018. (2) At closing , the Riverstone Contributor received consideration of 20,000,000 SRII Opco Common Units and the AM Contributor received consideration of 138,402,398 SRII Opco Common Units. The estimated fair value of an SRII Opco Common Unit was $7.90 per unit and reflects discounts for holding requirements and liquidity. (3) For a period of seven years following Closing, the AM Contributor will be entitled to receive earn- out consideration to be paid in the form of SRII Opco Common Units (and a corresponding number of shares of Class C Common Stock) if the 20 -day VWAP of our Class A Common Stock equals or exceeds the specified prices pursuant to the AM Contribution Agreement. Pursuant to ASC 805 and ASC 480, Distinguishing Liabilities from Equity (“ASC 480”), we have determined that the fair value of the earn-out consideration was approximately $284.1 million, which was classified as equity. The fair value of the contingent equity earn-out consideration was determined using the Monte Carlo simulation valuation method based on Level 3 inputs using the fair value hierarchy. The key inputs included the listed market price for Class A Common Stock, market volatility of a peer group of companies similar to the Company (due to the lack of trading activity in the Class A Common Stock), no dividend yield, an expected life of each earn-out threshold based on the remaining contractual term of the contingent liability earn-out period and a risk-free rate based on U.S. dollars overnight indexed swaps with a maturity equivalent to the earn-out’s expected life. (4) Settlement of preexisting working capital between Alta Mesa and Kingfisher.
Allocation Of Purchase Consideration	   At February 9,  2018  Estimated Fair Value of Assets Acquired (1)  Cash, cash equivalents and short term restricted cash $ 10,345  Accounts Receivable 101,745  Other Receivables 1,222  Receivables due from related party 907  Prepaid expenses and other current assets 1,405  Derivative financial instruments 352  Property and equipment: (2)  Oil and natural gas properties, successful efforts 2,314,858  Other property and equipment, net 43,318  Notes receivable due from related party 12,454  Deposits and other long-term assets 10,286  Total fair value of assets acquired 2,496,892  Estimated Fair Value of Liabilities Assumed (1)  Accounts payable and accrued liabilities 210,867  Advances from non-operators 6,803  Advances from related party 47,506  Asset retirement obligations 5,998  Derivative financial instruments 11,585  Long-term debt (3) 667,700  Other long-term liabilities 5,066  Total fair value of liabilities assumed 955,525  Total consideration and fair value $ 1,541,367 _________________ (1) The preliminary purchase price is allocated based on Alta Mesa’s STACK Assets. (2) The fair value measurements of oil and natural gas properties and asset retirement obligations are based on inputs that are not observable in the market and therefore represent Level 3 inputs. The fair values of oil and natural gas properties and asset retirement obligations were measured using valuation techniques that convert future cash flows to a single discounted amount. Significant inputs to the valuation of oil and natural gas properties include, but are not limited to recoverable reserves, production rates, future operating and development costs, future commodity prices, appropriate risk-adjusted discounts rates, and other relevant data. These inputs required significant judgments and estimates by management at the time of the valuation and are the most sensitive and may be subject to change. (3) Represents the approximate fair value of Alta Mesa’s $500 million aggregate principal amount of the 7.875% senior unsecured notes due December 15, 2024 using Level 1 inputs as of the acquisition date of approximately $533.6 million, and outstanding borrowings under the Alta Mesa Credit Facility (described in Note 11) of $134 .0 million as of the acquisition date. 
Kingfisher Midstream, LLC [Member]
Business Acquisition [Line Items]
Purchase Consideration	   At February 9,  2018  Preliminary Purchase Consideration:  Cash (1) $ 814,820  SRII Opco Common Units ( 55,000,000 valued at $7.90 per unit) (2) 434,640  Estimated fair value of contingent earn-out purchase consideration (3) 88,105  Settlement of preexisting working capital (4) (5,476)  Total purchase price consideration $ 1,332,089 _________________ (1) The cash consideration after estimated adjustments to net working capital, debt, transaction expenses, capital expenditures and banking fees was $814.8 million. (2) At closing, KFM Contributor received consideration of 55,000,000 SRII Opco Common Units. At closing, the estimated fair value of an SRII Opco Common Unit was assumed to be $7.90 per unit and reflects discounts for holding requirements and liquidity. (3) Pursuant to ASC 805 and ASC 480, the Kingfisher earn-out consideration has been valued at fair value as of the Closing Date and has been classified in stockholders’ equity. The fair value of the contingent equity earn-out consideration was determined using the Monte Carlo simulation valuation method based on Level 3 inputs using the fair value hierarchy. The key inputs included the quoted market price for the Company’s Class A Common Stock, market volatility of a peer group of companies similar to the Company (due to the lack of trading activity in the Company’s Class A Common Stock), no dividend yield, an expected life of each earn-out threshold based on the remaining contractual term of the contingent liability earn-out period and a risk-free rate based on U.S. Dollars overnight indexed swaps with a maturity equivalent to the earn-out’s expected life. (4) Settlement of preexisting working capital between Alta Mesa and Kingfisher. 
Allocation Of Purchase Consideration	   At February 9,  2018  Estimated Fair Value of Assets Acquired  Cash and cash equivalents $ 7,648  Accounts Receivable 4,334  Prepaid expenses 550  Property, plant and equipment: (1)  Pipeline 272,442  Other property, plant and equipment 519  Intangible assets (2) 472,432  Goodwill (3) 650,663  Total fair value of assets acquired 1,408,588  Estimated Fair Value of Liabilities Assumed  Accounts payable and accrued liabilities 33,499  Long-term debt 43,000  Total fair value of liabilities assumed 76,499  Total consideration and fair value $ 1,332,089 _________________ (1) The fair value measurements of crude oil, natural gas and NGL gathering, processing and storage assets are based on inputs that are not observable in the market and therefore represent Level 3 inputs. The fair values of gathering, processing and storage assets were measured using valuation techniques that convert future cash flows to a single discounted amount. These valuations required significant judgments and estimates made by management based on assumptions believed to be reasonable at the time of the valuation, but which are inherently uncertain. The estimates and assumptions are sensitive and may be subject to change. (2) The identifiable intangible assets acquired are primarily related to customer relationships held by Kingfisher prior to Closing. The intangible assets acquired were based upon the estimated fair value as of the acquisition date. The intangible assets have definite lives and are subject to amortization over their economic lives, currently ranging from approximately 10 - 15 years. (3) Goodwill is measured as the excess of the total purchase consideration over the net acquisition date fair value of the assets acquired and liabilities assumed. Goodwill will not be amortized but will be tested for impairment at least annually or whenever certain indicators of impairment are present. If, in the future, it is determined that goodwill is impaired, an impairment charge would be recorded at that time. The factors that make up the goodwill reflected in the preliminary purchase price allocation include expected synergies, including future cost efficiencies with continual flow of activity of Alta Mesa production into the Kingfisher processing facility as the basin expands, as well as other benefits that are expected to be generated. 

Property And Equipment (Tables)

Property And Equipment (Tables)	3 Months Ended
	Mar. 31, 2018
Property And Equipment [Abstract]
Summary Of Property And Equipment	   Successor Predecessor  March 31, December 31,  2018 2017    OIL AND NATURAL GAS PROPERTIES  Unproved properties $ 899,465 $ 84,590  Accumulated impairment of unproved properties — —  Unproved properties, net 899,465 84,590  Proved oil and natural gas properties 1,500,830 1,092,095  Accumulated depreciation, depletion, amortization and impairment (10,773) (256,122)  Proved oil and natural gas properties, net 1,490,057 835,973  TOTAL OIL AND NATURAL GAS PROPERTIES, net 2,389,522 920,563  OTHER PROPERTY AND EQUIPMENT  Land 4,954 2,912  Salt water disposal system 42,113 —  Plant and equipment 275,361 —  Office furniture and equipment, vehicles 979 20,008  Accumulated depreciation (1,285) (16,713)  OTHER PROPERTY AND EQUIPMENT, net 322,122 6,207  TOTAL PROPERTY, PLANT AND EQUIPMENT, net $ 2,711,644 $ 926,770 

Discontinued Operations (Tables

Discontinued Operations (Tables)	3 Months Ended
	Mar. 31, 2018
Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Schedule Of Discontinued Operations	As discussed in Note 1, Alta Mesa distributed the remainder of its non-STACK assets and related liabilities to the AM Contributor in connection with the closing of the Business Combination. The distribution of Alta Mesa’s remaining non-STACK assets and related liabilities during the first quarter of 2018 and the sale of Alta Mesa’s Weeks Island field during the fourth quarter of 2017 were part of Alta Mesa’s overall strategic shift to operate only in the eastern Anadarko Basin. As a result, the Predecessor’s non-STACK assets and liabilities have been presented as discontinued operations in the consolidated balance sheets. The operating results directly related to non-STACK assets and liabilities have been segregated and presented as discontinued operations within the consolidated financial statements in the 2018 Predecessor Period and the 2017 Predecessor Period. Prior to the Business Combination, Alta Mesa had notes payable to its founder (“Founder Notes”) that bear simple interest at 10% . In connection with the Transactions described in Note 1, the Founder Notes were converted into equity interest in the AM Contributor immediately prior to the closing of the Business Combination as they were considered part of the non-STACK asset distribution. The balance of the Founder Notes at the time of conversion was approximately $28.3 million including accrued interest. Interest on the Founder Notes was $0.1 million for the 2018 Predecessor Period and $0.3 million for the 2017 Predecessor Period.  The assets and liabilities directly related to the non-STACK assets have been reclassified to assets and liabilities associated with discontinued operations as follows (in thousands):     Predecessor  December 31,  2017   Assets associated with discontinued operations:  Current assets  Cash $ 61  Accounts receivable 4,980  Other receivables 154  Total current assets 5,195  Noncurrent assets  Investments in LLC - Cost 9,000  Proved oil and natural gas properties, net 15,408  Unproved properties, net 15,504  Land 2,706  Other long-term assets 1,167  Total noncurrent assets 43,785  Total assets associated with discontinued operations $ 48,980   Liabilities associated with discontinued operations:  Current liabilities  Accounts payable and accrued liabilities $ 7,882  Asset retirement obligations 7,537  Total current liabilities 15,419  Noncurrent liabilities  Asset retirement obligations, net of current 37,049  Founder's note 28,166  Other long-term liabilities 1,647  Total noncurrent liabilities 66,862  Total liabilities associated with discontinued operations $ 82,281  The results of operations of the non-STACK assets and other items directly related to the sale of the non-STACK assets have been reclassified in discontinued operations as follows (in thousands):     Predecessor  January 1, 2018 Three  Through Months Ended  February 8, 2018 March 31, 2017   Loss from Discontinued Operations  Operating revenues and other:  Oil $ 1,617 $ 12,405  Natural gas 1,023 3,094  Natural gas liquids 236 547  Other revenues 16 116  Total operating revenues 2,892 16,162  Loss on sale of assets (1,923) —  Total operating revenues and other 969 16,162  Operating expenses:  Lease operating expenses 1,770 7,960  Marketing and transportation 83 381  Production and ad valorem taxes 167 1,802  Workover expense 127 795  Exploration expense — 3,095  Depreciation, depletion and amortization expense 630 5,826  Impairment 5,560 32  Accretion 101 476  General and administrative expense 21 12  Total operating expenses 8,459 20,379  Interest expense (103) (298)  Loss from discontinued operations, net of state income taxes $ (7,593) $ (4,515)  The total operating and investing cash flows of the non-STACK assets are as follows (in thousands):      Predecessor  January 1, 2018 Three  Through Months Ended  February 8, 2018 March 31, 2017   Total operating cash flows of discontinued operations $ (6,838) $ 738  Total investing cash flows of discontinued operations (570) (910) 

Fair Value Disclosures (Tables)

Fair Value Disclosures (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Measurement Of Fair Value Of Assets And Liabilities On Recurring Basis	   Level 1 Level 2 Level 3 Total  (in thousands)  At March 31, 2018: (Successor)  Financial Assets:  Derivative contracts for oil and natural gas — $ 4,481 — $ 4,481  Financial Liabilities:  Derivative contracts for oil and natural gas — $ 33,749 — $ 33,749  At December 31, 2017: (Predecessor)  Financial Assets:  Derivative contracts for oil and natural gas — $ 4,416 — $ 4,416  Financial Liabilities:  Derivative contracts for oil and natural gas — $ 24,609 — $ 24,609 

Derivative Financial Instrume35

Derivative Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2018
Derivative [Line Items]
Fair Values Of Derivative Contracts	 Fair Values of Derivative Contracts:     Successor  March 31, 2018  Net Fair  Gross Gross amounts Value of Assets  Fair Value offset against assets presented in  Balance sheet location of Assets in the Balance Sheet the Balance Sheet   (in thousands)  Derivative financial instruments, current assets $ 1,539 $ (1,539) $ —  Derivative financial instruments, long-term assets 2,942 (2,893) 49  Total $ 4,481 $ (4,432) $ 49      Net Fair  Gross Gross amounts Value of Liabilities  Fair Value offset against liabilities presented in  Balance sheet location of Liabilities in the Balance Sheet the Balance Sheet   (in thousands)  Derivative financial instruments, current liabilities $ 27,940 $ (1,539) $ 26,401  Derivative financial instruments, long-term liabilities 5,809 (2,893) 2,916  Total $ 33,749 $ (4,432) $ 29,317      Predecessor  December 31, 2017  Net Fair  Gross Gross amounts Value of Assets  Fair Value offset against assets presented in  Balance sheet location of Assets in the Balance Sheet the Balance Sheet  (in thousands)  Derivative financial instruments, current assets $ 1,406 $ (1,190) $ 216  Derivative financial instruments, long-term assets 3,010 (3,002) 8  Total $ 4,416 $ (4,192) $ 224      Net Fair  Gross Gross amounts Value of Liabilities  Fair Value offset against liabilities presented in  Balance sheet location of Liabilities in the Balance Sheet the Balance Sheet  (in thousands)  Derivative financial instruments, current liabilities $ 20,493 $ (1,190) $ 19,303  Derivative financial instruments, long-term liabilities 4,116 (3,002) 1,114  Total $ 24,609 $ (4,192) $ 20,417 
Effect Of Derivative Instruments In The Consolidated Statements Of Operations	   Successor Predecessor  Derivatives not February 9, 2018 January 1, 2018 Three  designated as hedging Through Through Months Ended  instruments under ASC 815 March 31, 2018 February 8, 2018 March 31, 2017  (in thousands)  Gain (loss) on derivative contracts  Oil commodity contracts $ (22,579) $ 5,431 $ 26,085   Natural gas commodity contracts (67) 1,867 3,899   Natural gas liquids commodity contracts — — 258  Total gain (loss) on derivative contracts $ (22,646) $ 7,298 $ 30,242 
Oil Derivative Contracts [Member]
Derivative [Line Items]
Open Derivative Contracts	OIL DERIVATIVE CONTRACTS       Volume Weighted Range  Period and Type of Contract in Bbls Average High Low  2018  Price Swap Contracts 1,832,000 $ 53.22 $ 61.26 $ 50.27  Collar Contracts  Short Call Options 1,559,000 61.09 64.60 60.50  Long Put Options 1,559,000 51.18 60.00 50.00  Short Put Options 1,559,000 41.48 52.50 40.00  2019  Collar Contracts  Short Call Options 1,788,500 61.84 65.35 56.50  Long Put Options 1,971,000 50.00 50.00 50.00  Short Put Options 1,971,000 38.43 40.00 37.50  2020  Collar Contracts  Short Call Options 183,000 60.20 60.20 60.20  Long Put Options 549,000 50.67 51.00 50.00  Short Put Options 549,000 40.00 40.00 40.00 
Natural Gas Derivative Contract [Member]
Derivative [Line Items]
Open Derivative Contracts	NATURAL GAS DERIVATIVE CONTRACTS      Volume in Weighted Range  Period and Type of Contract MMBtu Average High Low  2018  Price Swap Contracts 4,280,000 $ 2.80 $ 2.85 $ 2.75  Collar Contracts  Short Call Options 1,985,000 3.30 3.75 3.14  Long Put Options 1,680,000 2.82 2.90 2.75  Short Put Options 610,000 2.40 2.40 2.40  2019  Collar Contracts  Short Call Options 1,350,000 3.47 3.75 3.30  Long Put Options 900,000 2.90 2.90 2.90  Short Put Options 900,000 2.40 2.40 2.40 
Natural Gas Basis Swap Derivative Contracts [Member]
Derivative [Line Items]
Natural Gas Basis Swap Contracts	NATURAL GAS BASIS SWAP DERIVATIVE CONTRACTS      Weighted  Average Spread  Volume in MMBtu (1) Reference Price 1 (1) Reference Price 2 (1) Period ($ per MMBtu)  152,500 WAHA NYMEX Henry Hub Nov '18 — Dec '18 $ (1.05)  225,000 WAHA NYMEX Henry Hub Jan '19 — Mar '19 (1.05) _________________ (1) Represents short swaps that fix the basis differentials between WAHA and NYMEX Henry Hub. 
Oil Basis Swap Derivative Contracts [Member]
Derivative [Line Items]
Natural Gas Basis Swap Contracts	 OIL BASIS SWAP DERIVATIVE CONTRACTS      Weighted  Average Spread  Volume in Bbl (1) Reference Price 1 (1) Reference Price 2 (1) Period ($ per Bbl)  1,104,000 CMA Oil WTI July '18 — Dec '18 $ (0.54) _________________ (1) Represents basis swaps for the NYMEX CMA (Calendar Monthly Average) Roll that reconcile the trade month versus the delivery month for physical contract pricing.

Intangible Assets (Tables)

Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2018
Intangible Assets [Abstract]
Schedule Of Finite-Lived Customer Relationships	   March 31, 2018  Customer Relationships $ 472,432  Accumulated amortization (3,519)  Intangibles, net $ 468,913  Weighted average amortization (years) 12 
Estimated Amortization Expense	   Fiscal Year: March 31, 2018  Remainder of 2018 $ 15,839  2019 35,170  2020 42,002  2021 41,222  2022 40,562  Thereafter 294,118  Total amortization $ 468,913 

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	3 Months Ended
	Mar. 31, 2018
Asset Retirement Obligations [Abstract]
Summary Of Changes In Asset Retirement Obligations	   2018   Balance, as of January 1 (Predecessor) $ 10,469  Liabilities settled (63)  Revisions to estimates 63  Accretion expense 39  Balance, as of February 8 (Predecessor) 10,508   Balance, as of February 9 (Successor) $ —  Liabilities assumed from Business Combination 5,998  Liabilities incurred 421  Liabilities settled (166)  Revisions to estimates 300  Accretion expense 102  Balance, as of March 31 (Successor) 6,655  Less: Current portion 622  Long-term portion $ 6,033 

Long Term Debt, Net (Tables)

Long Term Debt, Net (Tables)	3 Months Ended
	Mar. 31, 2018
Long Term Debt, Net [Abstract]
Long-Term Debt, Net	   Successor Predecessor  March 31, December 31,  2018 2017   Alta Mesa senior secured revolving credit facility $ — $ 117,065  Kingfisher secured revolving credit facility 52,000 —  7.875% senior unsecured notes due 2024 500,000 500,000  Unamortized premium on senior unsecured notes 32,815 —  Unamortized deferred financing costs — (9,625)  Total long-term debt, net $ 584,815 $ 607,440 
Summary Of Future Maturities Of Long-Term Debt	   (in thousands)  2019 $ —  2020 —  2021 52,000  2022 —  2023 500,000  Thereafter —  $ 552,000 

Accounts Payable And Accrued 39

Accounts Payable And Accrued Liabilities (Tables)	3 Months Ended
	Mar. 31, 2018
Accounts Payable And Accrued Liabilities [Abstract]
Detail Of Accounts Payable And Accrued Liabilities	   Successor Predecessor  March 31, December 31,  2018 2017   Capital expenditures $ 50,117 $ 48,771  Revenues and royalties payable 31,861 29,514  Operating expenses/taxes 23,138 14,632  Interest 12,355 2,587  Derivative settlement payable 2,826 2,106  Other 540 4,301  Total accrued liabilities 120,837 101,911  Accounts payable 38,273 68,578  Accounts payable and accrued liabilities $ 159,110 $ 170,489 

Commitments And Contingencies (

Commitments And Contingencies (Tables)	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies [Abstract]
Future Base Rentals For Non-Cancelable Leases	   (in thousands)  Remainder of 2018 $ 1,284  2019 1,545  2020 1,593  2021 1,620  2022 839  Thereafter 368  $ 7,249 
Schedule Of Firm Transportation Contracts	  (in thousands)  Remainder of 2018 $ 9,702  2019 10,976  2020 7,876  2021 7,876  2022 7,876  Thereafter 84,742  $ 129,048 

Equity Based Compensation (Tabl

Equity Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary Of Stock Options Granted And Valuation Assumptions	  Successor  February 9, 2018  Through  March 31, 2018   Expected term (in years) 4.5  Expected stock volatility 64.5%  Dividend yield —  Risk-free interest rate 2.4% 
Schedule Of Stock Option	   Successor  Stock Options Weighted Average Grant - Date Fair Value Weighted Average Remaining Term (in years) Aggregate Intrinsic Value (in thousands)  Outstanding as of February 9, 2018 $ — —  Granted 4,143,231 4.62 4.3  Exercised — — —  Forfeited or expired — — —  Outstanding as of March 31, 2018 4,143,231 4.62 4.3 $ 19,129  Exercisable as of March 31, 2018 — $ — — $ — 
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule Of Restricted Stock	   Successor  Restricted Stock Awards Weighted Average Grant - Date Fair Value per share  Outstanding as of February 9, 2018 — $ —  Granted 1,233,470 8.94  Exercised — —  Forfeited or expired — —  Outstanding as of March 31, 2018 1,233,470 $ 8.94 
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule Of Restricted Stock Units	   Successor  RSUs Weighted Average Grant - Date Fair Value per unit  Outstanding as of February 9, 2018 — $ —  Granted 718,163 8.94  Exercised — —  Forfeited or expired — —  Outstanding as of March 31, 2018 718,163 $ 8.94 

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2018
Income Taxes [Abstract]
Schedule Of Components Of Income Tax Expense (Benefit)	   Successor  February 9, 2018  Through  March 31, 2018  Current taxes:  Federal $ —  State —  —  Deferred taxes:  Federal (3,111)  State (702)  (3,813)  Income tax benefit $ (3,813) 

Business Segment Information (T

Business Segment Information (Tables)	3 Months Ended
	Mar. 31, 2018
Business Segment Information [Abstract]
Schedule Of Results Of Reportable Segments	   Successor  February 9, 2018 Through March 31, 2018  Exploration and  Production Midstream Eliminations Total  (in thousands)  Operating revenues from external customers $ 27,353 $ 18,517 $ — $ 45,870  Operating inter-segment revenues 6,737 4,562 (11,299) —  Total operating revenues 34,090 23,079 (11,299) 45,870   Operating income (loss) (29,921) (1,618) — (31,539)  Other income (expense) (4,650) (248) — (4,898)  Segment net income (loss) before tax $ (34,571) $ (1,866) $ — $ (36,437)  Corporate general and administrative expenses 925  Income (loss) from continuing operations before income taxes $ (37,362) 
Schedule Of Segment Revenue By Product Line	   Successor  February 9, 2018 Through March 31, 2018  Exploration and  Production Midstream Eliminations Total  (in thousands)  Product line revenue:  Oil sales $ 40,278 $ — $ — $ 40,278  Natural gas sales 5,210 — — 5,210  Natural gas liquids sales 4,714 — — 4,714  Product sales — 15,106 (6,737) 8,369  Gathering and processing revenue — 7,973 (4,562) 3,411  Total product line revenue (1) $ 50,202 $ 23,079 $ (11,299) $ 61,982 _________________ (1) Total product line revenue excludes other revenue and gain (loss) on derivative contracts.
Summary Of Assets By Segment	   Successor  March 31, 2018  Exploration and  Production Midstream Eliminations Total  (in thousands)  Total segment assets $ 2,828,379 $ 1,415,497 $ (4,092) $ 4,239,784  Corporate assets 3,755  Total assets $ 4,243,539 

Description Of Business (Narrat

Description Of Business (Narrative) (Details) - USD ($)	Mar. 29, 2017	Mar. 31, 2018	Feb. 09, 2018
Business Acquisition [Line Items]
Proceeds from IPO	$ 1,014,300,000
Warrants sold	15,133,333
Proceeds from issuance of warrants	$ 22,700,000
Proceeds placed in trust account	1,035,000,000
Deferred underwriting commission placed in trust account	36,200,000
Underwriting expenses paid	$ 20,700,000
Alta Mesa Holdings GP, LLC [Member]
Business Acquisition [Line Items]
Economic interests			100.00%
Voting interests			90.00%
SRII Opco, LP [Member]
Business Acquisition [Line Items]
Noncontrolling interest		44.20%
SRII Opco, LP [Member] | Alta Mesa Holdings GP, LLC [Member]
Business Acquisition [Line Items]
Economic interests			100.00%
Voting interests			90.00%
SRII Opco, LP [Member] | Kingfisher Midstream, LLC [Member]
Business Acquisition [Line Items]
Economic interests			100.00%

Summary Of Significant Accoun45

Summary Of Significant Accounting Policies (Narrative) (Details) - USD ($) shares in Millions	Feb. 08, 2018	Feb. 08, 2018	Mar. 31, 2018	Feb. 28, 2018	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Feb. 09, 2018	Dec. 31, 2014
Summary Of Significant Accounting Policies [Line Items]
FDIC insured maximum amount			$ 250,000		$ 250,000
Liability for uncertain tax positions							$ 0
Fair value of senior notes payable			520,600,000		$ 520,600,000
Processing Plant And Pipelines [Member]
Summary Of Significant Accounting Policies [Line Items]
Depreciable life of property and equipment					35 years
Minimum [Member] | Other Property And Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Depreciable life of property and equipment					3 years
Maximum [Member] | Other Property And Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Depreciable life of property and equipment					7 years
7.875% Senior Unsecured Notes Due 2024 [Member] | Alta Mesa Holdings, LP [Member]
Summary Of Significant Accounting Policies [Line Items]
7.875% senior unsecured notes due 2024			500,000,000		$ 500,000,000
Fair value of senior notes payable								$ 533,600,000
Alta Mesa Holdings, LP [Member]
Summary Of Significant Accounting Policies [Line Items]
7.875% senior unsecured notes due 2024			500,000,000		500,000,000
Fair value of senior notes payable								$ 533,600,000
Alta Mesa Holdings, LP [Member] | 7.875% Senior Unsecured Notes Due 2024 [Member]
Summary Of Significant Accounting Policies [Line Items]
Face value of senior notes issued			$ 500,000,000		$ 500,000,000
Stated interest rate of senior notes			7.875%		7.875%
Alta Mesa Holdings, LP [Member] | 8% Senior Unsecured Notes Due 2019 [Member]
Summary Of Significant Accounting Policies [Line Items]
Stated interest rate of senior notes									8.00%
Successor [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment expense of proved properties			$ 0
Impairment expense of unproved properties			0
Other write-downs and impairment expense			0
Depreciation depletion and amortization related to oil and gas properties			10,800,000
Liability for uncertain tax positions			0		$ 0
7.875% senior unsecured notes due 2024			533,600,000		533,600,000
Impairment of intangible assets					$ 0
Income tax provision (benefit)			(3,813,000)
Successor [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangible assets userful life					10 years
Successor [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangible assets userful life					15 years
Successor [Member] | 7.875% Senior Unsecured Notes Due 2024 [Member]
Summary Of Significant Accounting Policies [Line Items]
7.875% senior unsecured notes due 2024			$ 500,000,000		$ 500,000,000
Successor [Member] | Warrant [Member]
Summary Of Significant Accounting Policies [Line Items]
Antidilutive securities excluded			63.2
Successor [Member] | Class C Common Stock [Member]
Summary Of Significant Accounting Policies [Line Items]
Antidilutive securities excluded			213.4
Successor [Member] | Stock Options, Restricted Stock And Restricted Units [Member]
Summary Of Significant Accounting Policies [Line Items]
Antidilutive securities excluded			6.1
Predecessor [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment expense of proved properties		$ 0					1,200,000
Impairment expense of unproved properties		0					0
Other write-downs and impairment expense		0					0
Depreciation depletion and amortization related to oil and gas properties		11,200,000					18,300,000
Depreciation, depletion, and amortization for midstream assets	$ 0			$ 0			0
Depreciation expense for other property and equipment		$ 600,000					700,000
Income tax provision (benefit)						$ 285,000
Predecessor [Member] | 7.875% Senior Unsecured Notes Due 2024 [Member]
Summary Of Significant Accounting Policies [Line Items]
7.875% senior unsecured notes due 2024							500,000,000
Predecessor [Member] | Alta Mesa Holdings, LP [Member]
Summary Of Significant Accounting Policies [Line Items]
Amount of excess of net assets							$ 333,200,000

Summary Of Significant Accoun46

Summary Of Significant Accounting Policies (Reconciliation Of Cash, Cash Equivalents And Restricted Cash) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Feb. 08, 2018	Dec. 31, 2017	Mar. 31, 2017	Feb. 28, 2017	Dec. 31, 2016
Successor [Member]
Summary Of Significant Accounting Policies [Line Items]
Cash and cash equivalents	$ 261,063
Short-term restricted cash	1,295
Total cash, cash equivalents and restricted cash	$ 262,358				$ 388
Predecessor [Member]
Summary Of Significant Accounting Policies [Line Items]
Cash and cash equivalents			$ 3,660
Short-term restricted cash			1,269
Cash of discontinued operations			61
Total cash, cash equivalents and restricted cash		$ 10,345	$ 4,990	$ 5,965		$ 7,618

Summary Of Significant Accoun47

Summary Of Significant Accounting Policies (Schedule Of Accounts Receivable ) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Successor [Member]
Summary Of Significant Accounting Policies [Line Items]
Oil, natural gas and natural gas liquids sales	$ 39,067
Joint interest billings	33,197
Pooling interest	37,626
Allowance for doubtful accounts	(65)
Total accounts receivable, net	$ 109,825
Predecessor [Member]
Summary Of Significant Accounting Policies [Line Items]
Oil, natural gas and natural gas liquids sales		$ 26,916
Joint interest billings		13,821
Pooling interest		35,839
Allowance for doubtful accounts		(415)
Total accounts receivable, net		$ 76,161

Summary Of Significant Accoun48

Summary Of Significant Accounting Policies (Schedule Of Earnings Per Share, Basic And Diluted) (Details) - Successor [Member] $ / shares in Units, $ in Thousands	2 Months Ended
	Mar. 31, 2018USD ($)$ / sharesshares
Income (loss) attributable to common stock | $	$ (13,235)
Weighted average common shares outstanding (Basic)	169,371,730
Weighted Average Number of Shares Outstanding, Diluted, Total	169,371,730
Basic and diluted | $ / shares	$ (0.08)

Supplemental Cash Flow Inform49

Supplemental Cash Flow Information (Supplemental Disclosures To The Consolidated Statements Of Cash Flows) (Details) - USD ($) $ in Thousands	Feb. 09, 2018	Feb. 08, 2018	Mar. 31, 2018	Feb. 28, 2018	Mar. 31, 2017
Successor [Member]
Supplemental Cash Flow Information [Line Items]
Cash paid for interest			$ 1,092
Non-cash Investing And Financing Activities:
Change in asset retirement obligations			421
Change in accruals or liabilities for capital expenditures			(36,866)
Equity issued in Business Combination	$ 2,058,635		$ 2,058,635
Predecessor [Member]
Supplemental Cash Flow Information [Line Items]
Cash paid for interest		$ 1,145			$ 1,162
Non-cash Investing And Financing Activities:
Change in asset retirement obligations					296
Change in accruals or liabilities for capital expenditures		4,712			$ 21,111
Distribution of non-STACK assets (net liability)		$ 33,102		$ (33,102)

Business Combination (Narrative

Business Combination (Narrative) (Details) - USD ($)	Feb. 09, 2018	Feb. 08, 2018	Aug. 16, 2017	Apr. 30, 2018	Feb. 28, 2018	Mar. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Warrants						62,966,666
Common Class C [Member]
Business Acquisition [Line Items]
Common stock, par value	$ 0.0001
Common stock par value	$ 0.0001
SRII Opco, LP [Member]
Business Acquisition [Line Items]
Earn-out consideration, Day for volume-weighted average price			20 days
Redeemable days after closing						7 years
SRII Opco, LP [Member] | Common Units [Member]
Business Acquisition [Line Items]
Shares issued to acquire businesses	59,871,031
SRII Opco, LP [Member]
Business Acquisition [Line Items]
Voting interests	44.20%
Payment towards acquisition of all working interests	$ 1,406,000,000
Number of shares acquired	169,371,730
Number of warrants acquired	62,966,666
Alta Mesa, Alta Mesa GP, And Kingfisher [Member] | SRII Opco, LP [Member]
Business Acquisition [Line Items]
Shares issued to acquire businesses	213,402,398
Percentage of outstanding shares issued	55.80%
Alta Mesa Holdings GP, LLC [Member]
Business Acquisition [Line Items]
Economic interests	100.00%
Voting interests	90.00%
Contribution to affiliates	$ 560,000,000
Alta Mesa Holdings GP, LLC [Member] | SRII Opco, LP [Member]
Business Acquisition [Line Items]
Economic interests	100.00%
Voting interests	90.00%
Kingfisher Midstream, LLC [Member]
Business Acquisition [Line Items]
Cash	$ 814,820,000
Kingfisher Midstream, LLC [Member] | SRII Opco, LP [Member]
Business Acquisition [Line Items]
Economic interests	100.00%
Shares issued to acquire businesses	55,000,000
Common stock, par value	$ 7.90
Common stock par value	$ 7.90
Alta Mesa Holdings, LP [Member]
Business Acquisition [Line Items]
Earn-out consideration, Day for volume-weighted average price						20 years
Alta Mesa Holdings, LP [Member] | SRII Opco, LP [Member]
Business Acquisition [Line Items]
Shares issued to acquire businesses	158,402,398
Common stock, par value	$ 7.90
Common stock par value	$ 7.90
Riverstone VI SR II Holdings, L.P. [Member] | Common Class A [Member]
Business Acquisition [Line Items]
Shares issued	$ 40,000,000
Warrants issued	13,333,333
Proceeds from stock issued	$ 400,000,000
KFM Contributor [Member] | SRII Opco, LP [Member]
Business Acquisition [Line Items]
Contribution to affiliates	$ 814,800,000
KFM Contributor [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Shares issued to acquire businesses				89,680
Closing adjustments				$ 5,000,000
Minority Voting Interest Holders In Alta Mesa GP [Member]
Business Acquisition [Line Items]
Voting interests	10.00%
AM Contributor [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Shares issued to acquire businesses				1,197,934
AM Contributor [Member] | Alta Mesa Holdings, LP [Member] | SRII Opco, LP [Member]
Business Acquisition [Line Items]
Shares issued to acquire businesses	138,402,398
SRII Opco, LP [Member] | Kingfisher Midstream, LLC [Member]
Business Acquisition [Line Items]
Economic interests	100.00%
SRII Opco, LP [Member] | Alta Mesa Holdings, LP [Member]
Business Acquisition [Line Items]
Economic interests	100.00%
Voting interests	90.00%
Predecessor [Member]
Business Acquisition [Line Items]
Common stock, par value							$ 0.0001
Other receivables							$ 1,388,000
Common stock par value							$ 0.0001
Predecessor [Member] | Alta Mesa Holdings, LP [Member]
Business Acquisition [Line Items]
Transaction-related costs		$ 65,200,000			$ 65,200,000		$ 65,200,000

Business Combination (Earn-Out

Business Combination (Earn-Out Consideration) (Details) - $ / shares	Feb. 09, 2018	Apr. 30, 2018
AM Contributor [Member] | Subsequent Event [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Earn-Out Consideration		1,197,934
KFM Contributor [Member] | Subsequent Event [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Earn-Out Consideration		89,680
SRII Opco, LP [Member] | $14.00 VWAP [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
20-Day VWAP	$ 14
SRII Opco, LP [Member] | $16.00 VWAP [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
20-Day VWAP	16
SRII Opco, LP [Member] | $18.00 VWAP [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
20-Day VWAP	18
SRII Opco, LP [Member] | $20.00 VWAP [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
20-Day VWAP	$ 20
SRII Opco, LP [Member] | AM Contributor [Member] | $14.00 VWAP [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Earn-Out Consideration	10,714,285
SRII Opco, LP [Member] | AM Contributor [Member] | $16.00 VWAP [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Earn-Out Consideration	9,375,000
SRII Opco, LP [Member] | AM Contributor [Member] | $18.00 VWAP [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Earn-Out Consideration	13,888,889
SRII Opco, LP [Member] | AM Contributor [Member] | $20.00 VWAP [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Earn-Out Consideration	12,500,000
SRII Opco, LP [Member] | KFM Contributor [Member] | $14.00 VWAP [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Earn-Out Consideration	7,142,857
SRII Opco, LP [Member] | KFM Contributor [Member] | $16.00 VWAP [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Earn-Out Consideration	6,250,000

Business Combination (Purchase

Business Combination (Purchase Consideration) (Details) - USD ($) $ / shares in Units, $ in Thousands	Feb. 09, 2018	Mar. 31, 2018
Kingfisher Midstream, LLC [Member]
Business Acquisition [Line Items]
Cash	$ 814,820
SRII Opco Common Units	434,640
Estimated fair value of contingent earn-out purchase consideration	88,105
Settlement of preexisting relationship at fair value	(5,476)
Total consideration paid	$ 1,332,089
Alta Mesa Holdings GP, LLC [Member]
Business Acquisition [Line Items]
Economic interests	100.00%
Voting interests	90.00%
SRII Opco, LP [Member]
Business Acquisition [Line Items]
Redeemable days after closing		7 years
SRII Opco, LP [Member] | Alta Mesa Holdings, LP [Member]
Business Acquisition [Line Items]
SRII Opco Common Units	$ 1,251,782
Estimated fair value of contingent earn-out purchase consideration	284,109
Settlement of preexisting relationship at fair value	5,476
Total consideration paid	$ 1,541,367
Common units	158,402,398
Common stock par value	$ 7.90
SRII Opco, LP [Member] | Kingfisher Midstream, LLC [Member]
Business Acquisition [Line Items]
Common units	55,000,000
Common stock par value	$ 7.90
Total consideration including transaction costs	$ 814,800
Economic interests	100.00%
SRII Opco, LP [Member] | Alta Mesa Holdings GP, LLC [Member]
Business Acquisition [Line Items]
Economic interests	100.00%
Voting interests	90.00%
SRII Opco, LP [Member] | AM Contributor [Member] | Alta Mesa Holdings, LP [Member]
Business Acquisition [Line Items]
Common units	138,402,398
SRII Opco, LP [Member] | Riverstone Contributor Agreement [Member] | Alta Mesa Holdings, LP [Member]
Business Acquisition [Line Items]
Common units	20,000,000

Business Combination (Allocatio

Business Combination (Allocation Of Purchase Consideration) (Details) - USD ($) $ in Thousands	Feb. 09, 2018	Mar. 31, 2018
Business Acquisition [Line Items]
Senior secured revolving credit facility	$ 134,000
Fair value of senior notes payable		$ 520,600
Alta Mesa Holdings, LP [Member]
Business Acquisition [Line Items]
Cash, cash equivalents and short term restricted cash	10,345
Accounts Receivable	101,745
Other Receivables	1,222
Receivables due from related party	907
Prepaid expenses and other current assets	1,405
Derivative financial instruments	352
Oil and natural gas properties, successful efforts	2,314,858
Other property and equipment, net	43,318
Notes receivable due from affiliate	12,454
Deposits and other long-term assets	10,286
Total fair value of assets acquired	2,496,892
Accounts payable and accrued liabilities	210,867
Advances from non-operators	6,803
Advances from related party	47,506
Asset retirement obligations	5,998
Derivative financial instruments	11,585
Long-term debt	667,700
Other long-term liabilities	5,066
Total fair value of liabilities assumed	955,525
Total consideration and fair value	1,541,367
Alta Mesa Holdings, LP [Member] | 7.875% Senior Unsecured Notes Due 2024 [Member]
Business Acquisition [Line Items]
7.875% senior unsecured notes due 2024		500,000
Fair value of senior notes payable	533,600
Alta Mesa Holdings, LP [Member] | 7.875% Senior Unsecured Notes Due 2024 [Member] | Level 1 [Member]
Business Acquisition [Line Items]
Fair value of senior notes payable	533,600
Kingfisher Midstream, LLC [Member]
Business Acquisition [Line Items]
Cash, cash equivalents and short term restricted cash	7,648
Accounts Receivable	4,334
Prepaid expenses and other current assets	550
Pipeline	272,442
Other property and equipment, net	519
Intangible assets	472,432
Goodwill	650,663
Total fair value of assets acquired	1,408,588
Accounts payable and accrued liabilities	33,499
Long-term debt	43,000
Total fair value of liabilities assumed	76,499
Total consideration and fair value	$ 1,332,089
Alta Mesa Credit Facility [Member] | Alta Mesa Holdings, LP [Member]
Business Acquisition [Line Items]
Balance outstanding		$ 134,000
Minimum [Member] | Kingfisher Midstream, LLC [Member]
Business Acquisition [Line Items]
Intangible assets userful life	10 years
Maximum [Member] | Kingfisher Midstream, LLC [Member]
Business Acquisition [Line Items]
Intangible assets userful life	15 years

Business Combination (Summary O

Business Combination (Summary Of Pro Forma Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Business Combination [Abstract]
Total operating revenues	$ 112,037	$ 75,452
Net income (loss)	(12,100)	25,265
Net income (loss) attributable to Alta Mesa Resources, Inc	$ (5,281)	$ 8,218
Basic and diluted net income (loss) per share	$ (0.03)	$ 0.05

Property And Equipment (Summary

Property And Equipment (Summary Of Property And Equipment) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Successor [Member]
Property, Plant and Equipment [Line Items]
Unproved properties	$ 899,465
Unproved properties, net	899,465
Proved oil and natural gas properties	1,500,830
Accumulated depreciation, depletion, amortization and impairment	(10,773)
Proved oil and natural gas properties, net	1,490,057
TOTAL OIL AND NATURAL GAS PROPERTIES, net	2,389,522
Land	4,954
Salt water disposal system	42,113
Property and equipment	275,361
Office furniture and equipment, vehicles	979
Accumulated depreciation	(1,285)
OTHER PROPERTY AND EQUIPMENT, net	322,122
Total property, plant and equipment, net	$ 2,711,644
Predecessor [Member]
Property, Plant and Equipment [Line Items]
Unproved properties		$ 84,590
Unproved properties, net		84,590
Proved oil and natural gas properties		1,092,095
Accumulated depreciation, depletion, amortization and impairment		(256,122)
Proved oil and natural gas properties, net		835,973
TOTAL OIL AND NATURAL GAS PROPERTIES, net		920,563
Land		2,912
Office furniture and equipment, vehicles		20,008
Accumulated depreciation		(16,713)
OTHER PROPERTY AND EQUIPMENT, net		6,207
Total property, plant and equipment, net		$ 926,770

Discontinued Operations (Narrat

Discontinued Operations (Narrative) (Details) - Predecessor [Member] - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Feb. 08, 2018	Mar. 31, 2017	Dec. 31, 2017	Mar. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Interest on notes payable to founder	$ 103	$ 298
Notes Payable To Founder [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Effective rate of interest				10.00%
Notes payable to founder				$ 28,300
Interest on notes payable to founder	$ 100		$ 300

Discontinued Operations (Schedu

Discontinued Operations (Schedule Of Assets And Liabilities Reclassified In Discontinued Operation) (Details) - Predecessor [Member] $ in Thousands	Dec. 31, 2017USD ($)
Current assets associated with discontinued operations:
Total current assets	$ 5,195
Noncurrent assets associated with discontinued operations:
Total noncurrent assets	43,785
Current liabilities associated with discontinued operations
Total current liabilities	15,419
Noncurrent liabilities associated with discontinued operations
Total noncurrent liabilities	66,862
Weeks Island Field, Louisiana [Member] | Non-Stack Assets [Member] | Discontinued Operations, Disposed of by Sale [Member]
Current assets associated with discontinued operations:
Cash	61
Accounts receivable	4,980
Other receivables	154
Total current assets	5,195
Noncurrent assets associated with discontinued operations:
Investments in LLC - Cost	9,000
Proved oil and natural gas properties, net	15,408
Unproved properties, net	15,504
Land	2,706
Other long-term assets	1,167
Total noncurrent assets	43,785
Total assets associated with discontinued operations	48,980
Current liabilities associated with discontinued operations
Accounts payable and accrued liabilities	7,882
Asset retirement obligations	7,537
Total current liabilities	15,419
Noncurrent liabilities associated with discontinued operations
Asset retirement obligations, net of current	37,049
Founder's note	28,166
Other long-term liabilities	1,647
Total noncurrent liabilities	66,862
Total liabilities associated with discontinued operations	$ 82,281

Discontinued Operations (Sche58

Discontinued Operations (Schedule Of Operations And Other Items Reclassified In Discontinued Operations) (Details) - Non-Stack Assets [Member] - Predecessor [Member] - Weeks Island Field, Louisiana [Member] - Discontinued Operations, Disposed of by Sale [Member] - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Feb. 08, 2018	Mar. 31, 2017
Operating revenue and other loss from discontinued operations
Oil	$ 1,617	$ 12,405
Natural gas	1,023	3,094
Natural gas liquids	236	547
Other revenues	16	116
Total operating revenues	2,892	16,162
Loss on sale of assets	(1,923)
Total operating revenues and other	969	16,162
Operating expenses from discontinued operations:
Lease operating expenses	1,770	7,960
Marketing and transportation	83	381
Production and ad valorem taxes	167	1,802
Workover expense	127	795
Exploration expense		3,095
Depreciation, depletion, and amortization expense	630	5,826
Impairment	5,560	32
Accretion	101	476
General and administrative expense	21	12
Total operating expenses	8,459	20,379
Interest expense	103	298
Loss from discontinued operations, net of state income taxes	$ (7,593)	$ (4,515)

Discontinued Operations (Total

Discontinued Operations (Total Operating And Investing Cash Flows Of Discontinued Operations) (Details) - Predecessor [Member] - Weeks Island Field, Louisiana [Member] - Discontinued Operations, Disposed of by Sale [Member] - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Feb. 08, 2018	Mar. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total operating cash flows of discontinued operations	$ (6,838)	$ 738
Total investing cash flows of discontinued operations	$ (570)	$ (910)

Fair Value Disclosures (Narrati

Fair Value Disclosures (Narrative) (Details) - USD ($)	2 Months Ended		3 Months Ended	12 Months Ended
	Mar. 31, 2018	Feb. 28, 2018	Mar. 31, 2017	Dec. 31, 2017	Feb. 09, 2018
Fair Value Disclosures [Line Items]
Fair value of senior notes payable	$ 520,600,000
Alta Mesa Holdings, LP [Member]
Fair Value Disclosures [Line Items]
Face value of senior notes issued	500,000,000
Fair value of senior notes payable					$ 533,600,000
Successor [Member]
Fair Value Disclosures [Line Items]
Asset retirement obligation measured at fair value	400,000
Face value of senior notes issued	$ 533,600,000
Predecessor [Member]
Fair Value Disclosures [Line Items]
Carrying value of oil and gas properties				$ 3,300,000
Written down fair value of oil and gas properties				2,100,000
Impairment charges to oil and gas properties			$ 1,188,000	1,200,000
Asset retirement obligation measured at fair value		$ 0		$ 300,000

Fair Value Disclosures (Measure

Fair Value Disclosures (Measurement Of Fair Value Of Assets And Liabilities On Recurring Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Successor [Member]
Financial Assets:
Derivative contracts for oil and natural gas	$ 4,481
Financial Liabilities:
Derivative contracts for oil and natural gas	33,749
Successor [Member] | Level 2 [Member]
Financial Assets:
Derivative contracts for oil and natural gas	4,481
Financial Liabilities:
Derivative contracts for oil and natural gas	$ 33,749
Predecessor [Member]
Financial Assets:
Derivative contracts for oil and natural gas		$ 4,416
Financial Liabilities:
Derivative contracts for oil and natural gas		24,609
Predecessor [Member] | Level 2 [Member]
Financial Assets:
Derivative contracts for oil and natural gas		4,416
Financial Liabilities:
Derivative contracts for oil and natural gas		$ 24,609

Derivative Financial Instrume62

Derivative Financial Instruments (Narrative) (Details)	3 Months Ended
	Mar. 31, 2018
Derivatives, Fair Value [Line Items]
Derivative Asset, Setoff Rights, Description	SuccessorPredecessorDerivatives not February 9, 2018 January 1, 2018Three designated as hedgingThroughThroughMonths Endedinstruments under ASC 815March 31, 2018February 8, 2018March 31, 2017(in thousands)Gain (loss) on derivative contractsOil commodity contracts $ (22,579)$ 5,431$ 26,085Natural gas commodity contracts (67) 1,867 3,899Natural gas liquids commodity contracts - - 258Total gain (loss) on derivative contracts$ (22,646)$ 7,298$ 30,242Although our counterparties provide no collateral, the master derivative agreements with each counterparty effectively allow us, so long as we are not a defaulting party, after a default or the occurrence of a termination event, to set-off an unpaid hedging agreement receivable against the interest of the counterparty in any outstanding balance under the Alta Mesa Credit Facility described in Note 11- Long Term Debt, net.If a counterparty were to default in payment of an obligation under the master derivative agreements, we could be exposed to commodity price fluctuations, and the protection intended by the hedge could be lost. The value of our derivative financial instruments would be impacted.
Netting presentation for derivatives	Derivative contracts are subject to master netting arrangements and are presented on a net basis in the consolidated balance sheets. This netting can cause derivative assets to be ultimately presented in a liability account on the consolidated balance sheets. Likewise, derivative liabilities could be presented in a derivative asset account.
Commodity Derivative Contract [Member]
Derivatives, Fair Value [Line Items]
Derivatives, Use of Derivatives	We account for our derivative contracts under the provisions of ASC 815. We have entered into forward-swap contracts and collar contracts to reduce our exposure to price risk in the spot market for oil, natural gas and natural gas liquids. From time to time, we also utilize financial basis swap contracts, which address the price differential between market-wide benchmark prices and other benchmark pricing referenced in certain of our oil, natural gas and natural gas liquids sales contracts. Substantially all of our hedging agreements are executed by affiliates of our lenders under the Alta Mesa Credit Facility described in Note 11, and are collateralized by the security interests of the respective affiliated lenders in certain of our assets under the Alta Mesa Credit Facility. The contracts settle monthly and are scheduled to coincide with oil production equivalent to barrels (Bbl) per month, natural gas production equivalent to volumes in millions of British thermal units (MMBtu) per month, and natural gas liquids production to volumes in gallons (Gal) per month. The contracts represent agreements between us and the counterparties to exchange cash based on a designated price, or in the case of financial basis hedging contracts, based on a designated price differential between various benchmark prices. Cash settlement occurs monthly.
Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivatives, Use of Derivatives	From time to time, we enter into interest rate swap agreements with financial institutions to mitigate the risk of loss due to changes in interest rates.

Derivative Financial Instrume63

Derivative Financial Instruments (Fair Values Of Derivative Contracts) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Successor [Member]
Derivatives, Fair Value [Line Items]
Gross Fair Value of Assets	$ 4,481
Derivative assets, Gross amounts offset against assets in the Balance Sheet	(4,432)
Derivative Asset, Net Fair Value of Assets presented in the Balance Sheet	49
Gross Fair Value of Liabilities	33,749
Derivative liabilities, Gross amounts offset against liabilities in the Balance Sheet	(4,432)
Derivative Liability, Net Fair Value of Liabilities presented in the Balance Sheet	29,317
Successor [Member] | Derivative Assets Current [Member]
Derivatives, Fair Value [Line Items]
Gross Fair Value of Assets	1,539
Derivative assets, Gross amounts offset against assets in the Balance Sheet	(1,539)
Successor [Member] | Derivative Asset Non-Current [Member]
Derivatives, Fair Value [Line Items]
Gross Fair Value of Assets	2,942
Derivative assets, Gross amounts offset against assets in the Balance Sheet	(2,893)
Derivative Asset, Net Fair Value of Assets presented in the Balance Sheet	49
Successor [Member] | Derivative Liabilities Current [Member]
Derivatives, Fair Value [Line Items]
Gross Fair Value of Liabilities	27,940
Derivative liabilities, Gross amounts offset against liabilities in the Balance Sheet	(1,539)
Derivative Liability, Net Fair Value of Liabilities presented in the Balance Sheet	26,401
Successor [Member] | Derivative Liabilities Non Current [Member]
Derivatives, Fair Value [Line Items]
Gross Fair Value of Liabilities	5,809
Derivative liabilities, Gross amounts offset against liabilities in the Balance Sheet	(2,893)
Derivative Liability, Net Fair Value of Liabilities presented in the Balance Sheet	$ 2,916
Predecessor [Member]
Derivatives, Fair Value [Line Items]
Gross Fair Value of Assets		$ 4,416
Derivative assets, Gross amounts offset against assets in the Balance Sheet		(4,192)
Derivative Asset, Net Fair Value of Assets presented in the Balance Sheet		224
Gross Fair Value of Liabilities		24,609
Derivative liabilities, Gross amounts offset against liabilities in the Balance Sheet		(4,192)
Derivative Liability, Net Fair Value of Liabilities presented in the Balance Sheet		20,417
Predecessor [Member] | Derivative Assets Current [Member]
Derivatives, Fair Value [Line Items]
Gross Fair Value of Assets		1,406
Derivative assets, Gross amounts offset against assets in the Balance Sheet		(1,190)
Derivative Asset, Net Fair Value of Assets presented in the Balance Sheet		216
Predecessor [Member] | Derivative Asset Non-Current [Member]
Derivatives, Fair Value [Line Items]
Gross Fair Value of Assets		3,010
Derivative assets, Gross amounts offset against assets in the Balance Sheet		(3,002)
Derivative Asset, Net Fair Value of Assets presented in the Balance Sheet		8
Predecessor [Member] | Derivative Liabilities Current [Member]
Derivatives, Fair Value [Line Items]
Gross Fair Value of Liabilities		20,493
Derivative liabilities, Gross amounts offset against liabilities in the Balance Sheet		(1,190)
Derivative Liability, Net Fair Value of Liabilities presented in the Balance Sheet		19,303
Predecessor [Member] | Derivative Liabilities Non Current [Member]
Derivatives, Fair Value [Line Items]
Gross Fair Value of Liabilities		4,116
Derivative liabilities, Gross amounts offset against liabilities in the Balance Sheet		(3,002)
Derivative Liability, Net Fair Value of Liabilities presented in the Balance Sheet		$ 1,114

Derivative Financial Instrume64

Derivative Financial Instruments (Effect Of Derivative Instruments In The Consolidated Statements Of Operations) (Details) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended
	Feb. 08, 2018	Mar. 31, 2018	Mar. 31, 2017
Successor [Member]
Derivative Instruments, Gain [Line Items]
Total gains (loss) on derivative contracts		$ (22,646)
Successor [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Oil Commodity Contracts [Member]
Derivative Instruments, Gain [Line Items]
Total gains (loss) on derivative contracts		(22,579)
Successor [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Natural Gas Commodity Contracts [Member]
Derivative Instruments, Gain [Line Items]
Total gains (loss) on derivative contracts		$ (67)
Predecessor [Member]
Derivative Instruments, Gain [Line Items]
Total gains (loss) on derivative contracts	$ 7,298		$ 30,242
Predecessor [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Oil Commodity Contracts [Member]
Derivative Instruments, Gain [Line Items]
Total gains (loss) on derivative contracts	5,431		26,085
Predecessor [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Natural Gas Commodity Contracts [Member]
Derivative Instruments, Gain [Line Items]
Total gains (loss) on derivative contracts	$ 1,867		3,899
Predecessor [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Natural Gas Liquids Commodity Contract [Member]
Derivative Instruments, Gain [Line Items]
Total gains (loss) on derivative contracts			$ 258

Derivative Financial Instrume65

Derivative Financial Instruments (Oil Derivative Contracts) (Details) - Oil Derivative Contracts [Member]	3 Months Ended
	Mar. 31, 2018$ / bblbbl
Price Swap Contracts [Member] | 2018 [Member]
Derivative [Line Items]
Volume in Bbls | bbl	1,832,000
Weighted Average Swap Price	53.22
Price Swap Contracts [Member] | 2018 [Member] | Maximum [Member]
Derivative [Line Items]
Swap Price	61.26
Price Swap Contracts [Member] | 2018 [Member] | Minimum [Member]
Derivative [Line Items]
Swap Price	50.27
Short Call Options [Member] | 2018 [Member]
Derivative [Line Items]
Volume in Bbls | bbl	1,559,000
Weighted Average Option Price	61.09
Short Call Options [Member] | 2018 [Member] | Maximum [Member]
Derivative [Line Items]
Option Price	64.60
Short Call Options [Member] | 2018 [Member] | Minimum [Member]
Derivative [Line Items]
Option Price	60.50
Short Call Options [Member] | 2019 [Member]
Derivative [Line Items]
Volume in Bbls | bbl	1,788,500
Weighted Average Option Price	61.84
Short Call Options [Member] | 2019 [Member] | Maximum [Member]
Derivative [Line Items]
Option Price	65.35
Short Call Options [Member] | 2019 [Member] | Minimum [Member]
Derivative [Line Items]
Option Price	56.50
Short Call Options [Member] | 2020 [Member]
Derivative [Line Items]
Volume in Bbls | bbl	183,000
Weighted Average Option Price	60.20
Short Call Options [Member] | 2020 [Member] | Maximum [Member]
Derivative [Line Items]
Option Price	60.20
Short Call Options [Member] | 2020 [Member] | Minimum [Member]
Derivative [Line Items]
Option Price	60.20
Long Put Options [Member] | 2018 [Member]
Derivative [Line Items]
Volume in Bbls | bbl	1,559,000
Weighted Average Option Price	51.18
Long Put Options [Member] | 2018 [Member] | Maximum [Member]
Derivative [Line Items]
Option Price	60
Long Put Options [Member] | 2018 [Member] | Minimum [Member]
Derivative [Line Items]
Option Price	50
Long Put Options [Member] | 2019 [Member]
Derivative [Line Items]
Volume in Bbls | bbl	1,971,000
Weighted Average Option Price	50
Long Put Options [Member] | 2019 [Member] | Maximum [Member]
Derivative [Line Items]
Option Price	50
Long Put Options [Member] | 2019 [Member] | Minimum [Member]
Derivative [Line Items]
Option Price	50
Long Put Options [Member] | 2020 [Member]
Derivative [Line Items]
Volume in Bbls | bbl	549,000
Weighted Average Option Price	50.67
Long Put Options [Member] | 2020 [Member] | Maximum [Member]
Derivative [Line Items]
Option Price	51
Long Put Options [Member] | 2020 [Member] | Minimum [Member]
Derivative [Line Items]
Option Price	50
Short Put Options [Member] | 2018 [Member]
Derivative [Line Items]
Volume in Bbls | bbl	1,559,000
Weighted Average Option Price	41.48
Short Put Options [Member] | 2018 [Member] | Maximum [Member]
Derivative [Line Items]
Option Price	52.50
Short Put Options [Member] | 2018 [Member] | Minimum [Member]
Derivative [Line Items]
Option Price	40
Short Put Options [Member] | 2019 [Member]
Derivative [Line Items]
Volume in Bbls | bbl	1,971,000
Weighted Average Option Price	38.43
Short Put Options [Member] | 2019 [Member] | Maximum [Member]
Derivative [Line Items]
Option Price	40
Short Put Options [Member] | 2019 [Member] | Minimum [Member]
Derivative [Line Items]
Option Price	37.50
Short Put Options [Member] | 2020 [Member]
Derivative [Line Items]
Volume in Bbls | bbl	549,000
Weighted Average Option Price	40
Short Put Options [Member] | 2020 [Member] | Maximum [Member]
Derivative [Line Items]
Option Price	40
Short Put Options [Member] | 2020 [Member] | Minimum [Member]
Derivative [Line Items]
Option Price	40

Derivative Financial Instrume66

Derivative Financial Instruments (Natural Gas Derivative Contracts) (Details) - Natural Gas Derivative Contract [Member]	3 Months Ended
	Mar. 31, 2018MMBTU$ / MMBTU
2018 [Member] | Price Swap Contracts [Member]
Derivative [Line Items]
Volume in MMbtu | MMBTU	4,280,000
Weighted Average Swap Price	2.80
2018 [Member] | Price Swap Contracts [Member] | Maximum [Member]
Derivative [Line Items]
Swap Price	2.85
2018 [Member] | Price Swap Contracts [Member] | Minimum [Member]
Derivative [Line Items]
Swap Price	2.75
2018 [Member] | Short Call Options [Member]
Derivative [Line Items]
Volume in MMbtu | MMBTU	1,985,000
Weighted Average Option Price	3.30
2018 [Member] | Short Call Options [Member] | Maximum [Member]
Derivative [Line Items]
Option Price	3.75
2018 [Member] | Short Call Options [Member] | Minimum [Member]
Derivative [Line Items]
Option Price	3.14
2018 [Member] | Long Put Options [Member]
Derivative [Line Items]
Volume in MMbtu | MMBTU	1,680,000
Weighted Average Option Price	2.82
2018 [Member] | Long Put Options [Member] | Maximum [Member]
Derivative [Line Items]
Option Price	2.90
2018 [Member] | Long Put Options [Member] | Minimum [Member]
Derivative [Line Items]
Option Price	2.75
2018 [Member] | Short Put Options [Member]
Derivative [Line Items]
Volume in MMbtu | MMBTU	610,000
Weighted Average Option Price	2.40
2018 [Member] | Short Put Options [Member] | Maximum [Member]
Derivative [Line Items]
Option Price	2.40
2018 [Member] | Short Put Options [Member] | Minimum [Member]
Derivative [Line Items]
Option Price	2.40
2019 [Member] | Short Call Options [Member]
Derivative [Line Items]
Volume in MMbtu | MMBTU	1,350,000
Weighted Average Option Price	3.47
2019 [Member] | Short Call Options [Member] | Maximum [Member]
Derivative [Line Items]
Option Price	3.75
2019 [Member] | Short Call Options [Member] | Minimum [Member]
Derivative [Line Items]
Option Price	3.30
2019 [Member] | Long Put Options [Member]
Derivative [Line Items]
Volume in MMbtu | MMBTU	900,000
Weighted Average Option Price	2.90
2019 [Member] | Long Put Options [Member] | Maximum [Member]
Derivative [Line Items]
Option Price	2.90
2019 [Member] | Long Put Options [Member] | Minimum [Member]
Derivative [Line Items]
Option Price	2.90
2019 [Member] | Short Put Options [Member]
Derivative [Line Items]
Volume in MMbtu | MMBTU	900,000
Weighted Average Option Price	2.40
2019 [Member] | Short Put Options [Member] | Maximum [Member]
Derivative [Line Items]
Option Price	2.40
2019 [Member] | Short Put Options [Member] | Minimum [Member]
Derivative [Line Items]
Option Price	2.40

Derivative Financial Instrume67

Derivative Financial Instruments (Natural Gas Basis Swap Derivative Contracts) (Details) - Natural Gas Basis Swap Derivative Contracts [Member]	3 Months Ended
	Mar. 31, 2018MMBTU$ / MMBTU
Nov 2018 to Dec 2018 [Member]
Derivative [Line Items]
Volume in MMbtu | MMBTU	152,500
First remaining period of term of derivative contract	Nov. 1, 2018
Last remaining period of term of derivative contract	Dec. 31, 2018
Weighted average spread | $ / MMBTU	(1.05)
Jan 2019 to Mar 2019 [Member]
Derivative [Line Items]
Volume in MMbtu | MMBTU	225,000
First remaining period of term of derivative contract	Jan. 1, 2019
Last remaining period of term of derivative contract	Mar. 31, 2019
Weighted average spread | $ / MMBTU	(1.05)

Derivative Financial Instrume68

Derivative Financial Instruments (Oil Basis Swap Derivative Contracts) (Details) - Oil Basis Swap Derivative Contracts [Member] - Jul 2018 to Dec 2018 [Member]	3 Months Ended
	Mar. 31, 2018$ / bblbbl
Derivative [Line Items]
Volume in Bbls | bbl	1,104,000
First remaining period of term of derivative contract	Jul. 1, 2018
Last remaining period of term of derivative contract	Dec. 31, 2018
Weighted average spread | $ / bbl	(0.54)

Intangible Assets (Narrative) (

Intangible Assets (Narrative) (Details) - USD ($)	1 Months Ended	2 Months Ended	12 Months Ended
	Feb. 08, 2018	Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Intangible assets		$ 468,913,000
Successor [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, amortization expense		3,500,000
Intangible assets		$ 468,913,000
Predecessor [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, amortization expense	$ 0		$ 0
Intangible assets			$ 0

Intangible Assets (Schedule Of

Intangible Assets (Schedule Of Finite-Lived Customer Relationships) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Finite-Lived Intangible Assets [Line Items]
Customer relationships	$ 472,432
Accumulated amortization	(3,519)
Intangibles, net	$ 468,913
Weighted average amortization	12 years
Successor [Member]
Finite-Lived Intangible Assets [Line Items]
Intangibles, net	$ 468,913

Intangible Assets (Estimated Am

Intangible Assets (Estimated Amortization Expense) (Details) $ in Thousands	Mar. 31, 2018USD ($)
Intangible Assets [Abstract]
Remainder of 2018	$ 15,839
2,019	35,170
2,020	42,002
2,021	41,222
2,022	40,562
Thereafter	294,118
Intangibles, net	$ 468,913

Asset Retirement Obligations (S

Asset Retirement Obligations (Summary Of Changes In Asset Retirement Obligations) (Details) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended			3 Months Ended
	Feb. 08, 2018	Mar. 31, 2018	Mar. 31, 2018	Feb. 28, 2018	Mar. 31, 2017	Feb. 28, 2018	Dec. 31, 2017
Asset Retirement Obligation [Line Items]
Less: Current portion		$ 622	$ 622
Long-term portion		6,033	6,033
Successor [Member]
Asset Retirement Obligation [Line Items]
Liabilities assumed in Business Combination			5,998
Liabilities incurred			421
Liabilities settled			(166)
Revisions to estimates			300
Accretion expense		102	102
Balance, end of period		6,655	6,655
Less: Current portion		622	622
Long-term portion		$ 6,033	$ 6,033
Predecessor [Member]
Asset Retirement Obligation [Line Items]
Balance, beginning of period	$ 10,469			$ 10,469
Liabilities incurred				63
Revisions to estimates				63
Accretion expense	39			39	$ 96
Balance, end of period	$ 10,469			$ 10,469		$ 10,508	$ 10,469
Less: Current portion							69
Long-term portion							$ 10,400

Long Term Debt, Net (Narrative)

Long Term Debt, Net (Narrative) (Details) - USD ($)	1 Months Ended	3 Months Ended		12 Months Ended
	Feb. 08, 2018	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Apr. 30, 2018	Feb. 09, 2018	Aug. 08, 2017	Dec. 31, 2014
Debt Instrument [Line Items]
Senior secured revolving credit facility						$ 134,000,000
7th Amended And Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Senior secured revolving credit facility				$ 117,100,000
Alta Mesa Credit Facility [Member]
Debt Instrument [Line Items]
Letter of credit outstanding		$ 13,600,000
Minimum working capital ratio		1
Amount borrowed		$ 0
Debt covenants description		The principal amounts borrowed are payable on the maturity date of February 9, 2023. Alta Mesa has a choice of borrowing in Eurodollars or at the reference rate, with such borrowings bearing interest, payable quarterly for reference rate loans and one month, three month or six month periods for Eurodollar loans. Eurodollar loans bear interest at a rate per annum equal to the rate at the LIBOR, plus an applicable margin ranging from 2.00% and 3.00%. Reference rate loans bear interest at a rate per annum equal to the greater of (i) the agent bank's reference rate, (ii) the federal funds effective rate plus 50 basis points and (iii) the rate for one month Eurodollar loans plus 1%, plus a margin ranging from 1.00% to 2.00%. The next scheduled redetermination of the borrowing base is in October 2018. The borrowing base may be reduced in connection with the next redetermination of its borrowing base. The amounts outstanding under Alta Mesa Credit Facility are secured by first priority liens on substantially all of Alta Mesa's and its material operating subsidiaries' oil and natural gas properties and associated assets and all of the equity of our material operating subsidiaries that are guarantors of the Alta Mesa Credit Facility. Additionally, SRII Opco and Alta Mesa GP have pledged their respective limited partner interests in Alta Mesa as security for its obligations. If an event of default occurs under the Alta Mesa Credit Facility, the administrative agent will have the right to proceed against the pledged capital stock and take control of substantially all of Alta Mesa's assets and its material operating subsidiaries that are guarantors. The Alta Mesa Credit Facility contains restrictive covenants that may limit Alta Mesa's ability to, among other things, incur additional indebtedness, sell assets, guaranty or make loans to others, make investments, enter into mergers, make certain payments and distributions, enter into or be party to hedge agreements, amend organizational documents, incur liens and engage in certain other transactions without the prior consent of the lenders. The Alta Mesa Credit Facility permits Alta Mesa to make distributions to any parent entity (i) to pay for reimbursement of third party costs and expenses that are general and administrative expenses incurred in the ordinary course of business by such parent entity or (ii) in order to permit such parent entity to (x) make permitted tax distributions and (y) pay the obligations under the Tax Receivable Agreement. See Note 17 - Income Taxes for further information regarding the Tax Receivable Agreement. In addition, Alta Mesa can make restricted payments, so long as certain conditions are met, to any direct or indirect parent for the sole purpose of making a loan or capital contribution to Kingfisher in an amount up to $300 million until August 9, 2018.The Alta Mesa Credit Facility also requires Alta Mesa to maintain the following two financial ratios:a current ratio, tested quarterly, commencing within the fiscal quarter ending June 30, 2018, of Alta Mesa's consolidated current assets to its consolidated current liabilities of not less than 1.0 to 1.0 as of the end of each fiscal quarter; anda leverage ratio, tested quarterly, commencing with the fiscal quarter ending June 30, 2018, of Alta Mesa's consolidated debt (other than obligations under hedge agreements) as of the end of such fiscal quarter to Alta Mesa's consolidated earnings before interest, taxes, depreciation, depletion, amortization and exploration expenses ("EBITDAX") annualized by multiplying EBITDAX for the period of (A) the fiscal quarter ending June 30, 2018 times 4, (B) the two fiscal quarter periods ending September 30, 2018 times 2, (C) the three fiscal quarter periods ending December 31, 2018 times 4/3rds and (D) for each fiscal quarter on or after March 31, 2019, EBITDAX times 4/4ths, of not greater than 4.0 to 1.0. Alta Mesa will be required to maintain financial ratios commencing on the fiscal quarter ending June 30, 2018.
Credit facility amount						1,000,000
Alta Mesa Credit Facility [Member] | Federal Funds Effective Swap Rate [Member]
Debt Instrument [Line Items]
Margin interest rate		50.00%
Alta Mesa Credit Facility [Member] | Eurodollar [Member]
Debt Instrument [Line Items]
Margin interest rate		1.00%
Alta Mesa Credit Facility [Member] | Minimum [Member] | Federal Funds Effective Swap Rate [Member]
Debt Instrument [Line Items]
Margin interest rate		1.00%
Alta Mesa Credit Facility [Member] | Minimum [Member] | Eurodollar [Member]
Debt Instrument [Line Items]
Margin interest rate		2.00%
Alta Mesa Credit Facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Credit facility borrowing base						$ 350,000,000
Alta Mesa Credit Facility [Member] | Maximum [Member] | Federal Funds Effective Swap Rate [Member]
Debt Instrument [Line Items]
Margin interest rate		2.00%
Alta Mesa Credit Facility [Member] | Maximum [Member] | Eurodollar [Member]
Debt Instrument [Line Items]
Margin interest rate		3.00%
Kingfisher Credit Facility [Member]
Debt Instrument [Line Items]
Senior secured revolving credit facility		$ 52,000,000
Kingfisher Credit Facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
Commitment fee		0.50%
Kingfisher Credit Facility [Member] | Minimum [Member] | Eudodollar Loans And Base Rate Loans [Member]
Debt Instrument [Line Items]
Margin interest rate		3.25%
Kingfisher Credit Facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Commitment fee		0.375%
Kingfisher Credit Facility [Member] | Maximum [Member] | Eudodollar Loans And Base Rate Loans [Member]
Debt Instrument [Line Items]
Margin interest rate		2.25%
Alta Mesa Holdings, LP [Member]
Debt Instrument [Line Items]
Period following closing additional borrowings can be made		120 days
7.875% senior unsecured notes due 2024		$ 500,000,000
Default amount		20,000,000
Alta Mesa Holdings, LP [Member] | Credit Facility And Senior Notes [Member]
Debt Instrument [Line Items]
Deferred financing cost write-off				11,400,000
Alta Mesa Holdings, LP [Member] | 8% Senior Unsecured Notes Due 2019 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior notes								8.00%
Alta Mesa Holdings, LP [Member] | 7.875% Senior Unsecured Notes Due 2024 [Member]
Debt Instrument [Line Items]
Face value of senior notes issued		$ 500,000,000
Maturity date of debt		Dec. 15, 2024
Stated interest rate of senior notes		7.875%
First annual payment date		June 15
Second annual payment date		December 15
Redemption percentage of aggregate remaining outstanding		65.00%
Alta Mesa Holdings, LP [Member] | 7.875% Senior Unsecured Notes Due 2024 [Member] | Prior to December 15, 2019 [Member]
Debt Instrument [Line Items]
Redemption price plus make-whole premium		100.00%
Redemption price		107.875%
Alta Mesa Holdings, LP [Member] | 7.875% Senior Unsecured Notes Due 2024 [Member] | Twelve Mos Beginning December 15, 2019 [Member]
Debt Instrument [Line Items]
Redemption price		105.906%
Alta Mesa Holdings, LP [Member] | 7.875% Senior Unsecured Notes Due 2024 [Member] | Twelve Mos Beginning December 15, 2020 [Member]
Debt Instrument [Line Items]
Redemption price		103.938%
Alta Mesa Holdings, LP [Member] | 7.875% Senior Unsecured Notes Due 2024 [Member] | Twelve Mos Beginning December 15, 2021 [Member]
Debt Instrument [Line Items]
Redemption price		101.969%
Alta Mesa Holdings, LP [Member] | 7.875% Senior Unsecured Notes Due 2024 [Member] | Twelve Mos Beginning December 15, 2022 [Member]
Debt Instrument [Line Items]
Redemption price		100.00%
Alta Mesa Holdings, LP [Member] | Maximum [Member] | 7.875% Senior Unsecured Notes Due 2024 [Member]
Debt Instrument [Line Items]
Redemption percentage of Senior Notes		35.00%
Alta Mesa Holdings, LP [Member] | Alta Mesa Credit Facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Credit facility amount		$ 300,000,000
Kingfisher Midstream, LLC [Member] | Kingfisher Credit Facility [Member]
Debt Instrument [Line Items]
Face value of senior notes issued		$ 20,000,000
Maturity date of debt		Aug. 8, 2021
Credit facility amount		$ 50,000,000
Senior secured revolving credit facility		$ 250,000,000					$ 200,000,000
Payment term		4 years
Subsequent Event [Member] | Alta Mesa Holdings, LP [Member]
Debt Instrument [Line Items]
Credit facility borrowing base					$ 400,000,000
Predecessor [Member]
Debt Instrument [Line Items]
Amortization of deferred financing costs	$ 200,000			1,000,000
Amortization of deferred financing costs	$ 171,000		$ 962,000
Predecessor [Member] | Credit Facility, Term Loan Facility And Senior Notes [Member]
Debt Instrument [Line Items]
Deferred financing costs		$ 0
Predecessor [Member] | 7.875% Senior Unsecured Notes Due 2024 [Member]
Debt Instrument [Line Items]
Deferred financing costs				9,625,000
7.875% senior unsecured notes due 2024				500,000,000
Predecessor [Member] | Alta Mesa Holdings, LP [Member]
Debt Instrument [Line Items]
Senior secured revolving credit facility				$ 117,065,000
Successor [Member]
Debt Instrument [Line Items]
Amortization of deferred financing costs		0
7.875% senior unsecured notes due 2024		533,600,000
Unamortized premium		800,000
Unamortized bond premium on senior unsecured notes		800,000
Successor [Member] | 7.875% Senior Unsecured Notes Due 2024 [Member]
Debt Instrument [Line Items]
7.875% senior unsecured notes due 2024		$ 500,000,000
Successor [Member] | Alta Mesa Credit Facility [Member]
Debt Instrument [Line Items]
Maximum leverage ratio		4
Deferred financing costs		$ 1,000,000
Successor [Member] | Kingfisher Midstream, LLC [Member]
Debt Instrument [Line Items]
Senior secured revolving credit facility		$ 52,000,000

Long Term Debt, Net (Long-Term

Long Term Debt, Net (Long-Term Debt, Net) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Feb. 09, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Senior secured revolving credit facility		$ 134,000
Alta Mesa Holdings, LP [Member]
Debt Instrument [Line Items]
7.875% senior unsecured notes due 2024	$ 500,000
7th Amended And Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Senior secured revolving credit facility			$ 117,100
7.875% Senior Unsecured Notes Due 2024 [Member] | Alta Mesa Holdings, LP [Member]
Debt Instrument [Line Items]
Maturity date of debt	Dec. 15, 2024
Stated interest rate of senior notes	7.875%
Successor [Member]
Debt Instrument [Line Items]
7.875% senior unsecured notes due 2024	$ 533,600
Unamortized bond premium on senior unsecured notes	800
Total long-term debt, net	584,815
Successor [Member] | Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Unamortized bond premium on senior unsecured notes	32,815
Successor [Member] | Kingfisher Midstream, LLC [Member]
Debt Instrument [Line Items]
Senior secured revolving credit facility	52,000
Successor [Member] | 7.875% Senior Unsecured Notes Due 2024 [Member]
Debt Instrument [Line Items]
7.875% senior unsecured notes due 2024	$ 500,000
Predecessor [Member]
Debt Instrument [Line Items]
Total long-term debt, net			607,440
Predecessor [Member] | Alta Mesa Holdings, LP [Member]
Debt Instrument [Line Items]
Senior secured revolving credit facility			117,065
Predecessor [Member] | 7.875% Senior Unsecured Notes Due 2024 [Member]
Debt Instrument [Line Items]
7.875% senior unsecured notes due 2024			500,000
Unamortized deferred financing costs			$ (9,625)

Long Term Debt, Net (Summary Of

Long Term Debt, Net (Summary Of Future Maturities Of Long-Term Debt) (Details) - Successor [Member] $ in Thousands	Mar. 31, 2018USD ($)
Summary of future maturities of long-term debt
2,021	$ 52,000
2,023	500,000
Total long-term debt	$ 552,000

Accounts Payable And Accrued 76

Accounts Payable And Accrued Liabilities (Detail Of Accounts Payable And Accrued Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Predecessor [Member]
Accounts Payable And Accrued Liabilities [Line Items]
Capital expenditures		$ 48,771
Revenues and royalties payable		29,514
Operating expenses/taxes		14,632
Interest		2,587
Derivatives settlement payable		2,106
Other		4,301
Total accrued liabilities		101,911
Accounts payable		68,578
Accounts payable and accrued liabilities		$ 170,489
Successor [Member]
Accounts Payable And Accrued Liabilities [Line Items]
Capital expenditures	$ 50,117
Revenues and royalties payable	31,861
Operating expenses/taxes	23,138
Interest	12,355
Derivatives settlement payable	2,826
Other	540
Total accrued liabilities	120,837
Accounts payable	38,273
Accounts payable and accrued liabilities	$ 159,110

Commitments and Contingencies77

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended		2 Months Ended	3 Months Ended
	Feb. 08, 2018	Jan. 31, 2018	Mar. 31, 2018	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Commitment And Contingencies [Line Items]
Rent expense	$ 1,100		$ 1,500		$ 2,600
PAR value vested				$ 10,600
Litigation [Member]
Commitment And Contingencies [Line Items]
Accounts payable and accrued liabilities						$ 4,700
Payment for legal fees		$ 4,700
Successor [Member]
Commitment And Contingencies [Line Items]
Other long-term liabilities			1,934	1,934
Accounts payable and accrued liabilities			159,110	159,110
Nonqualified deferred compensation			$ 9,400	$ 9,400

Commitments And Contingencies78

Commitments And Contingencies (Future Base Rentals For Non-Cancelable Leases) (Details) $ in Thousands	Mar. 31, 2018USD ($)
Future base rentals for non-cancelable leases
Remainder of 2018	$ 1,284
2,019	1,545
2,020	1,593
2,021	1,620
2,022	839
Thereafter	368
Total future base rental	$ 7,249

Commitments And Contingencies79

Commitments And Contingencies (Schedule Of Firm Transportation Contracts) (Details) $ in Thousands	Mar. 31, 2018USD ($)
Commitments And Contingencies [Abstract]
Remainder of 2018	$ 9,702
2,019	10,976
2,020	7,876
2,021	7,876
2,022	7,876
Thereafter	84,742
Firm transportation contracts total	$ 129,048

Significant Risks And Uncerta80

Significant Risks And Uncertainties (Narrative) (Details)	3 Months Ended
	Mar. 31, 2018
Significant Risks And Uncertainties [Abstract]
Risks and uncertainties inherent	Our business makes us vulnerable to changes in wellhead prices of oil and natural gas. Historically, world-wide oil and natural gas prices and markets have been volatile, and may continue to be volatile in the future. Prices for oil and natural gas can fluctuate widely in response to relatively minor changes in the global and regional supply of and demand for oil and natural gas, as well as market uncertainty, economic conditions and a variety of additional factors. The duration and magnitude of changes in oil and natural gas prices cannot be predicted. Declines in oil and/or natural gas prices, or any other unfavorable market conditions could have a material adverse effect on our financial condition and on the carrying value of our proved oil and natural gas reserves. Low prices may also reduce our cash available for distribution, acquisitions and for servicing our indebtedness.

Shareholders' Equity And Part81

Shareholders' Equity And Partners' Capital (Narrative) (Details)	3 Months Ended
	Mar. 31, 2018item$ / sharesshares
Class of Warrant or Right [Line Items]
Warrants outstanding	62,966,666
Noncontrolling interest	55.80%
Alta Mesa Holdings GP, LLC [Member]
Class of Warrant or Right [Line Items]
Number of classes of interest | item	2
Alta Mesa Contributor [Member]
Class of Warrant or Right [Line Items]
Noncontrolling interest	36.20%
Kingfisher Contributor [Member]
Class of Warrant or Right [Line Items]
Noncontrolling interest	14.40%
Riverstone Contributor [Member]
Class of Warrant or Right [Line Items]
Noncontrolling interest	5.20%
Public Warrants [Member]
Class of Warrant or Right [Line Items]
Warrants outstanding	34,500,000
Number of shares called by each warrant	1
Warrant exercise price per share | $ / shares	$ 11.50
Private Placement [Member]
Class of Warrant or Right [Line Items]
Warrants outstanding	15,133,333
Warrants issued	13,333,333
Forward Purchase Warrants [Member]
Class of Warrant or Right [Line Items]
Shares issued during period	15,133,333
Common Class A [Member]
Class of Warrant or Right [Line Items]
Voting rights per share of stock | $ / shares	$ 1
Common Class A [Member] | Alta Mesa Holdings GP, LLC [Member]
Class of Warrant or Right [Line Items]
Percentage of economic interest held	100.00%
Common Class B [Member] | Alta Mesa Holdings GP, LLC [Member]
Class of Warrant or Right [Line Items]
Percentage of voting interest held	100.00%
Common Class C [Member]
Class of Warrant or Right [Line Items]
Shares issued during period	213,402,398
Preferred Class A [Member]
Class of Warrant or Right [Line Items]
Preferred stock, par value | $ / shares	$ 0.0001
Preferred Class B [Member]
Class of Warrant or Right [Line Items]
Preferred stock, par value | $ / shares	$ 0.0001
SRII Opco, LP [Member] | Common Class B [Member] | Alta Mesa Holdings GP, LLC [Member]
Class of Warrant or Right [Line Items]
Percentage of economic interest held	90.00%
Directors And Affiliates Of Bayou City And Highbridge [Member] | Common Class B [Member] | Alta Mesa Holdings GP, LLC [Member]
Class of Warrant or Right [Line Items]
Percentage of voting interest held	10.00%

Equity Based Compensation (Narr

Equity Based Compensation (Narrative) (Details) - USD ($) $ in Millions	Apr. 13, 2018	Feb. 09, 2018	Mar. 31, 2018	Mar. 31, 2018	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost			$ 18.1	$ 18.1	$ 18.1
Period for unrecognized compensation cost					2 years 9 months 18 days
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period					3 years
Unrecognized compensation cost			9.8	9.8	$ 9.8
Period for unrecognized compensation cost					2 years 9 months 18 days
Restricted Stock [Member] | Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards - Granted		73,376
Restricted Stock [Member] | Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards - Granted		1,160,094
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost			$ 5.3	$ 5.3	$ 5.3
Period for unrecognized compensation cost					9 months 18 days
Performance Restricted Stock Units [Member] | Subsequent Event [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares that may be earned	0.00%
Performance Restricted Stock Units [Member] | Subsequent Event [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares that may be earned	200.00%
Long Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized under plan			50,000,000	50,000,000	50,000,000
Option expiration period					7 years
Vesting period					3 years
Shares Under Options - Granted		4,143,231
Long Term Incentive Plan [Member] | Performance Restricted Stock Units [Member] | Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards - Granted		700,000
Long Term Incentive Plan [Member] | Vested On December 31, 2018 [Member] | Performance Restricted Stock Units [Member] | Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rate	20.00%
Long Term Incentive Plan [Member] | Vested On December 31, 2019 [Member] | Performance Restricted Stock Units [Member] | Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rate	30.00%
Long Term Incentive Plan [Member] | Vested On December 31, 2020 [Member] | Performance Restricted Stock Units [Member] | Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rate	50.00%
Successor [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Under Options - Granted			4,143,231
Non-cash stock-based compensation expense			$ 3.5
Successor [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards - Granted				1,233,470
Successor [Member] | Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards - Granted				718,163

Equity Based Compensation (Comp

Equity Based Compensation (Compensation Expense) (Details) $ in Thousands	2 Months Ended
	Mar. 31, 2018USD ($)
Successor [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity based compensation expense	$ 3,466

Equity Based Compensation (Summ

Equity Based Compensation (Summary Of Stock Options Granted And Valuation Assumptions) (Details) - Successor [Member] $ / shares in Units, $ in Thousands	2 Months Ended
	Mar. 31, 2018USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted | shares	4,143,231
Weighted average grant-date fair value | $ / shares	$ 4.62
Total fair value | $	$ 19,129
Expected term	4 years 6 months
Expected stock volatility	64.50%
Dividend yield
Risk-free interest rate	2.40%

Equity Based Compensation (Sche

Equity Based Compensation (Schedule Of Stock Option Plans) (Details) - Successor [Member] $ / shares in Units, $ in Thousands	2 Months Ended
	Mar. 31, 2018USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Under Options - Outstanding, beginning balance
Shares Under Options - Vested
Shares Under Options - Granted	4,143,231
Shares Under Options - Forfeited or expired
Shares Under Options - Outstanding, ending balance	4,143,231
Shares Under Options - Exercisable
Weighted Average Grant - Date Fair Value, Outstanding, beginning balance | $ / shares
Weighted Average Grant - Granted | $ / shares	4.62
Weighted Average Grant - Date Fair Value, Outstanding, ending balance | $ / shares	$ 4.62
Weighted Average Remaining Term - Outstanding, ending balance	4 years 3 months 18 days
Aggregate Intrinsic Value, Outstanding | $	$ 19,129

Equity Based Compensation (Sc86

Equity Based Compensation (Schedule Of Non-vested Stock Options) (Details) - Successor [Member]	2 Months Ended
	Mar. 31, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options vested
Options granted	4,143,231
Options - Exercisable
Weighted Average Grant - Granted | $ / shares	$ 4.62

Equity Based Compensation (Sc87

Equity Based Compensation (Schedule Of Restricted Stock) (Details) - Successor [Member] - Restricted Stock [Member]	2 Months Ended
	Mar. 31, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards - Granted | shares	1,233,470
Awards - Outstanding, ending balance | shares	1,233,470
Weighted Average Grant-Date Fair Value - Granted | $ / shares	$ 8.94
Weighted-Average Grant-Date Fair Value, Outstanding ending balance | $ / shares	$ 8.94

Equity Based Compensation (Sc88

Equity Based Compensation (Schedule Of Restricted Stock Units) (Details) - Successor [Member] - Restricted Stock Units [Member]	2 Months Ended
	Mar. 31, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards - Granted | shares	718,163
Awards - Outstanding, ending balance | shares	718,163
Weighted Average Grant-Date Fair Value - Granted | $ / shares	$ 8.94
Weighted-Average Grant-Date Fair Value, Outstanding ending balance | $ / shares	$ 8.94

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details)	3 Months Ended
	Mar. 31, 2018
Income Taxes [Abstract]
Percent of tax benefit under tax receivable agreement	85.00%
Discount rate	18.00%
Interest rate	100.00%
Accrue interest rate	500.00%

Income Taxes (Schedule Of Compo

Income Taxes (Schedule Of Components Of Income Tax Expense (Benefit)) (Details) - Successor [Member] $ in Thousands	2 Months Ended
	Mar. 31, 2018USD ($)
Income Taxes [Line Items]
Deferred, Federal	$ (3,111)
Deferred, State	(702)
Deferred taxes	(3,813)
Income tax expense (benefit)	$ (3,813)

Related Party Transactions (Nar

Related Party Transactions (Narrative) (Details)

Feb. 08, 2018USD ($)

Sep. 29, 2017USD ($)

Dec. 31, 2016USD ($)

Dec. 31, 2014USD ($)

Feb. 08, 2018USD ($)

Mar. 31, 2018USD ($)item

Feb. 28, 2018USD ($)

Mar. 31, 2018USD ($)item

Mar. 31, 2017USD ($)

Dec. 31, 2017USD ($)

Apr. 30, 2018USD ($)

Jan. 16, 2016item

David Murrell, VP Of Land And Business Development [Member]

Related Party Transaction [Line Items]

Contract termination period without penalty for either party

30 days

High Mesa [Member]

Related Party Transaction [Line Items]

Management services

$ 10,000

Alta Mesa Holdings, LP [Member] | 8% Senior Unsecured Notes Due 2019 [Member]

Related Party Transaction [Line Items]

Interest rate

8.00%

Alta Mesa Holdings, LP [Member] | Northwest Gas Processing [Member]

Related Party Transaction [Line Items]

Maturity date of debt

Feb. 28, 2019

Promissory note

$ 1,500,000

Interest rate

8.00%

First quarterly installment

Jan. 1, 2018

Alta Mesa Holdings, LP [Member] | High Mesa Services, LLC [Member] | Subsequent Event [Member]

Related Party Transaction [Line Items]

Promissory note

$ 1,500,000

Alta Mesa Holdings, LP [Member] | High Mesa Services, LLC [Member] | 8% Senior Unsecured Notes Due 2019 [Member]

Related Party Transaction [Line Items]

Maturity date of debt

Dec. 31, 2019

First quarterly installment

Jan. 1, 2015

Notes receivable due from related party

$ 8,500,000

$ 11,000,000

$ 11,000,000

$ 10,800,000

Alta Mesa Holdings, LP [Member] | High Mesa [Member]

Related Party Transaction [Line Items]

Notes receivable due from related party

$ 7,900,000

$ 7,900,000

800,000

Joint Development Agreement [Member] | Alta Mesa Holdings, LP [Member]

Related Party Transaction [Line Items]

Percent of interest reduced

12.50%

Percent of internal return rate

25.00%

Joint Development Agreement [Member] | Alta Mesa Holdings, LP [Member] | BCE-STACK [Member]

Related Party Transaction [Line Items]

Number of wells drilled | item

67

67

Number of wells remaining to be drilled | item

13

13

Percent committed to fund

100.00%

Drilling and completion costs

$ 3,200,000

Percent of working interest

80.00%

Percent of interest reduced

20.00%

Percent of internal return rate

15.00%

Threshold of project cost

$ 64,000,000

Advances from related party

$ 39,500,000

$ 39,500,000

Joint Development Agreement Tranche One and Two [Member] | Alta Mesa Holdings, LP [Member] | BCE-STACK [Member]

Related Party Transaction [Line Items]

Number of wells | item

40

Joint Development Agreement Tranche One [Member] | Alta Mesa Holdings, LP [Member] | BCE-STACK [Member]

Related Party Transaction [Line Items]

Number of wells | item

20

Joint Development Agreement Tranche Two [Member] | Alta Mesa Holdings, LP [Member] | BCE-STACK [Member]

Related Party Transaction [Line Items]

Number of wells | item

20

Joint Development Agreement Tranche Three and Four [Member] | BCE-STACK [Member]

Related Party Transaction [Line Items]

Number of wells | item

40

Successor [Member]

Related Party Transaction [Line Items]

Notes receivable due from related party

11,039,000

11,039,000

Interest on notes receivable due from related party

(162,000)

Receivables due from related party

7,892,000

7,892,000

Advances from related party

40,498,000

40,498,000

Accounts payable from related party

1,578,000

$ 1,578,000

Successor [Member] | David Murrell, VP Of Land And Business Development [Member]

Related Party Transaction [Line Items]

Total expenditures for land consulting services

36,000

Successor [Member] | David McClure, VP Of Facilities And Midstream [Member]

Related Party Transaction [Line Items]

Total compensation

44,500

Successor [Member] | David Pepper [Member]

Related Party Transaction [Line Items]

Total compensation

23,200

Successor [Member] | Alta Mesa Holdings, LP [Member] | High Mesa Services, LLC [Member] | 8% Senior Unsecured Notes Due 2019 [Member]

Related Party Transaction [Line Items]

Interest on notes receivable due from related party

$ 100,000

Predecessor [Member]

Related Party Transaction [Line Items]

Notes receivable due from related party

12,369,000

Interest on notes receivable due from related party

$ (85,000)

$ (200,000)

Receivables due from related party

790,000

Advances from related party

23,390,000

Accrued payable to related party

5,476,000

Predecessor [Member] | David Murrell, VP Of Land And Business Development [Member]

Related Party Transaction [Line Items]

Total expenditures for land consulting services

$ 28,000

43,000

Predecessor [Member] | David McClure, VP Of Facilities And Midstream [Member]

Related Party Transaction [Line Items]

Total compensation

$ 938,500

67,500

Predecessor [Member] | David Pepper [Member]

Related Party Transaction [Line Items]

Total compensation

$ 153,100

38,700

Predecessor [Member] | Alta Mesa Holdings, LP [Member] | High Mesa Services, LLC [Member] | 8% Senior Unsecured Notes Due 2019 [Member]

Related Party Transaction [Line Items]

Interest on notes receivable due from related party

$ 100,000

$ 200,000

Predecessor [Member] | Notes Payable To Founder [Member]

Related Party Transaction [Line Items]

Effective rate of interest

10.00%

10.00%

Business Segment Information (N

Business Segment Information (Narrative) (Details)	3 Months Ended
	Mar. 31, 2018segment
Business Segment Information [Abstract]
Reportable segments	2
Operating segments	2

Business Segment Information (S

Business Segment Information (Schedule Of Results Of Reportable Segments) (Details) - Successor [Member] $ in Thousands	2 Months Ended
	Mar. 31, 2018USD ($)
Segment Reporting Information [Line Items]
Revenues	$ 45,870
Corporate general and administrative expenses	34,557
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	(37,362)
Operating [Member]
Segment Reporting Information [Line Items]
Operating revenues and other from external customers	45,870
Revenues	45,870
Operating [Member] | Inter-segment [Member]
Segment Reporting Information [Line Items]
Revenues	(11,299)
Operating [Member] | Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	(11,299)
Operating [Member] | Exploration And Production [Member]
Segment Reporting Information [Line Items]
Operating revenues and other from external customers	27,353
Revenues	34,090
Operating [Member] | Exploration And Production [Member] | Inter-segment [Member]
Segment Reporting Information [Line Items]
Revenues	6,737
Operating [Member] | Midstream Services [Member]
Segment Reporting Information [Line Items]
Operating revenues and other from external customers	18,517
Revenues	23,079
Operating [Member] | Midstream Services [Member] | Inter-segment [Member]
Segment Reporting Information [Line Items]
Revenues	4,562
Segment [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	(31,539)
Other income (expense)	(4,898)
Segment net income (loss) before tax	(36,437)
Segment [Member] | Exploration And Production [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	(29,921)
Other income (expense)	(4,650)
Segment net income (loss) before tax	(34,571)
Segment [Member] | Midstream Services [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	(1,618)
Other income (expense)	(248)
Segment net income (loss) before tax	(1,866)
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Corporate general and administrative expenses	$ 925

Business Segment Information 94

Business Segment Information (Schedule Of Segment Revenue By Product Line) (Details) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended
	Feb. 08, 2018	Mar. 31, 2018	Mar. 31, 2017
Successor [Member]
Segment Reporting Information [Line Items]
Revenues		$ 45,870
Successor [Member] | Oil Sales [Member]
Segment Reporting Information [Line Items]
Revenues		40,278
Successor [Member] | Natural Gas Sales [Member]
Segment Reporting Information [Line Items]
Revenues		5,210
Successor [Member] | Natural Gas Liquids Sales [Member]
Segment Reporting Information [Line Items]
Revenues		4,714
Successor [Member] | Product Sales [Member]
Segment Reporting Information [Line Items]
Revenues		8,369
Successor [Member] | Gathering And Processing [Member]
Segment Reporting Information [Line Items]
Revenues		3,411
Successor [Member] | Product Line Revenue [Member]
Segment Reporting Information [Line Items]
Revenues		61,982
Successor [Member] | Eliminations [Member] | Product Sales [Member]
Segment Reporting Information [Line Items]
Revenues		(6,737)
Successor [Member] | Eliminations [Member] | Gathering And Processing [Member]
Segment Reporting Information [Line Items]
Revenues		(4,562)
Successor [Member] | Eliminations [Member] | Product Line Revenue [Member]
Segment Reporting Information [Line Items]
Revenues		(11,299)
Successor [Member] | Exploration And Production [Member] | Oil Sales [Member]
Segment Reporting Information [Line Items]
Revenues		40,278
Successor [Member] | Exploration And Production [Member] | Natural Gas Sales [Member]
Segment Reporting Information [Line Items]
Revenues		5,210
Successor [Member] | Exploration And Production [Member] | Natural Gas Liquids Sales [Member]
Segment Reporting Information [Line Items]
Revenues		4,714
Successor [Member] | Exploration And Production [Member] | Product Line Revenue [Member]
Segment Reporting Information [Line Items]
Revenues		50,202
Successor [Member] | Midstream Services [Member] | Product Sales [Member]
Segment Reporting Information [Line Items]
Revenues		15,106
Successor [Member] | Midstream Services [Member] | Gathering And Processing [Member]
Segment Reporting Information [Line Items]
Revenues		7,973
Successor [Member] | Midstream Services [Member] | Product Line Revenue [Member]
Segment Reporting Information [Line Items]
Revenues		$ 23,079
Predecessor [Member]
Segment Reporting Information [Line Items]
Revenues	$ 47,434		$ 95,079

Business Segment Information 95

Business Segment Information (Summary Of Assets By Segment) (Details) - Successor [Member] $ in Thousands	Mar. 31, 2018USD ($)
Segment Reporting Information [Line Items]
Assets	$ 4,243,539
Segment [Member]
Segment Reporting Information [Line Items]
Assets	4,239,784
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Assets	3,755
Eliminations [Member] | Segment [Member]
Segment Reporting Information [Line Items]
Assets	(4,092)
Exploration And Production [Member] | Segment [Member]
Segment Reporting Information [Line Items]
Assets	2,828,379
Midstream Services [Member] | Segment [Member]
Segment Reporting Information [Line Items]
Assets	$ 1,415,497

Subsequent Events (Narrative) (

Subsequent Events (Narrative) (Details) $ in Millions	May 10, 2018inmibbl	Apr. 01, 2018USD ($)	Mar. 31, 2018a
Cimarron Express [Member]
Subsequent Event [Line Items]
Number of acres dedicated in agreement | a			120,000
Kingfisher Midstream, LLC [Member] | Cimarron Express [Member]
Subsequent Event [Line Items]
Ownership percentage in equity method			50.00%
Kingfisher Midstream, LLC [Member] | Cimarron Express [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Length of pipeline | mi	65
Production	90,000
Expandable	175,000
Kingfisher Midstream, LLC [Member] | Cimarron Express [Member] | Subsequent Event [Member] | Crude Oil [Member]
Subsequent Event [Line Items]
Length of pipeline | in	16
Ergon, Inc. [Member] | Cimarron Express [Member]
Subsequent Event [Line Items]
Ownership percentage in equity method			50.00%
Alta Mesa Holdings, LP [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Additional lease commitment obligations | $		$ 17.6
Lease expiration year		2,028