Condensed Consolidated Statements Of Operations (Unaudited) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		5 Months Ended	6 Months Ended
	Feb. 08, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2019
Revenue
Operating revenue		$ 133,305	$ 111,482	$ 169,372	$ 269,134
Gain (loss) on sale of assets		0	(63)	5,076	1,483
Gain (loss) on derivatives		12,412	(29,219)	(51,230)	(11,365)
Total revenue		145,717	82,200	123,218	259,252
Operating expenses
Lease operating		15,114	12,679	20,996	35,058
Transportation, processing and marketing		6,837	5,396	8,755	11,440
Midstream operating		6,520	3,313	3,900	12,671
Cost of sales for purchased gathered production		8,720	8,902	12,711	18,415
Production taxes		5,117	2,606	4,021	10,600
Workovers		807	333	1,578	1,120
Exploration		3,289	8,083	9,668	5,343
Depreciation, depletion and amortization		38,009	33,934	49,613	75,908
Impairment of assets		6,500	0	0	6,500
General and administrative		27,172	22,456	60,208	56,690
Total operating expenses		118,085	97,702	171,450	233,745
Operating income		27,632	(15,502)	(48,232)	25,507
Other income (expense)
Interest expense		(16,755)	(11,779)	(17,223)	(32,215)
Interest income		79	824	1,370	130
Equity in earnings of unconsolidated subsidiaries		643	0	0	742
Total other income (expense), net		(16,033)	(10,955)	(15,853)	(31,343)
Income (loss) from continuing operations before income taxes		11,599	(26,457)	(64,085)	(5,836)
Income tax provision (benefit)		0	(3,791)	(7,665)	0
Income (loss) from continuing operations		11,599	(22,666)	(56,420)	(5,836)
Loss from discontinued operations, net of tax		0	0	0	0
Net income (loss)		11,599	(22,666)	(56,420)	(5,836)
Net income (loss) attributable to noncontrolling interests		9,354	(16,066)	(36,490)	326
Net income (loss) attributable to Alta Mesa Resources, Inc. stockholders		$ 2,245	$ (6,600)	$ (19,930)	$ (6,162)
Income (loss) per share - basic and diluted (in USD per share)		$ 0.01	$ (0.04)	$ (0.12)	$ (0.03)
Weighted average shares outstanding - basic (in shares)		180,742,049	173,345,982	171,908,486	180,505,318
Weighted average shares outstanding - diluted (in shares)		180,742,049	207,965,929	208,112,707	180,505,318
Oil
Revenue
Operating revenue		$ 90,668	$ 75,291	$ 115,569	$ 177,031
Natural gas
Revenue
Operating revenue		12,384	7,980	13,190	30,834
Natural gas liquids
Revenue
Operating revenue		10,251	10,241	14,955	21,467
Sales of gathered production
Revenue
Operating revenue		10,439	8,924	12,797	19,999
Midstream revenue
Revenue
Operating revenue		6,549	6,817	10,077	13,704
Other
Revenue
Operating revenue		$ 3,014	$ 2,229	$ 2,784	$ 6,099
Predecessor
Revenue
Operating revenue	$ 40,136
Gain (loss) on sale of assets	840
Gain (loss) on derivatives	6,663
Total revenue	47,639
Operating expenses
Lease operating	4,408
Transportation, processing and marketing	3,725
Midstream operating	0
Cost of sales for purchased gathered production	0
Production taxes	953
Workovers	423
Exploration	7,003
Depreciation, depletion and amortization	11,670
Impairment of assets	0
General and administrative	21,234
Total operating expenses	49,416
Operating income	(1,777)
Other income (expense)
Interest expense	(5,511)
Interest income	172
Equity in earnings of unconsolidated subsidiaries	0
Total other income (expense), net	(5,339)
Income (loss) from continuing operations before income taxes	(7,116)
Income tax provision (benefit)	0
Income (loss) from continuing operations	(7,116)
Loss from discontinued operations, net of tax	(7,746)
Net income (loss)	(14,862)
Net income (loss) attributable to Alta Mesa Resources, Inc. stockholders	(14,862)
Predecessor | Oil
Revenue
Operating revenue	30,972
Predecessor | Natural gas
Revenue
Operating revenue	4,276
Predecessor | Natural gas liquids
Revenue
Operating revenue	4,000
Predecessor | Sales of gathered production
Revenue
Operating revenue	0
Predecessor | Midstream revenue
Revenue
Operating revenue	0
Predecessor | Other
Revenue
Operating revenue	$ 888