Condensed Consolidated Statements Of Operations (Unaudited) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		8 Months Ended	9 Months Ended
	Feb. 08, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2019
Revenue
Operating revenue		$ 119,543	$ 151,034	$ 320,406	$ 388,677
Gain (loss) on sale of assets		(106)	(18)	5,058	1,377
Gain (loss) on derivatives		(379)	(11,212)	(62,442)	(11,744)
Total revenue		119,058	139,804	263,022	378,310
Operating expenses
Lease operating		14,192	16,351	37,347	49,250
Transportation, processing and marketing		6,179	5,181	13,936	17,619
Midstream operating		6,621	4,507	8,407	19,292
Cost of sales for purchased gathered production		7,656	9,461	22,172	26,071
Production taxes		4,673	6,311	10,332	15,273
Workovers		783	1,065	2,643	1,903
Exploration		40,847	1,029	10,697	46,190
Depreciation, depletion and amortization		36,999	53,103	102,716	112,907
Impairment of assets		691,123	0	0	697,623
General and administrative		27,992	11,902	72,110	84,682
Total operating expenses		837,065	108,910	280,360	1,070,810
Operating income		(718,007)	30,894	(17,338)	(692,500)
Other income (expense)
Interest expense		(15,145)	(12,347)	(29,570)	(47,360)
Interest income		69	357	1,727	199
Equity in earnings of unconsolidated subsidiaries		(29)	0	0	713
Reorganization items, net		22,467	0	0	22,467
Total other income (expense), net		7,362	(11,990)	(27,843)	(23,981)
Income (loss) from continuing operations before income taxes		(710,645)	18,904	(45,181)	(716,481)
Income tax provision (benefit)		0	1,504	(6,161)	0
Income (loss) from continuing operations		(710,645)	17,400	(39,020)	(716,481)
Loss from discontinued operations, net of tax		0	0	0	0
Net income (loss)		(710,645)	17,400	(39,020)	(716,481)
Net income (loss) attributable to noncontrolling interests		(368,458)	10,427	(26,063)	(368,132)
Net income (loss) attributable to Alta Mesa Resources, Inc. stockholders		$ (342,187)	$ 6,973	$ (12,957)	$ (348,349)
Income (loss) per share - basic (in USD per share)		$ (1.87)	$ 0.04	$ (0.07)	$ (1.92)
Income (loss) per share - diluted (in USD per share)		$ (1.87)	$ 0.04	$ (0.08)	$ (1.92)
Oil
Revenue
Operating revenue		$ 84,010	$ 107,253	$ 222,822	$ 261,041
Natural gas
Revenue
Operating revenue		10,788	11,959	25,149	41,622
Natural gas liquids
Revenue
Operating revenue		8,333	13,880	28,835	29,800
Sales of gathered production
Revenue
Operating revenue		8,387	9,129	21,926	28,386
Midstream revenue
Revenue
Operating revenue		5,882	7,802	17,879	19,586
Other
Revenue
Operating revenue		$ 2,143	$ 1,011	$ 3,795	$ 8,242
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
Reorganization items, net	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