For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

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Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Revenue from Contracts with Customers Disaggregation of oil, gas, and NGL production revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 1,126,188	$ 1,585,750	$ 1,636,357
Concentration Risk, Percentage	100.00%	100.00%	100.00%
Revenue, Remaining Performance Obligation, Amount	$ 0
Midland Basin [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	879,577	$ 1,195,736	$ 1,064,607
South Texas [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 246,611	$ 390,014	514,514
Rocky Mountain [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax			$ 57,236
Revenue Benchmark [Member] \| Geographic Concentration Risk [Member] \| Midland Basin [Member]
Segment Reporting Information [Line Items]
Concentration Risk, Percentage	78.00%	75.00%	65.00%
Revenue Benchmark [Member] \| Geographic Concentration Risk [Member] \| South Texas [Member]
Segment Reporting Information [Line Items]
Concentration Risk, Percentage	22.00%	25.00%	32.00%
Revenue Benchmark [Member] \| Geographic Concentration Risk [Member] \| Rocky Mountain [Member]
Segment Reporting Information [Line Items]
Concentration Risk, Percentage			3.00%
Oil production revenue [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 853,568	$ 1,183,212	$ 1,065,676
Oil production revenue [Member] \| Midland Basin [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	802,494	1,119,786	938,004
Oil production revenue [Member] \| South Texas [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	51,074	63,426	72,821
Oil production revenue [Member] \| Rocky Mountain [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax			54,851
Gas production revenue [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	187,459	262,529	354,450
Gas production revenue [Member] \| Midland Basin [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	76,759	75,827	125,603
Gas production revenue [Member] \| South Texas [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	110,700	186,702	227,252
Gas production revenue [Member] \| Rocky Mountain [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax			1,595
NGL production revenue [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	85,161	140,009	216,231
NGL production revenue [Member] \| Midland Basin [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	324	123	1,000
NGL production revenue [Member] \| South Texas [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 84,837	$ 139,886	214,441
NGL production revenue [Member] \| Rocky Mountain [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax			$ 790