Acquisition of oil and gas properties.

No definition available.

Name:	ampy_AcquisitionOfOilAndGasProperties
Namespace Prefix:	ampy_
Data Type:	num:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

Discounted future net cash flows relating to proved oil and gas reserves ten percent annual discount for estimated timing of cash flows discount factor.

+ References

No definition available.

+ Details

Name:	ampy_DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesTenPercentAnnualDiscountForEstimatedTimingOfCashFlowsDiscountFactor
Namespace Prefix:	ampy_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Divestiture of oil and gas properties.

+ References

No definition available.

+ Details

Name:	ampy_DivestitureOfOilAndGasProperties
Namespace Prefix:	ampy_
Data Type:	num:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

Proved developed and undeveloped reserve downward recovery energy.

+ References

No definition available.

+ Details

Name:	ampy_ProvedDevelopedAndUndevelopedReserveDownwardRecoveryEnergy
Namespace Prefix:	ampy_
Data Type:	num:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

Proved developed and undeveloped reserve upward recovery energy.

+ References

No definition available.

+ Details

Name:	ampy_ProvedDevelopedAndUndevelopedReserveUpwardRecoveryEnergy
Namespace Prefix:	ampy_
Data Type:	num:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

Proved developed and undeveloped reserves downward revision due to updated well performance data.

+ References

No definition available.

+ Details

Name:	ampy_ProvedDevelopedAndUndevelopedReservesDownwardRevisionDueToUpdatedWellPerformanceData
Namespace Prefix:	ampy_
Data Type:	num:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

Proved developed and undeveloped reserves downward revision due to updated well performance data and increase in anticipated development and maintenance cost.

+ References

No definition available.

+ Details

Name:	ampy_ProvedDevelopedAndUndevelopedReservesDownwardRevisionDueToUpdatedWellPerformanceDataAndIncreaseInAnticipatedDevelopmentAndMaintenanceCost
Namespace Prefix:	ampy_
Data Type:	num:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

Supplemental oil and gas reserve information.

+ References

No definition available.

+ Details

Name:	ampy_SupplementalOilAndGasReserveInformationLineItems
Namespace Prefix:	ampy_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Energy measure of increase in quantity of proved reserve of oil and gas resulting from the extension of the proved acreage of previously discovered reservoir or discovery of new field with proved reserve or of new reservoir of proved reserve in old field, stated in a unit of energy. For example, but not limited to, barrel of oil equivalents (BOE) or one thousand cubic feet of natural gas equivalent (Mcfe).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Form 20-F
-Section Item 18
-Subsection Instruction 2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61831-109447

+ Details

Name:	srt_ProvedDevelopedAndUndevelopedReserveExtensionAndDiscoveryEnergy
Namespace Prefix:	srt_
Data Type:	num:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

Energy measure of increase (decrease) of quantity of proved reserve of oil and gas, stated in a unit of energy. For example, but not limited to, barrel of oil equivalents (BOE) or one thousand cubic feet of natural gas equivalent (Mcfe).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Form 20-F
-Section Item 18
-Subsection Instruction 2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61831-109447

+ Details

Name:	srt_ProvedDevelopedAndUndevelopedReserveNetEnergyPeriodIncreaseDecrease
Namespace Prefix:	srt_
Data Type:	num:energyItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_StatementScenarioAxis=ampy_PredecessorCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Supplemental Oil and Gas Information (Unaudited) - Additional Information (Detail) - MMBoe	4 Months Ended	8 Months Ended	12 Months Ended
	May 04, 2017	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018
Supplemental Oil And Gas Reserve Information [Line Items]
Percent of discount factor to proved reserves			10.00%
Increase (reduction) in reserves		(16.5)	(22.8)	(24.7)
Downward price revisions in proved reserve			25.9
Downward revisions due to updated well performance data			12.1
Acquisition of oil and gas properties			69.7
Upward price revisions in proved reserve		2.2		4.6
Downward revisions due to updated well performance data and increase in anticipated development and maintenance cost		12.8		10.6
Extensions and discoveries		1.2		1.9
Divestiture of oil and gas properties				11.0
Predecessor [Member]
Supplemental Oil And Gas Reserve Information [Line Items]
Increase (reduction) in reserves	28.7
Downward revisions due to updated well performance data	1.5
Upward price revisions in proved reserve	34.1