Risk Management and Derivative Instruments - Additional Information (Detail) - USD ($)	1 Months Ended	9 Months Ended
Apr. 30, 2020	Sep. 30, 2020
Derivative Instruments Gain Loss [Line Items]
Conditional rights of set-off under ISDA Master Agreement reduce the maximum amount of loss due to credit risk		$ 13,900,000
Crude Oil
Derivative Instruments Gain Loss [Line Items]
Cash proceeds form crude oil hedges	$ 18,000,000.0

The terms of the ISDA Agreements provide us and each of our counterparties with rights of set-off upon the occurrence of defined acts of default by either us or our counterparty to a derivative, whereby the party not in default may set-off all liabilities owed to the defaulting party against all net derivative asset receivables from the defaulting party.

No definition available.

Name:	ampy_ConcentrationRiskCreditRiskFinancialInstrumentReducedCreditExposure
Namespace Prefix:	ampy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration