CONTINGENCIES, COMMITMENTS, AND GUARANTEES - APC Other Matters (Details) - Alabama Power - Fish Kill Investigation	Oct. 16, 2019 USD ($)
Alabama Department of Environmental Management (ADEM)
Loss Contingencies [Line Items]
Litigation settlement, amount awarded to other party	$ 50,000
Alabama Department Of Conservation And Natural Resources
Loss Contingencies [Line Items]
Litigation settlement, amount awarded to other party	$ 172,000

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.

No definition available.

Name:	us-gaap_LossContingenciesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration