NATURE OF BUSINESS, SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND OTHER - Property, Plant and Equipment (Details)	12 Months Ended
Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Period before costs expensed for no proved reserves	1 year
Maximum \| Gas plant and power plant assets
Property, Plant and Equipment [Line Items]
Expected useful lives	30 years
Maximum \| Other non- producing property and equipment
Property, Plant and Equipment [Line Items]
Expected useful lives	20 years

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

No definition available.

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration