INVESTMENTS IN UNCONSOLIDATED AFFILIATES - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) company	Dec. 31, 2020 USD ($) company	Dec. 31, 2019 USD ($)	Feb. 08, 2019
Schedule of Equity Method Investments [Line Items]
Equity in earnings of unconsolidated affiliates, net of impairment	$ 14,200	$ 14,200	$ 42,200
Dividends received from equity method investees	$ 21,600	$ 21,800	48,900
Number of companies that transmit hydro electricity imported from The Hydro-Quebec System in Canada | company	2	2
Payments to acquire investments	$ 327,385	$ 239,673	$ 416,337
Offshore Wind Business - North East Offshore
Schedule of Equity Method Investments [Line Items]
Carrying amount of equity method investments in excess of the underlying equity in net assets	300,400	$ 264,100
Goodwill	$ 168,900
Ownership interest	50.00%
Revolution Wind And South Fork Wind
Schedule of Equity Method Investments [Line Items]
Ownership interest				50.00%
Hydro-Quebec System
Schedule of Equity Method Investments [Line Items]
Ownership interest	14.50%	14.50%
Payments to acquire investments	$ 9,000	$ 8,600
Renewable Energy Fund
Schedule of Equity Method Investments [Line Items]
Other-than-temporary impairment		$ 2,800