COMMON SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Noncontrolling Interest [Line Items]
Net income attributable to noncontrolling interests	$ 1,412,394	$ 1,228,046	$ 1,212,686
Noncontrolling interest - preferred stock of subsidiaries	155,570	155,570
CL&P and NSTAR Electric
Noncontrolling Interest [Line Items]
Net income attributable to noncontrolling interests	$ 7,500	$ 7,500	$ 7,500