REVENUES (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended | | |
Mar. 31, 2022 | Mar. 31, 2021 | Dec. 31, 2021 | Sep. 01, 2021 | May 06, 2021 |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | $ 3,452,000 | $ 2,771,700 | | | |
Alternative Revenue Programs | 15,800 | 52,500 | | | |
Other Revenues | 3,500 | 1,600 | | | |
Operating Revenues | 3,471,310 | 2,825,840 | | | |
(Customer Credits)/Reserve at CL&P related to PURA Settlement Agreement and Storm Performance Penalty | $ (58,412) | $ 30,000 | | | |
Operating Lease, Income, Comprehensive Income [Extensible Enumeration] | Operating Revenues | Operating Revenues | | | |
Lease revenue | $ 1,000 | $ 1,600 | | | |
Unfavorable Regulatory Action | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Loss contingency, estimate of possible earnings impact, non-compliance with performance standards | | | | | $ 28,400 |
CL&P | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Operating Revenues | 1,285,831 | 987,274 | | | |
(Customer Credits)/Reserve at CL&P related to PURA Settlement Agreement and Storm Performance Penalty | $ (58,412) | $ 30,000 | | | |
Operating Lease, Income, Comprehensive Income [Extensible Enumeration] | Operating Revenues | Operating Revenues | | | |
Lease revenue | $ 200 | $ 200 | | | |
CL&P | Unfavorable Regulatory Action | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Loss contingency, estimate of possible earnings impact, non-compliance with performance standards | | | | $ 28,400 | |
CL&P | Unfavorable Regulatory Action | Sales | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
(Customer Credits)/Reserve at CL&P related to PURA Settlement Agreement and Storm Performance Penalty | 65,000 | | | | |
NSTAR Electric | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Operating Revenues | $ 863,176 | $ 737,043 | | | |
Operating Lease, Income, Comprehensive Income [Extensible Enumeration] | Operating Revenues | Operating Revenues | | | |
Lease revenue | $ 600 | $ 1,100 | | | |
PSNH | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Operating Revenues | $ 339,427 | $ 293,435 | | | |
Operating Lease, Income, Comprehensive Income [Extensible Enumeration] | Operating Revenues | Operating Revenues | | | |
Total Retail Tariff Sales Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | $ 2,857,900 | $ 2,476,300 | | | |
Residential | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 1,771,200 | 1,560,000 | | | |
Commercial | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 932,400 | 779,900 | | | |
Industrial | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 154,300 | 136,400 | | | |
Wholesale Transmission Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 105,900 | 92,500 | | | |
Wholesale Market Sales Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 399,800 | 176,300 | | | |
Other Revenues from Contracts with Customers | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 30,400 | 26,600 | | | |
(Reserve for)/Amortization of Revenues Subject to Refund | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 58,000 | | | | |
Operating Segments | CL&P | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 1,430,100 | 1,102,700 | | | |
Alternative Revenue Programs | 1,300 | 8,900 | | | |
Other Revenues | 100 | 200 | | | |
Operating Segments | NSTAR Electric | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 1,004,700 | 838,500 | | | |
Alternative Revenue Programs | (8,200) | 13,800 | | | |
Other Revenues | 2,000 | 1,100 | | | |
Operating Segments | PSNH | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 395,100 | 333,700 | | | |
Alternative Revenue Programs | (3,300) | 3,000 | | | |
Other Revenues | 900 | 0 | | | |
Operating Segments | Total Retail Tariff Sales Revenues | CL&P | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 874,800 | 796,700 | | | |
Operating Segments | Total Retail Tariff Sales Revenues | NSTAR Electric | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 770,000 | 655,300 | | | |
Operating Segments | Total Retail Tariff Sales Revenues | PSNH | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 292,900 | 257,300 | | | |
Operating Segments | Residential | CL&P | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 599,100 | 545,800 | | | |
Operating Segments | Residential | NSTAR Electric | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 404,600 | 362,400 | | | |
Operating Segments | Residential | PSNH | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 182,500 | 157,800 | | | |
Operating Segments | Commercial | CL&P | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 242,200 | 214,200 | | | |
Operating Segments | Commercial | NSTAR Electric | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 331,300 | 268,300 | | | |
Operating Segments | Commercial | PSNH | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 88,400 | 77,800 | | | |
Operating Segments | Industrial | CL&P | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 33,500 | 36,700 | | | |
Operating Segments | Industrial | NSTAR Electric | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 34,100 | 24,600 | | | |
Operating Segments | Industrial | PSNH | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 22,000 | 21,700 | | | |
Operating Segments | Wholesale Transmission Revenues | CL&P | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 209,100 | 189,000 | | | |
Operating Segments | Wholesale Transmission Revenues | NSTAR Electric | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 165,200 | 147,100 | | | |
Operating Segments | Wholesale Transmission Revenues | PSNH | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 71,900 | 58,200 | | | |
Operating Segments | Wholesale Market Sales Revenues | CL&P | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 279,900 | 109,700 | | | |
Operating Segments | Wholesale Market Sales Revenues | NSTAR Electric | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 57,900 | 24,400 | | | |
Operating Segments | Wholesale Market Sales Revenues | PSNH | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 27,700 | 15,000 | | | |
Operating Segments | Other Revenues from Contracts with Customers | CL&P | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 7,900 | 7,300 | | | |
Operating Segments | Other Revenues from Contracts with Customers | NSTAR Electric | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 11,600 | 11,700 | | | |
Operating Segments | Other Revenues from Contracts with Customers | PSNH | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 2,600 | 3,200 | | | |
Operating Segments | (Reserve for)/Amortization of Revenues Subject to Refund | CL&P | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 58,400 | 0 | | | |
Operating Segments | (Reserve for)/Amortization of Revenues Subject to Refund | NSTAR Electric | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Operating Segments | (Reserve for)/Amortization of Revenues Subject to Refund | PSNH | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Operating Segments | Reserves For Revenues Subject To Refund | CL&P | Unfavorable Regulatory Action | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | | | $ 93,400 | | |
Other | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 383,500 | 343,000 | | | |
Alternative Revenue Programs | 0 | 0 | | | |
Other Revenues | 0 | 0 | | | |
Operating Revenues | 383,500 | 343,000 | | | |
Other | Total Retail Tariff Sales Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Other | Residential | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Other | Commercial | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Other | Industrial | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Other | Wholesale Transmission Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 24,400 | 19,200 | | | |
Other | Wholesale Market Sales Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Other | Other Revenues from Contracts with Customers | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 359,100 | 323,800 | | | |
Other | (Reserve for)/Amortization of Revenues Subject to Refund | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | | | | |
Eliminations | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | (723,400) | (647,200) | | | |
Alternative Revenue Programs | 13,600 | 2,200 | | | |
Other Revenues | 0 | 0 | | | |
Operating Revenues | (709,800) | (645,000) | | | |
Eliminations | Total Retail Tariff Sales Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | (5,600) | (4,900) | | | |
Eliminations | Residential | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Eliminations | Commercial | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | (1,100) | (1,400) | | | |
Eliminations | Industrial | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | (4,500) | (3,500) | | | |
Eliminations | Wholesale Transmission Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | (364,700) | (321,000) | | | |
Eliminations | Wholesale Market Sales Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Eliminations | Other Revenues from Contracts with Customers | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | (353,100) | (321,300) | | | |
Eliminations | (Reserve for)/Amortization of Revenues Subject to Refund | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | | | | |
Eliminations | CL&P | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Operating Revenues | (145,700) | (124,500) | | | |
Eliminations | NSTAR Electric | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Operating Revenues | (135,300) | (116,400) | | | |
Eliminations | PSNH | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Operating Revenues | (53,300) | (43,300) | | | |
Electric Distribution | Operating Segments | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 2,378,700 | 1,876,200 | | | |
Alternative Revenue Programs | 4,800 | 23,000 | | | |
Other Revenues | 2,800 | 1,100 | | | |
Operating Revenues | 2,386,300 | 1,900,300 | | | |
Electric Distribution | Operating Segments | Total Retail Tariff Sales Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 1,937,100 | 1,708,900 | | | |
Electric Distribution | Operating Segments | Residential | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 1,186,200 | 1,066,000 | | | |
Electric Distribution | Operating Segments | Commercial | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 661,300 | 559,900 | | | |
Electric Distribution | Operating Segments | Industrial | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 89,600 | 83,000 | | | |
Electric Distribution | Operating Segments | Wholesale Transmission Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Electric Distribution | Operating Segments | Wholesale Market Sales Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 365,500 | 149,100 | | | |
Electric Distribution | Operating Segments | Other Revenues from Contracts with Customers | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 17,700 | 18,200 | | | |
Electric Distribution | Operating Segments | (Reserve for)/Amortization of Revenues Subject to Refund | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 58,400 | | | | |
Natural Gas Distribution | Operating Segments | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 917,000 | 757,500 | | | |
Alternative Revenue Programs | 10,200 | 22,800 | | | |
Other Revenues | 400 | 200 | | | |
Operating Revenues | 927,600 | 780,500 | | | |
Natural Gas Distribution | Operating Segments | Total Retail Tariff Sales Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 882,500 | 729,800 | | | |
Natural Gas Distribution | Operating Segments | Residential | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 556,800 | 466,300 | | | |
Natural Gas Distribution | Operating Segments | Commercial | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 257,600 | 207,600 | | | |
Natural Gas Distribution | Operating Segments | Industrial | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 68,100 | 55,900 | | | |
Natural Gas Distribution | Operating Segments | Wholesale Transmission Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Natural Gas Distribution | Operating Segments | Wholesale Market Sales Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 33,500 | 26,400 | | | |
Natural Gas Distribution | Operating Segments | Other Revenues from Contracts with Customers | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 1,000 | 1,300 | | | |
Natural Gas Distribution | Operating Segments | (Reserve for)/Amortization of Revenues Subject to Refund | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | | | | |
Electric Transmission | Operating Segments | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 450,000 | 397,700 | | | |
Alternative Revenue Programs | (15,000) | 2,700 | | | |
Other Revenues | 200 | 200 | | | |
Operating Revenues | 435,200 | 400,600 | | | |
Electric Transmission | Operating Segments | Total Retail Tariff Sales Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Electric Transmission | Operating Segments | Residential | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Electric Transmission | Operating Segments | Commercial | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Electric Transmission | Operating Segments | Industrial | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Electric Transmission | Operating Segments | Wholesale Transmission Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 446,200 | 394,300 | | | |
Electric Transmission | Operating Segments | Wholesale Market Sales Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Electric Transmission | Operating Segments | Other Revenues from Contracts with Customers | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 3,800 | 3,400 | | | |
Electric Transmission | Operating Segments | (Reserve for)/Amortization of Revenues Subject to Refund | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | | | | |
Water Distribution | Operating Segments | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 46,200 | 44,500 | | | |
Alternative Revenue Programs | 2,200 | 1,800 | | | |
Other Revenues | 100 | 100 | | | |
Operating Revenues | 48,500 | 46,400 | | | |
Water Distribution | Operating Segments | Total Retail Tariff Sales Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 43,900 | 42,500 | | | |
Water Distribution | Operating Segments | Residential | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 28,200 | 27,700 | | | |
Water Distribution | Operating Segments | Commercial | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 14,600 | 13,800 | | | |
Water Distribution | Operating Segments | Industrial | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 1,100 | 1,000 | | | |
Water Distribution | Operating Segments | Wholesale Transmission Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 0 | 0 | | | |
Water Distribution | Operating Segments | Wholesale Market Sales Revenues | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 800 | 800 | | | |
Water Distribution | Operating Segments | Other Revenues from Contracts with Customers | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | 1,900 | $ 1,200 | | | |
Water Distribution | Operating Segments | (Reserve for)/Amortization of Revenues Subject to Refund | | | | | |
Disaggregation of Revenue [Line Items] | | | | | |
Revenues from Contracts with Customers | $ (400) | | | | |