XML 118 R99.htm IDEA: XBRL DOCUMENT
v3.23.3

REVENUES (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022 | Dec. 31, 2021 | Sep. 01, 2021
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | $ 2,833,500 | $ 3,259,400 | $ 9,211,000 | $ 9,273,000 |  |
Alternative Revenue Programs | (48,200) | (46,600) | (14,000) | (22,700) |  |
Other Revenues | 6,200 | 2,800 | 19,500 | 9,300 |  |
Operating Revenues | 2,791,482 | 3,215,645 | 9,216,467 | 9,259,596 |  |
Customer Credits Distributed in 2022 at CL&P related to PURA Settlement Agreement and Storm Performance Penalty |  |  | 0 | (72,041) |  |
CL&P |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Operating Revenues | 1,190,096 | 1,369,101 | 3,563,150 | 3,690,614 |  |
Customer Credits Distributed in 2022 at CL&P related to PURA Settlement Agreement and Storm Performance Penalty |  |  | 0 | (72,041) |  |
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 Distributed in 2022 at CL&P related to PURA Settlement Agreement and Storm Performance Penalty |  |  |  |  | $ 65,000 |
NSTAR Electric |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Operating Revenues | 953,531 | 1,105,452 | 2,728,782 | 2,752,278 |  |
PSNH |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Operating Revenues | 353,074 | 430,642 | 1,123,300 | 1,077,124 |  |
Total Retail Tariff Sales Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 2,441,000 | 2,752,600 | 8,129,800 | 7,799,600 |  |
Residential |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 1,503,600 | 1,633,300 | 4,952,700 | 4,663,000 |  |
Commercial |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 816,300 | 984,000 | 2,778,100 | 2,718,600 |  |
Industrial |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 121,100 | 135,300 | 399,000 | 418,000 |  |
Wholesale Transmission Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 133,600 | 133,900 | 342,600 | 333,100 |  |
Wholesale Market Sales Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 227,600 | 340,900 | 647,800 | 987,300 |  |
Other Revenues from Contracts with Customers |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 31,300 | 25,100 | 90,800 | 81,300 |  |
Amortization of/(Reserve for) Revenues Subject to Refund |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers |  | 6,900 |  | 71,700 |  |
Operating Segments | CL&P |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 1,396,200 | 1,589,900 | 3,972,200 | 4,111,400 |  |
Alternative Revenue Programs | (49,300) | (65,100) | 28,000 | 28,300 |  |
Other Revenues | 2,400 | 200 | 7,100 | 500 |  |
Operating Segments | NSTAR Electric |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 1,129,200 | 1,268,500 | 3,194,500 | 3,181,700 |  |
Alternative Revenue Programs | (29,000) | (20,500) | (43,500) | (14,400) |  |
Other Revenues | 1,900 | 1,800 | 6,300 | 5,400 |  |
Operating Segments | PSNH |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 411,000 | 497,000 | 1,247,700 | 1,227,400 |  |
Alternative Revenue Programs | 900 | (7,200) | 32,400 | 8,800 |  |
Other Revenues | 700 | 600 | 2,300 | 2,100 |  |
Operating Segments | Total Retail Tariff Sales Revenues | CL&P |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 1,029,300 | 1,092,200 | 3,000,700 | 2,784,500 |  |
Operating Segments | Total Retail Tariff Sales Revenues | NSTAR Electric |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 901,800 | 1,016,500 | 2,535,400 | 2,471,800 |  |
Operating Segments | Total Retail Tariff Sales Revenues | PSNH |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 303,800 | 381,000 | 959,700 | 929,700 |  |
Operating Segments | Residential | CL&P |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 703,900 | 739,100 | 2,059,900 | 1,864,400 |  |
Operating Segments | Residential | NSTAR Electric |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 480,500 | 507,600 | 1,318,700 | 1,239,000 |  |
Operating Segments | Residential | PSNH |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 191,500 | 246,200 | 603,500 | 580,500 |  |
Operating Segments | Commercial | CL&P |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 286,400 | 311,200 | 836,700 | 808,700 |  |
Operating Segments | Commercial | NSTAR Electric |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 389,400 | 469,600 | 1,121,000 | 1,128,800 |  |
Operating Segments | Commercial | PSNH |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 88,700 | 110,400 | 287,500 | 280,500 |  |
Operating Segments | Industrial | CL&P |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 39,000 | 41,900 | 104,100 | 111,400 |  |
Operating Segments | Industrial | NSTAR Electric |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 31,900 | 39,300 | 95,700 | 104,000 |  |
Operating Segments | Industrial | PSNH |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 23,600 | 24,400 | 68,700 | 68,700 |  |
Operating Segments | Wholesale Transmission Revenues | CL&P |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 245,100 | 250,300 | 613,300 | 575,200 |  |
Operating Segments | Wholesale Transmission Revenues | NSTAR Electric |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 186,400 | 183,800 | 521,000 | 512,700 |  |
Operating Segments | Wholesale Transmission Revenues | PSNH |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 88,700 | 86,200 | 223,900 | 213,100 |  |
Operating Segments | Wholesale Market Sales Revenues | CL&P |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 112,800 | 232,900 | 330,400 | 656,300 |  |
Operating Segments | Wholesale Market Sales Revenues | NSTAR Electric |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 28,600 | 57,500 | 102,100 | 163,100 |  |
Operating Segments | Wholesale Market Sales Revenues | PSNH |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 13,500 | 26,700 | 51,900 | 75,800 |  |
Operating Segments | Other Revenues from Contracts with Customers | CL&P |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 7,700 | 7,500 | 24,700 | 22,800 |  |
Operating Segments | Other Revenues from Contracts with Customers | NSTAR Electric |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 12,400 | 10,700 | 36,000 | 34,100 |  |
Operating Segments | Other Revenues from Contracts with Customers | PSNH |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 5,000 | 3,100 | 12,200 | 8,800 |  |
Operating Segments | Amortization of/(Reserve for) Revenues Subject to Refund | CL&P |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 1,300 | 7,000 | 3,100 | 72,600 |  |
Operating Segments | Amortization of/(Reserve for) Revenues Subject to Refund | NSTAR Electric |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Operating Segments | Amortization of/(Reserve for) Revenues Subject to Refund | PSNH |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Operating Segments | Amortization Of (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 | 394,700 | 343,500 | 1,217,300 | 1,062,700 |  |
Alternative Revenue Programs | 0 | 0 | 0 | 0 |  |
Other Revenues | 0 | 0 | 0 | 0 |  |
Operating Revenues | 394,700 | 343,500 | 1,217,300 | 1,062,700 |  |
Other | Total Retail Tariff Sales Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Other | Residential |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Other | Commercial |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Other | Industrial |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Other | Wholesale Transmission Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 29,900 | 0 | 79,400 |  |
Other | Wholesale Market Sales Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Other | Other Revenues from Contracts with Customers |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 394,700 | 313,600 | 1,217,300 | 983,300 |  |
Other | Amortization of/(Reserve for) Revenues Subject to Refund |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers |  | 0 |  | 0 |  |
Eliminations |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | (784,900) | (735,100) | (2,244,300) | (2,041,200) |  |
Alternative Revenue Programs | 31,900 | 52,600 | (50,800) | (46,900) |  |
Other Revenues | 0 | 0 | 0 | 0 |  |
Operating Revenues | (753,000) | (682,500) | (2,295,100) | (2,088,100) |  |
Eliminations | Total Retail Tariff Sales Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | (5,900) | (6,900) | (18,000) | (19,000) |  |
Eliminations | Residential |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Eliminations | Commercial |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | (1,100) | (1,700) | (3,400) | (4,200) |  |
Eliminations | Industrial |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | (4,800) | (5,200) | (14,600) | (14,800) |  |
Eliminations | Wholesale Transmission Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | (386,600) | (416,300) | (1,015,600) | (1,047,300) |  |
Eliminations | Wholesale Market Sales Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Eliminations | Other Revenues from Contracts with Customers |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | (392,400) | (311,900) | (1,210,700) | (974,900) |  |
Eliminations | Amortization of/(Reserve for) Revenues Subject to Refund |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers |  | 0 |  | 0 |  |
Consolidations Eliminations | CL&P |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Operating Revenues | (159,200) | (155,900) | (444,100) | (449,600) |  |
Consolidations Eliminations | NSTAR Electric |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Operating Revenues | (148,600) | (144,300) | (428,500) | (420,400) |  |
Consolidations Eliminations | PSNH |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Operating Revenues | (59,500) | (59,800) | (159,100) | (161,200) |  |
Electric Distribution | Operating Segments |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 2,410,300 | 2,830,400 | 7,039,800 | 7,204,500 |  |
Alternative Revenue Programs | (43,800) | (37,700) | (40,700) | (26,200) |  |
Other Revenues | 4,800 | 2,400 | 15,200 | 7,500 |  |
Operating Revenues | 2,371,300 | 2,795,100 | 7,014,300 | 7,185,800 |  |
Electric Distribution | Operating Segments | Total Retail Tariff Sales Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 2,234,500 | 2,489,000 | 6,495,300 | 6,184,000 |  |
Electric Distribution | Operating Segments | Residential |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 1,375,900 | 1,492,900 | 3,982,100 | 3,683,900 |  |
Electric Distribution | Operating Segments | Commercial |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 764,100 | 890,500 | 2,244,700 | 2,216,000 |  |
Electric Distribution | Operating Segments | Industrial |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 94,500 | 105,600 | 268,500 | 284,100 |  |
Electric Distribution | Operating Segments | Wholesale Transmission Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Electric Distribution | Operating Segments | Wholesale Market Sales Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 154,900 | 317,100 | 484,400 | 895,200 |  |
Electric Distribution | Operating Segments | Other Revenues from Contracts with Customers |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 20,900 | 17,300 | 60,100 | 53,400 |  |
Electric Distribution | Operating Segments | Amortization of/(Reserve for) Revenues Subject to Refund |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers |  | 7,000 |  | 71,900 |  |
Natural Gas Distribution | Operating Segments |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 219,800 | 228,300 | 1,647,700 | 1,564,200 |  |
Alternative Revenue Programs | (2,400) | (2,800) | 21,900 | 4,300 |  |
Other Revenues | 900 | 100 | 3,000 | 900 |  |
Operating Revenues | 218,300 | 225,600 | 1,672,600 | 1,569,400 |  |
Natural Gas Distribution | Operating Segments | Total Retail Tariff Sales Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 146,900 | 205,000 | 1,483,300 | 1,472,100 |  |
Natural Gas Distribution | Operating Segments | Residential |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 83,000 | 94,700 | 858,000 | 870,000 |  |
Natural Gas Distribution | Operating Segments | Commercial |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 33,700 | 76,700 | 483,600 | 456,900 |  |
Natural Gas Distribution | Operating Segments | Industrial |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 30,200 | 33,600 | 141,700 | 145,200 |  |
Natural Gas Distribution | Operating Segments | Wholesale Transmission Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Natural Gas Distribution | Operating Segments | Wholesale Market Sales Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 71,600 | 22,700 | 160,500 | 89,300 |  |
Natural Gas Distribution | Operating Segments | Other Revenues from Contracts with Customers |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 1,300 | 600 | 3,900 | 2,800 |  |
Natural Gas Distribution | Operating Segments | Amortization of/(Reserve for) Revenues Subject to Refund |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers |  | 0 |  | 0 |  |
Electric Transmission | Operating Segments |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 525,000 | 523,700 | 1,372,300 | 1,312,200 |  |
Alternative Revenue Programs | (33,600) | (55,100) | 57,600 | 48,900 |  |
Other Revenues | 200 | 200 | 500 | 500 |  |
Operating Revenues | 491,600 | 468,800 | 1,430,400 | 1,361,600 |  |
Electric Transmission | Operating Segments | Total Retail Tariff Sales Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Electric Transmission | Operating Segments | Residential |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Electric Transmission | Operating Segments | Commercial |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Electric Transmission | Operating Segments | Industrial |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Electric Transmission | Operating Segments | Wholesale Transmission Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 520,200 | 520,300 | 1,358,200 | 1,301,000 |  |
Electric Transmission | Operating Segments | Wholesale Market Sales Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Electric Transmission | Operating Segments | Other Revenues from Contracts with Customers |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 4,800 | 3,400 | 14,100 | 10,500 |  |
Electric Transmission | Operating Segments | Amortization of/(Reserve for) Revenues Subject to Refund |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers |  | 0 |  | 700 |  |
Water Distribution | Operating Segments |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 68,600 | 68,600 | 178,200 | 170,600 |  |
Alternative Revenue Programs | (300) | (3,600) | (2,000) | (2,800) |  |
Other Revenues | 300 | 100 | 800 | 400 |  |
Operating Revenues | 68,600 | 65,100 | 177,000 | 168,200 |  |
Water Distribution | Operating Segments | Total Retail Tariff Sales Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 65,500 | 65,500 | 169,200 | 162,500 |  |
Water Distribution | Operating Segments | Residential |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 44,700 | 45,700 | 112,600 | 109,100 |  |
Water Distribution | Operating Segments | Commercial |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 19,600 | 18,500 | 53,200 | 49,900 |  |
Water Distribution | Operating Segments | Industrial |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 1,200 | 1,300 | 3,400 | 3,500 |  |
Water Distribution | Operating Segments | Wholesale Transmission Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 0 | 0 | 0 | 0 |  |
Water Distribution | Operating Segments | Wholesale Market Sales Revenues |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | 1,100 | 1,100 | 2,900 | 2,800 |  |
Water Distribution | Operating Segments | Other Revenues from Contracts with Customers |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers | $ 2,000 | 2,100 | $ 6,100 | 6,200 |  |
Water Distribution | Operating Segments | Amortization of/(Reserve for) Revenues Subject to Refund |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |
Revenues from Contracts with Customers |  | $ (100) |  | $ (900) |  |

X
- Definition Loss Contingency, Estimate of Possible Loss, Non-Compliance Fine + References No definition available. + Details
Name: | es_LossContingencyEstimateOfPossibleLossNonComplianceFine
Namespace Prefix: | es_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479806/606-10-50-5 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479777/606-10-55-91 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479777/606-10-55-91 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479777/606-10-55-91 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479777/606-10-55-91 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479777/606-10-55-91 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479777/606-10-55-91 Reference 8: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (g) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479777/606-10-55-91 + Details
Name: | us-gaap_DisaggregationOfRevenueLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of gain (loss) recognized in settlement of litigation and insurance claims. Excludes claims within an insurance entity's normal claims settlement process. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-1 + Details
Name: | us-gaap_GainLossRelatedToLitigationSettlement
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 924 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 11.L) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479941/924-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479806/606-10-50-5 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 30 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-30 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-42 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-22 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-32 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 40 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-40 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-22 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-32 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 41 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-41 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479806/606-10-50-4 + Details
Name: | us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of revenue that is not accounted for under Topic 606. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(1)) -SubTopic 10 -Topic 220 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2 + Details
Name: | us-gaap_RevenueNotFromContractWithCustomer
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of revenue that is not accounted for under Topic 606, classified as other. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(1)(e)) -SubTopic 10 -Topic 220 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2 + Details
Name: | us-gaap_RevenueNotFromContractWithCustomerOther
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481687/323-10-50-3 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 28 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482907/825-10-50-28 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(1)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(i)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(ii)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iii)(A)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iv)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(5)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(i)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(A)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(B)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iv)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(5)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 30 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-30 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-42 Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-22 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-32 Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 40 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-40 Reference 20: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-22 Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-32 Reference 22: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 41 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-41 Reference 23: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 235 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-05(b)(2)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479557/942-235-S99-1 + Details
Name: | us-gaap_Revenues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=es_TheConnecticutLightAndPowerCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LossContingenciesByNatureOfContingencyAxis=us-gaap_UnfavorableRegulatoryActionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_SalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=es_NstarElectricCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=es_PublicServiceCompanyOfNewHampshirePSNHMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=es_TotalRetailSalesRevenueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=es_ResidentialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=es_CommercialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=es_IndustrialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=es_WholesaleTransmissionRevenueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=es_WholesaleMarketSalesRevenueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=es_OtherRevenueAdjustmentsfromContractswithCustomersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=es_ReserveAdjustmentforRevenueSubjecttoRefundMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=es_AmortizationOfReservesForRevenuesSubjectToRefundMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidationItemsAxis=us-gaap_CorporateNonSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidationItemsAxis=us-gaap_IntersegmentEliminationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidationItemsAxis=srt_ConsolidationEliminationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=es_EversourceElectricDistributionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=es_NaturalGasDistributionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=es_EversourceElectricTransmissionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=es_WaterDistributionSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |