XML 156 R121.htm IDEA: XBRL DOCUMENT v3.22.4
EMPLOYEE BENEFITS - Schedule of Components of Net Periodic Benefit Costs (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Pension and SERP      
Defined Benefit Plan Disclosure [Line Items]      
Service Cost $ 70.1 $ 85.8 $ 76.2
Interest Cost 154.5 130.0 177.8
Expected Return on Plan Assets (523.6) (437.5) (400.3)
Actuarial Loss 116.0 243.9 202.0
Prior Service Cost/(Credit) 1.4 1.4 1.2
Total Net Periodic Benefit Plan Expense/(Income) $ (181.6) $ 23.6 56.9
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration] Other Income, Net Other Income, Net  
PBOP      
Defined Benefit Plan Disclosure [Line Items]      
Service Cost $ 11.6 $ 13.5 10.2
Interest Cost 20.2 17.4 24.6
Expected Return on Plan Assets (89.9) (79.1) (73.6)
Actuarial Loss 0.0 8.9 8.4
Prior Service Cost/(Credit) (21.7) (21.2) (21.2)
Total Net Periodic Benefit Plan Expense/(Income) $ (79.8) $ (60.5) (51.6)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration] Other Income, Net Other Income, Net  
CL&P | Pension and SERP      
Defined Benefit Plan Disclosure [Line Items]      
Service Cost $ 18.7 $ 23.0 21.8
Interest Cost 31.3 27.3 37.3
Expected Return on Plan Assets (106.3) (86.8) (79.2)
Actuarial Loss 16.2 45.5 39.2
Prior Service Cost/(Credit) 0.0 0.0 0.0
Total Net Periodic Benefit Plan Expense/(Income) (40.1) 9.0 19.1
Intercompany Income Allocations (16.0) 8.0 9.1
CL&P | PBOP      
Defined Benefit Plan Disclosure [Line Items]      
Service Cost 2.0 2.3 1.7
Interest Cost 3.7 3.2 4.4
Expected Return on Plan Assets (11.4) (10.3) (9.9)
Actuarial Loss 0.0 1.8 1.1
Prior Service Cost/(Credit) 1.1 1.1 1.1
Total Net Periodic Benefit Plan Expense/(Income) (4.6) (1.9) (1.6)
Intercompany Income Allocations (3.7) (1.6) (1.1)
NSTAR Electric | Pension and SERP      
Defined Benefit Plan Disclosure [Line Items]      
Service Cost 13.8 15.8 15.4
Interest Cost 32.8 26.8 38.6
Expected Return on Plan Assets (128.4) (108.1) (103.0)
Actuarial Loss 32.8 61.6 55.2
Prior Service Cost/(Credit) 0.3 0.3 0.3
Total Net Periodic Benefit Plan Expense/(Income) (48.7) (3.6) 6.5
Intercompany Income Allocations (12.4) 8.8 8.9
NSTAR Electric | PBOP      
Defined Benefit Plan Disclosure [Line Items]      
Service Cost 2.0 2.4 2.1
Interest Cost 5.3 4.4 6.6
Expected Return on Plan Assets (42.4) (36.9) (34.0)
Actuarial Loss 0.0 2.4 2.5
Prior Service Cost/(Credit) (17.0) (17.0) (17.0)
Total Net Periodic Benefit Plan Expense/(Income) (52.1) (44.7) (39.8)
Intercompany Income Allocations (3.6) (1.9) (1.4)
PSNH | Pension and SERP      
Defined Benefit Plan Disclosure [Line Items]      
Service Cost 6.9 8.9 8.2
Interest Cost 16.9 14.5 19.4
Expected Return on Plan Assets (56.1) (47.5) (44.7)
Actuarial Loss 7.9 20.7 15.6
Prior Service Cost/(Credit) 0.0 0.0 0.0
Total Net Periodic Benefit Plan Expense/(Income) (24.4) (3.4) (1.5)
Intercompany Income Allocations (3.6) 2.7 2.9
PSNH | PBOP      
Defined Benefit Plan Disclosure [Line Items]      
Service Cost 1.1 1.2 0.9
Interest Cost 2.2 1.8 2.8
Expected Return on Plan Assets (6.7) (6.1) (5.7)
Actuarial Loss 0.0 0.7 0.8
Prior Service Cost/(Credit) 0.4 0.4 0.4
Total Net Periodic Benefit Plan Expense/(Income) (3.0) (2.0) (0.8)
Intercompany Income Allocations $ (1.2) $ (0.6) $ (0.5)