XML 157 R130.htm IDEA: XBRL DOCUMENT v3.24.0.1
Benefit Plans and Other Postretirement Benefits - Amounts Recognized in the Balance Sheets and OCI (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Pension Benefits      
Amounts recognized in balance sheet      
Other current liabilities $ 0 $ 0  
Other non-current liabilities 172 192  
Amounts recognized in accumulated OCI      
Net loss/(gain) 73 110  
Prior service cost/(credit) 0 1  
Total/Net accumulated OCI 73 111  
Other changes in plan assets and benefit obligations recognized in other comprehensive income      
Net actuarial (gain)/loss (31) 74  
Amortization of net actuarial loss (6) (3)  
Amortization of prior service cost 0 0  
Effect of settlement/curtailment (1) (14)  
Other changes in plan assets and benefit obligations recognized in other comprehensive income (38) 57  
Net periodic benefit cost/(credit) 21 18 $ (27)
Net recognized in net periodic pension (credit)/cost and OCI (17) 75  
Significant components of NRG's domestic pension plan      
Projected benefit obligation 1,023 1,036 1,452
Accumulated benefit obligation 1,015 1,022  
Fair value of plan assets 851 844 1,336
Other Postretirement Benefits Plan      
Amounts recognized in balance sheet      
Other current liabilities 5 7  
Other non-current liabilities 70 77  
Amounts recognized in accumulated OCI      
Net loss/(gain) (14) (7)  
Prior service cost/(credit) (4) (12)  
Total/Net accumulated OCI (18) (19)  
Other changes in plan assets and benefit obligations recognized in other comprehensive income      
Net actuarial (gain)/loss (5) (11)  
Amortization of net actuarial loss (1) (2)  
Amortization of prior service cost 8 8  
Effect of settlement/curtailment (1) 0  
Other changes in plan assets and benefit obligations recognized in other comprehensive income 1 (5)  
Net periodic benefit cost/(credit) (3) (4) (6)
Net recognized in net periodic pension (credit)/cost and OCI (2) (9)  
Significant components of NRG's domestic pension plan      
Projected benefit obligation 75 84 105
Fair value of plan assets $ 0 $ 0 $ 0