Debt and Credit Facilities Debt and Credit Facilities (Short-Term Liquidity) (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2018
Dec. 31, 2017
Commercial Paper $ 594 $ 542
Commitments of Single Institution as Percentage of Total Commitments 8.00%  
Line of Credit Facility, Remaining Borrowing Capacity $ 3,417  
Line of Credit Facility, Maximum Borrowing Capacity 4,200  
Line of Credit Facility, Fair Value of Amount Outstanding 783  
PSE And G [Member]    
Line of Credit Facility, Remaining Borrowing Capacity 584  
Line of Credit Facility, Maximum Borrowing Capacity 600  
Line of Credit Facility, Fair Value of Amount Outstanding [1] 16  
Power [Member]    
Line of Credit Facility, Remaining Borrowing Capacity 1,942  
Line of Credit Facility, Maximum Borrowing Capacity 2,100  
Line of Credit Facility, Fair Value of Amount Outstanding 158  
Five Year Credit Facility Maturing March 2022 [Member] | PSE And G [Member]    
Line of Credit Facility, Remaining Borrowing Capacity $ 584  
Debt Instrument, Maturity Date, Description Mar 2022  
Line of Credit Facility, Maximum Borrowing Capacity $ 600  
Line of Credit Facility, Fair Value of Amount Outstanding 16  
Five Year Credit Facility Maturing March 2022 [Member] | Power [Member]    
Line of Credit Facility, Remaining Borrowing Capacity $ 1,854  
Debt Instrument, Maturity Date, Description Mar 2022  
Line of Credit Facility, Maximum Borrowing Capacity $ 1,900  
Line of Credit Facility, Fair Value of Amount Outstanding 46  
Three Year Credit Facilities Maturing March 2020 [Member] | Power [Member]    
Line of Credit Facility, Remaining Borrowing Capacity $ 88  
Debt Instrument, Maturity Date, Description Mar 2020  
Line of Credit Facility, Maximum Borrowing Capacity $ 200  
Line of Credit Facility, Fair Value of Amount Outstanding 112  
PSEG [Member]    
Line of Credit Facility, Remaining Borrowing Capacity 891  
Line of Credit Facility, Maximum Borrowing Capacity 1,500  
Line of Credit Facility, Fair Value of Amount Outstanding [1] 609  
PSEG [Member] | Five Year Credit Facility Maturing March 2022 [Member]    
Line of Credit Facility, Remaining Borrowing Capacity $ 891  
Debt Instrument, Maturity Date, Description Mar 2022  
Line of Credit Facility, Maximum Borrowing Capacity $ 1,500  
Line of Credit Facility, Fair Value of Amount Outstanding 609  
PSEG [Member] | Five Year Credit Facility Maturing March 2022 [Member]    
Commercial Paper $ 594  
Short-term Debt, Weighted Average Interest Rate, at Point in Time 2.57%  
[1] The primary use of PSEG’s and PSE&G’s credit facilities is to support their respective Commercial Paper Programs, under which as of March 31, 2018, PSEG had $594 million outstanding at a weighted average interest rate of 2.57%. PSE&G had no amounts outstanding under its Commercial Paper Program as of March 31, 2018.