Revenues Revenues (Details)
$ in Millions
 3 Months Ended
Mar. 31, 2018
USD ($)
$ / mwd
MW
Jun. 30, 2017
USD ($)
Mar. 31, 2017
USD ($)
Revenues [Line Items]      
Lease Receivable adjustment   $ 15 $ 55
Revenue from Contract with Customers $ 2,644   2,366
Revenues Unrelated to Contracts with Customers [1] 174   225
Total Operating Revenues 2,818   2,591
Electric Distribution Contracts [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 690   701
Gas Distribution [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 756   754
Electric Transmission [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 312   299
Electricity and Related Products [Member] | PJM [Member] | Third Party Sales [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 498   314
Electricity and Related Products [Member] | PJM [Member] | Sales to Affiliates [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Electricity and Related Products [Member] | NY ISO [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 59   36
Electricity and Related Products [Member] | ISO New England [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 47   11
Gas Sales [Member] | Third Party Sales [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 64   52
Gas Sales [Member] | Sales to Affiliates [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Other Revenues from Contracts with Customers [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers [2] 218   199
PSE And G [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 1,833   1,817
Revenues Unrelated to Contracts with Customers [1] 12   9
Total Operating Revenues 1,845   1,826
PSE And G [Member] | Electric Distribution Contracts [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 690   701
PSE And G [Member] | Gas Distribution [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 759   755
PSE And G [Member] | Electric Transmission [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 312   299
PSE And G [Member] | Electricity and Related Products [Member] | PJM [Member] | Third Party Sales [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
PSE And G [Member] | Electricity and Related Products [Member] | PJM [Member] | Sales to Affiliates [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
PSE And G [Member] | Electricity and Related Products [Member] | NY ISO [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
PSE And G [Member] | Electricity and Related Products [Member] | ISO New England [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
PSE And G [Member] | Gas Sales [Member] | Third Party Sales [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
PSE And G [Member] | Gas Sales [Member] | Sales to Affiliates [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
PSE And G [Member] | Other Revenues from Contracts with Customers [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers [2] 72   62
Power [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 1,251   1,008
Revenues Unrelated to Contracts with Customers [1] 152   261
Total Operating Revenues 1,403   1,269
Anticipated Contract Revenues $ 180    
Power [Member] | PJM [Member] | June 2017 to May 2018 [Member]      
Revenues [Line Items]      
Dollars Per Megawatt-Day | $ / mwd 171    
Load (MW) | MW 9,700    
Power [Member] | PJM [Member] | June 2018 to May 2019 [Member]      
Revenues [Line Items]      
Dollars Per Megawatt-Day | $ / mwd 205    
Load (MW) | MW 9,200    
Power [Member] | PJM [Member] | June 2019 to May 2020 [Member]      
Revenues [Line Items]      
Dollars Per Megawatt-Day | $ / mwd 116    
Load (MW) | MW 8,900    
Power [Member] | PJM [Member] | June 2020 to May 2021 [Member]      
Revenues [Line Items]      
Dollars Per Megawatt-Day | $ / mwd 174    
Load (MW) | MW 7,800    
Power [Member] | ISO New England [Member] | June 2017 to May 2018 [Member]      
Revenues [Line Items]      
Dollars Per Megawatt-Day | $ / mwd 231    
Load (MW) | MW 850    
Power [Member] | ISO New England [Member] | June 2018 to May 2019 [Member]      
Revenues [Line Items]      
Dollars Per Megawatt-Day | $ / mwd 314    
Load (MW) | MW 830    
Power [Member] | ISO New England [Member] | June 2019 to May 2020 [Member]      
Revenues [Line Items]      
Dollars Per Megawatt-Day | $ / mwd 231    
Load (MW) | MW 850    
Power [Member] | ISO New England [Member] | June 2020 to May 2021 [Member]      
Revenues [Line Items]      
Dollars Per Megawatt-Day | $ / mwd 174    
Load (MW) | MW 850    
Power [Member] | ISO New England [Member] | June 2021 to May 2022 [Member]      
Revenues [Line Items]      
Dollars Per Megawatt-Day | $ / mwd 152    
Load (MW) | MW 460    
Power [Member] | Electric Distribution Contracts [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers $ 0   0
Power [Member] | Gas Distribution [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Power [Member] | Electric Transmission [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Power [Member] | Electricity and Related Products [Member] | PJM [Member] | Third Party Sales [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 498   314
Power [Member] | Electricity and Related Products [Member] | PJM [Member] | Sales to Affiliates [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 176   184
Power [Member] | Electricity and Related Products [Member] | NY ISO [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 59   36
Power [Member] | Electricity and Related Products [Member] | ISO New England [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 47   11
Power [Member] | Gas Sales [Member] | Third Party Sales [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 64   52
Power [Member] | Gas Sales [Member] | Sales to Affiliates [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 397   401
Power [Member] | Other Revenues from Contracts with Customers [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers [2] 10   10
Other [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 137   128
Revenues Unrelated to Contracts with Customers [1] 10   (45)
Total Operating Revenues 147   83
Anticipated Contract Revenues 64    
Other [Member] | Electric Distribution Contracts [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Other [Member] | Gas Distribution [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Other [Member] | Electric Transmission [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Other [Member] | Electricity and Related Products [Member] | PJM [Member] | Third Party Sales [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Other [Member] | Electricity and Related Products [Member] | PJM [Member] | Sales to Affiliates [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Other [Member] | Electricity and Related Products [Member] | NY ISO [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Other [Member] | Electricity and Related Products [Member] | ISO New England [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Other [Member] | Gas Sales [Member] | Third Party Sales [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Other [Member] | Gas Sales [Member] | Sales to Affiliates [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Other [Member] | Other Revenues from Contracts with Customers [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers [2] 137   128
Eliminations [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers (577)   (587)
Revenues Unrelated to Contracts with Customers [1] 0   0
Total Operating Revenues (577)   (587)
Eliminations [Member] | Electric Distribution Contracts [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Eliminations [Member] | Gas Distribution [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers (3)   (1)
Eliminations [Member] | Electric Transmission [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Eliminations [Member] | Electricity and Related Products [Member] | PJM [Member] | Third Party Sales [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Eliminations [Member] | Electricity and Related Products [Member] | PJM [Member] | Sales to Affiliates [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers (176)   (184)
Eliminations [Member] | Electricity and Related Products [Member] | NY ISO [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Eliminations [Member] | Electricity and Related Products [Member] | ISO New England [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Eliminations [Member] | Gas Sales [Member] | Third Party Sales [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers 0   0
Eliminations [Member] | Gas Sales [Member] | Sales to Affiliates [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers (397)   (401)
Eliminations [Member] | Other Revenues from Contracts with Customers [Member]      
Revenues [Line Items]      
Revenue from Contract with Customers [2] $ (1)   $ (1)
Bridgeport Harbor 5 [Member] | Power [Member] | ISO New England [Member]      
Revenues [Line Items]      
Load (MW) | MW 480    
[1] Includes primarily alternative revenues at PSE&G, derivative contracts at Power, and lease contracts in Other. In 2017, Other includes a $55 million loss related to Energy Holdings’ investments in leases.
[2] Includes primarily revenues from appliance repair services at PSE&G, solar power projects and energy management and fuel service contracts with LIPA at Power, and PSEG LI’s OSA with LIPA in Other.