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.