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.