Recent Accounting Standards New Standards Adopted (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019	Jan. 01, 2018	Dec. 31, 2016
New Accounting Pronouncement, Early Adoption [Line Items]
Operating Revenues	$ 2,478	$ 2,302	$ 2,316	$ 2,980	$ 2,468	$ 2,394	$ 2,016	$ 2,818	$ 10,076	$ 9,696	$ 9,094
Energy Costs									3,372	3,225	2,778
Operation and Maintenance									3,111	3,069	2,901
After-tax adjustment for new accounting standard					0					0		$ 81	$ 176
Accumulated other comprehensive income (loss)	15,089				14,377				15,089	14,377	13,847			$ 13,130
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Reclassification of deferred rent liabilities and incentives				21
Accounting Standards Update 2018-02 [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Estimated Change in Expense related to new presentation of pension and OPEB costs									81
Public Service Electric and Gas Company
New Accounting Pronouncement, Early Adoption [Line Items]
Operating Revenues	1,607	1,604	1,382	2,032	1,645	1,595	1,386	1,845	6,625	6,471	6,324
Energy Costs									2,738	2,520	2,421
Operation and Maintenance									1,581	1,575	1,458
Accumulated other comprehensive income (loss)	11,903				10,900				11,903	10,900	9,834			8,712
Public Service Electric and Gas Company | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Estimated Change in Expense related to new presentation of pension and OPEB costs				91
PSEG Power LLC
New Accounting Pronouncement, Early Adoption [Line Items]
Operating Revenues	1,115	$ 771	$ 1,083	1,416	1,108	$ 868	$ 767	$ 1,403	4,385	4,146	3,860
Energy Costs									2,118	2,197	1,913
Operation and Maintenance									1,040	1,053	1,046
After-tax adjustment for new accounting standard					0					0		$ 69	$ 175
Accumulated other comprehensive income (loss)	$ 5,890				$ 5,960				5,890	$ 5,960	$ 5,967			$ 5,799
PSEG Power LLC | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Estimated Change in Expense related to new presentation of pension and OPEB costs				46
PSEG Power LLC | Accounting Standards Update 2018-02 [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Estimated Change in Expense related to new presentation of pension and OPEB costs									$ 69
Operating Lease Right of Use Assets [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Estimated Change in Expense related to new presentation of pension and OPEB costs				261
Operating Lease Liabilities [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Estimated Change in Expense related to new presentation of pension and OPEB costs				$ 282