Fair Value Measurements (Narrative) (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Net Assets Measured At Fair Value On A Recurring Basis	$ 3,100	$ 2,600
Net Assets Measured At Fair Value On A Recurring Basis Measured Using Unobservable Input And Classified As Level3	$ 7	$ 7

Net Assets Measured At Fair Value On A Recurring Basis Measured Using Unobservable Input And Classified As Level3

No definition available.

Name:	pseg_NetAssetsMeasuredAtFairValueOnRecurringBasisMeasuredUsingUnobservableInputAndClassifiedAsLevel3
Namespace Prefix:	pseg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant