Financial Risk Management Activities (Narrative) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Other Comprehensive Income before Reclassifications	$ (9)	$ 77	$ (3)
Floating Rate term loans	14,558
Net cash collateral received in connection with net derivative contracts	153	44
Accumulated Other Comprehensive Income (Loss) on interest rate derivatives	(1)		2
PSEG [Member]
Derivatives, Fair Value [Line Items]
Floating Rate term loans	2,450	2,100
Amount of reduction in interest expense attributed to interest rate swaps designated as fair value hedges			6
Power [Member]
Derivatives, Fair Value [Line Items]
Net Credit Exposure With Counterparties After Applying Collateral	253
Other Comprehensive Income before Reclassifications	(3)	78	$ (3)
Floating Rate term loans	2,850	2,400
Credit Risk Derivative Liabilities, at Fair Value	22	30
Aggregate fair value of derivative contracts in a liability position that contains triggers for additional collateral	7	13
Additional collateral aggregate fair value	$ 15	17
Power [Member] | Senior Notes Three Point Eight Five Percent due Two Thousand Twenty Three [Member]
Derivatives, Fair Value [Line Items]
Stated interest rate of debt instrument	3.85%
Floating Rate term loans	$ 700	$ 0
Debt Instrument, Face Amount	700
Cash Flow Hedging [Member] | PSEG [Member]
Derivatives, Fair Value [Line Items]
Aggregate amount of series of interest rate swaps converting to variable-rate debt	$ 500