Financial Risk Management Activities (Narrative) (Detail) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016 USD ($) Counterparty	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) Counterparty	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Derivatives, Fair Value [Line Items]
Net cash collateral received in connection with net derivative contracts		$ (18)		$ (18)		$ (55)
Aggregate fair value of derivative contracts in a liability position that contains triggers for additional collateral		42		42		78
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax		2		2
Power [Member]
Derivatives, Fair Value [Line Items]
Net exposure		282		282
Net cash collateral received in connection with net derivative contracts	[1],[2]	$ (18)		$ (18)		(55)
Number of active counterparties on credit risk derivatives | Counterparty		135		135
Power [Member] | Senior Notes 3.00% Due June 2021 [Member]
Derivatives, Fair Value [Line Items]
Stated interest rate of debt instrument		3.00%		3.00%
Debt Instrument, Face Amount		$ 700		$ 700
PSEG [Member]
Derivatives, Fair Value [Line Items]
Fair value of interest rate swaps designated as underlying hedges						6
Aggregate fair value of derivative contracts in a liability position that contains triggers for additional collateral		11		11		12
Additional collateral aggregate fair value		31		31		66
Amount of reduction in interest expense attributed to interest rate swaps designated as fair value hedges		(2)	$ (5)	(6)	$ (15)
Gain (Loss) on Hedging Activity		2
PSEG [Member] | Loans Payable [Member]
Derivatives, Fair Value [Line Items]
Long-term Debt, Gross		500		500
Non Current Assets [Member]
Derivatives, Fair Value [Line Items]
Net cash collateral received in connection with net derivative contracts		(14)		(14)		$ (16)
Investment Grade - External Rating [Member] | Power [Member]
Derivatives, Fair Value [Line Items]
Net exposure		249		$ 249
Credit exposure, percentage				92.00%
Fair Value Hedging [Member] | PSEG [Member]
Derivatives, Fair Value [Line Items]
Aggregate amount of series of interest rate swaps converting to variable-rate debt		550		$ 550
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		500
Cash Flow Hedging [Member] | PSEG [Member] | Senior Notes 3.00% Due June 2021 [Member]
Derivatives, Fair Value [Line Items]
Aggregate amount of series of interest rate swaps converting to variable-rate debt		$ 400		$ 400

[1] Represents the netting of fair value balances with the same counterparty (where the right of offset exists) and the application of collateral. All cash collateral received or posted that has been allocated to derivative positions, where the right of offset exists, has been offset on the Condensed Consolidated Balance Sheets. As of September 30, 2016 and December 31, 2015, net cash collateral (received) paid of $(18) million and $(55) million, respectively, were netted against the corresponding net derivative contract positions. Of the $(18) million as of September 30, 2016, $(13) million and $(14) million of cash collateral were netted against current assets and noncurrent assets, respectively, and $9 million was netted against current liabilities. Of the $(55) million as of December 31, 2015, $(53) million and $(16) million were netted against current assets and noncurrent assets, respectively, and $12 million and $2 million were netted against current liabilities and noncurrent liabilities, respectively.

[2] Substantially all of Power’s and PSEG’s derivative instruments are contracts subject to master netting agreements. Contracts not subject to master netting or similar agreements are immaterial and did not have any collateral posted or received as of September 30, 2016 and December 31, 2015. PSE&G does not have any derivative contracts subject to master netting or similar agreements.