Fair Value Measurements (Changes In Level 3 Assets And (Liabilities) Measured At Fair Value On A Recurring Basis) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Settlements		$ 24		$ 21
Net Assets Measured At Fair Value On A Recurring Basis		2,600		2,600
Net Assets Measured At Fair Value On A Recurring Basis Measured Using Unobservable Input And Classified As Level3		7		1
Net Derivative Assets (Liabilities) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs				1		$ 13
Opening Balance		1
Included in Income	[1]	26		13
Included in Regulatory Assets/Liabilities	[2]	5		(7)
Purchases, (Sales)		0		3
Issuances (Settlements)	[3]	(24)		(21)
Transfers In (Out)		(1)	[4]	0
Closing Balance		7		1
Net Derivative Assets (Liabilities) [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs				6		11
Opening Balance		6
Included in Income	[1]	26		13
Included in Regulatory Assets/Liabilities	[2]	0		0
Purchases, (Sales)		0		3
Issuances (Settlements)	[3]	(24)		(21)
Transfers In (Out)		(1)	[4]	0
Closing Balance		7		6
Net Derivative Assets (Liabilities) [Member] | PSE&G [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs				(5)		$ 2
Opening Balance		(5)
Included in Income	[1]	0		0
Included in Regulatory Assets/Liabilities		5		(7)	[2]
Purchases, (Sales)		0		0
Issuances (Settlements)	[3]	0		0
Transfers In (Out)		0	[4]	0
Closing Balance		0		(5)
Operating Revenues [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains and losses attributable to changes in net derivative assets and liabilities, included in Operating Income		14		25
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)		(9)		(5)
Energy Costs [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains and losses attributable to changes in net derivative assets and liabilities, included in Operating Income		$ 12		$ (12)

[1] PSEG’s and Power’s gains(losses) attributable to changes in net derivative assets and liabilities for 2017 include $14 million in Operating Revenues, of which $(9) million is unrealized and $12 million in Energy Costs, all of which is unrealized. For 2016, $25 million is included in Operating Revenues, of which $(5) million is unrealized, and $(12) million is in Energy Costs, all of which is realized.

[2] Mainly includes gains/losses on PSE&G’s derivative contracts that are not included in either earnings or Accumulated Other Comprehensive Income, as they are deferred as a Regulatory Asset/Liability and are expected to be recovered from/returned to PSE&G’s customers.

[3] Represents $(24) million and $(21) million in settlements for derivative contracts in 2017 and 2016, respectively.

[4] During the year ended December 31, 2017, $(1) million of net derivatives assets/liabilities were transferred from Level 2 to Level 3.