Fair Value Measurements (Changes In Level 3 Assets And (Liabilities) Measured At Fair Value On A Recurring Basis) (Detail) - USD ($) $ in Millions		3 Months Ended			9 Months Ended
		Sep. 30, 2017		Sep. 30, 2016	Sep. 30, 2017		Sep. 30, 2016
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, unrealized				$ 4
Settlements		$ (3)		(4)	$ (28)		$ (24)
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		3		8	29		24
Gains and losses attributable to changes in net derivative assets and liabilities, unrealized					1
Net Derivative Assets (Liabilities) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance		6		5	1		13
Included in Income		3	[1]	8	(29)	[1]	(24)	[1]
Included in Regulatory Assets/Liabilities	[2]	0		(2)	5		(6)
Purchases, (Sales)		0		4	0		4
Issuances (Settlements)	[3]	(3)		(4)	(28)		(24)
Transfers In (Out)	[4]	0		0	(1)		0
Closing Balance		6		11	6		11
Net Derivative Assets (Liabilities) [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance		6		7	6		11
Included in Income		3	[1]	8	(29)	[1]	(24)	[1]
Included in Regulatory Assets/Liabilities	[2]	0		0	0		0
Purchases, (Sales)		0		4	0		4
Issuances (Settlements)	[3]	(3)		(4)	(28)		(24)
Transfers In (Out)	[4]	0		0	(1)		0
Closing Balance		6		15	6		15
Net Derivative Assets (Liabilities) [Member] | PSE And G [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance		0		(2)	(5)		2
Included in Income		0	[1]	0	0	[1]	0	[1]
Included in Regulatory Assets/Liabilities	[2]	0		(2)	5		(6)
Purchases, (Sales)		0		0	0		0
Issuances (Settlements)	[3]	0		0	0		0
Transfers In (Out)	[4]	0		0	0		0
Closing Balance		$ 0		$ (4)	$ 0		$ (4)

[1] PSEG’s and Power’s gains and losses attributable to changes in net derivative assets and liabilities include $3 million and $29 million in Operating Income for the three months and nine months ended September 30, 2017, respectively. The $3 million in Operating Income is realized. Of the $29 million in Operating Income, $1 million is unrealized.

[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 $(3) million and $(28) million in settlements for the three months and nine months ended September 30, 2017, respectively.

[4] During the three months ended September 30, 2017 there were no transfers in to or out of Level 3. During the nine months ended September 30, 2017, $(1) million of net derivatives assets/liabilities were transferred from Level 2 to Level 3. There were no transfers in to or out of Level 3 during three months and nine months ended September 30, 2016.