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
		Mar. 31, 2017	Mar. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Settlements		$ (22)	$ (15)
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		19	15
Gains and losses attributable to changes in net derivative assets and liabilities, unrealized		3
Net Derivative Assets (Liabilities) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance		1	13
Included in Income	[1]	(19)	(15)
Included in Regulatory Assets/Liabilities	[2]	6	8
Purchases, (Sales)		0	0
Issuances (Settlements)	[3]	(22)	(15)
Transfers In (Out)	[4]	(1)	0
Closing Balance		3	21
Net Derivative Assets (Liabilities) [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance		6	11
Included in Income	[1]	(19)	(15)
Included in Regulatory Assets/Liabilities	[2]	0	0
Purchases, (Sales)		0	0
Issuances (Settlements)	[3]	(22)	(15)
Transfers In (Out)	[4]	(1)	0
Closing Balance		2	11
Net Derivative Assets (Liabilities) [Member] | PSE And G [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance		(5)	2
Included in Income	[1]	0	0
Included in Regulatory Assets/Liabilities	[2]	6	8
Purchases, (Sales)		0	0
Issuances (Settlements)	[3]	0	0
Transfers In (Out)	[4]	0	0
Closing Balance		$ 1	$ 10

[1] PSEG’s and Power’s gains and losses attributable to changes in net derivative assets and liabilities include $19 million and $15 million in Operating Income for the three months ended March 31, 2017 and 2016, respectively. Of the $19 million in Operating Income, $3 million is unrealized. The $15 million in Operating Income 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 $(22) million and $(15) million in settlements for the three months ended March 31, 2017 and 2016, respectively.

[4] During the three months ended March 31, 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 2016.