Commitments And Contingent Liabilities (Guaranteed Obligations) (Detail) - USD ($) $ in Millions		Jun. 30, 2016	Dec. 31, 2015
Loss Contingencies [Line Items]
Line of Credit Facility, Fair Value of Amount Outstanding		$ 226
Line of Credit Facility, Remaining Borrowing Capacity		3,927
Power [Member]
Loss Contingencies [Line Items]
Face Value of Outstanding Guarantees		1,809	$ 1,734
Exposure under Current Guarantees		136	172
Letters of Credit Margin Posted		160	122
Letters of Credit Margin Received		130	192
Counterparty Cash Margin Deposited		0	0
Counterparty Cash Margin Received		(4)	(15)
Net Broker Balance Deposited (Received)		30	(5)
Other Letters of Credit		51	$ 51
Line of Credit Facility, Fair Value of Amount Outstanding		202
Line of Credit Facility, Remaining Borrowing Capacity		2,351
Pse And G [Member]
Loss Contingencies [Line Items]
Line of Credit Facility, Fair Value of Amount Outstanding	[1]	14
Line of Credit Facility, Remaining Borrowing Capacity		586
PennEast Natural Gas Pipeline [Member] | Power [Member]
Loss Contingencies [Line Items]
Face Value of Outstanding Guarantees		106
755 MW Gas-Fired Combined Cycle Generating Station [Member] | Power [Member]
Loss Contingencies [Line Items]
Face Value of Outstanding Guarantees		$ 21

[1] The primary use of PSEG's and PSE&G's credit facilities is to support their respective CP Programs. PSEG and PSE&G had no amounts outstanding under their respective CP Programs as of June 30, 2016.