Trust Investments (Fair Values And Gross Unrealized Gains And Losses For The Securities) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018
Rabbi Trust [Member]
Schedule of Trust Investments [Line Items]
Cost	$ 228		$ 228
Gross Unrealized Gains	18		2
Gross Unrealized Losses	0		(6)
Fair Value	246		224
Rabbi Trust [Member] | Domestic Equity Securities [Member]
Schedule of Trust Investments [Line Items]
Cost	21		22
Equity Securities, FV-NI, Unrealized Gain	7		1
Gross Unrealized Losses	0		0
Fair Value	28		23
Rabbi Trust [Member] | International Equity Securities [Member]
Schedule of Trust Investments [Line Items]
Cost	0		0
Equity Securities, FV-NI, Unrealized Gain	0		0
Gross Unrealized Losses	0		0
Fair Value	0		0
Rabbi Trust [Member] | Equity Securities [Member]
Schedule of Trust Investments [Line Items]
Cost	21		22
Equity Securities, FV-NI, Unrealized Gain	7		1
Gross Unrealized Losses	0		0
Fair Value	28		23
Unrealized Gains (Losses) on Equity Securities still held	6
Rabbi Trust [Member] | Government Obligations [Member]
Schedule of Trust Investments [Line Items]
Cost	100		110
Gross Unrealized Gains	4		1
Gross Unrealized Losses	0		(2)
Fair Value	104		109
Rabbi Trust [Member] | Corporate Debt Securities [Member]
Schedule of Trust Investments [Line Items]
Cost	107		96
Gross Unrealized Gains	7		0
Gross Unrealized Losses	0		(4)
Fair Value	114		92
Rabbi Trust [Member] | Debt Securities [Member]
Schedule of Trust Investments [Line Items]
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent	8
Cost	207		206
Gross Unrealized Gains	11		1
Gross Unrealized Losses	0		(6)
Fair Value	218		201
PSEG Power LLC | Nuclear Decommissioning Trust (NDT) Fund [Member]
Schedule of Trust Investments [Line Items]
Cost	1,858		1,769
Gross Unrealized Gains	374		192
Gross Unrealized Losses	(18)		(83)
Fair Value	2,214	[1]	1,878
PSEG Power LLC | Nuclear Decommissioning Trust (NDT) Fund [Member] | Domestic Equity Securities [Member]
Schedule of Trust Investments [Line Items]
Cost	425		447
Equity Securities, FV-NI, Unrealized Gain	238		153
Gross Unrealized Losses	(4)		(29)
Fair Value	659		571
PSEG Power LLC | Nuclear Decommissioning Trust (NDT) Fund [Member] | International Equity Securities [Member]
Schedule of Trust Investments [Line Items]
Cost	400		323
Equity Securities, FV-NI, Unrealized Gain	103		36
Gross Unrealized Losses	(11)		(30)
Fair Value	492		329
PSEG Power LLC | Nuclear Decommissioning Trust (NDT) Fund [Member] | Equity Securities [Member]
Schedule of Trust Investments [Line Items]
Cost	825		770
Equity Securities, FV-NI, Unrealized Gain	341		189
Gross Unrealized Losses	(15)		(59)
Fair Value	1,151		900
Unrealized Gains (Losses) on Equity Securities still held	194
PSEG Power LLC | Nuclear Decommissioning Trust (NDT) Fund [Member] | Government Obligations [Member]
Schedule of Trust Investments [Line Items]
Cost	563		498
Gross Unrealized Gains	16		2
Gross Unrealized Losses	(2)		(9)
Fair Value	577		491
PSEG Power LLC | Nuclear Decommissioning Trust (NDT) Fund [Member] | Corporate Debt Securities [Member]
Schedule of Trust Investments [Line Items]
Cost	470		501
Gross Unrealized Gains	17		1
Gross Unrealized Losses	(1)		(15)
Fair Value	486		487
PSEG Power LLC | Nuclear Decommissioning Trust (NDT) Fund [Member] | Debt Securities [Member]
Schedule of Trust Investments [Line Items]
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent	17
Cost	1,033		999
Gross Unrealized Gains	33		3
Gross Unrealized Losses	(3)		(24)
Fair Value	$ 1,063		$ 978

[1] The NDT Fund Investments table excludes foreign currency of $2 million as of December 31, 2019, which is part of the NDT Fund.