Financial Information By Business Segments (Financial Information By Business Segments) (Detail) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Operating Revenues		$ 2,096	$ 2,263	$ 2,133	$ 2,592	$ 2,090	$ 2,450	$ 1,905	$ 2,616	$ 9,084	$ 9,061	$ 10,415
Depreciation and Amortization										1,986	1,476	1,214
Operating Income (Loss)		362	$ 693	$ 196	$ 178	(175)	$ 577	$ 347	$ 827	1,429	1,576	2,962
Income from Equity Method Investments										14	11	12
Interest Income										30	30	31
Interest Expense										(391)	(385)	(393)
Income (Loss) before Income Taxes										1,268	1,298	2,680
Income Tax Expense (Benefit)										(306)	411	1,001
Net Income (Loss)										1,574	887	1,679
Gross Additions to Long-Lived Assets										4,190	4,199	3,863
Total Assets		42,716				40,070				42,716	40,070	37,535
Investments in Equity Method Subsidiaries		87				102				87	102	119
Retained Earnings [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)										1,574	887	1,679
Operating Segments [Member] | Power [Member]
Segment Reporting Information [Line Items]
Operating Revenues										3,930	4,023	4,928
Depreciation and Amortization										1,268	881	291
Operating Income (Loss)										(359)	13	1,430
Income from Equity Method Investments										14	11	14
Interest Income										3	4	2
Interest Expense										(50)	(84)	(121)
Income (Loss) before Income Taxes										(250)	(43)	1,367
Income Tax Expense (Benefit)										(729)	(61)	511
Net Income (Loss)										479	18	856
Gross Additions to Long-Lived Assets										1,231	1,343	1,117
Total Assets		12,418				12,193				12,418	12,193	12,250
Investments in Equity Method Subsidiaries		87				102				87	102	119
Operating Segments [Member] | PSE&G [Member]
Segment Reporting Information [Line Items]
Operating Revenues										6,234	6,221	6,636
Depreciation and Amortization										685	565	892
Operating Income (Loss)										1,752	1,614	1,462
Income from Equity Method Investments										0	0	0
Interest Income										24	24	25
Interest Expense										(303)	(289)	(280)
Income (Loss) before Income Taxes										1,536	1,404	1,257
Income Tax Expense (Benefit)										563	515	470
Net Income (Loss)										973	889	787
Gross Additions to Long-Lived Assets										2,919	2,816	2,692
Total Assets		28,554				26,288				28,554	26,288	23,677
Investments in Equity Method Subsidiaries		0				0				0	0	0
Operating Segments [Member] | Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues	[1]									466	370	462
Depreciation and Amortization	[1]									33	30	31
Operating Income (Loss)	[1]									36	(51)	70
Income from Equity Method Investments	[1]									0	0	(2)
Interest Income	[1]									5	4	33
Interest Expense	[1]									(40)	(14)	(21)
Income (Loss) before Income Taxes	[1]									(18)	(63)	56
Income Tax Expense (Benefit)	[1]									(140)	(43)	20
Net Income (Loss)	[1]									122	(20)	36
Gross Additions to Long-Lived Assets	[1]									40	40	54
Total Assets	[1]	2,666				2,373				2,666	2,373	2,810
Investments in Equity Method Subsidiaries	[1]	0				0				0	0	0
Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	[2]									(1,546)	(1,553)	(1,611)
Depreciation and Amortization	[2]									0	0	0
Operating Income (Loss)	[2]									0	0	0
Income from Equity Method Investments	[2]									0	0	0
Interest Income	[2]									(2)	(2)	(29)
Interest Expense	[2]									2	2	29
Income (Loss) before Income Taxes	[2]									0	0	0
Income Tax Expense (Benefit)	[2]									0	0	0
Net Income (Loss)	[2]									0		0
Gross Additions to Long-Lived Assets	[2]									0	0	0
Total Assets	[2]	(922)				(784)				(922)	(784)	(1,202)
Investments in Equity Method Subsidiaries	[2]	$ 0				$ 0				$ 0	$ 0	$ 0

[1] Includes amounts applicable to Energy Holdings and PSEG LI, which are below the quantitative threshold for separate disclosure as reportable segments. Other also includes amounts applicable to PSEG (parent corporation) and Services.

[2] Intercompany eliminations primarily relate to intercompany transactions between PSE&G and Power. For a further discussion of the intercompany transactions between PSE&G and Power, see Note 24. Related-Party Transactions.