Trust Investments (Proceeds From The Sales Of And The Net Realized Gains On Securities in the NDT and Rabbi Trusts) (Detail) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 30, 2022		Sep. 30, 2021		Sep. 30, 2022	Sep. 30, 2021
Schedule of Trust Investments [Line Items]
Proceeds from Sale of Trust Investments						$ 1,281	$ 1,657
Net Gains (Losses) on Trust Investments		$ (97)		$ (17)		(352)	124
Nuclear Decommissioning Trust (NDT) Fund [Member]
Schedule of Trust Investments [Line Items]
Proceeds from Sale of Trust Investments	[1]	404		387		1,218	1,522
Gross Realized Gains		13		32		63	194
Gross Realized Losses		(38)		(17)		(103)	(55)
Net Realized Gains (Losses)	[2]	(25)		15		(40)	139
Unrealized Gain (Loss) on Equity Securities		(70)		(33)		(301)	(20)
Net Gains (Losses) on Trust Investments		(95)		(18)		(341)	119
Rabbi Trust [Member]
Schedule of Trust Investments [Line Items]
Proceeds from Sale of Trust Investments		15	[1]	41	[1]	63	135
Gross Realized Gains		0		4		3	11
Gross Realized Losses		(1)		(3)		(7)	(6)
Net Realized Gains (Losses)	[3]	(1)		1		(4)	5
Unrealized Gain (Loss) on Equity Securities		(1)		0		(7)	0
Net Gains (Losses) on Trust Investments		$ (2)		$ 1		$ (11)	$ 5

[1] Includes activity in accounts related to the liquidation of funds being transitioned within the trust.

[2] The cost of these securities was determined on the basis of specific identification.

[3] The cost of these securities was determined on the basis of specific identification.