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				6 Months Ended
		Jun. 30, 2023		Jun. 30, 2022		Jun. 30, 2023	Jun. 30, 2022
Schedule of Trust Investments [Line Items]
Proceeds from Sale of Trust Investments						$ 721	$ 862
Net Gains (Losses) on Trust Investments		$ 57		$ (187)		103	(255)
Nuclear Decommissioning Trust (NDT) Fund [Member]
Schedule of Trust Investments [Line Items]
Proceeds from Sale of Trust Investments	[1]	308		341		704	814
Gross Realized Gains		25		21		46	50
Gross Realized Losses		(28)		(31)		(55)	(65)
Net Realized Gains (Losses)	[2]	(3)		(10)		(9)	(15)
Unrealized Gain (Loss) on Equity Securities		60		(170)		111	(231)
Net Gains (Losses) on Trust Investments		57		(180)		102	(246)
Rabbi Trust [Member]
Schedule of Trust Investments [Line Items]
Proceeds from Sale of Trust Investments		11	[1]	20	[1]	17	48
Gross Realized Gains		3		2		4	3
Gross Realized Losses		(4)		(4)		(5)	(6)
Net Realized Gains (Losses)	[3]	(1)		(2)		(1)	(3)
Unrealized Gain (Loss) on Equity Securities		1		(5)		2	(6)
Net Gains (Losses) on Trust Investments		$ 0		$ (7)		$ 1	$ (9)

[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.