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
		Mar. 31, 2023	Mar. 31, 2022
Schedule of Trust Investments [Line Items]
Proceeds from Sale of Trust Investments		$ 402	$ 501
Net Gains (Losses) on Trust Investments		46	(68)
Nuclear Decommissioning Trust (NDT) Fund [Member]
Schedule of Trust Investments [Line Items]
Proceeds from Sale of Trust Investments	[1]	396	473
Gross Realized Gains		21	29
Gross Realized Losses		(27)	(34)
Net Realized Gains (Losses)	[2]	(6)	(5)
Unrealized Gain (Loss) on Equity Securities		51	(61)
Net Gains (Losses) on Trust Investments		45	(66)
Rabbi Trust [Member]
Schedule of Trust Investments [Line Items]
Proceeds from Sale of Trust Investments		6	28
Gross Realized Gains		1	1
Gross Realized Losses		(1)	(2)
Net Realized Gains (Losses)	[3]	0	(1)
Unrealized Gain (Loss) on Equity Securities		1	(1)
Net Gains (Losses) on Trust Investments		$ 1	$ (2)

[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.