Trust Investments (Proceeds From The Sales Of And The Net Realized Gains On Securities) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Schedule of Trust Investments [Line Items]
Net Gains (Losses) on NDT Fund Investments		$ 189	$ (265)	$ 194
Nuclear Decommissioning Trust (NDT) Fund [Member]
Schedule of Trust Investments [Line Items]
Proceeds from sales	[1]	1,685	1,521	1,930
Gross Realized Gains		142	86	236
Gross Realized Losses		100	136	70
Net Realized Gains (Losses) on NDT Fund	[2]	42	(50)	166
Net Unrealized Gains (Losses) on Equity Securities		146	(205)	19
Net Gains (Losses) on NDT Fund Investments		188	(255)	185
Rabbi Trust [Member]
Schedule of Trust Investments [Line Items]
Proceeds from sales		29	65	170
Gross Realized Gains		5	5	16
Gross Realized Losses		6	9	8
Net Realized Gains (Losses) on NDT Fund	[3]	(1)	(4)	8
Net Unrealized Gains (Losses) on Equity Securities		2	(6)	1
Net Gains (Losses) on NDT Fund Investments		$ 1	$ (10)	$ 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.