Compensation and Benefit Plans (OPEB Assets Fair Value) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Domestic mortgage backed securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual plan asset allocations, percentage	20.00%	16.00%
Postretirement Benefits Other Than Pensions
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	$ 2,773	$ 2,713
Receivables and payables, net	(1)	4
Net plan assets available for benefits	$ 2,772	$ 2,717	$ 2,465
Publicly traded equity investments located in the US (percent)	68.00%	66.00%
Postretirement Benefits Other Than Pensions | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	$ 1,002	$ 669
Postretirement Benefits Other Than Pensions | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	1,120	1,270
Postretirement Benefits Other Than Pensions | NAV
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	651	774
Postretirement Benefits Other Than Pensions | U.S. government and agency securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	823	410
Postretirement Benefits Other Than Pensions | U.S. government and agency securities | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	813	380
Postretirement Benefits Other Than Pensions | U.S. government and agency securities | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	10	30
Postretirement Benefits Other Than Pensions | U.S. government and agency securities | NAV
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits Other Than Pensions | Corporate stocks
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	$ 148	$ 227
Postretirement Benefits Other Than Pensions | Corporate stocks | Russell Indexes
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Performance percentage benchmark, percentage	73.00%	70.00%
Postretirement Benefits Other Than Pensions | Corporate stocks | MSCI All Country World Index
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Performance percentage benchmark, percentage	27.00%	30.00%
Postretirement Benefits Other Than Pensions | Corporate stocks | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	$ 145	$ 224
Postretirement Benefits Other Than Pensions | Corporate stocks | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	3	3
Postretirement Benefits Other Than Pensions | Corporate stocks | NAV
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits Other Than Pensions | Corporate notes and bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	997	1,079
Postretirement Benefits Other Than Pensions | Corporate notes and bonds | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits Other Than Pensions | Corporate notes and bonds | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	997	1,079
Postretirement Benefits Other Than Pensions | Corporate notes and bonds | NAV
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits Other Than Pensions | Common/collective funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	$ 544	$ 693
Postretirement Benefits Other Than Pensions | Common/collective funds | Non-index U.S. equity fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual plan asset allocations, percentage	25.00%	22.00%
Postretirement Benefits Other Than Pensions | Common/collective funds | MSCI All Country World Index Investable Market Index
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual plan asset allocations, percentage	65.00%	70.00%
Postretirement Benefits Other Than Pensions | Common/collective funds | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	$ 0	$ 0
Postretirement Benefits Other Than Pensions | Common/collective funds | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits Other Than Pensions | Common/collective funds | NAV
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	544	693
Postretirement Benefits Other Than Pensions | Partnerships/joint ventures
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	107	81
Postretirement Benefits Other Than Pensions | Partnerships/joint ventures | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits Other Than Pensions | Partnerships/joint ventures | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits Other Than Pensions | Partnerships/joint ventures | NAV
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	107	81
Postretirement Benefits Other Than Pensions | Registered investment companies
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	44	65
Postretirement Benefits Other Than Pensions | Registered investment companies | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	44	65
Postretirement Benefits Other Than Pensions | Registered investment companies | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits Other Than Pensions | Registered investment companies | NAV
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits Other Than Pensions | Interest-bearing cash
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	51	26
Postretirement Benefits Other Than Pensions | Interest-bearing cash | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits Other Than Pensions | Interest-bearing cash | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	51	26
Postretirement Benefits Other Than Pensions | Interest-bearing cash | NAV
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits Other Than Pensions | Other investments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	59	132
Postretirement Benefits Other Than Pensions | Other investments | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits Other Than Pensions | Other investments | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	59	132
Postretirement Benefits Other Than Pensions | Other investments | NAV
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits Other Than Pensions | Collateralized mortgage obligations and other asset backed securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Receivables and payables, net	$ 150	$ 170
Postretirement Benefits Other Than Pensions | Private equity and venture capital funds including branded consumer products, clean and information technology and healthcare
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual plan asset allocations, percentage	54.00%	46.00%
Postretirement Benefits Other Than Pensions | Asset backed securities including distressed mortgages
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual plan asset allocations, percentage	35.00%	36.00%
Postretirement Benefits Other Than Pensions | Broad range of financial assets in all global markets
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual plan asset allocations, percentage	11.00%	18.00%
Postretirement Benefits Other Than Pensions | Municipal securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	$ 44	$ 61
Postretirement Benefits Other Than Pensions | Money Market Fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual plan asset allocations, percentage	61.00%	51.00%
Postretirement Benefits Other Than Pensions | Defined Benefit Plan, Equity Securities, Small Cap
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual plan asset allocations, percentage	39.00%	49.00%
SCE | Postretirement Benefits Other Than Pensions
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net plan assets available for benefits	$ 2,772	$ 2,717	$ 2,464