Schedule I - Condensed Financial Information of Parent (Details)	1 Months Ended		3 Months Ended								12 Months Ended
	Jan. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2017 USD ($)	Aug. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Assets:
Cash and cash equivalents	$ 1,091,000,000	$ 1,091,000,000	$ 1,091,000,000			$ 96,000,000	$ 96,000,000			$ 161,000,000	$ 96,000,000	$ 161,000,000	$ 132,000,000	$ 1,091,000,000		$ 96,000,000	$ 161,000,000	$ 132,000,000
Other current assets														202,000,000		177,000,000
Total current assets														3,729,000,000		2,123,000,000
Other long-term assets														374,000,000		416,000,000
Total assets														52,580,000,000		51,319,000,000
Liabilities and equity:
Short-term debt														2,393,000,000		1,307,000,000
Current portion of long-term debt														481,000,000		981,000,000
Other current liabilities														1,265,000,000		991,000,000
Total current liabilities														7,068,000,000		5,912,000,000
Long-term debt														11,642,000,000		10,175,000,000
Total equity														13,866,000,000		14,187,000,000	13,388,000,000	12,982,000,000
Total liabilities and equity														52,580,000,000		$ 51,319,000,000
Condensed Statements of Income:
Interest income from affiliates			3,220,000,000	$ 3,672,000,000	$ 2,965,000,000	2,463,000,000	2,884,000,000	$ 3,767,000,000	$ 2,777,000,000	2,440,000,000	12,320,000,000	11,869,000,000	11,524,000,000
Operating expenses and interest expense											10,827,000,000	9,777,000,000	9,516,000,000
Operating income			(16,000,000)	561,000,000	469,000,000	479,000,000	566,000,000	695,000,000	381,000,000	448,000,000	1,493,000,000	2,092,000,000	2,008,000,000
Income tax expense (benefit)											281,000,000	177,000,000	486,000,000
Income from continuing operations			(534,000,000)	501,000,000	309,000,000	392,000,000	347,000,000	451,000,000	310,000,000	305,000,000	668,000,000	1,413,000,000	1,082,000,000
Income from discontinued operations, net of tax			0	0	0	0	13,000,000	0	(2,000,000)	1,000,000	0	12,000,000	35,000,000
Condensed Statements of Comprehensive Income
Other comprehensive income, net of tax											10,000,000	3,000,000	2,000,000
Comprehensive income											575,000,000	1,314,000,000	1,022,000,000
Condensed Statements of Cash Flows:
Net cash provided by operating activities											3,587,000,000	3,256,000,000	4,509,000,000
Cash flows from financing activities:
Long-term debt issued											2,233,000,000	397,000,000	1,420,000,000
Repayments of Long-term Debt											(1,285,000,000)	(220,000,000)	(762,000,000)
Short-term debt financing, net											1,084,000,000	611,000,000	(572,000,000)
Payments for stock-based compensation											(393,000,000)	(237,000,000)	(197,000,000)
Receipts from stock option exercises											215,000,000	135,000,000	128,000,000
Dividends paid											(707,000,000)	(626,000,000)	(544,000,000)
Net cash provided by (used in) financing activities											1,007,000,000	95,000,000	(588,000,000)
Net cash used in investing activities											(3,599,000,000)	(3,416,000,000)	(3,892,000,000)
Net increase (decrease) in cash and cash equivalents											995,000,000	(65,000,000)	29,000,000
Cash and cash equivalents, beginning of year	1,091,000,000					96,000,000				161,000,000	96,000,000	161,000,000	132,000,000
Cash and cash equivalents, end of year		1,091,000,000	1,091,000,000				96,000,000				1,091,000,000	96,000,000	161,000,000
Senior Notes Due 2017
Debt and Credit Agreements
Interest rate on debt (as a percent)																3.75%
Multi-year credit facilities
Debt and Credit Agreements
Commitment														1,250,000,000
Outstanding borrowings														(1,139,000,000)		$ (538,000,000)
Amount available														111,000,000
Weighted average interest rate (as a percent)																0.97%
Senior notes | 2.125% Senior notes due 2020
Debt and Credit Agreements
Debt, face amount						$ 400,000,000
Interest rate on debt (as a percent)						2.125%
Senior notes | 2.40% Senior notes due 2022
Debt and Credit Agreements
Debt, face amount															$ 400,000,000
Interest rate on debt (as a percent)															2.40%
Senior notes | 2.95% Senior notes due 2023
Debt and Credit Agreements
Debt, face amount														$ 400,000,000
Interest rate on debt (as a percent)														2.95%
Edison International Parent and Other
Assets:
Cash and cash equivalents	524,000,000	524,000,000	524,000,000			$ 6,000,000	6,000,000			7,000,000	6,000,000	7,000,000	8,000,000	$ 524,000,000		$ 6,000,000	7,000,000	8,000,000
Other current assets														340,000,000		261,000,000
Total current assets														864,000,000		267,000,000
Investments in subsidiaries														13,659,000,000		13,459,000,000
Deferred income taxes														500,000,000		646,000,000
Other long-term assets														91,000,000		108,000,000
Total assets														15,114,000,000		14,480,000,000
Liabilities and equity:
Short-term debt														1,139,000,000		539,000,000
Current portion of long-term debt														0		400,000,000
Other current liabilities														467,000,000		484,000,000
Total current liabilities														1,606,000,000		1,423,000,000
Long-term debt														1,193,000,000		397,000,000
Other long-term liabilities														644,000,000		664,000,000
Total equity														11,671,000,000		11,996,000,000
Total liabilities and equity														15,114,000,000		14,480,000,000
Condensed Statements of Income:
Interest income from affiliates											0	6,000,000	3,000,000
Operating expenses and interest expense											92,000,000	86,000,000	78,000,000
Operating income											(92,000,000)	(80,000,000)	(75,000,000)
Equity in earnings of subsidiaries											739,000,000	1,337,000,000	1,025,000,000
Income before income taxes											647,000,000	1,257,000,000	950,000,000
Income tax expense (benefit)											82,000,000	(42,000,000)	(35,000,000)
Income from continuing operations											565,000,000	1,299,000,000	985,000,000
Income from discontinued operations, net of tax											0	12,000,000	35,000,000
Net income											565,000,000	1,311,000,000	1,020,000,000
Condensed Statements of Comprehensive Income
Net income											565,000,000	1,311,000,000	1,020,000,000
Other comprehensive income, net of tax											10,000,000	3,000,000	2,000,000
Comprehensive income											575,000,000	1,314,000,000	1,022,000,000
Condensed Statements of Cash Flows:
Net cash provided by operating activities											462,000,000	493,000,000	641,000,000
Cash flows from financing activities:
Long-term debt issued											798,000,000	400,000,000	0
Long-term debt issuance costs											(5,000,000)	(3,000,000)	0
Repayments of Long-term Debt											(400,000,000)	0	0
Payable due to affiliates											8,000,000	34,000,000	54,000,000
Short-term debt financing, net											600,000,000	(108,000,000)	26,000,000
Payments for stock-based compensation											(260,000,000)	(95,000,000)	(114,000,000)
Receipts from stock option exercises											144,000,000	51,000,000	72,000,000
Dividends paid											(707,000,000)	(626,000,000)	(544,000,000)
Net cash provided by (used in) financing activities											178,000,000	(347,000,000)	(506,000,000)
Capital contributions to affiliate											(122,000,000)	(147,000,000)	(30,000,000)
Loans to affiliate											0	0	(106,000,000)
Net cash used in investing activities											(122,000,000)	(147,000,000)	(136,000,000)
Net increase (decrease) in cash and cash equivalents											518,000,000	(1,000,000)	(1,000,000)
Cash and cash equivalents, beginning of year	524,000,000					6,000,000				7,000,000	6,000,000	7,000,000	8,000,000
Cash and cash equivalents, end of year		524,000,000	524,000,000				6,000,000				524,000,000	6,000,000	7,000,000
Basis of Presentation
Cash dividends received from consolidated subsidiaries											573,000,000	701,000,000	758,000,000
Related Party Transactions
Current receivables due from affiliates														256,000,000		262,000,000
Current payables due to affiliates														235,000,000		221,000,000
Long-term receivables due from affiliate														81,000,000		103,000,000
Long-term payables due to affiliates														$ 200,000,000		$ 243,000,000
Edison International Parent and Other | Senior Notes Due 2017
Debt and Credit Agreements
Interest rate on debt (as a percent)																3.75%
Senior notes																$ 400,000,000
Edison International Parent and Other | Credit Facility July 2020
Debt and Credit Agreements
Commitment					1,250,000,000
Edison International Parent and Other | Revolving credit facility maturing in July 2018
Debt and Credit Agreements
Covenant requirement, consolidated debt to total capitalization, ratio														0.65
Consolidated debt to total capitalization, ratio														0.51
Edison International Parent and Other | SCE
Related Party Transactions
Expenses from services provided by SCE											3,000,000	3,000,000	3,000,000
Interest expense from loans due to affiliates											5,000,000	3,000,000	6,000,000
Edison International Parent and Other
Liabilities and equity:
Current portion of long-term debt														$ 2,000,000		402,000,000
Long-term debt														1,214,000,000		421,000,000
SCE
Assets:
Cash and cash equivalents	515,000,000	515,000,000	515,000,000			39,000,000	39,000,000			26,000,000	39,000,000	26,000,000	38,000,000	515,000,000		39,000,000	26,000,000	38,000,000
Other current assets														160,000,000		148,000,000
Total current assets														3,087,000,000		2,031,000,000
Other long-term assets														237,000,000		232,000,000
Total assets														51,515,000,000		50,891,000,000
Liabilities and equity:
Short-term debt														1,238,000,000		769,000,000
Current portion of long-term debt														479,000,000		579,000,000
Other current liabilities														1,224,000,000		729,000,000
Total current liabilities														5,887,000,000		4,707,000,000
Long-term debt														10,428,000,000		9,754,000,000
Total equity														14,672,000,000		14,483,000,000	13,672,000,000	$ 13,282,000,000
Total liabilities and equity														51,515,000,000		50,891,000,000
Condensed Statements of Income:
Interest income from affiliates			3,193,000,000	3,652,000,000	2,953,000,000	2,456,000,000	2,874,000,000	3,752,000,000	2,768,000,000	2,435,000,000	12,254,000,000	11,830,000,000	11,485,000,000
Operating expenses and interest expense											10,656,000,000	9,613,000,000	9,405,000,000
Operating income			(4,000,000)	$ 578,000,000	$ 517,000,000	507,000,000	594,000,000	$ 721,000,000	$ 429,000,000	472,000,000	1,598,000,000	2,217,000,000	2,080,000,000
Income tax expense (benefit)											(30,000,000)	256,000,000	507,000,000
Condensed Statements of Comprehensive Income
Other comprehensive income, net of tax											1,000,000	2,000,000	6,000,000
Condensed Statements of Cash Flows:
Net cash provided by operating activities											3,725,000,000	3,523,000,000	4,624,000,000
Cash flows from financing activities:
Long-term debt issued											1,445,000,000	0	1,413,000,000
Repayments of Long-term Debt											(882,000,000)	(217,000,000)	(761,000,000)
Short-term debt financing, net											469,000,000	719,000,000	(619,000,000)
Payments for stock-based compensation											(86,000,000)	(127,000,000)	(78,000,000)
Receipts from stock option exercises											48,000,000	76,000,000	68,000,000
Dividends paid											(697,000,000)	(824,000,000)	(874,000,000)
Net cash provided by (used in) financing activities											243,000,000	(219,000,000)	(812,000,000)
Net cash used in investing activities											(3,492,000,000)	(3,291,000,000)	(3,824,000,000)
Net increase (decrease) in cash and cash equivalents											476,000,000	13,000,000	(12,000,000)
Cash and cash equivalents, beginning of year	515,000,000					$ 39,000,000				$ 26,000,000	39,000,000	26,000,000	38,000,000
Cash and cash equivalents, end of year		515,000,000	$ 515,000,000				$ 39,000,000				$ 515,000,000	$ 39,000,000	$ 26,000,000
Basis of Presentation
Minimum percentage of weighted-average common equity component authorization, set by CPUC (as a percent)											48.00%
Weighted-average common equity component authorization, set by CPUC remaining over number of months (in months)											13 months
After-tax charge excused from capital structure											$ 448,000,000
Period for calculation of weighted average common equity component (months)											13 months
Weighted-average common equity component of total capitalization (as a percent)											50.00%
Capacity to pay additional dividends											$ 511,000,000
Restriction on net assets														$ 14,200,000,000
Debt and Credit Agreements
Weighted average interest rate (as a percent)														2.56%
SCE | Pro forma
Basis of Presentation
Weighted-average common equity component authorization, set by CPUC remaining over number of months (in months)											13 months
Period for calculation of weighted average common equity component (months)											13 months
Weighted-average common equity component of total capitalization (as a percent)											50.10%
SCE | Multi-year credit facilities
Debt and Credit Agreements
Commitment														$ 2,750,000,000
Outstanding borrowings														(1,238,000,000)
Amount available														$ 1,413,000,000
Weighted average interest rate (as a percent)														2.46%
Line of credit
Debt and Credit Agreements
Borrowings from credit facility		500,000,000
Line of credit | SCE
Debt and Credit Agreements
Borrowings from credit facility		$ 500,000,000
Subsequent event | Edison International Parent and Other | Term Loan Agreement
Debt and Credit Agreements
Debt, face amount	$ 500,000,000
Basis points	60.00%
Subsequent event | Line of credit
Debt and Credit Agreements
Repayment on borrowings	$ 500,000,000
Subsequent event | Line of credit | SCE
Debt and Credit Agreements
Repayment on borrowings	$ 500,000,000
Related-party note receivable converted into capital contribution
Related Party Transactions
Conversion of note											$ 184,000,000
Commercial paper | Multi-year credit facilities
Debt and Credit Agreements
Outstanding borrowings														$ (639,000,000)
Weighted average interest rate (as a percent)														1.70%
Commercial paper | SCE | Multi-year credit facilities
Debt and Credit Agreements
Outstanding borrowings																$ (769,000,000)
Weighted average interest rate (as a percent)														1.75%		0.90%
Common Stock
Basis of Presentation
Dividends declared but not paid														$ 197,000,000		$ 177,000,000	156,000,000
Common Stock | SCE
Basis of Presentation
Dividends declared but not paid														$ 212,000,000		$ 0	$ 0