Commitments and Contingencies (Power Purchase Agreement - Operating and Capital Leases) (Details) - SCE $ in Millions	Dec. 31, 2017 USD ($)
Operating Leases
Operating Leases
2018	$ 335
2019	262
2020	234
2021	198
2022	174
Thereafter	1,222
Total future commitments	2,425
Capital Leases
Capital Leases
2018	2
2019	2
2020	2
2021	3
2022	3
Thereafter	21
Total future commitments	33
Amount representing executory costs	(15)
Amount representing interest	(8)
Net commitments	$ 10

Amount of minimum lease payments for capital leases.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84164817&loc=d3e45280-112737

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Amount of minimum lease payments for capital leases due in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amounts to be paid by lessee to lessor for maintenance, insurance, and tax expenses related to the leased asset.

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Amount necessary to reduce net minimum lease payments to present value for capital leases.

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Present value of minimum lease payments for capital leases net of executory costs, including amounts paid by the lessee to the lessor for insurance, maintenance and taxes.

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Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 55
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-URI http://asc.fasb.org/extlink&oid=82846649&loc=d3e38371-112697

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-SubTopic 20
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-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77902758&loc=d3e41502-112717

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-URI http://asc.fasb.org/extlink&oid=82846649&loc=d3e38371-112697

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