v3.8.0.1

SAN ONOFRE NUCLEAR GENERATING STATION - NUCLEAR INSURANCE (Details) - San Diego Gas and Electric Company [Member] - USD ($) $ in Millions | Apr. 05, 2018 | Mar. 31, 2018 | Jan. 09, 2018 | Jan. 05, 2018 | Jan. 04, 2018
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Schedule Of Nuclear Insurance [Line Items] |  |  |  |  |
Maximum nuclear liability insurance coverage |  | $ 450.0 |  | $ 100.0 | $ 450.0
Maximum secondary financial protection |  | 110.0 |  |  |
Annual maximum secondary financial protection contribution by company |  | 560.0 |  |  |
Federal nuclear property damage insurance, minimum required |  | 50.0 | $ 1,060.0 |  |
Nuclear property damage insurance |  | 1,500.0 |  |  |
Maximum premium assessment under nuclear property damage insurance |  | 10.4 |  |  |
Maximum nuclear property insurance terrorism coverage |  | $ 3,240.0 |  |  |
Subsequent Event [Member] |  |  |  |  |
Schedule Of Nuclear Insurance [Line Items] |  |  |  |  |
Spent nuclear fuel storage insurance | $ 500.0 |  |  |  |

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- Definition Federal Nuclear Property Damage Insurance + References No definition available. + Details
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Namespace Prefix: | sre_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Definition Federal nuclear property damage insurance, minimum required + References No definition available. + Details
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Balance Type: | debit
Period Type: | instant

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- References No definition available. + Details
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Namespace Prefix: | sre_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- References No definition available. + Details
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Namespace Prefix: | sre_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- References No definition available. + Details
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Namespace Prefix: | sre_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- References No definition available. + Details
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- References No definition available. + Details
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Namespace Prefix: | sre_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- References No definition available. + Details
Name: | sre_SecondaryFinancialProtectionMaximum
Namespace Prefix: | sre_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Definition Spent Nuclear Fuel Storage Insurance + References No definition available. + Details
Name: | sre_SpentNuclearFuelStorageInsurance
Namespace Prefix: | sre_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |