Regulatory Accounting (Details) - Hurricane Harvey [Member] $ in Millions	Sep. 30, 2017 USD ($)
Estimated restoration costs covered by insurance	$ 17
Recorded increase in regulatory assets	7
Recorded insurance receivables	2
Minimum [Member]
Estimated costs to restore damaged facilities	25
Maximum [Member]
Estimated costs to restore damaged facilities	$ 30

Estimated costs to restore electric delivery system and natural gas distribution facilities damaged during Hurricane Harvey.

No definition available.

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- Definition

Represents the estimated total storm restoration costs covered by insurance.

+ References

No definition available.

+ Details

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- Definition

Amount due in settlement of a claim for reimbursement from an insurance company when the Company has suffered a loss covered under an insurance policy. For classified balance sheets, represents the current amount receivable, that is amounts expected to be collected within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.8)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 340
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382

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- Details

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