The settlement agreement for regulated assets resulted in new depreciation rates that reduce annual depreciation.

No definition available.

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- Definition

The length of pipelines used for delivering natural gas.

+ References

No definition available.

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- Definition

The percentage of pipeline used for delivering natural gas.

+ References

No definition available.

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- Definition

Allowed rate basefor equity in capital structure for all investor sources of capital.

+ References

No definition available.

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- Definition

Amount of increase (decrease) in accumulated depreciation, depletion and amortization of property, plant and equipment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

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- Definition

The expense charged against earnings during the period to allocate the capitalized costs of regulatory assets over the periods expected to benefit from such costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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- Definition

Carrying amount as of the balance sheet date of capitalized costs of a regulated entity, consisting of the planning, implementing, and monitoring activities which are designed to encourage consumers to modify their level and pattern of energy usage, which are expected to be recoverable through rate adjustments after one year or beyond 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 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 340
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=77907324&loc=d3e43603-110378

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- Definition

The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

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- Definition

Percentage of public utility's approved equity to capital, including debt and equity.

+ References

No definition available.

+ Details

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- Definition

Percentage of public utility's approved return on equity.

+ References

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Amortization period for the recovery of regulatory asset, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period.

+ 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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- Definition

Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer. Such costs are capitalized if they meet both of the following criteria: a. It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b. Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs. If the revenue will be provided through an automatic rate-adjustment clause, this criterion requires that the regulator's intent clearly be to permit recovery of the previously incurred cost.

+ References

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- Details

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- Details

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Regulatory Assets and Liabilities (ROE of People Gas System Division) (Details) $ in Millions, $ in Millions		1 Months Ended	12 Months Ended
	Sep. 12, 2018 USD ($)	Jan. 31, 2019 USD ($)	Dec. 31, 2018 CAD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2012 USD ($) km	Dec. 31, 2017 CAD ($)
Public Utilities, General Disclosures [Line Items]
Regulatory Assets			$ 1,569				$ 1,411
Regulatory Assets, Current			165				138
Environmental remediations [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets			$ 31				$ 41
Peoples Gas System Division [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Approved Return on Equity, Percentage			10.75%
Length Of Pipeline, percentage						5.00%
Length Of Pipeline \| km						800
Amortization of Regulatory Asset	$ 11
Replacement program						$ 80
Regulatory Asset Amortization Period						10 years
Peoples Gas System Division [Member] \| Subsequent Event [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities Allowed Rate Base		$ 12
Increase (decrease) depreciation rates		$ (10)
Peoples Gas System Division [Member] \| Environmental remediations [Member]
Public Utilities, General Disclosures [Line Items]
Reduction in annual depreciation				$ 16
Regulatory Assets					$ 32
Regulatory Assets, Current					21
Depreciation				$ 5	$ 16
Peoples Gas System Division [Member] \| Maximum [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Approved Return on Equity, Percentage			11.75%
Public Utilities, Approved Equity Capital Structure, Percentage			54.70%
Peoples Gas System Division [Member] \| Minimum [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Approved Return on Equity, Percentage			9.25%