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Regulatory Matters Narrative (Details) $ in Millions	Sep. 30, 2020 USD ($)
Incremental O&M - COVID | Columbia Of Ohio
Regulated Operations
Regulatory Assets	$ 1.9
Incremental O&M and Bad Debt - COVID | NIPSCO
Regulated Operations
Regulatory Assets	4.8
Incremental O&M and Bad Debt - COVID | Columbia Of Maryland
Regulated Operations
Regulatory Assets	0.5
Incremental Bad Debt - COVID | Columbia Of Pennsylvania
Regulated Operations
Regulatory Assets	$ 1.3

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- Definition

Regulated Operations

+ References

No definition available.

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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://fasb.org/us-gaap/role/ref/legacyRef
-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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