Electric utility segment - Asset Retirement Obligations (Details) - Hawaiian Electric Company, Inc. and Subsidiaries - USD ($)	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Regulatory Projects and Legal Obligations [Line Items]
ARO, recognition impact on earnings	$ 0
Changes in the asset retirement obligation liability
Balance at the beginning of the period	10,692,000	$ 10,324,000
Accretion expense	423,000	405,000
Liabilities incurred	0	0
Liabilities settled	(5,000)	(37,000)
Balance at the end of the period	$ 11,110,000	$ 10,692,000

Represents the amount of impact on earnings from recognition of asset retirement obligations (AROs).

No definition available.

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Period Type:	duration

- Definition

-- None. No documentation exists for this element. --

+ References

No definition available.

+ Details

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- Definition

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848

+ Details

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Period Type:	duration

- Definition

Amount of asset retirement obligations incurred during the period.

+ References

+ Details

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Period Type:	duration

- Definition

Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset.

+ References

+ Details

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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- Details

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