Shareholders' equity Reclassification Out Of AOCI (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reclassification Adjustment Out of Accumulated Other Comprehensive Income [Line Items]
Interest rate contracts (settled in 2011)	$ 76,352	$ 75,479	$ 78,151
Amortization of transition obligation, prior service credit and net losses recognized during the period in net periodic benefit cost	(11,344)	(23,280)	(15,291)
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets	(207,833)	222,595	(75,471)
Amount reclassified from AOCI
Reclassification Adjustment Out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications	217,698	(199,818)	90,917
Amount reclassified from AOCI \| Unrealized losses on derivatives
Reclassification Adjustment Out of Accumulated Other Comprehensive Income [Line Items]
Net realized gains on securities	(1,715)	(738)	(81)
Interest rate contracts (settled in 2011)	236	235	236
Amount reclassified from AOCI \| Retirement benefit plans
Reclassification Adjustment Out of Accumulated Other Comprehensive Income [Line Items]
Amortization of transition obligation, prior service credit and net losses recognized during the period in net periodic benefit cost	11,344	23,280	15,291
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets	207,833	(222,595)	75,471
Hawaiian Electric Company, Inc. and Subsidiaries
Reclassification Adjustment Out of Accumulated Other Comprehensive Income [Line Items]
Amortization of transition obligation, prior service credit and net losses recognized during the period in net periodic benefit cost	(10,212)	(20,694)	(13,673)
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets	(207,833)	222,595	(75,471)
Hawaiian Electric Company, Inc. and Subsidiaries \| Amount reclassified from AOCI
Reclassification Adjustment Out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications	218,045	(201,901)	89,144
Hawaiian Electric Company, Inc. and Subsidiaries \| Amount reclassified from AOCI \| Retirement benefit plans
Reclassification Adjustment Out of Accumulated Other Comprehensive Income [Line Items]
Amortization of transition obligation, prior service credit and net losses recognized during the period in net periodic benefit cost	10,212	20,694	13,673
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets	$ 207,833	$ (222,595)	$ 75,471

The amount of interest expense, other than on deposit liabilities and other bank borrowings.

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- Definition

Reclassification adjustments on pension and post retirement benefits for the accounting impact of the decisions issued by the Public Utilities Commission, net of income taxes.

+ References

No definition available.

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- Definition

The adjustment out of other comprehensive income for actuarial gains or losses, prior service gains or losses, and net transition asset or obligation recognized as a component of net periodic benefit cost during the period, after tax.

+ References

No definition available.

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- Definition

The net gain (loss) realized from the sale, exchange, redemption, or retirement of securities, not separately or otherwise categorized as trading, available-for-sale, or held-to-maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.13(h))

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 13

-Subparagraph h

-Article 9

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.3)

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 3

-Article 7

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- Definition

Amount after tax of reclassification adjustments of other comprehensive income (loss).

+ References

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