Earnings per share and shareholders' equity (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Reclassifications out of accumulated other comprehensive income/(loss)
Interest expense	$ 19,100	$ 19,456
Amortization of transition obligation, prior service credit and net losses recognized during the period in net periodic benefit cost	(5,459)	(2,813)
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets	4,911	2,510
Amount reclassified from AOCI
Reclassifications out of accumulated other comprehensive income/(loss)
Total reclassifications	4,058	(1,353)
Net unrealized gains (losses) on securities \| Amount reclassified from AOCI
Reclassifications out of accumulated other comprehensive income/(loss)
Revenues-bank (net gains on sales of securities)	3,451	(1,715)
Derivatives qualified as cash flow hedges Interest rate contracts (settled in 2011) \| Interest rate contracts \| Amount reclassified from AOCI
Reclassifications out of accumulated other comprehensive income/(loss)
Interest expense	59	59
Retirement benefit plans \| Amount reclassified from AOCI
Reclassifications out of accumulated other comprehensive income/(loss)
Amortization of transition obligation, prior service credit and net losses recognized during the period in net periodic benefit cost	5,459	2,813
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets	(4,911)	(2,510)
Hawaiian Electric Company, Inc. and Subsidiaries
Reclassifications out of accumulated other comprehensive income/(loss)
Amortization of transition obligation, prior service credit and net losses recognized during the period in net periodic benefit cost	(4,933)	(2,519)
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets	4,911	2,510
Hawaiian Electric Company, Inc. and Subsidiaries \| Amount reclassified from AOCI
Reclassifications out of accumulated other comprehensive income/(loss)
Total reclassifications	22	9
Hawaiian Electric Company, Inc. and Subsidiaries \| Retirement benefit plans \| Amount reclassified from AOCI
Reclassifications out of accumulated other comprehensive income/(loss)
Amortization of transition obligation, prior service credit and net losses recognized during the period in net periodic benefit cost	4,933	2,519
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets	$ (4,911)	$ (2,510)

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.

+ Details

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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

No definition available.

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