Bank segment (HEI only) Securities Sold Under Agreements to Repurchase, Including Related Collateral Received From or Pledged to Counterparties (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Securities sold under agreements to repurchase
Gross amount of recognized liabilities, repurchase agreements	$ 191,000,000	$ 145,000,000
Net amount of liabilities presented in the Balance Sheet, repurchase agreements	191,000,000	145,000,000
Financial instruments	191,000,000	145,000,000
Identical securities
Securities sold under agreements to repurchase
Repurchase liability	190,656,000	145,000,000	146,000,000
Average amount outstanding during the year	155,000,000	147,000,000	173,000,000
Maximum amount outstanding as of any month-end	195,000,000	151,000,000	189,000,000
Weighted-average interest rate as of end of the period (as a percent)	1.45%	1.75%	1.74%
Weighted-average interest rate during the year (as a percent)	1.67%	1.74%	1.56%
Weighted-average remaining days to maturity as of end of the period	343 days	367 days	489 days
Overnight
Securities sold under agreements to repurchase
Repurchase liability	84,758,000
Weighted-average interest rate as of end of the period (as a percent)	0.15%
1 to 29 days
Securities sold under agreements to repurchase
Repurchase liability	0
Weighted-average interest rate as of end of the period (as a percent)	0.00%
30 to 90 days
Securities sold under agreements to repurchase
Repurchase liability	0
Weighted-average interest rate as of end of the period (as a percent)	0.00%
Over 90 days
Securities sold under agreements to repurchase
Repurchase liability	105,898,000
Weighted-average interest rate as of end of the period (as a percent)	2.50%
Financial institution
Securities sold under agreements to repurchase
Net amount of liabilities presented in the Balance Sheet, repurchase agreements	50,000,000	51,000,000
Financial instruments	50,000,000	51,000,000
Government entities
Securities sold under agreements to repurchase
Net amount of liabilities presented in the Balance Sheet, repurchase agreements	56,000,000
Financial instruments	56,000,000
Commercial account holders
Securities sold under agreements to repurchase
Net amount of liabilities presented in the Balance Sheet, repurchase agreements	85,000,000	94,000,000
Financial instruments	$ 85,000,000	$ 94,000,000

Average amount to be repaid to the counterparty to the repurchase agreement at a future date.

No definition available.

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- Definition

Represents the interest rate on assets sold under agreements to repurchase.

+ References

No definition available.

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- Definition

Maximum amount to be repaid to the counterparty to the repurchase agreement at a future date.

+ References

No definition available.

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- Definition

Weighted-average remaining period of maturity for a group of securities or other assets sold under repurchase agreements, as of end of the period.

+ References

No definition available.

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- Definition

Amount of right to receive financial instruments collateral under master netting arrangements that have not been offset against securities sold under agreement to repurchase.

+ References

No definition available.

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- Definition

Interest rate on the amount to be repaid to the counterparty to the repurchase agreement when the carrying amount (or market value, if higher than the carrying amount) of securities or other assets sold under the repurchase agreement exceeds 10 percent of total assets.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph m

-Subparagraph 1

-Article 4

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(m)(1)(i)(A)(ii))

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- Definition

Amount to be repaid to the counterparty to the repurchase agreement when the carrying amount (or market value, if higher than the carrying amount) of securities or other assets sold under the repurchase agreement exceeds 10 percent of total assets.

+ References

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- Definition

Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.13(1))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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Amount, before effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References

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

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-Name Accounting Standards Codification

-Topic 210

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