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- Definition

The interest rate used to adjust for the time value of money for the plan.

+ References

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- Definition

Expected rate of compensation increases (for pay-related plans).

+ References

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- Definition

The interest rate used to adjust for the time value of money.

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- Definition

An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Expected Long-Term Rate of Return on Plan Assets
-URI http://asc.fasb.org/extlink&oid=6512046

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(3)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

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- Definition

Expected rate of compensation increases (for pay-related plans).

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Target allocation of investments of this type to total plan assets presented on a weighted average basis.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)(i)
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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
-Section 50
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

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- Definition

Target allocation maximum percentage of investments of this type to total plan assets presented on a weighted average basis.

+ References

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- Definition

Target allocation minimum percentage of investments of this type to total plan assets presented on a weighted average basis.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
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-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e2446-114920

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- Definition

Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

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- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

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No definition available.

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Percentage employer matches of the employee's percentage contribution matched.

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Retirement benefits - Weighted Average Asset Allocation of Defined Benefit Retirement Plans and Weighted Average Assumptions(Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Hawaiian Electric Company, Inc. and Subsidiaries
Net periodic pension/benefit cost (years ended)
Employer's additional matching contribution on employee deferrals (as a percent)	50.00%
Maximum percentage of participant deferrals eligible for Employer contribution match, towards defined contribution plan	6.00%
American Savings Bank (ASB)
Net periodic pension/benefit cost (years ended)
Maximum percentage of participant deferrals eligible for Employer contribution match, towards defined contribution plan	4.00%
Hawaii Electric Light Company, Inc. (HELCO)
Net periodic pension/benefit cost (years ended)
Employer's additional matching contribution on employee deferrals (as a percent)	50.00%
Maximum percentage of participant deferrals eligible for Employer contribution match, towards defined contribution plan	6.00%
Pension benefits
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation (as a percent)	100.00%	100.00%
Asset category, Target
Target (as a percent)	100.00%
Benefit obligation
Discount rate (as a percent)	4.26%	4.60%	4.22%
Rate of compensation increase (as a percent)	3.50%	3.50%	3.50%
Net periodic pension/benefit cost (years ended)
Discount rate (as a percent)	4.60%	4.22%	5.09%
Expected return on plan assets (as a percent)	7.75%	7.75%	7.75%
Rate of compensation increase (as a percent)	3.50%	3.50%	3.50%
Pension benefits \| American Savings Bank (ASB)
Net periodic pension/benefit cost (years ended)
Expected return on plan assets (as a percent)	4.80%	4.22%
Pension benefits \| Equity securities managers
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation (as a percent)	71.00%	70.00%
Asset category, Target
Target (as a percent)	70.00%
Target minimum range (as a percent)	65.00%
Target maximum range (as a percent)	75.00%
Pension benefits \| Fixed income securities managers
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation (as a percent)	29.00%	30.00%
Asset category, Target
Target (as a percent)	30.00%
Target minimum range (as a percent)	25.00%
Target maximum range (as a percent)	35.00%
Other benefits
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation (as a percent)	100.00%	100.00%
Asset category, Target
Target (as a percent)	100.00%
Benefit obligation
Discount rate (as a percent)	4.22%	4.57%	4.17%
Net periodic pension/benefit cost (years ended)
Discount rate (as a percent)	4.57%	4.17%	5.03%
Expected return on plan assets (as a percent)	7.75%	7.75%	7.75%
Other benefits \| Equity securities managers
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation (as a percent)	70.00%	70.00%
Asset category, Target
Target (as a percent)	70.00%
Target minimum range (as a percent)	65.00%
Target maximum range (as a percent)	75.00%
Other benefits \| Fixed income securities managers
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation (as a percent)	30.00%	30.00%
Asset category, Target
Target (as a percent)	30.00%
Target minimum range (as a percent)	25.00%
Target maximum range (as a percent)	35.00%