XML 77 R61.htm IDEA: XBRL DOCUMENT v3.8.0.1

Credit agreements and long-term debt (Details)	Oct. 06, 2017 USD ($)	Jun. 29, 2017 USD ($)	Sep. 30, 2017 USD ($) Institution	Dec. 31, 2016 USD ($)
Debt Disclosure [Abstract]
Number of financial institutions (in institutions) | Institution			8
Line of credit facility
Credit agreement
Revolving noncollateralized credit facility with a letter of credit sub-facility			$ 150,000,000
Amount outstanding under facilities			0	$ 0
Line of credit facility | Hawaiian Electric Company
Credit agreement
Revolving noncollateralized credit facility with a letter of credit sub-facility			200,000,000
Amount outstanding under facilities			$ 0	$ 0
Special Purpose Revenue Bonds | Refunding Series 2017A Special Purpose Revenue Bonds [Member]
Credit agreement
Aggregate principal amount		$ 125,000,000
Fixed coupon interest rate		3.10%
Special Purpose Revenue Bonds | Refunding Series 2017B Special Purpose Revenue Bonds
Credit agreement
Aggregate principal amount		$ 140,000,000
Fixed coupon interest rate		4.00%
Special Purpose Revenue Bonds | Refunding Series 2007B Special Purpose Revenue Bonds
Credit agreement
Fixed coupon interest rate		4.60%
Aggregate principal amount		$ 125,000,000
Special Purpose Revenue Bonds | Refunding Series 2007B Special Purpose Revenue Bonds | Subsequent Event
Credit agreement
Repayments of debt	$ 125,000,000
Special Purpose Revenue Bonds | Series 2007A Special Purpose Revenue Bonds
Credit agreement
Fixed coupon interest rate		4.65%
Aggregate principal amount		$ 140,000,000
Special Purpose Revenue Bonds | Euro Term Loan | Subsequent Event
Credit agreement
Proceeds from Department loan	$ 125,000,000
Debt instrument term	364 days
Interest rate for first month	1.99%
Special Purpose Revenue Bonds | Hawaiian Electric Company | Refunding Series 2017A Special Purpose Revenue Bonds [Member]
Credit agreement
Proceeds from Department loan		62,000,000
Special Purpose Revenue Bonds | Hawaiian Electric Company | Refunding Series 2017B Special Purpose Revenue Bonds
Credit agreement
Proceeds from Department loan		100,000,000
Special Purpose Revenue Bonds | HELCO | Refunding Series 2017A Special Purpose Revenue Bonds [Member]
Credit agreement
Proceeds from Department loan		8,000,000
Special Purpose Revenue Bonds | HELCO | Refunding Series 2017B Special Purpose Revenue Bonds
Credit agreement
Proceeds from Department loan		20,000,000
Special Purpose Revenue Bonds | Maui Electric | Refunding Series 2017A Special Purpose Revenue Bonds [Member]
Credit agreement
Proceeds from Department loan		55,000,000
Special Purpose Revenue Bonds | Maui Electric | Refunding Series 2017B Special Purpose Revenue Bonds
Credit agreement
Proceeds from Department loan		$ 20,000,000

X

- Definition

Debt Instrument, Interest Rate, Annualized

+ References

No definition available.

+ Details

Name:	he_DebtInstrumentInterestRateAnnualized
Namespace Prefix:	he_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Represents the number of financial institutions with which the entity entered into a revolving Non Collateralized credit agreement with a letter of credit sub-facility.

+ References

No definition available.

+ Details

Name:	he_NumberOfFinancialInstitutions
Namespace Prefix:	he_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- References

No definition available.

+ Details

Name:	us-gaap_DebtDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- 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.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Face (par) amount of the original debt instrument that was repurchased.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentRepurchasedFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Fair value of the amount outstanding under the credit facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13433-108611

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13476-108611

+ Details

Name:	us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

The cash inflow from the issuance of long-term debt that is not secured by collateral. Excludes proceeds from tax exempt unsecured debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromIssuanceOfUnsecuredDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The cash outflow to repay long-term debt that is not secured by collateral. Excludes repayments of tax exempt unsecured debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3291-108585

+ Details

Name:	us-gaap_RepaymentsOfUnsecuredDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=us-gaap_SubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=he_RefundingSeries2017ASpecialPurposeRevenueBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=he_RefundingSeries2017BSpecialPurposeRevenueBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=he_RefundingSeries2007BDue2026Debt4.60PercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=he_Series2007ASpecialPurposeRevenueBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=he_EurodollarTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=he_HawaiiElectricLightCompanyIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=he_MauiElectricCompanyLimitedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: