Bank segment (HEI only) - Deposit Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Weighted-average stated rate
Savings	0.07%	0.07%
Checking, interest-bearing	0.03%	0.02%
Money market	0.09%	0.12%
Time certificates	1.26%	1.00%
Total weighted-average stated rate	0.20%	0.15%
Deposit liabilities
Savings	$ 2,303,450	$ 2,208,594
Checking
Interest-bearing	944,833	890,633
Noninterest-bearing	896,292	817,867
Commercial checking	863,941	821,184
Money market	114,797	153,126
Time certificates	767,284	657,525
Total Amount	5,890,597	5,548,929
Certificate accounts of $100,000 or more	433,400	328,100
Term certificates outstanding, scheduled maturities
2018	401,650
2019	114,434
2020	123,310
2021	71,729
2022	52,860
Thereafter	3,301
Total	767,284
Overdrawn deposit accounts classified as loans	1,700	1,800
Interest expense on deposit liabilities by type of deposit
Time certificates	7,687	5,390	$ 3,747
Savings	1,567	1,402	1,257
Money market	168	202	205
Interest-bearing checking	238	173	139
Interest expense on deposit liabilities	$ 9,660	$ 7,167	$ 5,348

Interest expense incurred on all interest-bearing checking.

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- Definition

Amount of noninterest-bearing domestic commercial checking deposit liabilities.

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No definition available.

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Overdrawn Deposit Accounts

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No definition available.

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- Definition

The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

+ 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 210.9-03.12)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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- References

No definition available.

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- Definition

Amount of interest-bearing domestic certificate of deposit liabilities.

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Amount of interest-bearing domestic checking deposit liabilities.

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Amount of interest-bearing domestic money market demand account deposit liabilities.

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- Definition

Amount of interest-bearing domestic savings deposit liabilities. Saving deposits bear interest and have no stated maturity.

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- Definition

Aggregate amount of interest expense on all deposits.

+ 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 210.9-04.6)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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Interest expense incurred on all money market deposits.

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Interest expense incurred on all savings account deposits.

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The aggregate interest expense incurred on time deposits, including certificates of deposits, in domestic offices.

+ References

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Amount of noninterest-bearing domestic checking deposit liabilities.

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Amount of time deposits maturing after the fifth fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of time deposits maturing in the fifth fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of time deposits maturing in the fourth fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of time deposits maturing in the next fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Industry Guide
-Number 3
-Section V
-Paragraph D-E

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Amount of time deposits maturing in the third fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of time deposits maturing in the second fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of time deposit liabilities, including certificates of deposit.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 405
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=50488274&loc=d3e64164-112818

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.12)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Industry Guide
-Number 3
-Section V
-Paragraph D-E

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Amount of time deposit liabilities, including certificates of deposit, in denominations of $100,000 or more.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Industry Guide
-Number 3
-Section V
-Paragraph D-E

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The weighted average interest rate for all domestic deposit liabilities.

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No definition available.

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- Definition

The weighted average interest rate for domestic certificates of deposit liabilities.

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No definition available.

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The weighted average interest rate for domestic checking deposit liabilities.

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No definition available.

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- Definition

The weighted average interest rate for domestic money market demand account deposit liabilities.

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No definition available.

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- Definition

The weighted average interest rate for domestic savings deposit liabilities.

+ References

No definition available.

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