Bank segment (HEI only) - Allowance For Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Allowance for credit losses:
Beginning balance	$ 101,201	$ 53,355	$ 52,119
Charge-offs	(9,700)	(26,154)	(28,662)
Recoveries	6,054	4,748	6,418
Net (charge-offs) recoveries	(3,646)	(21,406)	(22,244)
Provision for credit losses	(26,425)	49,811	23,480
Ending balance	71,130	101,201	53,355	$ 52,119
Average loans outstanding	$ 5,220,491	$ 5,340,287	$ 4,986,830
Net charge-offs (recoveries) to average loans	0.07%	0.40%	0.45%
Ending balance: individually evaluated for impairment			$ 2,691
Ending balance: collectively evaluated for impairment			50,664
Financing Receivables:
Loans held for investment			5,120,664
Ending balance: individually evaluated for impairment			40,737
Ending balance: collectively evaluated for impairment			$ 5,079,927
Accounting standards update, extensible Llist			Accounting Standards Update 2016-13 [Member]	Accounting Standards Update 2016-13 [Member]
Commercial
Allowance for credit losses:
Beginning balance	$ 25,462	$ 10,245	$ 9,225
Charge-offs	(1,561)	(5,819)	(6,811)
Recoveries	1,468	872	2,351
Net (charge-offs) recoveries	(93)	(4,947)	(4,460)
Provision for credit losses	(9,571)	19,242	5,480
Ending balance	15,798	25,462	10,245	$ 9,225
Average loans outstanding	$ 856,226	$ 935,663	$ 620,206
Net charge-offs (recoveries) to average loans	0.01%	0.53%	0.72%
Ending balance: individually evaluated for impairment			$ 1,015
Ending balance: collectively evaluated for impairment			9,230
Financing Receivables:
Loans held for investment			670,674
Ending balance: individually evaluated for impairment			8,418
Ending balance: collectively evaluated for impairment			662,256
Consumer
Allowance for credit losses:
Beginning balance	$ 23,950	$ 16,206	16,769
Charge-offs	(8,027)	(19,900)	(21,677)
Recoveries	4,320	3,381	2,967
Net (charge-offs) recoveries	(3,707)	(16,519)	(18,710)
Provision for credit losses	(4,659)	7,800	18,147
Ending balance	15,584	23,950	16,206	16,769
Average loans outstanding	$ 135,609	$ 215,994	$ 270,340
Net charge-offs (recoveries) to average loans	2.73%	7.65%	6.92%
Ending balance: individually evaluated for impairment			$ 454
Ending balance: collectively evaluated for impairment			15,752
Financing Receivables:
Loans held for investment			257,921
Ending balance: individually evaluated for impairment			507
Ending balance: collectively evaluated for impairment			257,414
Impact of adoption of ASU No. 2016-13
Allowance for credit losses:
Beginning balance		$ 19,441
Ending balance			19,441
Impact of adoption of ASU No. 2016-13 | Commercial
Allowance for credit losses:
Beginning balance		922
Ending balance			922
Impact of adoption of ASU No. 2016-13 | Consumer
Allowance for credit losses:
Beginning balance		16,463
Ending balance			16,463
Residential 1-4 family | Real estate
Allowance for credit losses:
Beginning balance	$ 4,600	2,380	1,976
Charge-offs	(67)	(7)	(26)
Recoveries	92	394	854
Net (charge-offs) recoveries	25	387	828
Provision for credit losses	1,920	(317)	(424)
Ending balance	6,545	4,600	2,380	1,976
Average loans outstanding	$ 2,155,322	$ 2,148,848	$ 2,164,759
Net charge-offs (recoveries) to average loans	0.00%	(0.02%)	(0.04%)
Ending balance: individually evaluated for impairment			$ 898
Ending balance: collectively evaluated for impairment			1,482
Financing Receivables:
Loans held for investment			2,178,135
Ending balance: individually evaluated for impairment			15,600
Ending balance: collectively evaluated for impairment			2,162,535
Residential 1-4 family | Impact of adoption of ASU No. 2016-13 | Real estate
Allowance for credit losses:
Beginning balance		$ 2,150
Ending balance			2,150
Commercial real estate | Real estate
Allowance for credit losses:
Beginning balance	$ 35,607	15,053	14,505
Charge-offs	0	0	0
Recoveries	0	0	0
Net (charge-offs) recoveries	0	0	0
Provision for credit losses	(10,911)	20,346	548
Ending balance	24,696	35,607	15,053	14,505
Average loans outstanding	$ 1,046,276	$ 861,096	$ 781,531
Net charge-offs (recoveries) to average loans	0.00%	0.00%	0.00%
Ending balance: individually evaluated for impairment			$ 2
Ending balance: collectively evaluated for impairment			15,051
Financing Receivables:
Loans held for investment			824,830
Ending balance: individually evaluated for impairment			1,048
Ending balance: collectively evaluated for impairment			823,782
Commercial real estate | Impact of adoption of ASU No. 2016-13 | Real estate
Allowance for credit losses:
Beginning balance		$ 208
Ending balance			208
Home equity line of credit | Real estate
Allowance for credit losses:
Beginning balance	$ 6,813	6,922	6,371
Charge-offs	(45)	(77)	(144)
Recoveries	113	63	17
Net (charge-offs) recoveries	68	(14)	(127)
Provision for credit losses	(1,224)	446	678
Ending balance	5,657	6,813	6,922	6,371
Average loans outstanding	$ 885,759	$ 1,060,444	$ 1,043,479
Net charge-offs (recoveries) to average loans	(0.01%)	0.00%	0.01%
Ending balance: individually evaluated for impairment			$ 322
Ending balance: collectively evaluated for impairment			6,600
Financing Receivables:
Loans held for investment			1,092,125
Ending balance: individually evaluated for impairment			12,073
Ending balance: collectively evaluated for impairment			1,080,052
Home equity line of credit | Impact of adoption of ASU No. 2016-13 | Real estate
Allowance for credit losses:
Beginning balance		$ (541)
Ending balance			(541)
Residential land | Real estate
Allowance for credit losses:
Beginning balance	$ 609	449	479
Charge-offs	0	(351)	(4)
Recoveries	61	38	229
Net (charge-offs) recoveries	61	(313)	225
Provision for credit losses	(24)	537	(255)
Ending balance	646	609	449	479
Average loans outstanding	$ 18,227	$ 13,799	$ 14,065
Net charge-offs (recoveries) to average loans	(0.33%)	2.27%	(1.60%)
Ending balance: individually evaluated for impairment			$ 0
Ending balance: collectively evaluated for impairment			449
Financing Receivables:
Loans held for investment			14,704
Ending balance: individually evaluated for impairment			3,091
Ending balance: collectively evaluated for impairment			11,613
Residential land | Impact of adoption of ASU No. 2016-13 | Real estate
Allowance for credit losses:
Beginning balance		$ (64)
Ending balance			(64)
Commercial construction | Real estate
Allowance for credit losses:
Beginning balance	$ 4,149	2,097	2,790
Charge-offs	0	0	0
Recoveries	0	0	0
Net (charge-offs) recoveries	0	0	0
Provision for credit losses	(1,963)	1,763	(693)
Ending balance	2,186	4,149	2,097	2,790
Average loans outstanding	$ 111,711	$ 93,740	$ 81,937
Net charge-offs (recoveries) to average loans	0.00%	0.00%	0.00%
Ending balance: individually evaluated for impairment			$ 0
Ending balance: collectively evaluated for impairment			2,097
Financing Receivables:
Loans held for investment			70,605
Ending balance: individually evaluated for impairment			0
Ending balance: collectively evaluated for impairment			70,605
Commercial construction | Impact of adoption of ASU No. 2016-13 | Real estate
Allowance for credit losses:
Beginning balance		$ 289
Ending balance			289
Residential construction | Real estate
Allowance for credit losses:
Beginning balance	$ 11	3	4
Charge-offs	0	0	0
Recoveries	0	0	0
Net (charge-offs) recoveries	0	0	0
Provision for credit losses	7	(6)	(1)
Ending balance	18	11	3	$ 4
Average loans outstanding	$ 11,361	$ 10,703	$ 10,513
Net charge-offs (recoveries) to average loans	0.00%	0.00%	0.00%
Ending balance: individually evaluated for impairment			$ 0
Ending balance: collectively evaluated for impairment			3
Financing Receivables:
Loans held for investment			11,670
Ending balance: individually evaluated for impairment			0
Ending balance: collectively evaluated for impairment			11,670
Residential construction | Impact of adoption of ASU No. 2016-13 | Real estate
Allowance for credit losses:
Beginning balance		$ 14
Ending balance			$ 14