Bank segment (HEI only) - Allowance For Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	$ 52,119	$ 53,637	$ 55,533
Charge-offs	(28,662)	(20,517)	(16,813)
Recoveries	6,418	4,254	4,016
Provision	23,480	14,745	10,901
Valuation allowance, balance at the end of the period	53,355	52,119	53,637
Ending balance: individually evaluated for impairment	2,691	2,222	2,730
Ending balance: collectively evaluated for impairment	50,664	49,897	50,907
Financing Receivables:
Total financing receivables	5,120,664	4,843,634	4,671,577
Ending balance: individually evaluated for impairment	40,737	39,697	33,393
Ending balance: collectively evaluated for impairment	5,079,927	4,803,937	4,638,184
Residential 1-4 family
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	1,976	2,902	2,873
Charge-offs	(26)	(128)	(826)
Recoveries	854	74	157
Provision	(424)	(872)	698
Valuation allowance, balance at the end of the period	2,380	1,976	2,902
Ending balance: individually evaluated for impairment	898	876	1,248
Ending balance: collectively evaluated for impairment	1,482	1,100	1,654
Financing Receivables:
Total financing receivables	2,178,135	2,143,397	2,118,047
Ending balance: individually evaluated for impairment	15,600	16,494	18,284
Ending balance: collectively evaluated for impairment	2,162,535	2,126,903	2,099,763
Commercial real estate
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	14,505	15,796	16,004
Charge-offs	0	0	0
Recoveries	0	0	0
Provision	548	(1,291)	(208)
Valuation allowance, balance at the end of the period	15,053	14,505	15,796
Ending balance: individually evaluated for impairment	2	7	65
Ending balance: collectively evaluated for impairment	15,051	14,498	15,731
Financing Receivables:
Total financing receivables	824,830	748,398	733,106
Ending balance: individually evaluated for impairment	1,048	915	1,016
Ending balance: collectively evaluated for impairment	823,782	747,483	732,090
Home equity line of credit
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	6,371	7,522	5,039
Charge-offs	(144)	(353)	(14)
Recoveries	17	257	308
Provision	678	(1,055)	2,189
Valuation allowance, balance at the end of the period	6,922	6,371	7,522
Ending balance: individually evaluated for impairment	322	701	647
Ending balance: collectively evaluated for impairment	6,600	5,670	6,875
Financing Receivables:
Total financing receivables	1,092,125	978,237	913,052
Ending balance: individually evaluated for impairment	12,073	14,800	8,188
Ending balance: collectively evaluated for impairment	1,080,052	963,437	904,864
Residential land
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	479	896	1,738
Charge-offs	(4)	(18)	(210)
Recoveries	229	179	482
Provision	(255)	(578)	(1,114)
Valuation allowance, balance at the end of the period	449	479	896
Ending balance: individually evaluated for impairment	0	6	47
Ending balance: collectively evaluated for impairment	449	473	849
Financing Receivables:
Total financing receivables	14,704	13,138	15,797
Ending balance: individually evaluated for impairment	3,091	2,059	1,265
Ending balance: collectively evaluated for impairment	11,613	11,079	14,532
Commercial construction
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	2,790	4,671	6,449
Charge-offs	0	0	0
Recoveries	0	0	0
Provision	(693)	(1,881)	(1,778)
Valuation allowance, balance at the end of the period	2,097	2,790	4,671
Ending balance: individually evaluated for impairment	0	0	0
Ending balance: collectively evaluated for impairment	2,097	2,790	4,671
Financing Receivables:
Total financing receivables	70,605	92,264	108,273
Ending balance: individually evaluated for impairment	0	0	0
Ending balance: collectively evaluated for impairment	70,605	92,264	108,273
Residential construction
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	4	12	12
Charge-offs	0	0	0
Recoveries	0	0	0
Provision	(1)	(8)	0
Valuation allowance, balance at the end of the period	3	4	12
Ending balance: individually evaluated for impairment	0	0	0
Ending balance: collectively evaluated for impairment	3	4	12
Financing Receivables:
Total financing receivables	11,670	14,307	14,910
Ending balance: individually evaluated for impairment	0	0	0
Ending balance: collectively evaluated for impairment	11,670	14,307	14,910
Commercial
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	9,225	10,851	16,618
Charge-offs	(6,811)	(2,722)	(4,006)
Recoveries	2,351	2,136	1,852
Provision	5,480	(1,040)	(3,613)
Valuation allowance, balance at the end of the period	10,245	9,225	10,851
Ending balance: individually evaluated for impairment	1,015	628	694
Ending balance: collectively evaluated for impairment	9,230	8,597	10,157
Financing Receivables:
Total financing receivables	670,674	587,891	544,828
Ending balance: individually evaluated for impairment	8,418	5,340	4,574
Ending balance: collectively evaluated for impairment	662,256	582,551	540,254
Consumer
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	16,769	10,987	6,800
Charge-offs	(21,677)	(17,296)	(11,757)
Recoveries	2,967	1,608	1,217
Provision	18,147	21,470	14,727
Valuation allowance, balance at the end of the period	16,206	16,769	10,987
Ending balance: individually evaluated for impairment	454	4	29
Ending balance: collectively evaluated for impairment	15,752	16,765	10,958
Financing Receivables:
Total financing receivables	257,921	266,002	223,564
Ending balance: individually evaluated for impairment	507	89	66
Ending balance: collectively evaluated for impairment	$ 257,414	$ 265,913	$ 223,498