Bank segment (HEI only) - Allowance For Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	$ 53,637	$ 55,533	$ 50,038
Charge-offs	(20,517)	(16,813)	(14,245)
Recoveries	4,254	4,016	2,977
Provision	14,745	10,901	16,763
Valuation allowance, balance at the end of the period	52,119	53,637	55,533
Ending balance: individually evaluated for impairment	2,222	2,730	4,083
Ending balance: collectively evaluated for impairment	49,897	50,907	51,450
Financing Receivables:
Total financing receivables	4,843,634	4,671,577	4,743,619
Ending balance: individually evaluated for impairment	39,697	33,393	51,759
Ending balance: collectively evaluated for impairment	4,803,937	4,638,184	4,691,860
Residential 1-4 family
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	2,902	2,873	4,186
Charge-offs	(128)	(826)	(639)
Recoveries	74	157	421
Provision	(872)	698	(1,095)
Valuation allowance, balance at the end of the period	1,976	2,902	2,873
Ending balance: individually evaluated for impairment	876	1,248	1,352
Ending balance: collectively evaluated for impairment	1,100	1,654	1,521
Financing Receivables:
Total financing receivables	2,143,397	2,118,047	2,048,051
Ending balance: individually evaluated for impairment	16,494	18,284	19,854
Ending balance: collectively evaluated for impairment	2,126,903	2,099,763	2,028,197
Commercial real estate
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	15,796	16,004	11,342
Charge-offs	0	0	0
Recoveries	0	0	0
Provision	(1,291)	(208)	4,662
Valuation allowance, balance at the end of the period	14,505	15,796	16,004
Ending balance: individually evaluated for impairment	7	65	80
Ending balance: collectively evaluated for impairment	14,498	15,731	15,924
Financing Receivables:
Total financing receivables	748,398	733,106	800,395
Ending balance: individually evaluated for impairment	915	1,016	1,569
Ending balance: collectively evaluated for impairment	747,483	732,090	798,826
Home equity line of credit
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	7,522	5,039	7,260
Charge-offs	(353)	(14)	(112)
Recoveries	257	308	59
Provision	(1,055)	2,189	(2,168)
Valuation allowance, balance at the end of the period	6,371	7,522	5,039
Ending balance: individually evaluated for impairment	701	647	215
Ending balance: collectively evaluated for impairment	5,670	6,875	4,824
Financing Receivables:
Total financing receivables	978,237	913,052	863,163
Ending balance: individually evaluated for impairment	14,800	8,188	6,158
Ending balance: collectively evaluated for impairment	963,437	904,864	857,005
Residential land
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	896	1,738	1,671
Charge-offs	(18)	(210)	(138)
Recoveries	179	482	461
Provision	(578)	(1,114)	(256)
Valuation allowance, balance at the end of the period	479	896	1,738
Ending balance: individually evaluated for impairment	6	47	789
Ending balance: collectively evaluated for impairment	473	849	949
Financing Receivables:
Total financing receivables	13,138	15,797	18,889
Ending balance: individually evaluated for impairment	2,059	1,265	3,629
Ending balance: collectively evaluated for impairment	11,079	14,532	15,260
Commercial construction
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	4,671	6,449	4,461
Charge-offs	0	0	0
Recoveries	0	0	0
Provision	(1,881)	(1,778)	1,988
Valuation allowance, balance at the end of the period	2,790	4,671	6,449
Ending balance: individually evaluated for impairment	0	0	0
Ending balance: collectively evaluated for impairment	2,790	4,671	6,449
Financing Receivables:
Total financing receivables	92,264	108,273	126,768
Ending balance: individually evaluated for impairment	0	0	0
Ending balance: collectively evaluated for impairment	92,264	108,273	126,768
Residential construction
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	12	12	13
Charge-offs	0	0	0
Recoveries	0	0	0
Provision	(8)	0	(1)
Valuation allowance, balance at the end of the period	4	12	12
Ending balance: individually evaluated for impairment	0	0	0
Ending balance: collectively evaluated for impairment	4	12	12
Financing Receivables:
Total financing receivables	14,307	14,910	16,080
Ending balance: individually evaluated for impairment	0	0	0
Ending balance: collectively evaluated for impairment	14,307	14,910	16,080
Commercial
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	10,851	16,618	17,208
Charge-offs	(2,722)	(4,006)	(5,943)
Recoveries	2,136	1,852	1,093
Provision	(1,040)	(3,613)	4,260
Valuation allowance, balance at the end of the period	9,225	10,851	16,618
Ending balance: individually evaluated for impairment	628	694	1,641
Ending balance: collectively evaluated for impairment	8,597	10,157	14,977
Financing Receivables:
Total financing receivables	587,891	544,828	692,051
Ending balance: individually evaluated for impairment	5,340	4,574	20,539
Ending balance: collectively evaluated for impairment	582,551	540,254	671,512
Consumer
Allowance for loan losses:
Valuation allowance, balance at the beginning of the period	10,987	6,800	3,897
Charge-offs	(17,296)	(11,757)	(7,413)
Recoveries	1,608	1,217	943
Provision	21,470	14,727	9,373
Valuation allowance, balance at the end of the period	16,769	10,987	6,800
Ending balance: individually evaluated for impairment	4	29	6
Ending balance: collectively evaluated for impairment	16,765	10,958	6,794
Financing Receivables:
Total financing receivables	266,002	223,564	178,222
Ending balance: individually evaluated for impairment	89	66	10
Ending balance: collectively evaluated for impairment	$ 265,913	$ 223,498	$ 178,212