Bank segment (HEI only) - Credit Risk Profile Based on Payment Activity for Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Credit risk profile based on payment activity for loans
Total past due	$ 25,969	$ 23,603
Current	4,817,665	4,647,974
Total financing receivables	4,843,634	4,671,577	$ 4,743,619
Recorded Investment greater than 90 days and accruing	0	0
Residential 1-4 family
Credit risk profile based on payment activity for loans
Total past due	8,869	8,318
Current	2,134,528	2,109,729
Total financing receivables	2,143,397	2,118,047	2,048,051
Recorded Investment greater than 90 days and accruing	0	0
Commercial real estate
Credit risk profile based on payment activity for loans
Total past due	0	0
Current	748,398	733,106
Total financing receivables	748,398	733,106	800,395
Recorded Investment greater than 90 days and accruing	0	0
Home equity line of credit
Credit risk profile based on payment activity for loans
Total past due	4,540	2,590
Current	973,697	910,462
Total financing receivables	978,237	913,052	863,163
Recorded Investment greater than 90 days and accruing	0	0
Residential land
Credit risk profile based on payment activity for loans
Total past due	328	648
Current	12,810	15,149
Total financing receivables	13,138	15,797	18,889
Recorded Investment greater than 90 days and accruing	0	0
Commercial construction
Credit risk profile based on payment activity for loans
Total past due	0	0
Current	92,264	108,273
Total financing receivables	92,264	108,273	126,768
Recorded Investment greater than 90 days and accruing	0	0
Residential construction
Credit risk profile based on payment activity for loans
Total past due	0	0
Current	14,307	14,910
Total financing receivables	14,307	14,910	16,080
Recorded Investment greater than 90 days and accruing	0	0
Commercial
Credit risk profile based on payment activity for loans
Total past due	1,144	4,580
Current	586,747	540,248
Total financing receivables	587,891	544,828	692,051
Recorded Investment greater than 90 days and accruing	0	0
Consumer
Credit risk profile based on payment activity for loans
Total past due	11,088	7,467
Current	254,914	216,097
Total financing receivables	266,002	223,564	$ 178,222
Recorded Investment greater than 90 days and accruing	0	0
30-59 days past due
Credit risk profile based on payment activity for loans
Total past due	10,440	7,237
30-59 days past due | Residential 1-4 family
Credit risk profile based on payment activity for loans
Total past due	3,757	1,532
30-59 days past due | Commercial real estate
Credit risk profile based on payment activity for loans
Total past due	0	0
30-59 days past due | Home equity line of credit
Credit risk profile based on payment activity for loans
Total past due	1,139	425
30-59 days past due | Residential land
Credit risk profile based on payment activity for loans
Total past due	9	23
30-59 days past due | Commercial construction
Credit risk profile based on payment activity for loans
Total past due	0	0
30-59 days past due | Residential construction
Credit risk profile based on payment activity for loans
Total past due	0	0
30-59 days past due | Commercial
Credit risk profile based on payment activity for loans
Total past due	315	1,825
30-59 days past due | Consumer
Credit risk profile based on payment activity for loans
Total past due	5,220	3,432
60-89 days past due
Credit risk profile based on payment activity for loans
Total past due	6,901	6,013
60-89 days past due | Residential 1-4 family
Credit risk profile based on payment activity for loans
Total past due	2,773	1,715
60-89 days past due | Commercial real estate
Credit risk profile based on payment activity for loans
Total past due	0	0
60-89 days past due | Home equity line of credit
Credit risk profile based on payment activity for loans
Total past due	681	114
60-89 days past due | Residential land
Credit risk profile based on payment activity for loans
Total past due	0	0
60-89 days past due | Commercial construction
Credit risk profile based on payment activity for loans
Total past due	0	0
60-89 days past due | Residential construction
Credit risk profile based on payment activity for loans
Total past due	0	0
60-89 days past due | Commercial
Credit risk profile based on payment activity for loans
Total past due	281	2,025
60-89 days past due | Consumer
Credit risk profile based on payment activity for loans
Total past due	3,166	2,159
Greater than 90 days
Credit risk profile based on payment activity for loans
Total past due	8,628	10,353
Greater than 90 days | Residential 1-4 family
Credit risk profile based on payment activity for loans
Total past due	2,339	5,071
Greater than 90 days | Commercial real estate
Credit risk profile based on payment activity for loans
Total past due	0	0
Greater than 90 days | Home equity line of credit
Credit risk profile based on payment activity for loans
Total past due	2,720	2,051
Greater than 90 days | Residential land
Credit risk profile based on payment activity for loans
Total past due	319	625
Greater than 90 days | Commercial construction
Credit risk profile based on payment activity for loans
Total past due	0	0
Greater than 90 days | Residential construction
Credit risk profile based on payment activity for loans
Total past due	0	0
Greater than 90 days | Commercial
Credit risk profile based on payment activity for loans
Total past due	548	730
Greater than 90 days | Consumer
Credit risk profile based on payment activity for loans
Total past due	$ 2,702	$ 1,876