Bank segment (HEI only) - Deposit Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Weighted-average stated rate
Savings	0.07%	0.07%
Checking, interest-bearing	0.09%	0.03%
Checking, Noninterest-bearing	0.00%	0.00%
Commercial checking	0.00%	0.00%
Money market	0.63%	0.09%
Time certificates	1.61%	1.26%
Total weighted-average stated rate	0.27%	0.20%
Deposit liabilities
Savings	$ 2,322,552	$ 2,303,450
Checking
Interest-bearing	1,055,019	944,833
Noninterest-bearing	932,608	896,292
Commercial checking	868,119	863,941
Money market	152,713	114,797
Time certificates	827,841	767,284
Total Amount	6,158,852	5,890,597
Certificate accounts of $100,000 or more	500,200	433,400
Term certificates outstanding, scheduled maturities
2019	508,833
2020	128,613
2021	107,095
2022	49,329
2023	30,456
Thereafter	3,515
Total	827,841
Overdrawn deposit accounts classified as loans	2,100	1,700
Interest expense on deposit liabilities by type of deposit
Time certificates	11,044	7,687	$ 5,390
Savings	1,639	1,567	1,402
Money market	602	168	202
Interest-bearing checking	706	238	173
Interest expense on deposit liabilities	$ 13,991	$ 9,660	$ 7,167