Bank segment (HEI only) - Capital And Ratio (Details) - American Savings Bank (ASB) $ in Thousands	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 leverage, actual capital	$ 750,851	$ 714,789
Tier 1 leverage, actual ratio	0.0778	0.0786
Tier 1 leverage, required capital	$ 386,265	$ 363,630
Tier 1 leverage, required ratio	0.0400	0.0400
Tier 1 leverage, required to be well capitalized capital	$ 482,831	$ 454,538
Tier 1 leverage, required to be well capitalized ratio	0.0500	0.0500
Common equity tier 1, actual capital	$ 750,851	$ 714,789
Common equity tier 1, actual ratio	12.15%	13.29%
Common equity tier 1, required capital	$ 278,076	$ 242,072
Common equity tier 1, required ratio	4.50%	4.50%
Common equity tier 1, required to be well capitalized, capital	$ 401,665	$ 349,659
Common equity tier 1, required to be well capitalized, ratio	6.50%	6.50%
Tier 1 capital, actual capital	$ 750,851	$ 714,789
Tier 1 capital, actual ratio	0.1215	0.1329
Tier 1 capital, required capital	$ 370,767	$ 322,762
Tier 1 capital, required ratio	0.0600	0.0600
Tier 1 capital, required to be well capitalized, capital	$ 494,356	$ 430,350
Tier 1 capital, required to be well capitalized, ratio	0.0800	0.0800
Total capital, actual capital	$ 811,729	$ 769,836
Total capital, actual ratio	0.1314	0.1431
Total capital, required capital	$ 494,356	$ 430,350
Total capital, required ratio	0.0800	0.0800
Total capital, required to be well capitalized, capital	$ 617,946	$ 537,937
Total capital, required to be well capitalized, ratio	0.1000	0.1000