Bank segment (HEI only) - Key Assumptions Used in Estimating the Fair Value of ASB's Mortgage Servicing Rights (Details) - Allowance for mortgage-servicing assets – bank $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Prepayment rate:
25 basis points adverse rate change	$ (92)	$ (714)
50 basis points adverse rate change	(214)	(1,608)
Discount rate:
25 basis points adverse rate change	(182)	(129)
50 basis points adverse rate change	(361)	(256)
American Savings Bank (ASB)
Mortgage Servicing Rights
Unpaid principal balance	$ 1,451,322	$ 1,481,899
Weighted average note rate	3.38%	3.38%
American Savings Bank (ASB) | Weighted average discount rate
Mortgage Servicing Rights
Weighted average measurement input	0.1000	0.0925
American Savings Bank (ASB) | Weighted average prepayment speed
Mortgage Servicing Rights
Weighted average measurement input	0.0656	0.0977