Bank segment (HEI only) - Loans Receivable, Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Nonaccrual [Line Items]
Percentage of benchmark loan to appraisal ratio in excess of which mortgage insurance is required	80.00%
Minimum benchmark percentage of loan to non-owner occupied residential property purchase	75.00%
Real estate loans for investors	$ 1,500.0	$ 1,500.0	$ 1,500.0
Loans to directors, executive directors, affiliates and any related interest of such individuals	10.7	13.1
Loan balances, related interests of individuals who are directors	10.0	10.0
Asset Pledged as Collateral with Right
Financing Receivable, Nonaccrual [Line Items]
Loans and leases receivable before fees, gross	$ 3,000.0	$ 2,800.0