Bank segment (HEI only) - Off Balance Sheet Arrangements and Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended
	Sep. 30, 2018	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
American Savings Bank (ASB)
Guarantees
Minimum reserve ratio	1.36%
FDIC insurance assessment		$ 3,600	$ 3,200	$ 2,300
Reserve for Off-balance Sheet Activities
Guarantees
Unused commitments to extend credit		2,079,144	1,911,729
Home equity line of credit
Guarantees
Unused commitments to extend credit		1,264,320	1,181,496
Commercial real estate
Guarantees
Unused commitments to extend credit		692,989	612,158
Consumer
Guarantees
Unused commitments to extend credit		85,768	62,090
Residential 1-4 family
Guarantees
Unused commitments to extend credit		20,546	44,262
Commercial and financial standby letters of credit
Guarantees
Unused commitments to extend credit		$ 15,521	$ 11,723