Bank segment (HEI only) - TDR Narrative (Details) - Residential land	12 Months Ended
Dec. 31, 2019
Troubled debt restructurings
Period of interest-only monthly payment term loan	3 years
Maximum
Troubled debt restructurings
Extension of maturity date	5 years

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_FinancingReceivableImpairedLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration