Amount of advances or credit lines available from the Federal Home Loan Bank (FHLB).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22 (b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13(3)(a))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

Name:	us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresAmountOfAvailableUnusedFunds
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Bank segment (HEI only) - FHLB Advances (Details) - American Savings Bank (ASB) - USD ($)	Feb. 28, 2020	Dec. 31, 2019	Dec. 31, 2018
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
FHLB advances		$ 0	$ 45,000,000
FHLB advances, unused funds		$ 2,300,000,000	$ 2,000,000,000.0
Subsequent Event
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
FHLB advances, unused funds	$ 1,500,000,000
Percent in first lien position	54.00%