Regulatory restrictions on net assets (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory restrictions on net assets
Restrictions on transfer of net assets to the parent in the form of cash dividends, loans and advances	$ 674
American Savings Bank (ASB)
Regulatory restrictions on net assets
Amount of net assets available for transfer	$ 91

Amount of restricted net assets of consolidated and unconsolidated subsidiaries as of the end of the most recently completed fiscal year.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(e)(3)(ii))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph e

-Subparagraph 3

-Article 4

Name:	us-gaap_AmountOfRestrictedNetAssetsForConsolidatedAndUnconsolidatedSubsidiaries
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant