Taxes (Details) - HECO (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2013	Sep. 30, 2013 Hawaiian Electric Company, Inc. and Subsidiaries	Sep. 30, 2012 Hawaiian Electric Company, Inc. and Subsidiaries
Revenue taxes
Revenue taxes included in Operating revenues		$ 198	$ 212
Revenue taxes included as expense in Taxes, other than income taxes		198	212
Out-of-period tax benefit related to utilities	$ 2.7

Discloses the amount included as operating expenses for the period related to revenues taxes, which is included in Taxes, other than income taxes.

No definition available.

Name:	he_OperatingExpensesRevenuesTaxes
Namespace Prefix:	he_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration