Consolidated Statements of Comprehensive Income (Parenthetical) - HECO (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Less: amortization of net loss, prior service gain and transition obligation included in net periodic benefit cost, tax benefits	$ 2,405	$ 1,477	$ 4,878	$ 2,108
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, taxes	2,095	1,370	4,257	2,801
Hawaiian Electric Company, Inc. and Subsidiaries
Less: amortization of net loss, prior service gain and transition obligation included in net periodic benefit cost, tax benefits	2,142	1,401	4,354	2,849
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, taxes	$ 2,095	$ 1,370	$ 4,257	$ 2,801

Tax effect on adjustment out of other comprehensive income for actuarial gains or losses, prior service gains or losses, and net transition asset or obligation recognized as a component of net periodic benefit cost during the period.

No definition available.

Name:	he_OtherComprehensiveIncomeReclassificationOfDefinedBenefitPlansNetGainLossPriorServiceGainLossAndReclassificationOfDefinedBenefitPlanNetTransitionAssetObligationRecognizedInNetPeriodicBenefitCostTax
Namespace Prefix:	he_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration