Fair value measurements (Tables)

9 Months Ended

Sep. 30, 2025

Fair Value Disclosures [Abstract]

Schedule of Carrying or Notional Amount, Fair Value and Placement in the Fair Value Hierarchy of the Company’s Financial Instruments

The following table presents the carrying or notional amount, fair value and placement in the fair value hierarchy of the Company’s financial instruments.

			Estimated fair value
(in thousands)	Carrying or notional amount		Quoted prices in active markets for identical assets  (Level 1)		Significant  other observable  inputs  (Level 2)		Total
September 30, 2025
Financial assets
HEI consolidated
Money market mutual funds	$	925,258	$	925,258	$	—	$	925,258
Hawaiian Electric consolidated
Money market mutual funds	402,575		402,575		—		402,575
Financial liabilities
HEI consolidated
Long-term debt, net	2,438,691		—		2,104,038		2,104,038
Hawaiian Electric consolidated
Long-term debt, net	2,182,533		—		1,871,292		1,871,292
December 31, 2024
Financial assets
HEI consolidated
Money market mutual funds	$	1,162,259	$	1,162,259	$	—	$	1,162,259
Derivative assets	29,312		—		1,629		1,629
Hawaiian Electric consolidated
Money market mutual funds	115,599		115,599		—		115,599
Financial liabilities
HEI consolidated
Short-term borrowings, net	48,623		—		48,623		48,623
Long-term debt, net	2,799,558		—		2,196,403		2,196,403
Hawaiian Electric consolidated
Short-term borrowings, net	48,623		—		48,623		48,623
Long-term debt, net	1,901,214		—		1,446,316		1,446,316