Retirement benefits (Tables)

3 Months Ended

Mar. 31, 2024

Retirement Benefits [Abstract]

Schedule of Components of Net Periodic Benefit Cost for Consolidated HEI

The components of net periodic pension costs (NPPC) and net periodic benefit costs (NPBC) for HEI consolidated and Hawaiian Electric consolidated were as follows:

	Three months ended March 31
	Pension benefits				Other benefits
(in thousands)	2024		2023		2024		2023
HEI consolidated
Service cost	$	11,264	$	11,396	$	281	$	344
Interest cost	26,506		25,621		1,867		2,157
Expected return on plan assets	(35,982)		(35,195)		(3,485)		(3,405)
Amortization of net prior period gain	—		—		—		(219)
Amortization of net actuarial (gain)/losses	111		188		(713)		(449)
Net periodic pension/benefit cost (return)	1,899		2,010		(2,050)		(1,572)
Impact of PUC D&Os	18,090		18,133		1,888		1,425
Net periodic pension/benefit cost (return) (adjusted for impact of PUC D&Os)	$	19,989	$	20,143	$	(162)	$	(147)
Hawaiian Electric consolidated
Service cost	$	10,916	$	11,019	$	278	$	340
Interest cost	24,627		23,698		1,779		2,063
Expected return on plan assets	(33,777)		(32,972)		(3,434)		(3,353)
Amortization of net prior period gain	—		—		—		(218)
Amortization of net actuarial (gain)/losses	12		19		(694)		(434)
Net periodic pension/benefit cost (return)	1,778		1,764		(2,071)		(1,602)
Impact of PUC D&Os	18,090		18,133		1,888		1,425
Net periodic pension/benefit cost (return) (adjusted for impact of PUC D&Os)	$	19,868	$	19,897	$	(183)	$	(177)