Retirement benefits (Tables)

3 Months Ended

Mar. 31, 2020

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)	2020		2019		2020		2019
HEI consolidated
Service cost	$	18,363	$	15,382	$	631	$	541
Interest cost	20,163		21,033		1,855		1,997
Expected return on plan assets	(28,466)		(27,998)		(3,038)		(3,086)
Amortization of net prior period (gain)/cost	3		(11)		(440)		(452)
Amortization of net actuarial (gains)/losses	8,057		3,839		50		(3)
Net periodic pension/benefit cost (return)	18,120		12,245		(942)		(1,003)
Impact of PUC D&Os	6,262		12,279		777		811
Net periodic pension/benefit cost (adjusted for impact of PUC D&Os)	$	24,382	$	24,524	$	(165)	$	(192)
Hawaiian Electric consolidated
Service cost	$	17,891	$	15,001	$	626	$	537
Interest cost	18,715		19,414		1,782		1,917
Expected return on plan assets	(26,855)		(26,164)		(2,990)		(3,035)
Amortization of net prior period (gain)/cost	2		2		(440)		(451)
Amortization of net actuarial losses	7,368		3,576		51		—
Net periodic pension/benefit cost (return)	17,121		11,829		(971)		(1,032)
Impact of PUC D&Os	6,262		12,279		777		811
Net periodic pension/benefit cost (adjusted for impact of PUC D&Os)	$	23,383	$	24,108	$	(194)	$	(221)