Condensed Consolidated Statements of Comprehensive Income (unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net unrealized gains (losses) on securities arising during the period, (taxes) benefits	$ (1,876)	$ 137	$ (8,335)	$ 1,619
Reclassification adjustment to net income, tax expense (benefits)	0	0	0	(289)
Amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, taxes (benefits)	(1,832)	(2,516)	(5,486)	(7,526)
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, taxes	1,639	2,290	4,916	6,872
Hawaiian Electric Company, Inc. and Subsidiaries
Reclassification adjustment to net income, tax expense (benefits)	0	0	0	(289)
Amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, taxes (benefits)	(1,648)	(2,306)	(4,945)	(6,916)
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, taxes	$ 1,639	$ 2,290	$ 4,916	$ 6,872