Condensed Consolidated Statements of Comprehensive Income (unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net unrealized gains (losses) on securities arising during the period, (taxes) benefits	$ (3,455)	$ 4,867
Unrealized interest rate hedging gain (loss), net of tax expense (benefits), net	(140)	0
Amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, taxes (benefits)	(870)	(1,792)
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, taxes	797	1,603
Hawaiian Electric Company, Inc. and Subsidiaries
Amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, taxes (benefits)	(805)	(1,614)
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, taxes	$ 797	$ 1,603