Condensed Consolidated Statements of Comprehensive Income (unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net unrealized gains (losses) on securities arising during the period, taxes (benefits)	$ 137	$ (1,417)	$ 1,619	$ 5,413
Reclassification adjustment for sale of securities, tax (benefits)	0	0	0	238
Effective portion of foreign currency hedge net unrealized gains, taxes	0	205	0	368
Reclassification adjustment to net income, taxes	0	110	(289)	75
Amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, tax benefits	(2,516)	(2,324)	(7,526)	(6,943)
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, taxes	2,290	2,109	6,872	6,327
Hawaiian Electric Company, Inc. and Subsidiaries
Effective portion of foreign currency hedge net unrealized gains, taxes	0	205	0	368
Reclassification adjustment to net income, taxes	0	110	(289)	110
Amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, tax benefits	(2,306)	(2,110)	(6,916)	(6,331)
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, taxes	$ 2,290	$ 2,109	$ 6,872	$ 6,327