Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income for common stock	$ 159,877	$ 168,129	$ 161,709
Net unrealized gains (losses) on available-for sale investment securities:
Net unrealized gains (losses) on available-for sale investment securities arising during the period, net of (taxes) benefits of $1,541, $(3,856) and $9,037 for 2015, 2014 and 2013, respectively	(2,334)	5,840	(13,686)
Less: reclassification adjustment for net realized gains included in net income, net of taxes of nil, $1,132 and $488 for 2015, 2014 and 2013, respectively	0	(1,715)	(738)
Derivatives qualified as cash flow hedges:
Less: reclassification adjustment to net income, net of tax benefits of $150, $150 and $150 for 2015, 2014 and 2013, respectively	235	236	235
Retirement benefit plans:
Net gains (losses) arising during the period, net of (taxes) benefits of ($3,753), $149,364 and ($142,478) for 2015, 2014 and 2013, respectively	5,889	(234,166)	223,177
Less: amortization of transition obligation, prior service credit and net losses recognized during the period in net periodic benefit cost, net of tax benefits of $14,344, $7,245 and $14,870 for 2015, 2014 and 2013, respectively	22,465	11,344	23,280
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of (taxes) benefits of $16,011, ($132,373) and $141,777 for 2015, 2014 and 2013, respectively	(25,139)	207,833	(222,595)
Other comprehensive income (loss), net of taxes	1,116	(10,628)	9,673
Comprehensive income attributable to Hawaiian Electric Company, Inc.	$ 160,993	$ 157,501	$ 171,382