Consolidated Statements of Comprehensive Income - HECO - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net income for common stock	$ 44,634	$ 127,142	$ 44,128	$ 32,352	$ 42,320	$ 50,673	$ 35,018	$ 31,866	$ 248,256	$ 159,877	$ 168,129
Other comprehensive income (loss), net of taxes:
Effective portion of foreign currency hedge net unrealized losses arising during the period, net of tax benefits of $179, nil and nil for 2016, 2015 and 2014, respectively									(281)	0	0
Less: reclassification adjustment to net income, net of taxes of $110, nil and nil for 2016, 2015 and 2014, respectively									(119)	235	236
Retirement benefit plans:
Net gains (losses) arising during the period, net of (taxes) benefits of nil, $(59) and $6,164 for 2016, 2015 and 2014, respectively									(43,510)	5,889	(234,166)
Less: amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of tax benefits of $566, $1,011 and $561 for 2016, 2015 and 2014, respectively									14,518	22,465	11,344
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of (taxes) benefits of $(18,206), $16,011 and $(132,373) for 2016, 2015 and 2014, respectively									28,584	(25,139)	207,833
Other comprehensive income (loss), net of taxes									(6,867)	1,116	(10,628)
Comprehensive income attributable to Hawaiian Electric Company, Inc.									241,389	160,993	157,501
Hawaiian Electric Company, Inc. and Subsidiaries
Net income for common stock	$ 34,119	$ 46,974	$ 35,857	$ 25,367	$ 32,993	$ 43,006	$ 32,841	$ 26,874	142,317	135,714	137,641
Other comprehensive income (loss), net of taxes:
Effective portion of foreign currency hedge net unrealized losses arising during the period, net of tax benefits of $179, nil and nil for 2016, 2015 and 2014, respectively									(281)	0	0
Less: reclassification adjustment to net income, net of taxes of $110, nil and nil for 2016, 2015 and 2014, respectively									(173)	0	0
Retirement benefit plans:
Net gains (losses) arising during the period, net of (taxes) benefits of nil, $(59) and $6,164 for 2016, 2015 and 2014, respectively									(42,631)	5,638	(218,608)
Less: amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of tax benefits of $566, $1,011 and $561 for 2016, 2015 and 2014, respectively									13,254	20,381	10,212
Less: reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of (taxes) benefits of $(18,206), $16,011 and $(132,373) for 2016, 2015 and 2014, respectively									28,584	(25,139)	207,833
Other comprehensive income (loss), net of taxes									(1,247)	880	(563)
Comprehensive income attributable to Hawaiian Electric Company, Inc.									$ 141,070	$ 136,594	$ 137,078