Electric utility subsidiary - Consolidating financial statements (Details 5) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities
Net income	$ 41,894	$ 41,061	$ 88,294	$ 75,213
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation of property, plant and equipment			86,397	79,843
Other amortization			4,014	2,868
Increase in deferred income taxes			28,252	40,403
Allowance for equity funds used during construction	(1,387)	(1,560)	(2,996)	(2,775)
Change in cash overdraft			(1,038)	0
Changes in assets and liabilities
Decrease (increase) in fuel oil stock			(27,206)	43,974
Increase in regulatory assets			(17,731)	(37,586)
Change in prepaid and accrued income and utility revenue taxes			(32,510)	(33,822)
Decrease in defined benefit pension and other postretirement benefit plans liability			(1,714)	(330)
Net cash provided by operating activities			46,195	130,792
Cash flows from investing activities
Capital expenditures			(149,253)	(158,830)
Contributions in aid of construction			13,209	17,188
Other			(16)	622
Net cash used in investing activities			(272,102)	(240,285)
Cash flows from financing activities
Common stock dividends			(62,892)	(48,921)
Net increase in short-term borrowings with original maturities of three months or less			79,693	42,093
Other			(252)	606
Net cash provided by financing activities			194,248	43,543
Net increase (decrease) in cash and cash equivalents			(31,659)	(65,950)
Hawaiian Electric Company
Cash flows from operating activities
Net income	34,500	28,963	70,190	53,662
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Equity in earnings of subsidiaries			(18,826)	(19,702)
Common stock dividends received from subsidiaries			13,038	14,227
Depreciation of property, plant and equipment			54,601	49,708
Other amortization			554	(160)
Increase in deferred income taxes			34,976	27,560
Change in tax credits, net			3,482	2,598
Allowance for equity funds used during construction	(1,417)	(1,247)	(2,889)	(2,230)
Changes in assets and liabilities
Decrease (increase) in accounts receivable			(4,840)	35,431
Decrease (increase) in accrued unbilled revenues			1,058	(2,095)
Decrease (increase) in fuel oil stock			(23,457)	38,428
Increase in materials and supplies			(229)	(4,069)
Increase in regulatory assets			(15,893)	(25,647)
Decrease in accounts payable			(54,777)	(36,971)
Change in prepaid and accrued income and utility revenue taxes			(33,867)	(25,831)
Decrease in defined benefit pension and other postretirement benefit plans liability			(281)	1,163
Change in other assets and liabilities			(19,897)	(12,731)
Net cash provided by operating activities			2,943	93,341
Cash flows from investing activities
Capital expenditures			(104,710)	(104,846)
Contributions in aid of construction			8,520	11,924
Other				623
Advances from (to) affiliates			(16,761)	(8,600)
Net cash used in investing activities			(112,951)	(100,899)
Cash flows from financing activities
Common stock dividends			(44,246)	(40,789)
Preferred stock dividends of Hawaiian Electric and subsidiaries			(540)	(540)
Net increase in short-term borrowings with original maturities of three months or less			101,989	45,542
Other			(334)	(6)
Net cash provided by financing activities			56,869	4,207
Net increase (decrease) in cash and cash equivalents			(53,139)	(3,351)
Cash and cash equivalents, beginning of period			61,245	8,265
Cash and cash equivalents, end of period	8,106	4,914	8,106	4,914
HELCO
Cash flows from operating activities
Net income	4,979	5,013	10,274	9,567
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation of property, plant and equipment			17,951	17,094
Other amortization			1,299	716
Increase in deferred income taxes			4,478	5,584
Change in tax credits, net			434	70
Allowance for equity funds used during construction	(121)	(192)	(186)	(330)
Changes in assets and liabilities
Decrease (increase) in accounts receivable			(1,527)	(2,281)
Decrease (increase) in accrued unbilled revenues			(352)	(2,848)
Decrease (increase) in fuel oil stock			1,661	5,812
Increase in materials and supplies			(246)	(1,480)
Increase in regulatory assets			(1,640)	(4,852)
Decrease in accounts payable			(5,621)	(2,513)
Change in prepaid and accrued income and utility revenue taxes			(3,709)	(6,171)
Decrease in defined benefit pension and other postretirement benefit plans liability			0	(128)
Change in other assets and liabilities			(2,586)	(3,171)
Net cash provided by operating activities			20,230	15,069
Cash flows from investing activities
Capital expenditures			(20,567)	(22,367)
Contributions in aid of construction			2,493	4,270
Advances from (to) affiliates			1,000	8,450
Net cash used in investing activities			(17,074)	(9,647)
Cash flows from financing activities
Common stock dividends			(5,813)	(7,194)
Preferred stock dividends of Hawaiian Electric and subsidiaries			(267)	(267)
Net increase in short-term borrowings with original maturities of three months or less			3,400
Other			(48)	(1)
Net cash provided by financing activities			(2,728)	(7,462)
Net increase (decrease) in cash and cash equivalents			428	(2,040)
Cash and cash equivalents, beginning of period			1,326	5,441
Cash and cash equivalents, end of period	1,754	3,401	1,754	3,401
Maui Electric
Cash flows from operating activities
Net income	5,109	3,884	8,960	10,544
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation of property, plant and equipment			10,644	10,068
Other amortization			1,744	2,328
Increase in deferred income taxes			5,932	5,636
Change in tax credits, net			311	329
Allowance for equity funds used during construction	151	(121)	79	(215)
Change in cash overdraft			(1,038)
Changes in assets and liabilities
Decrease (increase) in accounts receivable			708	(318)
Decrease (increase) in accrued unbilled revenues			1,549	54
Decrease (increase) in fuel oil stock			(5,410)	(266)
Increase in materials and supplies			(1,360)	(1,590)
Increase in regulatory assets			(198)	(7,087)
Decrease in accounts payable			(2,908)	(1,750)
Change in prepaid and accrued income and utility revenue taxes			(694)	(6,121)
Decrease in defined benefit pension and other postretirement benefit plans liability			(217)	(46)
Change in other assets and liabilities			(3,155)	5,929
Net cash provided by operating activities			14,947	17,495
Cash flows from investing activities
Capital expenditures			(20,457)	(23,038)
Contributions in aid of construction			2,196	994
Advances from (to) affiliates			0
Net cash used in investing activities			(18,261)	(22,044)
Cash flows from financing activities
Common stock dividends			(7,175)	(7,008)
Preferred stock dividends of Hawaiian Electric and subsidiaries			(191)	(191)
Net increase in short-term borrowings with original maturities of three months or less			13,361	8,600
Other			(75)	(2)
Net cash provided by financing activities			5,920	1,399
Net increase (decrease) in cash and cash equivalents			2,606	(3,150)
Cash and cash equivalents, beginning of period			153	3,349
Cash and cash equivalents, end of period	2,759	199	2,759	199
Other subsidiaries
Cash flows from operating activities
Net income	0	(1)	0	(1)
Changes in assets and liabilities
Net cash provided by operating activities			0	(1)
Cash flows from investing activities
Capital expenditures			0
Contributions in aid of construction			0
Advances from (to) affiliates			0
Net cash used in investing activities			0
Cash flows from financing activities
Net increase (decrease) in cash and cash equivalents			0	(1)
Cash and cash equivalents, beginning of period			101	104
Cash and cash equivalents, end of period	101	103	101	103
Consolidating adjustments
Cash flows from operating activities
Net income	(9,859)	(8,667)	(18,776)	(19,652)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Equity in earnings of subsidiaries			18,776	19,652
Common stock dividends received from subsidiaries			(12,988)	(14,202)
Changes in assets and liabilities
Decrease (increase) in accounts receivable			620	(579)
Change in other assets and liabilities			(620)	579
Net cash provided by operating activities			(12,988)	(14,202)
Cash flows from investing activities
Capital expenditures			0
Contributions in aid of construction			0
Advances from (to) affiliates			15,761	150
Net cash used in investing activities			15,761	150
Cash flows from financing activities
Common stock dividends			12,988	14,202
Net increase in short-term borrowings with original maturities of three months or less			(15,761)	(150)
Net cash provided by financing activities			(2,773)	14,052
Net increase (decrease) in cash and cash equivalents				0
Cash and cash equivalents, beginning of period				0
Cash and cash equivalents, end of period		0		0
HECO Consolidated
Cash flows from operating activities
Net income	34,729	29,192	70,648	54,120
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Equity in earnings of subsidiaries			(50)	(50)
Common stock dividends received from subsidiaries			50	25
Depreciation of property, plant and equipment			83,196	76,870
Other amortization			3,597	2,884
Increase in deferred income taxes			45,386	38,780
Change in tax credits, net			4,227	2,997
Allowance for equity funds used during construction	(1,387)	(1,560)	(2,996)	(2,775)
Change in cash overdraft			(1,038)	0
Changes in assets and liabilities
Decrease (increase) in accounts receivable			(5,039)	32,253
Decrease (increase) in accrued unbilled revenues			2,255	(4,889)
Decrease (increase) in fuel oil stock			(27,206)	43,974
Increase in materials and supplies			(1,835)	(7,139)
Increase in regulatory assets			(17,731)	(37,586)
Decrease in accounts payable			(63,306)	(41,234)
Change in prepaid and accrued income and utility revenue taxes			(38,270)	(38,123)
Decrease in defined benefit pension and other postretirement benefit plans liability			(498)	989
Change in other assets and liabilities			(26,258)	(9,394)
Net cash provided by operating activities			25,132	111,702
Cash flows from investing activities
Capital expenditures			(145,734)	(150,251)
Contributions in aid of construction			13,209	17,188
Other			0	623
Advances from (to) affiliates				0
Net cash used in investing activities			(132,525)	(132,440)
Cash flows from financing activities
Common stock dividends			(44,246)	(40,789)
Preferred stock dividends of Hawaiian Electric and subsidiaries			(998)	(998)
Net increase in short-term borrowings with original maturities of three months or less			102,989	53,992
Other			(457)	(9)
Net cash provided by financing activities			57,288	12,196
Net increase (decrease) in cash and cash equivalents			(50,105)	(8,542)
Cash and cash equivalents, beginning of period			62,825	17,159
Cash and cash equivalents, end of period	$ 12,720	$ 8,617	$ 12,720	$ 8,617