Consolidating financial information (Details 4) - HECO (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Balance			$ 1,593,865	$ 1,528,706
Net income (loss) for common stock	48,236	47,706	122,503	124,822
Other comprehensive income (loss), net of taxes	(897)	1,586	(9,263)	3,447
Common stock dividends			(91,739)	(89,902)
Balance	1,655,465	1,607,135	1,655,465	1,607,135
HECO
Balance			1,472,136	1,402,841
Net income (loss) for common stock	37,817	38,375	90,939	95,051
Other comprehensive income (loss), net of taxes	17	77	52	229
Common stock dividends			(61,183)	(54,783)
Balance	1,501,944	1,443,338	1,501,944	1,443,338
HELCO
Balance			268,908	280,468
Net income (loss) for common stock	5,444	4,728	14,744	15,830
Other comprehensive income (loss), net of taxes	(1)	5	(2)	18
Common stock dividends			(10,790)	(9,854)
Balance	272,860	286,462	272,860	286,462
MECO
Balance			228,927	235,568
Net income (loss) for common stock	5,351	6,558	15,704	12,198
Other comprehensive income (loss), net of taxes	0	7		19
Common stock dividends			(10,513)	(6,560)
Balance	234,118	241,225	234,118	241,225
Other subsidiaries
Balance			104	107
Net income (loss) for common stock	(1)	(1)	(2)	(3)
Other comprehensive income (loss), net of taxes	0
Balance	102	104	102	104
Consolidating adjustments
Balance			(497,939)	(516,143)
Net income (loss) for common stock	(10,794)	(11,285)	(30,446)	(28,025)
Other comprehensive income (loss), net of taxes	1	(12)	2	(37)
Common stock dividends			21,303	16,414
Balance	(507,080)	(527,791)	(507,080)	(527,791)
HECO Consolidated
Balance			1,472,136	1,402,841
Net income (loss) for common stock	37,817	38,375	90,939	95,051
Other comprehensive income (loss), net of taxes	17	77	52	229
Common stock dividends			(61,183)	(54,783)
Balance	$ 1,501,944	$ 1,443,338	$ 1,501,944	$ 1,443,338