Retirement benefits (Details) (USD $)	12 Months Ended																	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Minimum	Dec. 31, 2013 Maximum	Dec. 31, 2013 Hawaiian Electric Industries, Inc.	Dec. 31, 2013 Hawaiian Electric Company, Inc. and Subsidiaries	Dec. 31, 2012 Hawaiian Electric Company, Inc. and Subsidiaries	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries	Dec. 31, 2013 Hawaii Electric Light Company, Inc. (HELCO)	Dec. 31, 2012 Hawaii Electric Light Company, Inc. (HELCO)	Dec. 31, 2007 Hawaii Electric Light Company, Inc. (HELCO)	Dec. 31, 2013 Hawaiian Electric Company, Inc (HECO)	Dec. 31, 2012 Hawaiian Electric Company, Inc (HECO)	Dec. 31, 2007 Hawaiian Electric Company, Inc (HECO)	Dec. 31, 2013 Maui Electric Company, Limited (MECO)	Dec. 31, 2012 Maui Electric Company, Limited (MECO)	Dec. 31, 2007 Maui Electric Company, Limited (MECO)	Dec. 31, 2013 Pension benefits	Dec. 31, 2012 Pension benefits	Dec. 31, 2011 Pension benefits	Dec. 31, 2013 Pension benefits Hawaiian Electric Company, Inc. and Subsidiaries	Dec. 31, 2012 Pension benefits Hawaiian Electric Company, Inc. and Subsidiaries	Dec. 31, 2011 Pension benefits Hawaiian Electric Company, Inc. and Subsidiaries	Dec. 31, 2013 Other benefits	Dec. 31, 2012 Other benefits	Dec. 31, 2011 Other benefits	Dec. 31, 2013 Other benefits Hawaiian Electric Company, Inc. and Subsidiaries	Dec. 31, 2012 Other benefits Hawaiian Electric Company, Inc. and Subsidiaries	Dec. 31, 2011 Other benefits Hawaiian Electric Company, Inc. and Subsidiaries
Retirement benefits
Vested percentage of interest of each affected participant after participating employer terminates participation	100.00%
Number of years for which regulatory asset/liability for each utility will be amortized, beginning with respective utility's next rate case	5 years
Executive life and nonqualified pension plan expenses	$ 1,200,000	$ 1,600,000
Regulatory asset charges pretax	(364,000,000)	124,000,000
Regulatory assets						506,186,000	813,329,000		64,552,000	109,815,000	12,800,000	381,346,000	601,451,000		60,288,000	102,063,000
Regulatory assets recovery period									5 years
Value of plan assets requiring more than minimum level contributions required by law														0			0
Retirement benefits expense						30,000,000	32,000,000	34,000,000
Employer's additional matching contribution on employee deferrals (as a percent)					50.00%	50.00%
Maximum percentage of participant deferrals eligible for Employer contribution match, towards defined contribution plan					6.00%	6.00%
Changes in benefit obligation
Benefit obligation, balance at the beginning of the period																		1,590,304,000	1,322,430,000		1,449,445,000	1,203,943,000		194,135,000	190,549,000		187,110,000	184,240,000
Service cost																		56,405,000	43,221,000	35,016,000	54,482,000	41,603,000	33,627,000	4,306,000	4,211,000	4,409,000	4,163,000	4,014,000	4,238,000
Interest cost																		64,788,000	67,480,000	64,966,000	59,119,000	61,453,000	59,077,000	7,569,000	9,009,000	9,534,000	7,288,000	8,703,000	9,228,000
Actuarial losses (gains)																		(203,302,000)	217,205,000		(185,185,000)	197,718,000		(21,743,000)	(1,991,000)		(20,900,000)	(2,301,000)
Benefits paid and expenses																		(61,904,000)	(60,032,000)		(57,051,000)	(55,272,000)		(8,168,000)	(7,643,000)		(8,082,000)	(7,546,000)
Benefit obligation, balance at the end of the period																		1,446,291,000	1,590,304,000	1,322,430,000	1,320,810,000	1,449,445,000	1,203,943,000	176,099,000	194,135,000	190,549,000	169,579,000	187,110,000	184,240,000
Changes in fair value of plan assets
Fair value of plan assets, balance at the beginning of the period																		971,314,000	839,580,000		861,778,000	752,285,000		156,731,000	142,992,000		154,186,000	140,764,000
Actual return on plan assets																		194,130,000	115,794,000		172,822,000	103,941,000		29,164,000	18,477,000		28,700,000	18,206,000
Employer contributions																		82,083,000	74,923,000		80,325,000	60,442,000		954,000	2,780,000		839,000	2,634,000
Benefits paid and expenses																		(60,858,000)	(58,983,000)		(56,665,000)	(54,890,000)		(7,519,000)	(7,518,000)		(7,434,000)	(7,418,000)
Fair value of plan assets, balance at the end of the period																		1,186,669,000	971,314,000	839,580,000	1,058,260,000	861,778,000	752,285,000	179,330,000	156,731,000	142,992,000	176,291,000	154,186,000	140,764,000
Accrued benefit asset (liability), balance																		(259,622,000)	(618,990,000)		(262,550,000)	(587,667,000)		3,231,000	(37,404,000)		6,712,000	(32,924,000)
Other assets																		24,948,000	0		0	0		7,200,000	0		7,200,000
Other liabilities (short-term)																					(388,000)	(386,000)			0		(488,000)
Defined benefit pension and other postretirement benefit plans liability						(262,162,000)	(620,205,000)		(28,427,000)	(80,686,000)		(202,396,000)	(459,765,000)		(31,339,000)	(79,754,000)		(284,570,000)	(618,990,000)		(262,162,000)	(587,281,000)		(3,969,000)	(37,404,000)		0	(32,924,000)
Accrued benefit asset (liability), balance																		(259,622,000)	(618,990,000)		(262,550,000)	(587,667,000)		3,231,000	(37,404,000)		6,712,000	(32,924,000)
Changes in accumulated other comprehensive income
AOCI debit/(credit), balance at beginning of the period (excluding impact of PUC D&Os)																		680,781,000	533,537,000		623,588,000	488,556,000		18,846,000	28,684,000		17,432,000	27,390,000
Recognized during year - net recognized transition obligation																		0	(1,000)		0	0		0	0		0	9,000
Recognized during year - prior service credit																		97,000	325,000		464,000	689,000		1,793,000	1,793,000		1,803,000	1,803,000
Recognized during year - net actuarial losses																		(38,438,000)	(25,675,000)		(34,597,000)	(23,428,000)		(1,602,000)	(1,498,000)		(1,544,000)	(1,455,000)
Occurring during year - net actuarial losses (gains)																		(324,896,000)	172,595,000		293,482,000	(157,771,000)		(40,759,000)	(10,133,000)		39,598,000	10,315,000
AOCI debit/(credit), balance at end of the period (excluding impact of PUC D&Os)																		317,544,000	680,781,000	533,537,000	295,973,000	623,588,000	488,556,000	(21,722,000)	18,846,000	28,684,000	(21,907,000)	17,432,000	27,390,000
Cumulative impact of PUC D&Os																		(294,266,000)	(621,310,000)		(294,266,000)	(621,310,000)		19,206,000	(18,123,000)		19,206,000	(18,123,000)
AOCI debit/(credit), balance at end of the period																		23,278,000	59,471,000		1,707,000	2,278,000		(2,516,000)	723,000		(2,701,000)	(691,000)
Net actuarial loss																		317,639,000	680,973,000		295,825,000	623,904,000		(5,840,000)	36,521,000		(6,001,000)	35,141,000
Prior service gain																		(95,000)	(192,000)		148,000	(316,000)		(15,882,000)	(17,675,000)		(15,906,000)	(17,709,000)
AOCI debit/(credit), balance at end of the period (excluding impact of PUC D&Os)																		317,544,000	680,781,000	533,537,000	295,973,000	623,588,000	488,556,000	(21,722,000)	18,846,000	28,684,000	(21,907,000)	17,432,000	27,390,000
AOCI debit/(credit), balance at end of the period																		23,278,000	59,471,000		1,707,000	2,278,000		(2,516,000)	723,000		(2,701,000)	(691,000)
Income taxes																		(9,180,000)	(23,489,000)		(664,000)	(886,000)		980,000	(281,000)		1,050,000	269,000
AOCI debit/(credit), net of taxes (benefits) balance at the end of the period																		14,098,000	35,982,000		1,043,000	1,392,000		(1,536,000)	442,000		(1,651,000)	(422,000)
Defined benefit pension plans with accumulated benefit obligations in excess of plan assets
Aggregate accumulated benefit obligations																		1,200,000,000	1,400,000,000		1,200,000,000	1,200,000,000		400,000
Plan assets																		1,100,000,000	1,000,000,000		1,100,000,000	900,000,000		0
Defined benefit plans with benefit obligations in excess of plan assets
Aggregate projected benefit obligations																		1,400,000,000
Plan assets																		1,100,000,000
Expected cash funding for qualified defined benefit plans
2014																		59,000,000			58,000,000			72,000,000			67,000,000
2015																								75,000,000			69,000,000
2016																								78,000,000			72,000,000
2017																								81,000,000			75,000,000
2018																								85,000,000			77,000,000
2019 through 2023																								$ 483,000,000			$ 441,000,000
Fair value of plan assets, valuation difference amortized in first year (as a percent)	0.00%
Fair value of plan assets, valuation difference amortized in two to five years (as a percent)	25.00%
Number of past years for adding or subtracting the unamortized differences from fair value	4 years
Percentage of range around fair value	15.00%
Threshold percentage around fair value			85.00%	115.00%