Consolidated Statements of Capitalization (Parenthetical) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Common stock, authorized shares	200,000,000us-gaap_CommonStockSharesAuthorized	200,000,000us-gaap_CommonStockSharesAuthorized
Common stock, outstanding shares	102,565,266us-gaap_CommonStockSharesOutstanding	101,259,800us-gaap_CommonStockSharesOutstanding
Hawaiian Electric Company, Inc. and Subsidiaries
Common stock, authorized shares	50,000,000	50,000,000
Common stock, outstanding shares	15,805,327	15,429,105
Common stock, par value (in dollars per share)	$ 6.667	$ 6.667
Shares outstanding December 31, 2013	1,234,657	1,234,657
Hawaiian Electric Company, Inc. and Subsidiaries \| Series C, 4.25% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, dividend rate	4.25%	4.25%
Shares outstanding December 31, 2013	150,000	150,000
Hawaiian Electric Company, Inc. and Subsidiaries \| Series D, 5.00% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, dividend rate	5.00%	5.00%
Shares outstanding December 31, 2013	50,000	50,000
Hawaiian Electric Company, Inc. and Subsidiaries \| Series E, 5.00% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, dividend rate	5.00%	5.00%
Shares outstanding December 31, 2013	150,000	150,000
Hawaiian Electric Company, Inc. and Subsidiaries \| Series H, 5.25% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, dividend rate	5.25%	5.25%
Shares outstanding December 31, 2013	250,000	250,000
Hawaiian Electric Company, Inc. and Subsidiaries \| Series I, 5.00% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, dividend rate	5.00%	5.00%
Shares outstanding December 31, 2013	89,657	89,657
Hawaiian Electric Company, Inc. and Subsidiaries \| Series J, 4.75% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, dividend rate	4.75%	4.75%
Shares outstanding December 31, 2013	250,000	250,000
Hawaiian Electric Company, Inc. and Subsidiaries \| Series K, 4.65% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, dividend rate	4.65%	4.65%
Shares outstanding December 31, 2013	175,000	175,000
Hawaiian Electric Company, Inc. and Subsidiaries \| Preferred Stock $20 Par Value
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, Authorized shares	5,000,000	5,000,000
Hawaiian Electric Company, Inc. and Subsidiaries \| Preferred Stock $100 Par Value
Preferred stock, par value (in dollars per share)	$ 100	$ 100
Preferred stock, Authorized shares	7,000,000	7,000,000
Hawaiian Electric Company, Inc (HECO) \| 6.50%, series 2009, due 2039
Debt instrument, stated interest rate (as a percent)	6.50%	6.50%
Hawaiian Electric Company, Inc (HECO) \| 4.60%, refunding series 2007B, due 2026
Debt instrument, stated interest rate (as a percent)	4.60%	4.60%
Hawaiian Electric Company, Inc (HECO) \| 4.65%, series 2007A, due 2037
Debt instrument, stated interest rate (as a percent)	4.65%	4.65%
Hawaiian Electric Company, Inc (HECO) \| 4.80%, refunding series 2005A, due 2025
Debt instrument, stated interest rate (as a percent)	4.80%	4.80%
Hawaiian Electric Company, Inc (HECO) \| Hawaiian Electric, 4.45%, Series 2013A, due 2022
Debt instrument, stated interest rate (as a percent)	4.45%	4.45%
Hawaiian Electric Company, Inc (HECO) \| Hawaiian Electric, 4.84%, Series 2013B, due 2027
Debt instrument, stated interest rate (as a percent)	4.84%	4.84%
Hawaiian Electric Company, Inc (HECO) \| Hawaiian Electric, 5.65%, Series 2013C, due 2043
Debt instrument, stated interest rate (as a percent)	5.65%	5.65%
Hawaiian Electric Company, Inc (HECO) \| Senior notes 3.79%, Series 2012A, due 2018
Debt instrument, stated interest rate (as a percent)	3.79%	3.79%
Hawaiian Electric Company, Inc (HECO) \| Senior notes 4.03%, Series 2012B, due 2020
Debt instrument, stated interest rate (as a percent)	4.03%	4.03%
Hawaiian Electric Company, Inc (HECO) \| Senior notes 4.55%, due 2023
Debt instrument, stated interest rate (as a percent)	4.55%	4.55%
Hawaiian Electric Company, Inc (HECO) \| Senior notes 4.72%, Series 2012D, due 2029
Debt instrument, stated interest rate (as a percent)	4.72%	4.72%
Hawaiian Electric Company, Inc (HECO) \| Senior notes 5.39%, Series, 2012E, due 2042
Debt instrument, stated interest rate (as a percent)	5.39%	5.39%
Hawaiian Electric Company, Inc (HECO) \| Senior notes 4.53%, Series, 2012F, due 2032
Debt instrument, stated interest rate (as a percent)	4.53%	4.53%
Hawaiian Electric Company, Inc (HECO) \| 6.50% Junior subordinated deferrable interest debentures, series 2004, due 2034
Debt instrument, stated interest rate (as a percent)	6.50%	6.50%
Hawaii Electric Light Company, Inc. (HELCO) \| Series G, 7.625% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 100	$ 100
Preferred stock, dividend rate	7.625%	7.625%
Shares outstanding December 31, 2013	70,000	70,000
Hawaii Electric Light Company, Inc. (HELCO) \| 6.50%, series 2009, due 2039
Debt instrument, stated interest rate (as a percent)	6.50%	6.50%
Hawaii Electric Light Company, Inc. (HELCO) \| 4.60%, refunding series 2007B, due 2026
Debt instrument, stated interest rate (as a percent)	4.60%	4.60%
Hawaii Electric Light Company, Inc. (HELCO) \| 4.65%, series 2007A, due 2037
Debt instrument, stated interest rate (as a percent)	4.65%	4.65%
Hawaii Electric Light Company, Inc. (HELCO) \| 4.80%, refunding series 2005A, due 2025
Debt instrument, stated interest rate (as a percent)	4.80%	4.80%
Hawaii Electric Light Company, Inc. (HELCO) \| 5.50%, refunding series 1999A, due 2014
Debt instrument, stated interest rate (as a percent)		5.50%
Hawaii Electric Light Company, Inc. (HELCO) \| Hawaii Electric Light, 3.83%, Series 2013A, due 2020
Debt instrument, stated interest rate (as a percent)	3.83%	3.83%
Hawaii Electric Light Company, Inc. (HELCO) \| Hawaii Electric Light, 4.45%, Series 2013B, due 2022
Debt instrument, stated interest rate (as a percent)	4.45%	4.45%
Hawaii Electric Light Company, Inc. (HELCO) \| Hawaii Electric Light, 4.84%, Series 2013C, due 2027
Debt instrument, stated interest rate (as a percent)	4.84%	4.84%
Hawaii Electric Light Company, Inc. (HELCO) \| Senior notes 3.79%, Series 2012A, due 2018
Debt instrument, stated interest rate (as a percent)	3.79%	3.79%
Hawaii Electric Light Company, Inc. (HELCO) \| Senior notes 4.55%, due 2023
Debt instrument, stated interest rate (as a percent)	4.55%	4.55%
Maui Electric Company, Limited (MECO) \| Series H, 7.625% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 100	$ 100
Preferred stock, dividend rate	7.625%	7.625%
Shares outstanding December 31, 2013	50,000	50,000
Maui Electric Company, Limited (MECO) \| 4.60%, refunding series 2007B, due 2026
Debt instrument, stated interest rate (as a percent)	4.60%	4.60%
Maui Electric Company, Limited (MECO) \| 4.65%, series 2007A, due 2037
Debt instrument, stated interest rate (as a percent)	4.65%	4.65%
Maui Electric Company, Limited (MECO) \| 4.80%, refunding series 2005A, due 2025
Debt instrument, stated interest rate (as a percent)	4.80%	4.80%
Maui Electric Company, Limited (MECO) \| Maui Electric, 4.84%, Series 2013A, due 2027
Debt instrument, stated interest rate (as a percent)	4.84%	4.84%
Maui Electric Company, Limited (MECO) \| Maui Electric, 5.65%, Series 2013B, due 2043
Debt instrument, stated interest rate (as a percent)	5.65%	5.65%
Maui Electric Company, Limited (MECO) \| Senior notes 3.79%, Series 2012A, due 2018
Debt instrument, stated interest rate (as a percent)	3.79%	3.79%
Maui Electric Company, Limited (MECO) \| Senior notes 4.03%, Series 2012B, due 2020
Debt instrument, stated interest rate (as a percent)	4.03%	4.03%
Maui Electric Company, Limited (MECO) \| Senior notes 4.55%, due 2023
Debt instrument, stated interest rate (as a percent)	4.55%	4.55%

Face amount or stated value per share of common stock.

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