Consolidated Statements of Capitalization (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Common stock, authorized shares	200,000,000	200,000,000
Common stock, outstanding shares	102,565,266	101,259,800
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%