Consolidated Statements of Capitalization - HECO (USD $) In Thousands, except Share data, unless otherwise specified																														12 Months Ended																																						12 Months Ended																				12 Months Ended
	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries	Dec. 31, 2009 Hawaiian Electric Company, Inc. and Subsidiaries	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 6.50%, series 2009, due 2039	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 6.50%, series 2009, due 2039	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 4.60%, refunding series 2007B, due 2026	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 4.60%, refunding series 2007B, due 2026	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 4.65%, series 2007A, due 2037	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 4.65%, series 2007A, due 2037	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 4.80%, refunding series 2005A, due 2025	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 4.80%, refunding series 2005A, due 2025	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 5.00%, refunding series 2003B, due 2022	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 5.00%, refunding series 2003B, due 2022	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 5.10%, series 2002A, due 2032	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 5.10%, series 2002A, due 2032	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 5.70%, refunding series 2000, due 2020	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 5.70%, refunding series 2000, due 2020	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 6.15%, refunding series 1999D, due 2020	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 6.15%, refunding series 1999D, due 2020	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 6.20%, series 1999C, due 2029	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 6.20%, series 1999C, due 2029	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 5.75%, refunding series 1999B, due 2018	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 5.75%, refunding series 1999B, due 2018	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 4.95%, refunding series 1998A, due 2012	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 4.95%, refunding series 1998A, due 2012	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 5.65%, series 1997A, due 2027	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 5.65%, series 1997A, due 2027	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 5.45%, series 1993, due 2023	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Special Purpose Revenue Bonds, 5.45%, series 1993, due 2023	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Cumulative preferred stock not subject to mandatory redemption, C-4 1/4% Series	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Cumulative preferred stock not subject to mandatory redemption, C-4 1/4% Series	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Cumulative preferred stock not subject to mandatory redemption, D-5% Series	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Cumulative preferred stock not subject to mandatory redemption, D-5% Series	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Cumulative preferred stock not subject to mandatory redemption, E-5% Series	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Cumulative preferred stock not subject to mandatory redemption, E-5% Series	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Cumulative preferred stock not subject to mandatory redemption, H-5 1/4% Series	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Cumulative preferred stock not subject to mandatory redemption, H-5 1/4% Series	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Cumulative preferred stock not subject to mandatory redemption, l-5% Series	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Cumulative preferred stock not subject to mandatory redemption, l-5% Series	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Cumulative preferred stock not subject to mandatory redemption, J-4 3/4% Series	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Cumulative preferred stock not subject to mandatory redemption, J-4 3/4% Series	Dec. 31, 2011 Hawaiian Electric Company, Inc. and Subsidiaries Cumulative preferred stock not subject to mandatory redemption, K-4.65% Series	Dec. 31, 2010 Hawaiian Electric Company, Inc. and Subsidiaries Cumulative preferred stock not subject to mandatory redemption, K-4.65% Series	Dec. 31, 2011 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 6.50%, series 2009, due 2039	Dec. 31, 2010 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 6.50%, series 2009, due 2039	Dec. 31, 2011 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 4.60%, refunding series 2007B, due 2026	Dec. 31, 2010 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 4.60%, refunding series 2007B, due 2026	Dec. 31, 2011 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 4.65%, series 2007A, due 2037	Dec. 31, 2010 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 4.65%, series 2007A, due 2037	Dec. 31, 2011 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 4.80%, refunding series 2005A, due 2025	Dec. 31, 2010 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 4.80%, refunding series 2005A, due 2025	Dec. 31, 2011 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 5.00%, refunding series 2003B, due 2022	Dec. 31, 2010 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 5.00%, refunding series 2003B, due 2022	Dec. 31, 2011 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 4.75%, refunding series 2003A, due 2020	Dec. 31, 2010 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 4.75%, refunding series 2003A, due 2020	Dec. 31, 2011 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 6.15%, refunding series 1999D, due 2020	Dec. 31, 2010 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 6.15%, refunding series 1999D, due 2020	Dec. 31, 2011 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 5.75%, refunding series 1999B, due 2018	Dec. 31, 2010 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 5.75%, refunding series 1999B, due 2018	Dec. 31, 2011 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 5.50%, refunding series 1999A, due 2014	Dec. 31, 2010 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 5.50%, refunding series 1999A, due 2014	Dec. 31, 2011 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 4.95%, refunding series 1998A, due 2012	Dec. 31, 2010 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 4.95%, refunding series 1998A, due 2012	Dec. 31, 2011 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 5.65%, series 1997A, due 2027	Dec. 31, 2010 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 5.65%, series 1997A, due 2027	Dec. 31, 2011 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 5.45%, series 1993, due 2023	Dec. 31, 2010 Hawaii Electric Light Company, Inc. (HELCO) Special Purpose Revenue Bonds, 5.45%, series 1993, due 2023	Dec. 31, 2011 Hawaii Electric Light Company, Inc. (HELCO) Cumulative preferred stock not subject to mandatory redemption, G-7 5/8% Series	Dec. 31, 2010 Hawaii Electric Light Company, Inc. (HELCO) Cumulative preferred stock not subject to mandatory redemption, G-7 5/8% Series	Dec. 31, 2011 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 4.60%, refunding series 2007B, due 2026	Dec. 31, 2010 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 4.60%, refunding series 2007B, due 2026	Dec. 31, 2011 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 4.65%, series 2007A, due 2037	Dec. 31, 2010 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 4.65%, series 2007A, due 2037	Dec. 31, 2011 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 4.80%, refunding series 2005A, due 2025	Dec. 31, 2010 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 4.80%, refunding series 2005A, due 2025	Dec. 31, 2011 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 5.70%, refunding series 2000, due 2020	Dec. 31, 2010 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 5.70%, refunding series 2000, due 2020	Dec. 31, 2011 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 6.15%, refunding series 1999D, due 2020	Dec. 31, 2010 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 6.15%, refunding series 1999D, due 2020	Dec. 31, 2011 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 5.75%, refunding series 1999B, due 2018	Dec. 31, 2010 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 5.75%, refunding series 1999B, due 2018	Dec. 31, 2011 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 4.95%, refunding series 1998A, due 2012	Dec. 31, 2010 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 4.95%, refunding series 1998A, due 2012	Dec. 31, 2011 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 5.65%, series 1997A, due 2027	Dec. 31, 2010 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 5.65%, series 1997A, due 2027	Dec. 31, 2011 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 5.45%, series 1993, due 2023	Dec. 31, 2010 Maui Electric Company, Limited (MECO) Special Purpose Revenue Bonds, 5.45%, series 1993, due 2023	Dec. 31, 2011 Maui Electric Company, Limited (MECO) Cumulative preferred stock not subject to mandatory redemption, H-7 5/8% Series	Dec. 31, 2010 Maui Electric Company, Limited (MECO) Cumulative preferred stock not subject to mandatory redemption, H-7 5/8% Series
Common stock equity
Common stock of $6 2/3 par value Authorized: 50,000,000 shares. Outstanding: 2011, 14,233,723 shares, 2010, 13,830,823 shares, and 2009, 13,786,959 shares	$ 94,911	$ 92,224	$ 91,931
Premium on capital stock	426,921	389,609	385,659
Retained earnings	884,284	854,856	827,036
Accumulated other comprehensive income, net of income taxes:
Retirement benefit plans	(32)	709	1,782
Common stock equity	1,406,084	1,337,398	1,306,408
Preferred stock, Dividend Rate (as a percent)																														4.25%	4.25%	5.00%	5.00%	5.00%	5.00%	5.25%	5.25%	5.00%	5.00%	4.75%	4.75%	4.65%	4.65%																									7.625%	7.625%																			7.625%	7.625%
Cumulative preferred stock not subject to mandatory redemption (in shares)	1,234,657	1,234,657																												150,000	150,000	50,000	50,000	150,000	150,000	250,000	250,000	89,657	89,657	250,000	250,000	175,000	175,000																									70,000	70,000																			50,000	50,000
Cumulative preferred stock not subject to mandatory redemption	34,293	34,293																												3,000	3,000	1,000	1,000	3,000	3,000	5,000	5,000	1,793	1,793	5,000	5,000	3,500	3,500																									7,000	7,000																			5,000	5,000
Obligations to the State of Hawaii for the repayment of Special Purpose Revenue Bonds (subsidiary obligations unconditionally guaranteed by HECO):
Interest rate, (as a percent)	6.50%	6.50%		6.50%	6.50%	4.60%	4.60%	4.65%	4.65%	4.80%	4.80%	5.00%	5.00%	5.10%	5.10%	5.70%	5.70%	6.15%	6.15%	6.20%	6.20%	5.75%	5.75%	4.95%	4.95%	5.65%	5.65%	5.45%	5.45%															6.50%	6.50%	4.60%	4.60%	4.65%	4.65%	4.80%	4.80%	5.00%	5.00%	4.75%	4.75%	6.15%	6.15%	5.75%	5.75%	5.50%	5.50%	4.95%	4.95%	5.65%	5.65%	5.45%	5.45%			4.60%	4.60%	4.65%	4.65%	4.80%	4.80%	5.70%	5.70%	6.15%	6.15%	5.75%	5.75%	4.95%	4.95%	5.65%	5.65%	5.45%	5.45%
Total obligations to the State of Hawaii	1,007,900	1,007,900		90,000	90,000	62,000	62,000	100,000	100,000	40,000	40,000	40,000	40,000	40,000	40,000	46,000	46,000	16,000	16,000	35,000	35,000	30,000	30,000	42,580	42,580	50,000	50,000	50,000	50,000															60,000	60,000	8,000	8,000	20,000	20,000	5,000	5,000	12,000	12,000	14,000	14,000	3,000	3,000	11,000	11,000	11,400	11,400	7,200	7,200	30,000	30,000	20,000	20,000			55,000	55,000	20,000	20,000	2,000	2,000	20,000	20,000	1,000	1,000	9,000	9,000	7,720	7,720	20,000	20,000	30,000	30,000
Other long-term debt - unsecured:
Other long-term debt - unsecured: 6.50 %, series 2004, Junior subordinated deferrable interest debentures, due 2034	51,546	51,546
Interest rate, (as a percent)	6.50%	6.50%		6.50%	6.50%	4.60%	4.60%	4.65%	4.65%	4.80%	4.80%	5.00%	5.00%	5.10%	5.10%	5.70%	5.70%	6.15%	6.15%	6.20%	6.20%	5.75%	5.75%	4.95%	4.95%	5.65%	5.65%	5.45%	5.45%															6.50%	6.50%	4.60%	4.60%	4.65%	4.65%	4.80%	4.80%	5.00%	5.00%	4.75%	4.75%	6.15%	6.15%	5.75%	5.75%	5.50%	5.50%	4.95%	4.95%	5.65%	5.65%	5.45%	5.45%			4.60%	4.60%	4.65%	4.65%	4.80%	4.80%	5.70%	5.70%	6.15%	6.15%	5.75%	5.75%	4.95%	4.95%	5.65%	5.65%	5.45%	5.45%
Total long-term debt	1,059,446	1,059,446
Less unamortized discount	1,376	1,504
Less current portion long-term debt	57,500
Long-term debt, net	1,000,570	1,057,942
Total capitalization	$ 2,440,947	$ 2,429,633