Consolidated Statements of Changes in Shareholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common stock	Retained earnings	Accumulated other comprehensive income (loss)	Hawaiian Electric Company, Inc. and Subsidiaries	Hawaiian Electric Company, Inc. and Subsidiaries Common stock	Hawaiian Electric Company, Inc. and Subsidiaries Premium on capital stock	Hawaiian Electric Company, Inc. and Subsidiaries Retained earnings	Hawaiian Electric Company, Inc. and Subsidiaries Accumulated other comprehensive income (loss)
Beginning Balance at Dec. 31, 2011	$ 1,528,706	$ 1,349,446	$ 198,397	$ (19,137)	$ 1,402,841	$ 94,911	$ 426,921	$ 881,041	$ (32)
Balance (in shares) at Dec. 31, 2011		96,038,000				14,234,000
Increase (decrease) in stockholders' equity
Net income for common stock	138,658		138,658		99,276			99,276
Other comprehensive income (loss), net of tax benefits	(7,286)			(7,286)	(938)				(938)
Issuance of common stock: Dividend reinvestment and stock purchase plan	41,295	41,295			44,001
Issuance of common stock: Dividend reinvestment and stock purchase plan (in shares)		1,560,000
Issuance of common stock: Retirement savings and other plans	8,196	8,196
Issuance of common stock: Retirement savings and other plans (in shares)		330,000
Issuance of common stock: Expenses and other, net	4,547	4,547
Issuance of common stock, net of expenses						431,000
Issuance of common stock, net of expenses (in shares)					44,001	2,877	41,124
Dividend equivalents paid on equity-classified awards	(101)		(101)
Common stock dividends	(120,150)		(120,150)		(73,044)			(73,044)
Ending Balance at Dec. 31, 2012	1,593,865	1,403,484	216,804	(26,423)	1,472,136	97,788	468,045	907,273	(970)
Balance (in shares) at Dec. 31, 2012		97,928,000				14,665,000
Increase (decrease) in stockholders' equity
Net income for common stock	33,679				24,429
Ending Balance at Mar. 31, 2013
Beginning Balance at Dec. 31, 2012	1,593,865	1,403,484	216,804	(26,423)	1,472,136	97,788	468,045	907,273	(970)
Balance (in shares) at Dec. 31, 2012		97,928,000				14,665,000
Increase (decrease) in stockholders' equity
Net income for common stock	161,516		161,516		122,929			122,929
Other comprehensive income (loss), net of tax benefits	9,673			9,673	1,578				1,578
Partial settlement of equity forward (in shares)		1,300,000
Partial settlement of equity forward	33,409	33,409
Issuance of common stock: Dividend reinvestment and stock purchase plan	41,692	41,692			78,499
Issuance of common stock: Dividend reinvestment and stock purchase plan (in shares)		1,612,000
Issuance of common stock: Retirement savings and other plans	9,203	9,203
Issuance of common stock: Retirement savings and other plans (in shares)		420,000
Issuance of common stock: Expenses and other, net	338	338
Issuance of common stock, net of expenses						764,000
Issuance of common stock, net of expenses (in shares)					78,499	5,092	73,407
Common stock dividends	(122,626)		(122,626)		(81,578)			(81,578)
Ending Balance at Dec. 31, 2013	1,727,070	1,488,126	255,694	(16,750)	1,593,564	102,880	541,452	948,624	608
Balance (in shares) at Dec. 31, 2013	101,259,800	101,260,000				15,429,000
Beginning Balance at Sep. 30, 2013
Increase (decrease) in stockholders' equity
Net income for common stock	39,013				31,990
Ending Balance at Dec. 31, 2013	1,727,070				1,593,564
Balance (in shares) at Dec. 31, 2013	101,259,800
Increase (decrease) in stockholders' equity
Net income for common stock	45,927				35,420
Ending Balance at Mar. 31, 2014
Beginning Balance at Dec. 31, 2013	1,727,070	1,488,126	255,694	(16,750)	1,593,564	102,880	541,452	948,624	608
Balance (in shares) at Dec. 31, 2013	101,259,800	101,260,000				15,429,000
Increase (decrease) in stockholders' equity
Net income for common stock	168,320		168,320		137,641			137,641
Other comprehensive income (loss), net of tax benefits	(10,628)			(10,628)	(563)				(563)
Partial settlement of equity forward (in shares)		1,000,000
Partial settlement of equity forward	24,873	24,873
Issuance of common stock: Dividend reinvestment and stock purchase plan	2,461	2,461			39,994
Issuance of common stock: Dividend reinvestment and stock purchase plan (in shares)		95,000
Issuance of common stock: Retirement savings and other plans	6,816	6,816
Issuance of common stock: Retirement savings and other plans (in shares)		210,000
Issuance of common stock: Expenses and other, net	(979)	(979)
Issuance of common stock, net of expenses						376,000
Issuance of common stock, net of expenses (in shares)					39,994	2,508	37,486
Common stock dividends	(126,505)		(126,505)		(88,492)			(88,492)
Ending Balance at Dec. 31, 2014	1,791,428	1,521,297	297,509	(27,378)	1,682,144	105,388	578,938	997,773	45
Balance (in shares) at Dec. 31, 2014	102,565,266	102,565,000				15,805,000
Beginning Balance at Sep. 30, 2014
Increase (decrease) in stockholders' equity
Net income for common stock	33,157				29,112
Ending Balance at Dec. 31, 2014	$ 1,791,428				$ 1,682,144
Balance (in shares) at Dec. 31, 2014	102,565,266