Condensed Consolidated Statements of Changes in Shareholders' Equity and Common Stock Equity (unaudited) - USD ($) $ in Thousands	Total	Hawaiian Electric Company, Inc. and Subsidiaries	Common stock	Common stock Hawaiian Electric Company, Inc. and Subsidiaries	Premium on capital stock Hawaiian Electric Company, Inc. and Subsidiaries	Retained Earnings	Retained Earnings Hawaiian Electric Company, Inc. and Subsidiaries	Accumulated other comprehensive income (loss)	Accumulated other comprehensive income (loss) Hawaiian Electric Company, Inc. and Subsidiaries
Beginning Balance at Dec. 31, 2015	$ 1,927,640	$ 1,728,325	$ 1,629,136	$ 105,388	$ 578,930	$ 324,766	$ 1,043,082	$ (26,262)	$ 925
Beginning Balance (in shares) at Dec. 31, 2015			107,460,000	15,805,000
Increase (decrease) in stockholders' equity
Net income for common stock	203,622	108,198				203,622	108,198
Other comprehensive income, net of taxes	9,239	412						9,239	412
Issuance of common stock, net of expenses	28,285		$ 28,285
Issuance of common stock, net of expenses (in shares)			1,043,000
Common stock dividends	(100,398)	(70,199)				(100,398)	(70,199)
Common stock issuance expenses		(9)			(9)
Ending Balance at Sep. 30, 2016	2,068,388	1,766,727	$ 1,657,421	$ 105,388	578,921	427,990	1,081,081	(17,023)	1,337
Ending Balance (in shares) at Sep. 30, 2016			108,503,000	15,805,000
Beginning Balance at Dec. 31, 2016	$ 2,066,753	1,799,787	$ 1,660,910	$ 106,818	601,491	438,972	1,091,800	(33,129)	(322)
Beginning Balance (in shares) at Dec. 31, 2016	108,583,413		108,583,000	16,020,000
Increase (decrease) in stockholders' equity
Net income for common stock	$ 132,927	94,596				132,927	94,596
Other comprehensive income, net of taxes	3,909	521						3,909	521
Issuance of common stock, net of expenses	582		$ 582
Issuance of common stock, net of expenses (in shares)			203,000
Common stock dividends	(101,149)	(65,825)				(101,149)	(65,825)
Common stock issuance expenses		(4)			(4)
Ending Balance at Sep. 30, 2017	$ 2,103,022	$ 1,829,075	$ 1,661,492	$ 106,818	$ 601,487	$ 470,750	$ 1,120,571	$ (29,220)	$ 199
Ending Balance (in shares) at Sep. 30, 2017	108,785,978		108,786,000	16,020,000