Consolidated Statements of Changes in Common Stock Equity - HECO - USD ($) $ in Thousands	Total	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, 2016	$ 2,066,753	$ 438,972	$ (33,129)	$ 1,799,787	$ 106,818	$ 601,491	$ 1,091,800	$ (322)
Balance (in shares) at Dec. 31, 2016					16,020,000
Increase (decrease) in stockholders' equity
Net income for common stock	165,297	165,297		119,951			119,951
Other comprehensive income (loss), net of tax benefits	(1,372)		(1,372)	(688)				(688)
Reclass of AOCI for tax rate reduction impact1	(7,440)			(209)			209	(209)
Issuance of common stock, net of expenses				14,000	$ 816	13,184
Issuance of common stock, net of expenses (in shares)					122,000
Common stock dividends	(134,873)	(134,873)		(87,767)			(87,767)
Ending Balance at Dec. 31, 2017	2,097,386	476,836	(41,941)	1,845,283	$ 107,634	614,675	1,124,193	(1,219)
Balance (in shares) at Dec. 31, 2017					16,142,000
Increase (decrease) in stockholders' equity
Net income for common stock	201,774	201,774		143,653			143,653
Other comprehensive income (loss), net of tax benefits	(8,669)		(8,669)	1,318				1,318
Issuance of common stock, net of expenses				70,692	$ 4,062	66,630
Issuance of common stock, net of expenses (in shares)					609,000
Common stock dividends	(134,987)	(134,987)		(103,305)			(103,305)
Ending Balance at Dec. 31, 2018	$ 2,162,280	543,623	(50,610)	1,957,641	$ 111,696	681,305	1,164,541	99
Balance (in shares) at Dec. 31, 2018	108,879,245				16,751,000
Increase (decrease) in stockholders' equity
Net income for common stock	$ 217,882	217,882		156,840			156,840
Other comprehensive income (loss), net of tax benefits	30,571		30,571	(1,378)				(1,378)
Issuance of common stock, net of expenses				35,501	$ 1,982	33,519
Issuance of common stock, net of expenses (in shares)					297,000
Common stock dividends	(139,463)	(139,463)		(101,252)			(101,252)
Ending Balance at Dec. 31, 2019	$ 2,280,260	$ 622,042	$ (20,039)	$ 2,047,352	$ 113,678	$ 714,824	$ 1,220,129	$ (1,279)
Balance (in shares) at Dec. 31, 2019	108,973,328				17,048,000