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, 2017	$ 2,097,386	$ 1,845,283	$ 1,662,491	$ 107,634	$ 614,675	$ 476,836	$ 1,124,193	$ (41,941)	$ (1,219)
Beginning Balance (in shares) at Dec. 31, 2017			108,788,000	16,142,000
Increase (decrease) in stockholders' equity
Net income for common stock	40,247	27,475				40,247	27,475
Other comprehensive income (loss), net of tax (benefits)	(12,773)	31						(12,773)	31
Share-based expenses and other, net	658		$ 658
Issuance of common stock, net of expenses (in shares)			53,000
Common stock dividends	(33,741)	(25,826)				(33,741)	(25,826)
Common stock issuance expenses		(8)			(8)
Ending Balance at Mar. 31, 2018	2,091,777	1,846,955	$ 1,663,149	$ 107,634	614,667	483,342	1,125,842	(54,714)	(1,188)
Ending Balance (in shares) at Mar. 31, 2018			108,841,000	16,142,000
Beginning Balance at Dec. 31, 2018	$ 2,162,280	1,957,641	$ 1,669,267	$ 111,696	681,305	543,623	1,164,541	(50,610)	99
Beginning Balance (in shares) at Dec. 31, 2018	108,879,245		108,879,000	16,751,000
Increase (decrease) in stockholders' equity
Net income for common stock	$ 45,688	32,126				45,688	32,126
Other comprehensive income (loss), net of tax (benefits)	9,241	24						9,241	24
Share-based expenses and other, net	1,166		$ 1,166
Issuance of common stock, net of expenses (in shares)			58,000
Common stock dividends	(34,860)	(25,313)				(34,860)	(25,313)
Common stock issuance expenses		0
Ending Balance at Mar. 31, 2019	$ 2,183,515	$ 1,964,478	$ 1,670,433	$ 111,696	$ 681,305	$ 554,451	$ 1,171,354	$ (41,369)	$ 123
Ending Balance (in shares) at Mar. 31, 2019	108,936,912		108,937,000	16,751,000