Consolidated Statements of Changes in Common Stock Equity (unaudited) - 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, 2014	$ 1,790,573	$ 296,654	$ (27,378)	$ 1,682,144	$ 105,388	$ 578,938	$ 997,773	$ 45
Beginning Balance (in shares) at Dec. 31, 2014					15,805,000
Increase (decrease) in stockholders' equity
Net income for common stock	117,557	117,557		102,721			102,721
Other comprehensive income, net of taxes	5,361		5,361	11				11
Common stock dividends	(98,452)	(98,452)		(67,804)			(67,804)
Common stock issuance expenses				(8)		(8)
Ending Balance at Sep. 30, 2015	1,921,001	315,759	(22,017)	1,717,064	$ 105,388	578,930	1,032,690	56
Ending Balance (in shares) at Sep. 30, 2015					15,805,000
Beginning Balance at Dec. 31, 2015	$ 1,927,640	324,766	(26,262)	1,728,325	$ 105,388	578,930	1,043,082	925
Beginning Balance (in shares) at Dec. 31, 2015	107,460,406				15,805,000
Increase (decrease) in stockholders' equity
Net income for common stock	$ 203,622	203,622		108,198			108,198
Other comprehensive income, net of taxes	9,239		9,239	412				412
Common stock dividends	(100,398)	(100,398)		(70,199)			(70,199)
Common stock issuance expenses				(9)		(9)
Ending Balance at Sep. 30, 2016	$ 2,068,388	$ 427,990	$ (17,023)	$ 1,766,727	$ 105,388	$ 578,921	$ 1,081,081	$ 1,337
Ending Balance (in shares) at Sep. 30, 2016	108,503,210				15,805,000