Consolidated Statements of Changes in Common Stock Equity - HECO (USD $) In Thousands, except Share data, unless otherwise specified	Total	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) Hawaiian Electric Company, Inc. and Subsidiaries
Balance at Dec. 31, 2011	$ 1,528,706	$ 1,402,841	$ 94,911	$ 426,921	$ 881,041	$ (32)
Balance (in shares) at Dec. 31, 2011			14,234,000
Increase (decrease) in stockholders' equity
Net income for common stock	77,116	56,676			56,676
Other comprehensive income, net of taxes	1,861	152				152
Common stock dividends	(59,791)	(36,522)			(36,522)
Common stock issue expenses		1		1
Balance at Jun. 30, 2012	1,575,776	1,423,148	94,911	426,922	901,195	120
Balance (in shares) at Jun. 30, 2012			14,234,000
Balance at Mar. 31, 2012
Increase (decrease) in stockholders' equity
Net income for common stock	38,800	29,376
Other comprehensive income, net of taxes	1,550	75
Balance at Jun. 30, 2012	1,575,776	1,423,148	94,911
Balance (in shares) at Jun. 30, 2012			14,234,000
Balance at Dec. 31, 2012	1,593,865	1,472,136	97,788	468,045	907,273	(970)
Balance (in shares) at Dec. 31, 2012	97,928,403		14,665,000
Increase (decrease) in stockholders' equity
Net income for common stock	74,267	53,122			53,122
Other comprehensive income, net of taxes	(8,366)	35				35
Common stock dividends	(61,004)	(40,789)			(40,789)
Balance at Jun. 30, 2013	1,624,649	1,484,504	97,788	468,045	919,606	(935)
Balance (in shares) at Jun. 30, 2013	99,044,053		14,665,000
Balance at Mar. 31, 2013
Increase (decrease) in stockholders' equity
Net income for common stock	40,588	28,693
Other comprehensive income, net of taxes	(8,305)	17
Balance at Jun. 30, 2013	$ 1,624,649	$ 1,484,504	$ 97,788	$ 468,045
Balance (in shares) at Jun. 30, 2013	99,044,053		14,665,000