SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenues
Total revenues	$ 851,028	$ 886,355	$ 794,319	$ 710,633	$ 695,737	$ 694,541	$ 655,664	$ 619,040	$ 3,242,335	$ 2,664,982	$ 2,309,590
Expenses
Depreciation of property, plant and equipment									148,152	154,523	151,282
Total expenses									2,952,639	2,408,771	2,121,926
Operating income	68,170	94,490	63,661	63,375	59,242	72,631	63,631	60,707	289,696	256,211	187,664
Interest expenses									96,575	101,887	119,873
Income before income tax benefits									216,052	183,247	128,824
Income tax benefits									75,932	67,822	43,923
Net income									140,120	115,425	84,901
Hawaiian Electric Industries, Inc.
Revenues
Revenues									253	204	400
Equity in income of subsidiaries									158,722	134,470	100,896
Total revenues									158,975	134,674	101,296
Expenses
Operating, administrative and general									15,401	13,336	12,675
Depreciation of property, plant and equipment									227	320	409
Taxes, other than income taxes									409	314	337
Total expenses									16,037	13,970	13,421
Operating income									142,938	120,704	87,875
Interest expenses									22,013	19,961	18,517
Income before income tax benefits									120,925	100,743	69,358
Income tax benefits									17,305	12,792	13,653
Net income									$ 138,230	$ 113,535	$ 83,011