SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT- Statements of Income and Changes in Shareholders' Equity (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Expenses:
Depreciation of property, plant and equipment									$ 172,762	$ 160,061	$ 150,389
Interest expense									87,160	85,556	89,443
Income before income taxes									261,922	247,747	217,407
Income tax benefits									(91,712)	(84,341)	(76,859)
Net income	33,630	48,286	41,894	46,400	39,486	48,707	41,061	34,152	170,210	163,406	140,548
Hawaiian Electric Industries, Inc.
Revenues
Revenues									303	288	221
Equity in income of subsidiaries									188,534	180,359	157,883
Expenses:
Operating, administrative and general									20,921	16,063	16,191
Depreciation of property, plant and equipment									575	596	672
Taxes, other than income taxes									469	497	421
Interest expense									11,599	16,207	16,695
Income before income taxes									155,273	147,284	124,125
Income tax benefits									13,047	14,232	14,533
Net income									$ 168,320	$ 161,516	$ 138,658