SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT- Statements of Cash Flows (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2014	Dec. 31, 2013		Dec. 31, 2012
Cash flows from operating activities
Increase (decrease) in deferred income taxes		$ 103,916	$ 80,399	[1]	$ 90,848	[1]
Net cash provided by operating activities		325,420	361,568	[1]	278,934	[1]
Cash flows from investing activities
Capital expenditures		(364,826)	(389,438)	[1]	(370,715)	[1]
Net cash used in investing activities		(592,449)	(598,182)	[1]	(471,439)	[1]
Cash flows from financing activities
Net increase in short-term borrowings with original maturities of three months or less		13,490	21,789	[1]	14,872	[1]
Proceeds from issuance of long-term debt		125,000	286,000	[1]	457,000	[1]
Repayment of long-term debt		(111,400)	(216,000)	[1]	(375,500)	[1]
Excess tax benefits from share-based payment arrangements		277	430	[1]	61	[1]
Net proceeds from issuance of common stock		26,898	55,086	[1]	23,613	[1]
Common stock dividends		(126,458)	(98,383)	[1]	(96,202)	[1]
Net cash provided by (used in) financing activities		222,535	236,988	[1]	141,902	[1]
Net increase (decrease) in cash and cash equivalents		(44,494)	374	[1]	(50,603)	[1]
Cash and cash equivalents, January 1	[1]	220,036	219,662		270,265
Cash and cash equivalents, December 31		175,542	220,036	[1]	219,662	[1]
Issuance of common stock: Dividend reinvestment and stock purchase plan		2,461	41,692		41,295
As previously filed
Cash flows from operating activities
Increase (decrease) in deferred income taxes		59,184
Net cash provided by operating activities		301,479	327,146		234,542
Cash flows from investing activities
Capital expenditures		(339,721)	(353,879)		(325,480)
Net cash used in investing activities		(568,508)	(563,760)		(427,047)
Difference
Cash flows from operating activities
Increase (decrease) in deferred income taxes		44,732
Net cash provided by operating activities		23,941	34,422		44,392
Cash flows from investing activities
Capital expenditures		(25,105)	(35,559)		(45,235)
Net cash used in investing activities		(23,941)	(34,422)		(44,392)
Common stock
Cash flows from financing activities
Issuance of common stock: Dividend reinvestment and stock purchase plan		2,461	41,692		41,295
Hawaiian Electric Industries, Inc.
Cash flows from operating activities
Increase (decrease) in deferred income taxes		(3,269)	1,086
Changes in prepaid and accrued income taxes		3,223	(1,462)
Net cash provided by operating activities		100,794	82,274		127,118
Cash flows from investing activities
Capital expenditures		(74)	(201)		(410)
Investments in subsidiaries		(40,000)	(78,500)		(44,000)
Net cash used in investing activities		(40,074)	(78,701)		(44,410)
Cash flows from financing activities
Net increase (decrease) in notes payable to subsidiaries with original maturities of three months or less		(222)	56		(1,797)
Net increase in short-term borrowings with original maturities of three months or less		13,490	21,788		14,873
Proceeds from issuance of long-term debt		125,000	50,000		0
Repayment of long-term debt		(100,000)	(50,000)		(7,000)
Excess tax benefits from share-based payment arrangements		277	430		61
Net proceeds from issuance of common stock		26,898	55,086		23,613
Common stock dividends		(126,458)	(98,383)		(96,202)
Net cash provided by (used in) financing activities		(61,015)	(21,023)		(66,452)
Net increase (decrease) in cash and cash equivalents		(295)	(17,450)		16,256
Cash and cash equivalents, January 1		571	18,021		1,765
Cash and cash equivalents, December 31		276	571		18,021
Hawaiian Electric Industries, Inc. | As previously filed
Cash flows from operating activities
Increase (decrease) in deferred income taxes		(15,913)	15,228
Changes in prepaid and accrued income taxes		15,867	(15,604)
Hawaiian Electric Industries, Inc. | Difference
Cash flows from operating activities
Increase (decrease) in deferred income taxes		12,644	(14,142)
Changes in prepaid and accrued income taxes		(12,644)	14,142
Hawaiian Electric Industries, Inc. | Common stock
Cash flows from financing activities
Issuance of common stock: Dividend reinvestment and stock purchase plan		0	24,000		24,000
Hawaiian Electric Industries, Inc. | ASB Hawaii, Inc. | Consolidated subsidiary
Cash flows from financing activities
Accounts receivable reduction		2,400	2,300		1,800
HEI notes payable increase to ASHI		$ 2,500	$ 2,500		$ 2,500

[1] As restated - See Note 1, “Summary of significant accounting policies - Revision and restatements of previously issued financial statements.”