Carrying amount as of the balance sheet date of obligations due all related parties. For classified balance sheets, represents the current portion of such liabilities (due within one year or within the normal operating cycle if longer).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
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Related party transactions (Details) - Affiliated Entity - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Hawaiian Electric Company, Inc. and Subsidiaries
Related Party Transaction [Line Items]
General management and administrative services from related parties	$ 0.7	$ 1.7	$ 5.2	$ 4.9
Hawaiian Electric Company, Inc. and Subsidiaries \| Short-term Borrowings
Related Party Transaction [Line Items]
Short term borrowings	21.0		21.0
American Savings Bank (ASB)
Related Party Transaction [Line Items]
General management and administrative services from related parties	0.3	0.5	1.8	1.7
Hawaii Medical Service Association (HMSA) \| HMSA costs
Related Party Transaction [Line Items]
Expenses from transactions with related party	7.0	8.0	21.0	22.0
Hawaii Medical Service Association (HMSA) \| HMSA expense
Related Party Transaction [Line Items]
Expenses from transactions with related party	5.0	6.0	15.0	16.0
Hawaii Dental Service (HDS) \| HDS costs
Related Party Transaction [Line Items]
Expenses from transactions with related party	1.0	1.0	2.0	2.0
Hawaii Dental Service (HDS) \| HDS expense
Related Party Transaction [Line Items]
Expenses from transactions with related party	1.0	1.0	2.0	2.0
Hawaiian Electric Company, Inc. and Subsidiaries \| Hawaii Medical Service Association (HMSA) \| HMSA costs
Related Party Transaction [Line Items]
Expenses from transactions with related party	5.0	6.0	17.0	17.0
Hawaiian Electric Company, Inc. and Subsidiaries \| Hawaii Medical Service Association (HMSA) \| HMSA expense
Related Party Transaction [Line Items]
Expenses from transactions with related party	3.0	4.0	10.0	11.0
Hawaiian Electric Company, Inc. and Subsidiaries \| Hawaii Dental Service (HDS) \| HDS costs
Related Party Transaction [Line Items]
Expenses from transactions with related party	1.0	1.0	2.0	2.0
Hawaiian Electric Company, Inc. and Subsidiaries \| Hawaii Dental Service (HDS) \| HDS expense
Related Party Transaction [Line Items]
Expenses from transactions with related party	$ 0.0	$ 0.0	$ 1.0	$ 1.0