Basis of presentation - Basis of presentation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Total revenues	$ 798,657	$ 794,567	$ 1,582,406	$ 1,576,799
Operating income	82,275	80,207	170,581	149,032
Interest expense, net—other than on deposit liabilities and other bank borrowings	(20,022)	(18,442)	(39,478)	(37,173)
Income before income taxes	64,163	63,723	135,236	115,762
Income taxes	22,269	22,662	46,942	40,549
Property, plant and equipment, net of accumulated depreciation	3,980,096		3,980,096		3,865,514
Accumulated depreciation	(2,224,728)		(2,224,728)		(2,192,422)
Other assets	557,684		557,684		512,627
As previously filed
Total revenues		796,730		1,580,794
Operating income		82,370		153,027
Interest expense, net—other than on deposit liabilities and other bank borrowings		(19,613)		(39,401)
Income before income taxes		64,715		117,529
Income taxes		23,654		42,316
Property, plant and equipment, net of accumulated depreciation					3,858,947
Accumulated depreciation					(2,191,199)
Other assets					519,194
Difference
Total revenues		(2,163)		(3,995)
Operating income		(2,163)		(3,995)
Interest expense, net—other than on deposit liabilities and other bank borrowings		1,171		2,228
Income before income taxes		(992)		(1,767)
Income taxes		(992)		(1,767)
Property, plant and equipment, net of accumulated depreciation					6,567
Accumulated depreciation					(1,223)
Other assets					(6,567)
Hawaiian Electric Company, Inc. and Subsidiaries
Total revenues	738,429	728,525	1,458,491	1,445,966
Operating income	70,068	58,975	140,734	110,096
Income taxes	20,397	17,333	41,644	30,952
Property, plant and equipment, net of accumulated depreciation	3,906,664		3,906,664		3,792,329
Other assets					67,426
Hawaiian Electric Company, Inc. and Subsidiaries | As previously filed
Other assets					73,993
Hawaiian Electric Company, Inc. and Subsidiaries | Difference
Other assets					$ (6,567)