Basis of presentation - Basis of presentation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Revenues	$ 783,749	$ 782,232
Operating income	88,306	68,825
Interest expense, net—other than on deposit liabilities and other bank borrowings	(19,456)	(18,731)
Income before income taxes	71,073	52,039
Income taxes	24,673	17,887
Premises and equipment, net	3,908,392		3,865,514
Accumulated depreciation	(2,206,650)		(2,192,422)
Other assets	537,841		512,627
As previously filed
Revenues		784,064
Operating income		70,657
Interest expense, net—other than on deposit liabilities and other bank borrowings		(19,788)
Income before income taxes		52,814
Income taxes		18,662
Premises and equipment, net			3,858,947
Accumulated depreciation			(2,191,199)
Other assets			519,194
Difference
Revenues		(1,832)
Operating income		(1,832)
Interest expense, net—other than on deposit liabilities and other bank borrowings		1,057
Income before income taxes		(775)
Income taxes		(775)
Premises and equipment, net			6,567
Accumulated depreciation			(1,223)
Other assets			(6,567)
Hawaiian Electric Company, Inc. and Subsidiaries
Revenues	720,062	717,441
Operating income	70,666	51,121
Income taxes	21,247	13,619
Premises and equipment, net	3,835,452		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)