Income taxes Deferred Tax Assets and Liabilities Due to Book/Tax Differences (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets
Net operating loss	$ 0	$ 0
Other	64,870	56,526
Total deferred tax assets	64,870	56,526
Deferred tax liabilities
Property, plant and equipment	492,441	448,723
Repairs deduction	104,081	86,408
Regulatory assets, excluding amounts attributable to property, plant and equipment	34,261	33,795
Deferred RAM and RBA revenues	26,400	32,889
Retirement benefits	42,006	25,336
Other	46,558	62,945
Total deferred tax liabilities	745,747	690,096
Total deferred tax liabilities	680,877	633,570
Hawaiian Electric Company, Inc. and Subsidiaries
Deferred tax assets
Net operating loss	37,283	51,936
Other	20,238	17,663
Total deferred tax assets	57,521	69,599
Deferred tax liabilities
Property, plant and equipment	489,884	446,259
Repairs deduction	104,081	86,408
Regulatory assets, excluding amounts attributable to property, plant and equipment	34,261	33,795
Deferred RAM and RBA revenues	26,400	32,889
Retirement benefits	44,991	28,758
Other	12,710	14,929
Total deferred tax liabilities	712,327	643,038
Total deferred tax liabilities	$ 654,806	$ 573,439