Cash flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Supplemental disclosures of cash flow information
Interest paid to non-affiliates	$ 19,000	$ 20,000
Income taxes paid (including refundable credits)	4,000	1,000
Income taxes refunded (including refundable credits)	0	45,000
Supplemental disclosures of noncash activities
Common stock dividends reinvested in HEI common stock (financing)	0	6,000
Loans transferred from held for investment to held for sale (investing)	9,000	0
Common stock issued (gross) for director and executive/management compensation (financing)	9,000	6,000
Obligations to fund low income housing investments (operating)	1,000	0
AFUDC-equity (operating)	2,399	1,739
Hawaiian Electric Company, Inc. and Subsidiaries
Supplemental disclosures of cash flow information
Interest paid to non-affiliates	13,000	12,000
Income taxes paid (including refundable credits)	2,000	0
Income taxes refunded (including refundable credits)	0	20,000
Supplemental disclosures of noncash activities
AFUDC-equity (operating)	2,399	1,739
Estimated fair value of noncash contributions in aid of construction (investing)	0	1,000
Change in unpaid invoices and accruals (investing)	$ (52,000)	$ (48,000)