SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Valuation and qualifying accounts
Reclassifications of allowance from one customer account into long term assets		$ (4,934)	$ 841
Allowance for uncollectible accounts – electric utility | Hawaiian Electric Company, Inc. and Subsidiaries
Valuation and qualifying accounts
Balance at beginning of period	$ 1,480	1,178	1,121
Charged to costs and expenses	2,106	2,474	1,810
Charged to other accounts	795	(4,099)	785
Deductions	3,004	(1,927)	2,538
Balance at end of period	1,377	1,480	1,178
Allowance for uncollectible interest – bank | Bank
Valuation and qualifying accounts
Balance at beginning of period	373	367	1,834
Charged to costs and expenses	0	0	0
Charged to other accounts	(99)	6	0
Deductions	0	0	1,467
Balance at end of period	274	373	367
Allowance for losses for loans – bank | Bank
Valuation and qualifying accounts
Balance at beginning of period	52,119	53,637	55,533
Charged to costs and expenses	23,480	14,745	10,901
Charged to other accounts	6,418	4,254	4,016
Deductions	28,662	20,517	16,813
Balance at end of period	$ 53,355	52,119	53,637
Deferred tax valuation allowance – HEI
Valuation and qualifying accounts
Balance at beginning of period		$ 0	38
Charged to costs and expenses			0
Charged to other accounts			0
Deductions			38
Balance at end of period			$ 0