Bank segment - Income statement data (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Interest expense
Provision for credit losses	$ (3,763)	$ (7,035)
Noninterest income
Noninterest income	700,831	541,300
Noninterest expense
Income before income taxes	87,480	80,196
Income taxes	17,840	15,365
Net income attributable to Hawaiian Electric	69,640	64,831
Other comprehensive (loss) income, net of taxes/benefits	(117,159)	(44,016)
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	(47,992)	20,342
American Savings Bank (ASB)
Interest and dividend income
Interest and fees on loans	46,005	49,947
Interest and dividends on investment securities	13,984	8,673
Total interest and dividend income	59,989	58,620
Interest expense
Interest on deposit liabilities	947	1,462
Interest on other borrowings	5	27
Total interest expense	952	1,489
Net interest income	59,037	57,131
Provision for credit losses	(3,263)	(8,435)
Net interest income after provision for credit losses	62,300	65,566
Noninterest income
Gain on sale of real estate	1,002	0
Total noninterest income	16,128	19,039
Noninterest expense
Compensation and employee benefits	27,215	28,037
Occupancy	5,952	4,969
Data processing	4,151	4,351
Services	2,439	2,862
Equipment	2,329	2,222
Office supplies, printing and postage	1,060	1,044
Marketing	1,018	648
FDIC insurance	808	816
Other expense	3,241	2,554
Total noninterest expense	48,213	47,503
Income before income taxes	30,215	37,102
Income taxes	6,345	7,546
Net income attributable to Hawaiian Electric	23,870	29,556
Other comprehensive (loss) income, net of taxes/benefits	(122,441)	(45,754)
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	(98,571)	(16,198)
American Savings Bank (ASB) | Fees from other financial services
Noninterest income
Noninterest income	5,587	5,073
American Savings Bank (ASB) | Fee income on deposit liabilities
Noninterest income
Noninterest income	4,691	3,863
American Savings Bank (ASB) | Fee income on other financial products
Noninterest income
Noninterest income	2,718	2,442
American Savings Bank (ASB) | Bank-owned life insurance
Noninterest income
Noninterest income	681	2,561
American Savings Bank (ASB) | Mortgage banking income
Noninterest income
Noninterest income	1,077	4,300
American Savings Bank (ASB) | Gain on sale of investment securities, net
Noninterest income
Noninterest income	0	528
American Savings Bank (ASB) | Other income, net
Noninterest income
Noninterest income	$ 372	$ 272