Bank segment (HEI only) - Statements of Income Data (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Interest expense
Interest on deposit liabilities									$ 7,167	$ 5,348	$ 5,077
Total interest expense									88,558	88,476	87,160
Provision for loan losses									16,763	6,275	6,126
Noninterest expense
Income before income taxes									373,841	254,788	265,598
Income taxes									123,695	93,021	95,579
Net income	$ 45,107	$ 127,613	$ 44,601	$ 32,825	$ 42,793	$ 51,144	$ 35,491	$ 32,339	250,146	161,767	170,019
American Savings Bank (ASB)
Interest and dividend income
Interest and fees on loans									199,774	184,782	179,341
Interest and dividends on investment securities									19,184	15,120	11,945
Total interest and dividend income									218,958	199,902	191,286
Interest expense
Interest on deposit liabilities									7,167	5,348	5,077
Interest on other borrowings									5,588	5,978	5,731
Total interest expense									12,755	11,326	10,808
Net interest income									206,203	188,576	180,478
Provision for loan losses									16,763	6,275	6,126
Net interest income after provision for loan losses									189,440	182,301	174,352
Noninterest income
Fees from other financial services									22,384	22,211	21,747
Fee income on deposit liabilities									21,759	22,368	19,249
Fee income on other financial products									8,707	8,094	8,131
Bank-owned life insurance									4,637	4,078	3,949
Mortgage banking income									6,625	6,330	2,913
Gain on sale of investment securities									598	0	2,847
Other income, net									2,256	4,750	2,375
Total noninterest income									66,966	67,831	61,211
Noninterest expense
Compensation and employee benefits									90,117	90,518	79,885
Occupancy									16,321	16,365	17,197
Data processing									13,030	12,103	11,690
Services									11,054	10,204	10,269
Equipment									6,938	6,577	6,564
Office supplies, printing and postage									6,075	5,749	6,089
Marketing									3,489	3,463	3,999
FDIC insurance									3,543	3,274	3,261
Other expense									18,487	18,067	17,314
Total noninterest expense									169,054	166,320	156,268
Income before income taxes									87,352	83,812	79,295
Income taxes									30,073	29,082	27,994
Net income									$ 57,279	$ 54,730	$ 51,301