Bank segment (HEI only) - Credit Risk Profile by Internally Assigned Grade for Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Credit risk profile by internally assigned grade for loans
2020	$ 1,339,586
2019	590,363
2018	382,648
2017	335,784
2016	368,904
Prior	1,172,236
Revolving loans	1,093,287
Converted to term loans	62,418
Total	5,345,226	$ 5,120,664	$ 4,843,634
Consumer
Credit risk profile by internally assigned grade for loans
2020	29,546
2019	69,325
2018	38,635
2017	7,646
2016	307
Prior	348
Revolving loans	18,848
Converted to term loans	4,078
Total	168,733	257,921	266,002
Conversion of debt	2,800
Consumer | Current
Credit risk profile by internally assigned grade for loans
2020	28,818
2019	67,159
2018	37,072
2017	7,207
2016	293
Prior	348
Revolving loans	18,351
Converted to term loans	3,758
Total	163,006
Consumer | 30-59 days past due
Credit risk profile by internally assigned grade for loans
2020	406
2019	1,085
2018	727
2017	155
2016	4
Prior	0
Revolving loans	138
Converted to term loans	90
Total	2,605
Consumer | 60-89 days past due
Credit risk profile by internally assigned grade for loans
2020	191
2019	549
2018	427
2017	165
2016	3
Prior	0
Revolving loans	97
Converted to term loans	59
Total	1,491
Consumer | Greater than 90 days
Credit risk profile by internally assigned grade for loans
2020	131
2019	532
2018	409
2017	119
2016	7
Prior	0
Revolving loans	262
Converted to term loans	171
Total	1,631
Commercial
Credit risk profile by internally assigned grade for loans
2020	430,228
2019	148,663
2018	79,496
2017	40,218
2016	50,326
Prior	52,133
Revolving loans	111,534
Converted to term loans	24,150
Total	936,748	$ 670,674	$ 587,891
Conversion of debt	14,400
Pass | Commercial
Credit risk profile by internally assigned grade for loans
2020	392,088
2019	117,791
2018	75,533
2017	29,211
2016	12,520
Prior	35,770
Revolving loans	74,520
Converted to term loans	11,004
Total	748,437
Special Mention | Commercial
Credit risk profile by internally assigned grade for loans
2020	37,836
2019	23,087
2018	1,920
2017	6,990
2016	30,264
Prior	13,250
Revolving loans	31,362
Converted to term loans	11,218
Total	155,927
Substandard | Commercial
Credit risk profile by internally assigned grade for loans
2020	304
2019	7,785
2018	2,043
2017	4,017
2016	7,542
Prior	3,113
Revolving loans	5,265
Converted to term loans	1,928
Total	31,997
Doubtful | Commercial
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	387
Converted to term loans	0
Total	387
Residential 1-4 family | Real estate
Credit risk profile by internally assigned grade for loans
2020	567,282
2019	219,464
2018	111,243
2017	204,269
2016	184,888
Prior	857,093
Revolving loans	0
Converted to term loans	0
Total	2,144,239
Residential 1-4 family | Real estate | Current
Credit risk profile by internally assigned grade for loans
2020	567,282
2019	218,988
2018	111,243
2017	203,916
2016	184,888
Prior	849,788
Revolving loans	0
Converted to term loans	0
Total	2,136,105
Residential 1-4 family | Real estate | 30-59 days past due
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	2,629
Revolving loans	0
Converted to term loans	0
Total	2,629
Residential 1-4 family | Real estate | 60-89 days past due
Credit risk profile by internally assigned grade for loans
2020	0
2019	476
2018	0
2017	0
2016	0
Prior	2,314
Revolving loans	0
Converted to term loans	0
Total	2,790
Residential 1-4 family | Real estate | Greater than 90 days
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	353
2016	0
Prior	2,362
Revolving loans	0
Converted to term loans	0
Total	2,715
Home equity  line of credit
Credit risk profile by internally assigned grade for loans
Conversion of debt	11,300
Home equity  line of credit | Real estate
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	929,388
Converted to term loans	34,190
Total	963,578
Home equity  line of credit | Real estate | Current
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	927,106
Converted to term loans	33,228
Total	960,334
Home equity  line of credit | Real estate | 30-59 days past due
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	552
Converted to term loans	298
Total	850
Home equity  line of credit | Real estate | 60-89 days past due
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	267
Converted to term loans	75
Total	342
Home equity  line of credit | Real estate | Greater than 90 days
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	1,463
Converted to term loans	589
Total	2,052
Residential land | Real estate
Credit risk profile by internally assigned grade for loans
2020	8,357
2019	3,427
2018	1,598
2017	939
2016	22
Prior	1,274
Revolving loans	0
Converted to term loans	0
Total	15,617
Residential land | Real estate | Current
Credit risk profile by internally assigned grade for loans
2020	8,357
2019	3,427
2018	1,598
2017	939
2016	22
Prior	272
Revolving loans	0
Converted to term loans	0
Total	14,615
Residential land | Real estate | 30-59 days past due
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	702
Revolving loans	0
Converted to term loans	0
Total	702
Residential land | Real estate | 60-89 days past due
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	0
Converted to term loans	0
Total	0
Residential land | Real estate | Greater than 90 days
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	300
Revolving loans	0
Converted to term loans	0
Total	300
Residential construction | Real estate
Credit risk profile by internally assigned grade for loans
2020	6,919
2019	3,093
2018	385
2017	625
2016	0
Prior	0
Revolving loans	0
Converted to term loans	0
Total	11,022
Residential construction | Real estate | Current
Credit risk profile by internally assigned grade for loans
2020	6,919
2019	3,093
2018	385
2017	625
2016	0
Prior	0
Revolving loans	0
Converted to term loans	0
Total	11,022
Residential construction | Real estate | 30-59 days past due
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	0
Converted to term loans	0
Total	0
Residential construction | Real estate | 60-89 days past due
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	0
Converted to term loans	0
Total	0
Residential construction | Real estate | Greater than 90 days
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	0
Converted to term loans	0
Total	0
Commercial real estate | Real estate
Credit risk profile by internally assigned grade for loans
2020	280,864
2019	114,426
2018	124,301
2017	64,087
2016	127,799
Prior	261,388
Revolving loans	11,000
Converted to term loans	0
Total	983,865
Commercial real estate | Pass | Real estate
Credit risk profile by internally assigned grade for loans
2020	270,603
2019	63,301
2018	62,168
2017	28,432
2016	55,089
Prior	155,654
Revolving loans	11,000
Converted to term loans	0
Total	646,247
Commercial real estate | Special Mention | Real estate
Credit risk profile by internally assigned grade for loans
2020	10,261
2019	36,405
2018	57,952
2017	33,763
2016	68,287
Prior	48,094
Revolving loans	0
Converted to term loans	0
Total	254,762
Commercial real estate | Substandard | Real estate
Credit risk profile by internally assigned grade for loans
2020	0
2019	14,720
2018	4,181
2017	1,892
2016	4,423
Prior	57,640
Revolving loans	0
Converted to term loans	0
Total	82,856
Commercial real estate | Doubtful | Real estate
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	0
Converted to term loans	0
Total	0
Commercial construction | Real estate
Credit risk profile by internally assigned grade for loans
2020	16,390
2019	31,965
2018	26,990
2017	18,000
2016	5,562
Prior	0
Revolving loans	22,517
Converted to term loans	0
Total	121,424
Commercial construction | Pass | Real estate
Credit risk profile by internally assigned grade for loans
2020	14,480
2019	31,965
2018	26,990
2017	0
2016	5,562
Prior	0
Revolving loans	22,517
Converted to term loans	0
Total	101,514
Commercial construction | Special Mention | Real estate
Credit risk profile by internally assigned grade for loans
2020	1,910
2019	0
2018	0
2017	18,000
2016	0
Prior	0
Revolving loans	0
Converted to term loans	0
Total	19,910
Commercial construction | Substandard | Real estate
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	0
Converted to term loans	0
Total	0
Commercial construction | Doubtful | Real estate
Credit risk profile by internally assigned grade for loans
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	0
Converted to term loans	0
Total	$ 0