Allowance for credit losses - Performance of loans modified (Details) $ in Thousands	Sep. 30, 2023 USD ($)
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	$ 401,259
Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	35,577
Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	5,078
Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	2,678
Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	27,821
With payment default	5,152
Without payment default	22,669
Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	365,682
Construction
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	7,478
Construction | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Construction | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Construction | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Construction | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
With payment default	0
Without payment default	0
Construction | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	7,478
Mortgages
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	77,229
Mortgages | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	30,110
Mortgages | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	4,913
Mortgages | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	2,572
Mortgages | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	22,625
With payment default	4,299
Without payment default	18,326
Mortgages | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	47,119
Commercial | CRE non-owner occupied
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	53,682
Commercial | CRE non-owner occupied | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	122
Commercial | CRE non-owner occupied | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Commercial | CRE non-owner occupied | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Commercial | CRE non-owner occupied | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	122
With payment default	0
Without payment default	122
Commercial | CRE non-owner occupied | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	53,560
Commercial | CRE owner occupied
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	213,995
Commercial | CRE owner occupied | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	2,488
Commercial | CRE owner occupied | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Commercial | CRE owner occupied | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Commercial | CRE owner occupied | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	2,488
With payment default	0
Without payment default	2,488
Commercial | CRE owner occupied | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	211,507
Commercial | Commercial and Industrial
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	45,004
Commercial | Commercial and Industrial | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	1,735
Commercial | Commercial and Industrial | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Commercial | Commercial and Industrial | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Commercial | Commercial and Industrial | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	1,735
With payment default	729
Without payment default	1,006
Commercial | Commercial and Industrial | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	43,269
Consumer | Credit card
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	1,152
Consumer | Credit card | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	334
Consumer | Credit card | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	117
Consumer | Credit card | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	87
Consumer | Credit card | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	130
With payment default	93
Without payment default	37
Consumer | Credit card | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	818
Consumer | Personal loans
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	2,622
Consumer | Personal loans | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	746
Consumer | Personal loans | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	48
Consumer | Personal loans | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	19
Consumer | Personal loans | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	679
With payment default	0
Without payment default	679
Consumer | Personal loans | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	1,876
Consumer | Auto Loan
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	63
Consumer | Auto Loan | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	11
Consumer | Auto Loan | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Consumer | Auto Loan | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Consumer | Auto Loan | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	11
With payment default	0
Without payment default	11
Consumer | Auto Loan | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	52
Consumer | Other
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	34
Consumer | Other | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	31
Consumer | Other | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Consumer | Other | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Consumer | Other | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	31
With payment default	31
Without payment default	0
Consumer | Other | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	3
Puerto Rico
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	349,052
Puerto Rico | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	35,114
Puerto Rico | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	5,078
Puerto Rico | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	2,678
Puerto Rico | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	27,358
With payment default	5,049
Without payment default	22,309
Puerto Rico | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	313,938
Puerto Rico | Construction
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	2,169
Puerto Rico | Construction | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Puerto Rico | Construction | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Puerto Rico | Construction | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Puerto Rico | Construction | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
With payment default	0
Without payment default	0
Puerto Rico | Construction | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	2,169
Puerto Rico | Mortgages
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	71,399
Puerto Rico | Mortgages | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	29,776
Puerto Rico | Mortgages | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	4,913
Puerto Rico | Mortgages | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	2,572
Puerto Rico | Mortgages | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	22,291
With payment default	4,196
Without payment default	18,095
Puerto Rico | Mortgages | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	41,623
Puerto Rico | Commercial | CRE non-owner occupied
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	53,682
Puerto Rico | Commercial | CRE non-owner occupied | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	122
Puerto Rico | Commercial | CRE non-owner occupied | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Puerto Rico | Commercial | CRE non-owner occupied | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Puerto Rico | Commercial | CRE non-owner occupied | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	122
With payment default	0
Without payment default	122
Puerto Rico | Commercial | CRE non-owner occupied | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	53,560
Puerto Rico | Commercial | CRE owner occupied
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	173,930
Puerto Rico | Commercial | CRE owner occupied | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	2,488
Puerto Rico | Commercial | CRE owner occupied | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Puerto Rico | Commercial | CRE owner occupied | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Puerto Rico | Commercial | CRE owner occupied | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	2,488
With payment default	0
Without payment default	2,488
Puerto Rico | Commercial | CRE owner occupied | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	171,442
Puerto Rico | Commercial | Commercial and Industrial
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	44,176
Puerto Rico | Commercial | Commercial and Industrial | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	1,735
Puerto Rico | Commercial | Commercial and Industrial | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Puerto Rico | Commercial | Commercial and Industrial | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Puerto Rico | Commercial | Commercial and Industrial | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	1,735
With payment default	729
Without payment default	1,006
Puerto Rico | Commercial | Commercial and Industrial | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	42,441
Puerto Rico | Consumer | Credit card
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	1,152
Puerto Rico | Consumer | Credit card | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	334
Puerto Rico | Consumer | Credit card | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	117
Puerto Rico | Consumer | Credit card | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	87
Puerto Rico | Consumer | Credit card | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	130
With payment default	93
Without payment default	37
Puerto Rico | Consumer | Credit card | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	818
Puerto Rico | Consumer | Personal loans
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	2,447
Puerto Rico | Consumer | Personal loans | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	617
Puerto Rico | Consumer | Personal loans | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	48
Puerto Rico | Consumer | Personal loans | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	19
Puerto Rico | Consumer | Personal loans | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	550
With payment default	0
Without payment default	550
Puerto Rico | Consumer | Personal loans | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	1,830
Puerto Rico | Consumer | Auto Loan
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	63
Puerto Rico | Consumer | Auto Loan | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	11
Puerto Rico | Consumer | Auto Loan | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Puerto Rico | Consumer | Auto Loan | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Puerto Rico | Consumer | Auto Loan | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	11
With payment default	0
Without payment default	11
Puerto Rico | Consumer | Auto Loan | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	52
Puerto Rico | Consumer | Other
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	34
Puerto Rico | Consumer | Other | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	31
Puerto Rico | Consumer | Other | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Puerto Rico | Consumer | Other | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Puerto Rico | Consumer | Other | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	31
With payment default	31
Without payment default	0
Puerto Rico | Consumer | Other | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	3
Popular U.S.
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	52,207
Popular U.S. | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	463
Popular U.S. | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Popular U.S. | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Popular U.S. | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	463
With payment default	103
Without payment default	360
Popular U.S. | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	51,744
Popular U.S. | Construction
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	5,309
Popular U.S. | Construction | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Popular U.S. | Construction | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Popular U.S. | Construction | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Popular U.S. | Construction | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
With payment default	0
Without payment default	0
Popular U.S. | Construction | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	5,309
Popular U.S. | Mortgages
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	5,830
Popular U.S. | Mortgages | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	334
Popular U.S. | Mortgages | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Popular U.S. | Mortgages | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Popular U.S. | Mortgages | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	334
With payment default	103
Without payment default	231
Popular U.S. | Mortgages | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	5,496
Popular U.S. | Commercial | CRE owner occupied
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	40,065
Popular U.S. | Commercial | CRE owner occupied | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Popular U.S. | Commercial | CRE owner occupied | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Popular U.S. | Commercial | CRE owner occupied | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Popular U.S. | Commercial | CRE owner occupied | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
With payment default	0
Without payment default	0
Popular U.S. | Commercial | CRE owner occupied | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	40,065
Popular U.S. | Commercial | Commercial and Industrial
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	828
Popular U.S. | Commercial | Commercial and Industrial | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Popular U.S. | Commercial | Commercial and Industrial | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Popular U.S. | Commercial | Commercial and Industrial | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Popular U.S. | Commercial | Commercial and Industrial | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
With payment default	0
Without payment default	0
Popular U.S. | Commercial | Commercial and Industrial | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	828
Popular U.S. | Consumer | Personal loans
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	175
Popular U.S. | Consumer | Personal loans | Past due
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	129
Popular U.S. | Consumer | Personal loans | Past Due 30 To 59 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Popular U.S. | Consumer | Personal loans | Past Due 60 To 89 Days
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	0
Popular U.S. | Consumer | Personal loans | Past due 90 days or more
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	129
With payment default	0
Without payment default	129
Popular U.S. | Consumer | Personal loans | Current
Financing Receivable, Modifications [Line Items]
Loan performance in the last 12 months after modification	$ 46