Loans - Amortized cost basis and interest income recognized on non-accrual loans (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	$ 144,321	$ 177,104
Non-accrual with allowance	217,202	262,337
Construction
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0
Non-accrual with allowance	6,578
Mortgages
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	91,119	119,098
Non-accrual with allowance	108,304	143,781
Commercial | Commercial multi-family
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	588	242
Commercial | CRE non-owner occupied
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	9,577	17,093
Non-accrual with allowance	6,487	8,023
Commercial | CRE owner occupied
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	28,340	14,165
Non-accrual with allowance	10,626	14,920
Commercial | Commercial and Industrial
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	8,504	20,227
Non-accrual with allowance	16,699	18,369
Leasing
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	294	458
Non-accrual with allowance	6,548	5,483
Consumer | Home equity lines of credit
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	4,085	4,110
Consumer | Personal loans
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	4,562	4,623
Non-accrual with allowance	16,657	15,417
Consumer | Auto Loan
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	1,662	1,177
Non-accrual with allowance	38,606	39,801
Consumer | Other
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	263	263
Non-accrual with allowance	2,024	12,191
Puerto Rico
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	139,936	170,484
Non-accrual with allowance	193,889	231,525
Puerto Rico | Construction
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0
Non-accrual with allowance	6,578
Puerto Rico | Mortgages
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	90,611	119,027
Non-accrual with allowance	96,832	123,364
Puerto Rico | Commercial | Commercial multi-family
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	184	242
Puerto Rico | Commercial | CRE non-owner occupied
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	9,577	15,639
Non-accrual with allowance	5,753	8,023
Puerto Rico | Commercial | CRE owner occupied
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	24,463	9,070
Non-accrual with allowance	10,626	14,920
Puerto Rico | Commercial | Commercial and Industrial
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	8,504	20,227
Non-accrual with allowance	13,120	14,050
Puerto Rico | Leasing
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	294	458
Non-accrual with allowance	6,548	5,483
Puerto Rico | Consumer | Home equity lines of credit
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	0	0
Puerto Rico | Consumer | Personal loans
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	4,562	4,623
Non-accrual with allowance	14,020	13,459
Puerto Rico | Consumer | Auto Loan
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	1,662	1,177
Non-accrual with allowance	38,606	39,801
Puerto Rico | Consumer | Other
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	263	263
Non-accrual with allowance	1,622	12,183
Popular U.S.
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	4,385	6,620
Non-accrual with allowance	23,313	30,812
Popular U.S. | Construction
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0
Non-accrual with allowance	0
Popular U.S. | Mortgages
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	508	71
Non-accrual with allowance	11,472	20,417
Popular U.S. | Commercial | Commercial multi-family
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	404	0
Popular U.S. | Commercial | CRE non-owner occupied
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	1,454
Non-accrual with allowance	734	0
Popular U.S. | Commercial | CRE owner occupied
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	3,877	5,095
Non-accrual with allowance	0	0
Popular U.S. | Commercial | Commercial and Industrial
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	3,579	4,319
Popular U.S. | Leasing
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	0	0
Popular U.S. | Consumer | Home equity lines of credit
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	4,085	4,110
Popular U.S. | Consumer | Personal loans
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	2,637	1,958
Popular U.S. | Consumer | Auto Loan
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	0	0
Popular U.S. | Consumer | Other
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	$ 402	$ 8