Allowance for credit losses - Amortized cost basis of the loans modified to borrowers experiencing financial difficulties (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 759	$ 899
% of total class of Financing Receivables	0.00%	0.00%
Interest Rate Reduction | Mortgages
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 227
% of total class of Financing Receivables		0.00%
Interest Rate Reduction | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 387
% of total class of Financing Receivables	0.01%
Interest Rate Reduction | Consumer | Credit card
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 129	$ 497
% of total class of Financing Receivables	0.01%	0.05%
Interest Rate Reduction | Consumer | Personal loans
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 243	$ 172
% of total class of Financing Receivables	0.01%	0.01%
Interest Rate Reduction | Consumer | Other
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 3
% of total class of Financing Receivables		0.00%
Interest Rate Reduction | Puerto Rico
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 759	$ 899
% of total class of Financing Receivables	0.00%	0.00%
Interest Rate Reduction | Puerto Rico | Mortgages
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 227
% of total class of Financing Receivables		0.00%
Interest Rate Reduction | Puerto Rico | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 387
% of total class of Financing Receivables	0.01%
Interest Rate Reduction | Puerto Rico | Consumer | Credit card
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 129	$ 497
% of total class of Financing Receivables	0.01%	0.05%
Interest Rate Reduction | Puerto Rico | Consumer | Personal loans
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 243	$ 172
% of total class of Financing Receivables	0.01%	0.01%
Interest Rate Reduction | Puerto Rico | Consumer | Other
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 3
% of total class of Financing Receivables		0.00%
Interest Rate Reduction | Popular U.S.
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 0	$ 0
% of total class of Financing Receivables	0.00%	0.00%
Interest Rate Reduction | Popular U.S. | Mortgages
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 0
% of total class of Financing Receivables		0.00%
Interest Rate Reduction | Popular U.S. | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 0
% of total class of Financing Receivables	0.00%
Interest Rate Reduction | Popular U.S. | Consumer | Credit card
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 0	$ 0
% of total class of Financing Receivables	0.00%	0.00%
Interest Rate Reduction | Popular U.S. | Consumer | Personal loans
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 0	$ 0
% of total class of Financing Receivables	0.00%	0.00%
Interest Rate Reduction | Popular U.S. | Consumer | Other
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 0
% of total class of Financing Receivables		0.00%
Term extension
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 68,761	$ 25,431
% of total class of Financing Receivables	0.20%	0.08%
Term extension | Construction
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 3,518
% of total class of Financing Receivables		0.50%
Term extension | Mortgages
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 12,979	$ 16,374
% of total class of Financing Receivables	0.17%	0.22%
Term extension | Commercial | CRE non-owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 36,718
% of total class of Financing Receivables	0.73%
Term extension | Commercial | CRE owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 16,366	$ 1,754
% of total class of Financing Receivables	0.52%	0.06%
Term extension | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 2,494	$ 3,705
% of total class of Financing Receivables	0.04%	0.06%
Term extension | Consumer | Personal loans
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 204	$ 80
% of total class of Financing Receivables	0.01%	0.00%
Term extension | Puerto Rico
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 68,756	$ 20,006
% of total class of Financing Receivables	0.28%	0.09%
Term extension | Puerto Rico | Construction
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 0
% of total class of Financing Receivables		0.00%
Term extension | Puerto Rico | Mortgages
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 12,979	$ 14,521
% of total class of Financing Receivables	0.20%	0.24%
Term extension | Puerto Rico | Commercial | CRE non-owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 36,718
% of total class of Financing Receivables	1.23%
Term extension | Puerto Rico | Commercial | CRE owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 16,366	$ 1,754
% of total class of Financing Receivables	1.15%	0.12%
Term extension | Puerto Rico | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 2,494	$ 3,705
% of total class of Financing Receivables	0.05%	0.09%
Term extension | Puerto Rico | Consumer | Personal loans
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 199	$ 26
% of total class of Financing Receivables	0.01%	0.00%
Term extension | Popular U.S.
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 5	$ 5,425
% of total class of Financing Receivables	0.00%	0.06%
Term extension | Popular U.S. | Construction
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 3,518
% of total class of Financing Receivables		0.65%
Term extension | Popular U.S. | Mortgages
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 0	$ 1,853
% of total class of Financing Receivables	0.00%	0.14%
Term extension | Popular U.S. | Commercial | CRE non-owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 0
% of total class of Financing Receivables	0.00%
Term extension | Popular U.S. | Commercial | CRE owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 0	$ 0
% of total class of Financing Receivables	0.00%	0.00%
Term extension | Popular U.S. | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 0	$ 0
% of total class of Financing Receivables	0.00%	0.00%
Term extension | Popular U.S. | Consumer | Personal loans
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 5	$ 54
% of total class of Financing Receivables	0.00%	0.02%
Other-Than-Insignificant Payment Delays
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 16,232	$ 30,959
% of total class of Financing Receivables	0.05%	0.10%
Other-Than-Insignificant Payment Delays | Commercial | CRE non-owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 1,751
% of total class of Financing Receivables		0.04%
Other-Than-Insignificant Payment Delays | Commercial | CRE owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 10,312	$ 26,900
% of total class of Financing Receivables	0.33%	0.89%
Other-Than-Insignificant Payment Delays | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 5,920	$ 2,275
% of total class of Financing Receivables	0.08%	0.04%
Other-Than-Insignificant Payment Delays | Consumer | Other
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 33
% of total class of Financing Receivables		0.02%
Other-Than-Insignificant Payment Delays | Puerto Rico
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 16,232	$ 16,351
% of total class of Financing Receivables	0.07%	0.07%
Other-Than-Insignificant Payment Delays | Puerto Rico | Commercial | CRE non-owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 1,751
% of total class of Financing Receivables		0.06%
Other-Than-Insignificant Payment Delays | Puerto Rico | Commercial | CRE owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 10,312	$ 13,156
% of total class of Financing Receivables	0.72%	0.88%
Other-Than-Insignificant Payment Delays | Puerto Rico | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 5,920	$ 1,411
% of total class of Financing Receivables	0.12%	0.04%
Other-Than-Insignificant Payment Delays | Puerto Rico | Consumer | Other
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 33
% of total class of Financing Receivables		0.03%
Other-Than-Insignificant Payment Delays | Popular U.S.
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 0	$ 14,608
% of total class of Financing Receivables	0.00%	0.15%
Other-Than-Insignificant Payment Delays | Popular U.S. | Commercial | CRE non-owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 0
% of total class of Financing Receivables		0.00%
Other-Than-Insignificant Payment Delays | Popular U.S. | Commercial | CRE owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 0	$ 13,744
% of total class of Financing Receivables	0.00%	0.90%
Other-Than-Insignificant Payment Delays | Popular U.S. | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 0	$ 864
% of total class of Financing Receivables	0.00%	4.00%
Other-Than-Insignificant Payment Delays | Popular U.S. | Consumer | Other
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 0
% of total class of Financing Receivables		0.00%
Combination - Term Extension and Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 5,653	$ 11,353
% of total class of Financing Receivables	0.02%	0.04%
Combination - Term Extension and Interest Rate Reduction | Mortgages
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 3,460	$ 10,801
% of total class of Financing Receivables	0.04%	0.15%
Combination - Term Extension and Interest Rate Reduction | Commercial | CRE non-owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 891
% of total class of Financing Receivables	0.02%
Combination - Term Extension and Interest Rate Reduction | Commercial | CRE owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 101
% of total class of Financing Receivables		0.00%
Combination - Term Extension and Interest Rate Reduction | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 101
% of total class of Financing Receivables	0.00%
Combination - Term Extension and Interest Rate Reduction | Consumer | Personal loans
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 1,201	$ 422
% of total class of Financing Receivables	0.06%	0.02%
Combination - Term Extension and Interest Rate Reduction | Consumer | Auto Loan
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 29
% of total class of Financing Receivables		0.00%
Combination - Term Extension and Interest Rate Reduction | Puerto Rico
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 5,470	$ 11,025
% of total class of Financing Receivables	0.02%	0.05%
Combination - Term Extension and Interest Rate Reduction | Puerto Rico | Mortgages
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 3,422	$ 10,473
% of total class of Financing Receivables	0.05%	0.17%
Combination - Term Extension and Interest Rate Reduction | Puerto Rico | Commercial | CRE non-owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 891
% of total class of Financing Receivables	0.03%
Combination - Term Extension and Interest Rate Reduction | Puerto Rico | Commercial | CRE owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 101
% of total class of Financing Receivables		0.01%
Combination - Term Extension and Interest Rate Reduction | Puerto Rico | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 101
% of total class of Financing Receivables	0.00%
Combination - Term Extension and Interest Rate Reduction | Puerto Rico | Consumer | Personal loans
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 1,056	$ 422
% of total class of Financing Receivables	0.06%	0.03%
Combination - Term Extension and Interest Rate Reduction | Puerto Rico | Consumer | Auto Loan
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 29
% of total class of Financing Receivables		0.00%
Combination - Term Extension and Interest Rate Reduction | Popular U.S.
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 183	$ 328
% of total class of Financing Receivables	0.00%	0.00%
Combination - Term Extension and Interest Rate Reduction | Popular U.S. | Mortgages
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 38	$ 328
% of total class of Financing Receivables	0.00%	0.03%
Combination - Term Extension and Interest Rate Reduction | Popular U.S. | Commercial | CRE non-owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 0
% of total class of Financing Receivables	0.00%
Combination - Term Extension and Interest Rate Reduction | Popular U.S. | Commercial | CRE owner occupied
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 0
% of total class of Financing Receivables		0.00%
Combination - Term Extension and Interest Rate Reduction | Popular U.S. | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 0
% of total class of Financing Receivables	0.00%
Combination - Term Extension and Interest Rate Reduction | Popular U.S. | Consumer | Personal loans
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 145	$ 0
% of total class of Financing Receivables	0.10%	0.00%
Combination - Term Extension and Interest Rate Reduction | Popular U.S. | Consumer | Auto Loan
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis		$ 0
% of total class of Financing Receivables		0.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 331
% of total class of Financing Receivables	0.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 16
% of total class of Financing Receivables	0.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Consumer | Credit card
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 315
% of total class of Financing Receivables	0.03%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Puerto Rico
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 331
% of total class of Financing Receivables	0.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Puerto Rico | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 16
% of total class of Financing Receivables	0.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Puerto Rico | Consumer | Credit card
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 315
% of total class of Financing Receivables	0.03%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Popular U.S.
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 0
% of total class of Financing Receivables	0.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Popular U.S. | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 0
% of total class of Financing Receivables	0.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Popular U.S. | Consumer | Credit card
Financing Receivable, Modifications [Line Items]
Amortized Cost Basis	$ 0
% of total class of Financing Receivables	0.00%