Allowance for credit losses - Amortized cost basis of the loans modified to borrowers experiencing financial difficulties (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Financing Receivable
Amortized Cost Basis		$ 34,799		$ 169,623
Mortgages
Financing Receivable
Amortized Cost Basis		30,192		96,918
Commercial | CRE non-owner occupied
Financing Receivable
Amortized Cost Basis		1,326		4,777
Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis		2,471		15,567
Consumer | Credit card
Financing Receivable
Amortized Cost Basis		154		599
Consumer | Personal loans
Financing Receivable
Amortized Cost Basis		539		2,297
Consumer | Auto Loan
Financing Receivable
Amortized Cost Basis				28
Leasing
Financing Receivable
Amortized Cost Basis		$ 0		$ 12
Interest Rate Reduction
Financing Receivable
Amortized Cost Basis	$ 142,327		$ 143,263
% of total class of Financing Receivables	0.42%		0.42%
Interest Rate Reduction | Mortgages
Financing Receivable
Amortized Cost Basis	$ 76		$ 302
% of total class of Financing Receivables	0.00%		0.00%
Interest Rate Reduction | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis	$ 141,807		$ 141,807
% of total class of Financing Receivables	4.66%		4.66%
Interest Rate Reduction | Commercial | Commercial and industrial
Financing Receivable
Amortized Cost Basis	$ 43		$ 43
% of total class of Financing Receivables	0.00%		0.00%
Interest Rate Reduction | Consumer | Credit card
Financing Receivable
Amortized Cost Basis	$ 154		$ 565
% of total class of Financing Receivables	0.01%		0.05%
Interest Rate Reduction | Consumer | Personal loans
Financing Receivable
Amortized Cost Basis	$ 247		$ 543
% of total class of Financing Receivables	0.01%		0.03%
Interest Rate Reduction | Consumer | Other
Financing Receivable
Amortized Cost Basis			$ 3
% of total class of Financing Receivables			0.00%
Interest Rate Reduction | Puerto Rico
Financing Receivable
Amortized Cost Basis	$ 142,327		$ 143,260
% of total class of Financing Receivables	0.60%		0.60%
Interest Rate Reduction | Puerto Rico | Mortgages
Financing Receivable
Amortized Cost Basis	$ 76		$ 302
% of total class of Financing Receivables	0.00%		0.00%
Interest Rate Reduction | Puerto Rico | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis	$ 141,807		$ 141,807
% of total class of Financing Receivables	10.07%		10.07%
Interest Rate Reduction | Puerto Rico | Commercial | Commercial and industrial
Financing Receivable
Amortized Cost Basis	$ 43		$ 43
% of total class of Financing Receivables	0.00%		0.00%
Interest Rate Reduction | Puerto Rico | Consumer | Credit card
Financing Receivable
Amortized Cost Basis	$ 154		$ 565
% of total class of Financing Receivables	0.01%		0.05%
Interest Rate Reduction | Puerto Rico | Consumer | Personal loans
Financing Receivable
Amortized Cost Basis	$ 247		$ 540
% of total class of Financing Receivables	0.01%		0.03%
Interest Rate Reduction | Puerto Rico | Consumer | Other
Financing Receivable
Amortized Cost Basis			$ 3
% of total class of Financing Receivables			0.00%
Interest Rate Reduction | Popular U.S.
Financing Receivable
Amortized Cost Basis	$ 0		$ 3
% of total class of Financing Receivables	0.00%		0.00%
Interest Rate Reduction | Popular U.S. | Mortgages
Financing Receivable
Amortized Cost Basis	$ 0		$ 0
% of total class of Financing Receivables	0.00%		0.00%
Interest Rate Reduction | Popular U.S. | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis	$ 0		$ 0
% of total class of Financing Receivables	0.00%		0.00%
Interest Rate Reduction | Popular U.S. | Commercial | Commercial and industrial
Financing Receivable
Amortized Cost Basis	$ 0		$ 0
% of total class of Financing Receivables	0.00%		0.00%
Interest Rate Reduction | Popular U.S. | Consumer | Credit card
Financing Receivable
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
Amortized Cost Basis	$ 0		$ 3
% of total class of Financing Receivables	0.00%		0.00%
Interest Rate Reduction | Popular U.S. | Consumer | Other
Financing Receivable
Amortized Cost Basis			$ 0
% of total class of Financing Receivables			0.00%
Term Extension
Financing Receivable
Amortized Cost Basis	$ 56,921		$ 157,752
% of total class of Financing Receivables	0.17%		0.46%
Term Extension | Construction
Financing Receivable
Amortized Cost Basis			$ 7,478
% of total class of Financing Receivables			0.81%
Term Extension | Mortgages
Financing Receivable
Amortized Cost Basis	$ 17,990		$ 47,339
% of total class of Financing Receivables	0.24%		0.62%
Term Extension | Commercial | CRE non-owner occupied
Financing Receivable
Amortized Cost Basis	$ 8,760		$ 33,059
% of total class of Financing Receivables	0.17%		0.66%
Term Extension | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis	$ 13,514		$ 30,802
% of total class of Financing Receivables	0.44%		1.01%
Term Extension | Commercial | Commercial and industrial
Financing Receivable
Amortized Cost Basis	$ 16,535		$ 38,713
% of total class of Financing Receivables	0.25%		0.59%
Term Extension | Consumer | Personal loans
Financing Receivable
Amortized Cost Basis	$ 122		$ 325
% of total class of Financing Receivables	0.01%		0.02%
Term Extension | Consumer | Auto Loan
Financing Receivable
Amortized Cost Basis			$ 36
% of total class of Financing Receivables			0.00%
Term Extension | Puerto Rico
Financing Receivable
Amortized Cost Basis	$ 45,141		$ 120,382
% of total class of Financing Receivables	0.19%		0.51%
Term Extension | Puerto Rico | Construction
Financing Receivable
Amortized Cost Basis			$ 2,169
% of total class of Financing Receivables			1.27%
Term Extension | Puerto Rico | Mortgages
Financing Receivable
Amortized Cost Basis	$ 17,057		$ 41,916
% of total class of Financing Receivables	0.27%		0.67%
Term Extension | Puerto Rico | Commercial | CRE non-owner occupied
Financing Receivable
Amortized Cost Basis	$ 8,760		$ 33,059
% of total class of Financing Receivables	0.30%		1.12%
Term Extension | Puerto Rico | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis	$ 2,667		$ 4,293
% of total class of Financing Receivables	0.19%		0.30%
Term Extension | Puerto Rico | Commercial | Commercial and industrial
Financing Receivable
Amortized Cost Basis	$ 16,535		$ 38,713
% of total class of Financing Receivables	0.38%		0.89%
Term Extension | Puerto Rico | Consumer | Personal loans
Financing Receivable
Amortized Cost Basis	$ 122		$ 196
% of total class of Financing Receivables	0.01%		0.01%
Term Extension | Puerto Rico | Consumer | Auto Loan
Financing Receivable
Amortized Cost Basis			$ 36
% of total class of Financing Receivables			0.00%
Term Extension | Popular U.S.
Financing Receivable
Amortized Cost Basis	$ 11,780		$ 37,370
% of total class of Financing Receivables	0.11%		0.36%
Term Extension | Popular U.S. | Construction
Financing Receivable
Amortized Cost Basis			$ 5,309
% of total class of Financing Receivables			0.71%
Term Extension | Popular U.S. | Mortgages
Financing Receivable
Amortized Cost Basis	$ 933		$ 5,423
% of total class of Financing Receivables	0.07%		0.42%
Term Extension | Popular U.S. | Commercial | CRE non-owner occupied
Financing Receivable
Amortized Cost Basis	$ 0		$ 0
% of total class of Financing Receivables	0.00%		0.00%
Term Extension | Popular U.S. | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis	$ 10,847		$ 26,509
% of total class of Financing Receivables	0.66%		1.62%
Term Extension | Popular U.S. | Commercial | Commercial and industrial
Financing Receivable
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
Amortized Cost Basis	$ 0		$ 129
% of total class of Financing Receivables	0.00%		0.07%
Term Extension | Popular U.S. | Consumer | Auto Loan
Financing Receivable
Amortized Cost Basis			$ 0
% of total class of Financing Receivables			0.00%
Principal Forgiveness
Financing Receivable
Amortized Cost Basis			$ 18
% of total class of Financing Receivables			0.00%
Principal Forgiveness | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis			$ 18
% of total class of Financing Receivables			0.00%
Principal Forgiveness | Puerto Rico
Financing Receivable
Amortized Cost Basis			$ 18
% of total class of Financing Receivables			0.00%
Principal Forgiveness | Puerto Rico | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis			$ 18
% of total class of Financing Receivables			0.00%
Principal Forgiveness | Popular U.S.
Financing Receivable
Amortized Cost Basis			$ 0
% of total class of Financing Receivables			0.00%
Principal Forgiveness | Popular U.S. | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis			$ 0
% of total class of Financing Receivables			0.00%
Combination - Term Extension and Interest Rate Reduction
Financing Receivable
Amortized Cost Basis	$ 42,463		$ 65,335
% of total class of Financing Receivables	0.12%		0.19%
Combination - Term Extension and Interest Rate Reduction | Mortgages
Financing Receivable
Amortized Cost Basis	$ 7,691		$ 29,451
% of total class of Financing Receivables	0.10%		0.39%
Combination - Term Extension and Interest Rate Reduction | Commercial | CRE non-owner occupied
Financing Receivable
Amortized Cost Basis	$ 18,705		$ 18,705
% of total class of Financing Receivables	0.37%		0.37%
Combination - Term Extension and Interest Rate Reduction | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis	$ 14,683		$ 14,784
% of total class of Financing Receivables	0.48%		0.49%
Combination - Term Extension and Interest Rate Reduction | Commercial | Commercial and industrial
Financing Receivable
Amortized Cost Basis	$ 558		$ 614
% of total class of Financing Receivables	0.01%		0.01%
Combination - Term Extension and Interest Rate Reduction | Consumer | Personal loans
Financing Receivable
Amortized Cost Basis	$ 826		$ 1,754
% of total class of Financing Receivables	0.04%		0.09%
Combination - Term Extension and Interest Rate Reduction | Consumer | Auto Loan
Financing Receivable
Amortized Cost Basis			$ 27
% of total class of Financing Receivables			0.00%
Combination - Term Extension and Interest Rate Reduction | Puerto Rico
Financing Receivable
Amortized Cost Basis	$ 42,452		$ 64,885
% of total class of Financing Receivables	0.18%		0.27%
Combination - Term Extension and Interest Rate Reduction | Puerto Rico | Mortgages
Financing Receivable
Amortized Cost Basis	$ 7,691		$ 29,044
% of total class of Financing Receivables	0.12%		0.46%
Combination - Term Extension and Interest Rate Reduction | Puerto Rico | Commercial | CRE non-owner occupied
Financing Receivable
Amortized Cost Basis	$ 18,705		$ 18,705
% of total class of Financing Receivables	0.63%		0.63%
Combination - Term Extension and Interest Rate Reduction | Puerto Rico | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis	$ 14,683		$ 14,784
% of total class of Financing Receivables	1.04%		1.05%
Combination - Term Extension and Interest Rate Reduction | Puerto Rico | Commercial | Commercial and industrial
Financing Receivable
Amortized Cost Basis	$ 558		$ 614
% of total class of Financing Receivables	0.01%		0.01%
Combination - Term Extension and Interest Rate Reduction | Puerto Rico | Consumer | Personal loans
Financing Receivable
Amortized Cost Basis	$ 815		$ 1,711
% of total class of Financing Receivables	0.05%		0.10%
Combination - Term Extension and Interest Rate Reduction | Puerto Rico | Consumer | Auto Loan
Financing Receivable
Amortized Cost Basis			$ 27
% of total class of Financing Receivables			0.00%
Combination - Term Extension and Interest Rate Reduction | Popular U.S.
Financing Receivable
Amortized Cost Basis	$ 11		$ 450
% of total class of Financing Receivables	0.00%		0.00%
Combination - Term Extension and Interest Rate Reduction | Popular U.S. | Mortgages
Financing Receivable
Amortized Cost Basis	$ 0		$ 407
% 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
Amortized Cost Basis	$ 0		$ 0
% of total class of Financing Receivables	0.00%		0.00%
Combination - Term Extension and Interest Rate Reduction | Popular U.S. | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis	$ 0		$ 0
% of total class of Financing Receivables	0.00%		0.00%
Combination - Term Extension and Interest Rate Reduction | Popular U.S. | Commercial | Commercial and industrial
Financing Receivable
Amortized Cost Basis	$ 0		$ 0
% of total class of Financing Receivables	0.00%		0.00%
Combination - Term Extension and Interest Rate Reduction | Popular U.S. | Consumer | Personal loans
Financing Receivable
Amortized Cost Basis	$ 11		$ 43
% of total class of Financing Receivables	0.01%		0.02%
Combination - Term Extension and Interest Rate Reduction | Popular U.S. | Consumer | Auto Loan
Financing Receivable
Amortized Cost Basis			$ 0
% of total class of Financing Receivables			0.00%
Other-Than-Insignificant Payment Delays
Financing Receivable
Amortized Cost Basis	$ 12,267		$ 33,774
% of total class of Financing Receivables	0.04%		0.10%
Other-Than-Insignificant Payment Delays | Mortgages
Financing Receivable
Amortized Cost Basis			$ 137
% of total class of Financing Receivables			0.00%
Other-Than-Insignificant Payment Delays | Commercial | CRE non-owner occupied
Financing Receivable
Amortized Cost Basis			$ 1,736
% of total class of Financing Receivables			0.03%
Other-Than-Insignificant Payment Delays | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis	$ 8,980		$ 26,389
% of total class of Financing Receivables	0.29%		0.87%
Other-Than-Insignificant Payment Delays | Commercial | Commercial and industrial
Financing Receivable
Amortized Cost Basis	$ 3,287		$ 5,481
% of total class of Financing Receivables	0.05%		0.08%
Other-Than-Insignificant Payment Delays | Consumer | Other
Financing Receivable
Amortized Cost Basis			$ 31
% of total class of Financing Receivables			0.02%
Other-Than-Insignificant Payment Delays | Puerto Rico
Financing Receivable
Amortized Cost Basis	$ 12,267		$ 19,390
% of total class of Financing Receivables	0.05%		0.08%
Other-Than-Insignificant Payment Delays | Puerto Rico | Mortgages
Financing Receivable
Amortized Cost Basis			$ 137
% of total class of Financing Receivables			0.00%
Other-Than-Insignificant Payment Delays | Puerto Rico | Commercial | CRE non-owner occupied
Financing Receivable
Amortized Cost Basis			$ 1,736
% of total class of Financing Receivables			0.06%
Other-Than-Insignificant Payment Delays | Puerto Rico | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis	$ 8,980		$ 12,833
% of total class of Financing Receivables	0.64%		0.91%
Other-Than-Insignificant Payment Delays | Puerto Rico | Commercial | Commercial and industrial
Financing Receivable
Amortized Cost Basis	$ 3,287		$ 4,653
% of total class of Financing Receivables	0.08%		0.11%
Other-Than-Insignificant Payment Delays | Puerto Rico | Consumer | Other
Financing Receivable
Amortized Cost Basis			$ 31
% of total class of Financing Receivables			0.02%
Other-Than-Insignificant Payment Delays | Popular U.S.
Financing Receivable
Amortized Cost Basis	$ 0		$ 14,384
% of total class of Financing Receivables	0.00%		0.14%
Other-Than-Insignificant Payment Delays | Popular U.S. | Mortgages
Financing Receivable
Amortized Cost Basis			$ 0
% of total class of Financing Receivables			0.00%
Other-Than-Insignificant Payment Delays | Popular U.S. | Commercial | CRE non-owner occupied
Financing Receivable
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
Amortized Cost Basis	$ 0		$ 13,556
% of total class of Financing Receivables	0.00%		0.83%
Other-Than-Insignificant Payment Delays | Popular U.S. | Commercial | Commercial and industrial
Financing Receivable
Amortized Cost Basis	$ 0		$ 828
% of total class of Financing Receivables	0.00%		0.04%
Other-Than-Insignificant Payment Delays | Popular U.S. | Consumer | Other
Financing Receivable
Amortized Cost Basis			$ 0
% of total class of Financing Receivables			0.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction
Financing Receivable
Amortized Cost Basis	$ 455		$ 922
% of total class of Financing Receivables	0.00%		0.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Commercial | CRE non-owner occupied
Financing Receivable
Amortized Cost Basis	$ 182		$ 182
% of total class of Financing Receivables	0.00%		0.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Commercial | Commercial and industrial
Financing Receivable
Amortized Cost Basis	$ 78		$ 153
% of total class of Financing Receivables	0.00%		0.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Consumer | Credit card
Financing Receivable
Amortized Cost Basis	$ 195		$ 587
% of total class of Financing Receivables	0.02%		5.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Puerto Rico
Financing Receivable
Amortized Cost Basis	$ 455		$ 922
% of total class of Financing Receivables	0.00%		0.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Puerto Rico | Commercial | CRE non-owner occupied
Financing Receivable
Amortized Cost Basis	$ 182		$ 182
% of total class of Financing Receivables	0.01%		0.01%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Puerto Rico | Commercial | Commercial and industrial
Financing Receivable
Amortized Cost Basis	$ 78		$ 153
% of total class of Financing Receivables	0.00%		0.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Puerto Rico | Consumer | Credit card
Financing Receivable
Amortized Cost Basis	$ 195		$ 587
% of total class of Financing Receivables	0.00%		5.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Popular U.S.
Financing Receivable
Amortized Cost Basis	$ 0		$ 0
% of total class of Financing Receivables	0.00%		0.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Popular U.S. | Commercial | CRE non-owner occupied
Financing Receivable
Amortized Cost Basis	$ 0		$ 0
% of total class of Financing Receivables	0.00%		0.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Popular U.S. | Commercial | Commercial and industrial
Financing Receivable
Amortized Cost Basis	$ 0		$ 0
% of total class of Financing Receivables	0.00%		0.00%
Combination - Other-Than-Insignificant Payment Delays and Interest Rate Reduction | Popular U.S. | Consumer | Credit card
Financing Receivable
Amortized Cost Basis	$ 0		$ 0
% of total class of Financing Receivables	0.00%		0.00%
Combination - Other-Than-Insignificant Payment Delays and Principal Forgiveness
Financing Receivable
Amortized Cost Basis			$ 195
% of total class of Financing Receivables			0.00%
Combination - Other-Than-Insignificant Payment Delays and Principal Forgiveness | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis			$ 195
% of total class of Financing Receivables			0.01%
Combination - Other-Than-Insignificant Payment Delays and Principal Forgiveness | Puerto Rico
Financing Receivable
Amortized Cost Basis			$ 195
% of total class of Financing Receivables			0.00%
Combination - Other-Than-Insignificant Payment Delays and Principal Forgiveness | Puerto Rico | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis			$ 195
% of total class of Financing Receivables			0.01%
Combination - Other-Than-Insignificant Payment Delays and Principal Forgiveness | Popular U.S.
Financing Receivable
Amortized Cost Basis			$ 0
% of total class of Financing Receivables			0.00%
Combination - Other-Than-Insignificant Payment Delays and Principal Forgiveness | Popular U.S. | Commercial | CRE owner occupied
Financing Receivable
Amortized Cost Basis			$ 0
% of total class of Financing Receivables			0.00%