Segment reporting - Selected Balance Sheet information (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Segment Reporting Information [Line Items]
Assets	$ 69,736,936	$ 67,637,917	$ 70,729,675
Deposits	63,337,600	61,227,227
Puerto Rico
Segment Reporting Information [Line Items]
Assets	54,259,904	53,541,427
Loans	21,866,754	20,884,442
Deposits	52,035,227	51,138,790
Popular U.S.
Segment Reporting Information [Line Items]
Assets	14,218,288	12,718,775
Loans	11,625,969	10,643,964
Deposits	9,605,215	8,182,702
Other
Segment Reporting Information [Line Items]
Assets	1,258,744	1,377,715
Loans	541,829	554,744
Deposits	$ 1,697,158	$ 1,905,735