Segment reporting - Selected Balance Sheet information (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Segment Reporting Information [Line Items]
Assets	$ 70,936,939	$ 70,758,155	$ 67,675,759
Deposits	63,808,784	63,618,243
Puerto Rico
Segment Reporting Information [Line Items]
Assets	54,507,722	54,181,300
Loans	22,649,624	22,519,961
Deposits	51,350,879	51,282,007
Popular U.S.
Segment Reporting Information [Line Items]
Assets	15,186,839	15,343,156
Loans	11,931,955	12,006,012
Deposits	10,716,008	10,643,602
Other
Segment Reporting Information [Line Items]
Assets	1,242,378	1,233,699
Loans	542,511	543,299
Deposits	$ 1,741,897	$ 1,692,634