Segment reporting - Selected Balance Sheet information (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Segment Reporting Information
Total assets	$ 52,803,639	$ 52,115,324	$ 48,680,607
Deposits	44,797,176	43,758,606
Puerto Rico
Segment Reporting Information
Total assets	41,233,363	40,544,255
Loans	19,039,704	18,989,286
Deposits	35,768,869	34,664,243
Popular U.S.
Segment Reporting Information
Total assets	10,686,885	10,693,536
Loans	8,054,521	7,819,187
Deposits	7,589,707	7,664,792
Other
Segment Reporting Information
Total assets	883,391	877,533
Loans	655,902	657,603
Deposits	$ 1,438,600	$ 1,429,571