Revenue from contracts with customers - Revenue streams (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Service charges on deposit accounts
Revenue From Contract With Customer Excluding Assessed Tax	$ 41,312	$ 36,849	$ 121,085	$ 108,671
BPPR
Revenue From Contract With Customer Excluding Assessed Tax	102,745	87,912	297,550	246,506
BPPR | Service charges on deposit accounts
Revenue From Contract With Customer Excluding Assessed Tax	38,496	34,078	112,732	100,513
BPPR | Debit card fees
Revenue From Contract With Customer Excluding Assessed Tax	11,967	10,865	35,522	27,717
BPPR | Insurance fees, excluding reinsurance
Revenue From Contract With Customer Excluding Assessed Tax	9,416	9,269	27,489	25,140
BPPR | Credit card fees excluding late fees and membership fees
Revenue From Contract With Customer Excluding Assessed Tax	30,076	23,631	85,203	60,777
BPPR | Sale and administration of investment products
Revenue From Contract With Customer Excluding Assessed Tax	6,216	5,094	17,726	16,267
BPPR | Trust fees
Revenue From Contract With Customer Excluding Assessed Tax	6,574	4,975	18,878	16,092
Popular U.S.
Revenue From Contract With Customer Excluding Assessed Tax	4,387	3,865	12,347	11,390
Popular U.S. | Service charges on deposit accounts
Revenue From Contract With Customer Excluding Assessed Tax	2,816	2,771	8,353	8,158
Popular U.S. | Debit card fees
Revenue From Contract With Customer Excluding Assessed Tax	243	258	723	725
Popular U.S. | Insurance fees, excluding reinsurance
Revenue From Contract With Customer Excluding Assessed Tax	1,054	642	2,483	1,910
Popular U.S. | Credit card fees excluding late fees and membership fees
Revenue From Contract With Customer Excluding Assessed Tax	274	194	788	597
Popular U.S. | Sale and administration of investment products
Revenue From Contract With Customer Excluding Assessed Tax	0	0	0	0
Popular U.S. | Trust fees
Revenue From Contract With Customer Excluding Assessed Tax	$ 0	$ 0	$ 0	$ 0