Revenue from contracts with customers - Revenue streams (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Service charges on deposit accounts
Revenue From Contract With Customer Excluding Assessed Tax	$ 36,849	$ 40,969	$ 108,671	$ 119,277
BPPR
Revenue From Contract With Customer Excluding Assessed Tax	87,912	90,517	246,506	266,368
BPPR \| Service charges on deposit accounts
Revenue From Contract With Customer Excluding Assessed Tax	34,078	37,245	100,513	108,344
BPPR \| Debit card fees
Revenue From Contract With Customer Excluding Assessed Tax	10,865	11,459	27,717	34,110
BPPR \| Insurance fees, excluding reinsurance
Revenue From Contract With Customer Excluding Assessed Tax	9,269	8,921	25,140	29,786
BPPR \| Credit card fees excluding late fees and membership fees
Revenue From Contract With Customer Excluding Assessed Tax	23,631	21,901	60,777	61,579
BPPR \| Sale and administration of investment products
Revenue From Contract With Customer Excluding Assessed Tax	5,094	5,714	16,267	16,705
BPPR \| Trust fees
Revenue From Contract With Customer Excluding Assessed Tax	4,975	5,277	16,092	15,844
Popular U.S.
Revenue From Contract With Customer Excluding Assessed Tax	3,865	5,353	11,390	15,155
Popular U.S. \| Service charges on deposit accounts
Revenue From Contract With Customer Excluding Assessed Tax	2,771	3,724	8,158	10,933
Popular U.S. \| Debit card fees
Revenue From Contract With Customer Excluding Assessed Tax	258	260	725	813
Popular U.S. \| Insurance fees, excluding reinsurance
Revenue From Contract With Customer Excluding Assessed Tax	642	1,152	1,910	2,753
Popular U.S. \| Credit card fees excluding late fees and membership fees
Revenue From Contract With Customer Excluding Assessed Tax	194	217	597	656
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