Revenue from contracts with customers - Revenue streams (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Service charges on deposit accounts
Revenue From Contract With Customer Excluding Assessed Tax	$ 40,969	$ 38,147	$ 119,277	$ 111,704
BPPR
Revenue From Contract With Customer Excluding Assessed Tax	90,517	83,561	266,368	245,641
BPPR | Service charges on deposit accounts
Revenue From Contract With Customer Excluding Assessed Tax	37,245	34,869	108,344	101,824
BPPR | Debit card fees
Revenue From Contract With Customer Excluding Assessed Tax	11,459	10,723	34,110	33,543
BPPR | Insurance fees, excluding reinsurance
Revenue From Contract With Customer Excluding Assessed Tax	8,921	8,210	29,786	24,097
BPPR | Credit card fees excluding late fees and membership fees
Revenue From Contract With Customer Excluding Assessed Tax	21,901	19,029	61,579	54,513
BPPR | Sale and administration of investment products
Revenue From Contract With Customer Excluding Assessed Tax	5,714	5,696	16,705	16,071
BPPR | Trust fees
Revenue From Contract With Customer Excluding Assessed Tax	5,277	5,034	15,844	15,593
Popular U.S.
Revenue From Contract With Customer Excluding Assessed Tax	5,353	4,947	15,155	13,983
Popular U.S. | Service charges on deposit accounts
Revenue From Contract With Customer Excluding Assessed Tax	3,724	3,278	10,933	9,880
Popular U.S. | Debit card fees
Revenue From Contract With Customer Excluding Assessed Tax	260	261	813	763
Popular U.S. | Insurance fees, excluding reinsurance
Revenue From Contract With Customer Excluding Assessed Tax	1,152	1,187	2,753	2,642
Popular U.S. | Credit card fees excluding late fees and membership fees
Revenue From Contract With Customer Excluding Assessed Tax	217	221	656	698
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