Guarantees - Changes from customary respresentations and warranties related to loans sold by BPPR (Details) - Indemnification Guarantee - Banco Popular de Puerto Rico - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Guarantor Obligations [Line Items]
Balance as of beginning of period	$ 3,122	$ 3,825	$ 3,212	$ 10,837
Provision (reversal) for representations and warranties	(125)	(81)	(215)	(4,488)
Net charge-offs	0	0	0	(75)
Settlements paid	0	0	0	(2,530)
Balance as of end of period	$ 2,997	$ 3,744	$ 2,997	$ 3,744