Note Goodwill and other intangible assets (Carrying amount of goodwill by reportable segments) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Goodwill [Line Items]
Beginning Balance			$ 627,294	$ 626,388
Goodwill on acquisition			0	0
Purchase accounting adjustments			0	4,707
Goodwill impairment charge	$ 0	$ (3,801)	0	(3,801)
Ending Balance	627,294	627,294	627,294	627,294
Banco Popular de Puerto Rico
Goodwill [Line Items]
Beginning Balance			276,420	280,221
Goodwill on acquisition			0	0
Purchase accounting adjustments			0	0
Goodwill impairment charge		(3,801)	0	(3,801)
Ending Balance	276,420	276,420	276,420	276,420
Banco Popular North America
Goodwill [Line Items]
Beginning Balance			350,874	346,167
Goodwill on acquisition			0	0
Purchase accounting adjustments			0	4,707
Goodwill impairment charge		0	0	0
Ending Balance	$ 350,874	$ 350,874	$ 350,874	$ 350,874