Note Goodwill and other intangible assets (Carrying amount of goodwill by reportable segments) (Detail) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017
Goodwill [Line Items]
Beginning Balance	$ 627,294	$ 627,294
Goodwill on acquisition	0	0
Purchase accounting adjustments	0	0
Ending Balance	627,294	627,294
Banco Popular de Puerto Rico
Goodwill [Line Items]
Beginning Balance	276,420	276,420
Goodwill on acquisition	0	0
Purchase accounting adjustments	0	0
Goodwill impairment charge	0	0
Ending Balance	276,420	276,420
Popular Bank
Goodwill [Line Items]
Beginning Balance	350,874	350,874
Goodwill on acquisition	0	0
Purchase accounting adjustments	0	0
Goodwill impairment charge	0	0
Ending Balance	$ 350,874	$ 350,874

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Section 45
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-Publisher FASB
-Name Accounting Standards Codification
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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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