Note Commitments and contingencies (Legal Proceedings) - Additional Information (Detail) $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($) claims units
Hazard Insurance Commision Related Litigation
Legal Matters And Contingencies
Loss Contingency Damages Sought Value	$ 400.0
Lilliam Gonzalez Camacho v BPPR
Legal Matters And Contingencies
Loss Contingency Damages Sought Value	$ 400.0
Banco Popular de Puerto Rico
Legal Matters And Contingencies
Mortgage Related Investigation	The review found that while the mailing error extended to approximately 23,000 residential mortgage loans (approximately 50% of which are serviced by the Corporation for third parties), the number of borrowers actually harmed by the mailing error was substantially lower. This was due to, among other things, the fact that the Corporation regularly uses means other than the mail to communicate with borrowers, including email and hand delivery of written notices at our mortgage servicing centers or bank branches. Importantly, more than half of those borrowers potentially subject to such error actually closed on a loss mitigation alternative.
Banco Popular de Puerto Rico \| Lilliam Gonzalez Camacho v BPPR
Legal Matters And Contingencies
Loss Contingency Number Of Defendants \| units	20
Banco Popular de Puerto Rico \| Betteroads Asphalt and Betterecycling Corporation
Legal Matters And Contingencies
Loss Contingency Damages Sought Value	$ 900.0
Banco Popular de Puerto Rico \| Hector Robles Rodriguez v Municipio de Ceiba
Legal Matters And Contingencies
Loss Contingency Damages Sought Value	$ 30.0
Aggregate Arbitrations with Claimed Damages \| Popular Securities
Legal Matters And Contingencies
Loss Contingency Pending Claims Number \| claims	169
Loss Contingency Damages Sought Value	$ 201.0
One arbitration with Claimed damages \| Popular Securities
Legal Matters And Contingencies
Loss Contingency Pending Claims Number \| claims	1
Loss Contingency Damages Sought Value	$ 30.0
Minimum
Legal Matters And Contingencies
Loss Contingency Range Of Possible Loss Portion Not Accrued	0.0
Maximum
Legal Matters And Contingencies
Loss Contingency Range Of Possible Loss Portion Not Accrued	$ 31.5

Legal Matters And Contingencies [Line Items]

No definition available.

Name:	bpop_LegalMattersAndContingenciesLineItems
Namespace Prefix:	bpop_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Certain letters generated by the Corporation to conply with consumer financial protection vureau rules requiring written notification to borrowers who have submitted a loss mitigation application were not mailed to borrowers over a period of up to approximately three years due to a systems inferface error. The Corporation has notified applicable regulators and is conducting a review of its mortgage files to assess the scope of potential customer impact.

+ References

No definition available.

+ Details

Name:	bpop_MortgageRelatedInvestigation
Namespace Prefix:	bpop_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The value (monetary amount) of the award the plaintiff seeks in the legal matter.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14557-108349

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14435-108349

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14326-108349

+ Details

Name:	us-gaap_LossContingencyDamagesSoughtValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of defendants named in a legal action.

+ References

No definition available.

+ Details

Name:	us-gaap_LossContingencyNumberOfDefendants
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of pending claims pertaining to a loss contingency.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14435-108349

+ Details

Name:	us-gaap_LossContingencyPendingClaimsNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The difference between the maximum amount of estimated loss and the amount recorded as of the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 05
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=99385795&loc=d3e12631-108344

+ Details

Name:	us-gaap_LossContingencyRangeOfPossibleLossPortionNotAccrued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	srt_LitigationCaseAxis=bpop_HazardInsuranceCommisionRelatedLitigationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_LitigationCaseAxis=bpop_LilliamGonzalezCamachoVBpprMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=bpop_BancoPopularDePuertoRicoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_LitigationCaseAxis=bpop_BetteroadsAsphaltAndBetterecyclingCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_LitigationCaseAxis=bpop_HectorRoblesRodriguezVMunicipioDeCeibaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bpop_LossContingenciesByTypeOfCaseAxis=bpop_AggregateArbitrationsWithClaimedDamagesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=bpop_PopularSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bpop_LossContingenciesByTypeOfCaseAxis=bpop_OneArbitrationWithClaimedDamagesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: