Note Transfers of financial assets and servicing assets (Quantitative and qualitative information) (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Commercial
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Total principal amount of loans, net of unearned	$ 12,043,019	$ 11,488,861
Principal amount 60 days or more past due	290,759	305,281
Net credit losses (recoveries)	85,715	56,552
Construction
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Total principal amount of loans, net of unearned	779,449	880,029
Principal amount 60 days or more past due	13,848	170
Net credit losses (recoveries)	4,452	(2,630)
Legacy
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Total principal amount of loans, net of unearned	25,949	32,980
Principal amount 60 days or more past due	3,072	3,456
Net credit losses (recoveries)	(2,032)	(1,730)
Leasing
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Total principal amount of loans, net of unearned	934,773	809,990
Principal amount 60 days or more past due	5,140	4,464
Net credit losses (recoveries)	6,030	6,770
Mortgages
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Total principal amount of loans, net of unearned	8,620,667	8,891,107
Principal amount 60 days or more past due	1,315,384	2,193,772
Net credit losses (recoveries)	66,209	76,235
Consumer
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Total principal amount of loans, net of unearned	5,489,441	3,810,527
Principal amount 60 days or more past due	117,775	101,666
Net credit losses (recoveries)	122,170	105,655
Loans Securitized Sold
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Total principal amount of loans, net of unearned	1,333,987	1,488,305
Principal amount 60 days or more past due	129,443	497,304
Net credit losses (recoveries)	394	1,051
Loans Held-for-Sale
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Total principal amount of loans, net of unearned	51,422	132,395
Principal amount 60 days or more past due	0	872
Net credit losses (recoveries)	0	0
Loans Held In Portfolio
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Total principal amount of loans, net of unearned	26,507,889	24,810,068
Principal amount 60 days or more past due	1,616,535	2,176,239
Net credit losses (recoveries)	$ 282,150	242,649
Covered Under Loss Sharing Agreements With F D I C [Member]
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Total principal amount of loans, net of unearned		517,274
Principal amount 60 days or more past due		65,606
Net credit losses (recoveries)		$ 2,848

This is the sum of charge-offs (credit losses) on loans managed or securitized during the period.

No definition available.

Name:	bpop_NetCreditLossesDuringPeriodOnLoansManagedAndSecuritized
Namespace Prefix:	bpop_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This is the principal amount of loans (across all types of loans) that are overdue in payment by a set number of days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (e)(4)
-URI http://asc.fasb.org/extlink&oid=109247956&loc=d3e107314-111719

+ Details

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

- Definition

This is the sum of principal amount outstanding for both securitized and unsecuritized loans of all types.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109247956&loc=d3e107314-111719

+ Details

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

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_QualitativeAndQuantitativeInformationTransferorsContinuingInvolvementLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_ConstructionLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=bpop_LegacyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_FinanceLeasesPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_MortgageReceivablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=bpop_LoansSecuritizedSoldMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=bpop_LoansHeldForSaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=bpop_LoansHeldInPortfolioMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bpop_BankingAgenciesAxis=bpop_CoveredUnderLossSharingAgreementsWithFDICMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: