Commitments and Contingencies Disclosure [Line Items]

No definition available.

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

- Definition

Concentration of Risk Credit Facilities with the Puerto Rico government that is outstanding.

+ References

No definition available.

+ Details

Name:	bpop_ConcentrationOfRiskCreditFacilities
Namespace Prefix:	bpop_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The Corporations exposure to municipal loans and securities was concentrated in the municipalities of San Juan, Guaynabo, Carolina and Bayamon.

+ References

No definition available.

+ Details

Name:	bpop_ExposureMunicipalLoansAndSecurities
Namespace Prefix:	bpop_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount before allowance of consumer mortgage held and guaranteed by the Puerto Rico Housing Authority.

+ References

No definition available.

+ Details

Name:	bpop_LoansAndLeasesReceivableConsumerMortgageWithPrha
Namespace Prefix:	bpop_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the sum of net gains/losses on the sale of investment securities (excluding trading account securities), other-than-temporary impairments on equity securities and gains on prepayment penalties from investment securities redeemed.

+ References

No definition available.

+ Details

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

- Definition

Maximum amount of loss due to credit risk that, based on the gross fair value of the financial instrument, the entity would incur if parties to the financial instruments that make up the concentration failed completely to perform according to the terms of the contracts and the collateral or other security, if any, for the amount due proved to be of no value to the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13537-108611

+ Details

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

- Definition

The amount of other than temporary impairment (OTTI) losses on equity securities, OTTI related to credit losses on debt securities, and OTTI losses on debt securities when the entity intends to sell the securities or it is more likely than not that the entity will be required to sell the securities before recovery of its amortized cost basis. Additionally, this item includes OTTI losses recognized during the period on investments accounted for under the cost method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 8B
-URI http://asc.fasb.org/extlink&oid=82897076&loc=SL6284393-111563

+ Details

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

- Definition

Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

+ Details

Name:	us-gaap_ValuationAllowancesAndReservesBalance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_InvestmentTypeAxis=bpop_CofinaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bpop_SaleofavailableforsalesecuritiesaxisAxis=bpop_AfssecuritiessoldmemberMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bpop_ExposureTypeAxis=bpop_PrGovernmentDirectExposureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bpop_ObligationsTypeAxis=bpop_FromMunicipalitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bpop_ExposureTypeAxis=bpop_PrGovernmentIndirectExposureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bpop_ObligationsTypeAxis=us-gaap_BondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bpop_ObligationsTypeAxis=us-gaap_CommercialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bpop_ObligationsTypeAxis=bpop_PassThroughSecuritiesBackedByFnmaAndGnmaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bpop_ExposureTypeAxis=bpop_UsvigovernmentdirectexposureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bpop_ObligationsTypeAxis=bpop_FromusvigovernmentandpubliccorporationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bpop_LoansLeasesAndFinancialInstrumentsAxis=bpop_OutstandingBalanceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

Note Commitments and contingencies (Commitments) - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commitments and Contingencies Disclosure [Line Items]
Other-than-temporary impairment on investment securities		$ 8,299	$ 209	$ 14,445
Net (loss) gain and valuation adjustments on investment securities		$ 334	1,962	$ 141
Exposure Municipal Loans And Securities		74.00%
COFINA \| AFS Securities Sold [Member]
Commitments and Contingencies Disclosure [Line Items]
Net (loss) gain and valuation adjustments on investment securities	$ 100
PR Government Direct Exposure
Commitments and Contingencies Disclosure [Line Items]
Concentration Risk Credit Risk Financial Instrument Maximum Exposure		$ 483,580	584,491
PR Government Direct Exposure \| From Municipalities
Commitments and Contingencies Disclosure [Line Items]
Concentration Risk Credit Risk Financial Instrument Maximum Exposure		483,538
PR Government Indirect Exposure
Commitments and Contingencies Disclosure [Line Items]
Concentration Of Risk Credit Facilities		386,000	406,000
PR Government Indirect Exposure \| PR Housing Bonds backed by second mortgage loans
Commitments and Contingencies Disclosure [Line Items]
Concentration Of Risk Credit Facilities		44,000	43,000
PR Government Indirect Exposure \| Commercial real estate
Commitments and Contingencies Disclosure [Line Items]
Concentration Of Risk Credit Facilities		25,000	31,000
PR Government Indirect Exposure \| Pass Through securities that have been economically defeased and refunded
Commitments and Contingencies Disclosure [Line Items]
Concentration Of Risk Credit Facilities		7,000	6,000
USVI Government Direct Exposure \| From USVI Government And Public Corporations
Commitments and Contingencies Disclosure [Line Items]
Concentration Risk Credit Risk Financial Instrument Maximum Exposure		82,000
Outstanding Balance \| PR Government Direct Exposure
Commitments and Contingencies Disclosure [Line Items]
Concentration Of Risk Credit Facilities		483,580	529,339
Outstanding Balance \| PR Government Direct Exposure \| From Municipalities
Commitments and Contingencies Disclosure [Line Items]
Concentration Of Risk Credit Facilities		483,538
Outstanding Balance \| PR Government Indirect Exposure
Commitments and Contingencies Disclosure [Line Items]
Loans and Leases Receivable, Consumer, Mortgage with PRHA		310,000	326,000
Commitments To Extend Credit
Commitments and Contingencies Disclosure [Line Items]
Reserve of potential losses associated with unfunded loan commitments		10,000	9,000
Loans \| Outstanding Balance \| PR Government Direct Exposure
Commitments and Contingencies Disclosure [Line Items]
Concentration Of Risk Credit Facilities		434,493	458,794
Loans \| Outstanding Balance \| PR Government Direct Exposure \| From Municipalities
Commitments and Contingencies Disclosure [Line Items]
Concentration Of Risk Credit Facilities		434,493
Securities Investment \| Outstanding Balance \| PR Government Direct Exposure
Commitments and Contingencies Disclosure [Line Items]
Concentration Of Risk Credit Facilities		49,087	$ 70,545
Securities Investment \| Outstanding Balance \| PR Government Direct Exposure \| From Municipalities
Commitments and Contingencies Disclosure [Line Items]
Concentration Of Risk Credit Facilities		$ 49,045