Recalibration and updates of the enviromental factors adjustments.

No definition available.

Name:	bpop_ChangeAllowanceForLoanLossesRecalibrationAndEnhancementsOfEnviromentalFactorsAdjustments
Namespace Prefix:	bpop_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Historical loss period used to compute the base net loss rate in the determination for the general reserves of the allowance for loan losses.

+ References

No definition available.

+ Details

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

- Definition

Recent loss trend adjustment replaces the base loss rate, when these trends are higher than the respective base loss rates, up to a determined cap. The objective of this adjustment is to include information about recent increases in loss rates in a timely and prudent manner.

+ References

No definition available.

+ Details

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

- Definition

Percentage of the ALLL for our loan portfolios that utilized the recent loss trend adjustment instead of the base loss.

+ References

No definition available.

+ Details

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

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

- Definition

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554

+ Details

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

- Definition

Reflects the unfunded portion of contractual agreements to lend funds to borrowers for loans whose terms have been modified by troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18794-111554

+ Details

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

- Definition

Amount of expense related to estimated loss from loan and lease transactions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

+ Details

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

- Details

Name:	us-gaap_LiabilityForCatastropheClaimsByCatastrophicEventAxis=us-gaap_HurricaneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=bpop_MortgageConsumerPortfoliosMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=bpop_CommercialConstructionPortfoliosMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	bpop_GuaranteedByUsSponsoredEntitiesAxis=bpop_GuaranteedByUsSponsoredEntitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_LoansReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Note Allowance for loan losses (Allowance for loan losses - Additional Information) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Modifications [Line Items]
Recent Loss Trend Adjustment	12-months
Provision for Loan and Lease Losses	$ 325,424	$ 170,016	$ 241,478
Change Allowance For Loan Losses Recalibration And Updates Of The Enviromental Factors Adjustments	4,900
Hurricanes
Financing Receivable, Modifications [Line Items]
Provision for Loan and Lease Losses	67,615
Change Allowance For Loan Losses Recalibration And Updates Of The Enviromental Factors Adjustments	$ 60,000
Banco Popular North America
Financing Receivable, Modifications [Line Items]
Recent Loss Trend Adjustment Percentage	3.00%	0.11%
Non Covered Loans
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings	$ 1,258,327	$ 1,246,577
Change Allowance For Loan Losses Recalibration And Updates Of The Enviromental Factors Adjustments	$ 6,500
Non Covered Loans \| Banco Popular de Puerto Rico
Financing Receivable, Modifications [Line Items]
Recent Loss Trend Adjustment Percentage	69.00%	38.00%
Covered loans
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings	$ 5,885	$ 5,530
Provision for Loan and Lease Losses	5,742	(1,110)	$ 24,020
Change Allowance For Loan Losses Recalibration And Updates Of The Enviromental Factors Adjustments	1,600
Covered loans \| Hurricanes
Financing Receivable, Modifications [Line Items]
Provision for Loan and Lease Losses	5,800
Commercial \| Non Covered Loans
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings	$ 220,846	260,044
Mortgage and consumer
Financing Receivable, Modifications [Line Items]
Historical Loss Period	18-months
Commercial and construction
Financing Receivable, Modifications [Line Items]
Historical Loss Period	5-year
Mortgages \| Non Covered Loans
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings	$ 930,076	871,997
Mortgages \| Non Covered Loans \| Guaranteed By US Sponsored Entities
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings	449,000	407,000
Mortgages \| Covered loans
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings	5,885	5,530
Loan \| Commercial
Financing Receivable, Modifications [Line Items]
Outstanding commitments to lend additional funds to debtors owing receivables whose terms have been modified in troubled debt restructurings	$ 8,000	$ 8,000