Fair value of purchased MSRs, their related valuation assumptions and sensitivity to immediate changes in those assumptions (Detail) (Residential Mortgage, Purchased Mortgage Servicing Rights M S R [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2015	Dec. 31, 2014
Residential Mortgage \| Purchased Mortgage Servicing Rights M S R [Member]
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items]
Interests Continued To Be Held By Transferor Fair Value	$ 44,964	$ 38,160
Weighted average life (in years)	0 years 0 months 4526 days	0 years 0 months 4015 days
Servicing Assets And Servicing Liabilities At Fair Value Assumptions Used To Estimate Fair Value Prepayment Speed	8.10%	9.10%
Impact on fair value of 10% adverse change	(2,504)	(1,620)
Impact on fair value of 20% adverse change	(3,863)	(2,924)
Servicing Assets And Servicing Liabilities At Fair Value Assumptions Used To Estimate Fair Value Discount Rate	10.80%	10.70%
Impact on fair value of 10% adverse change	(2,703)	(1,603)
Impact on fair value of 20% adverse change	$ (4,224)	$ (2,877)

Fair value of purchased MSRs, their related valuation assumptions and sensitivity to immediate changes in those assumptions (Detail) (Residential Mortgage, Purchased Mortgage Servicing Rights M S R [Member], USD $)
In Thousands, unless otherwise specified

3 Months Ended

12 Months Ended

Mar. 31, 2015

Dec. 31, 2014

Residential Mortgage | Purchased Mortgage Servicing Rights M S R [Member]

Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items]

Interests Continued To Be Held By Transferor Fair Value

$ 44,964us-gaap_InterestsContinuedToBeHeldByTransferorFairValue
/ us-gaap_FairValueByAssetClassAxis
= bpop_PurchasedMortgageServicingRightsMSRMember
/ us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOfAdverseChangeInAssumptionByTypeOfFinancialInstrumentAxis
= us-gaap_ResidentialMortgageMember

$ 38,160us-gaap_InterestsContinuedToBeHeldByTransferorFairValue
/ us-gaap_FairValueByAssetClassAxis
= bpop_PurchasedMortgageServicingRightsMSRMember
/ us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOfAdverseChangeInAssumptionByTypeOfFinancialInstrumentAxis
= us-gaap_ResidentialMortgageMember

Weighted average life (in years)

0 years 0 months 4526 days

0 years 0 months 4015 days

Servicing Assets And Servicing Liabilities At Fair Value Assumptions Used To Estimate Fair Value Prepayment Speed

8.10%us-gaap_ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValuePrepaymentSpeed
/ us-gaap_FairValueByAssetClassAxis
= bpop_PurchasedMortgageServicingRightsMSRMember
/ us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOfAdverseChangeInAssumptionByTypeOfFinancialInstrumentAxis
= us-gaap_ResidentialMortgageMember

9.10%us-gaap_ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValuePrepaymentSpeed
/ us-gaap_FairValueByAssetClassAxis
= bpop_PurchasedMortgageServicingRightsMSRMember
/ us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOfAdverseChangeInAssumptionByTypeOfFinancialInstrumentAxis
= us-gaap_ResidentialMortgageMember

Impact on fair value of 10% adverse change

(2,504)us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOf10PercentAdverseChangeInPrepaymentSpeed
/ us-gaap_FairValueByAssetClassAxis
= bpop_PurchasedMortgageServicingRightsMSRMember
/ us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOfAdverseChangeInAssumptionByTypeOfFinancialInstrumentAxis
= us-gaap_ResidentialMortgageMember

(1,620)us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOf10PercentAdverseChangeInPrepaymentSpeed
/ us-gaap_FairValueByAssetClassAxis
= bpop_PurchasedMortgageServicingRightsMSRMember
/ us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOfAdverseChangeInAssumptionByTypeOfFinancialInstrumentAxis
= us-gaap_ResidentialMortgageMember

Impact on fair value of 20% adverse change

(3,863)us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOf20PercentAdverseChangeInPrepaymentSpeed
/ us-gaap_FairValueByAssetClassAxis
= bpop_PurchasedMortgageServicingRightsMSRMember
/ us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOfAdverseChangeInAssumptionByTypeOfFinancialInstrumentAxis
= us-gaap_ResidentialMortgageMember

(2,924)us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOf20PercentAdverseChangeInPrepaymentSpeed
/ us-gaap_FairValueByAssetClassAxis
= bpop_PurchasedMortgageServicingRightsMSRMember
/ us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOfAdverseChangeInAssumptionByTypeOfFinancialInstrumentAxis
= us-gaap_ResidentialMortgageMember

Servicing Assets And Servicing Liabilities At Fair Value Assumptions Used To Estimate Fair Value Discount Rate

10.80%us-gaap_ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueDiscountRate
/ us-gaap_FairValueByAssetClassAxis
= bpop_PurchasedMortgageServicingRightsMSRMember
/ us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOfAdverseChangeInAssumptionByTypeOfFinancialInstrumentAxis
= us-gaap_ResidentialMortgageMember

10.70%us-gaap_ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueDiscountRate
/ us-gaap_FairValueByAssetClassAxis
= bpop_PurchasedMortgageServicingRightsMSRMember
/ us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOfAdverseChangeInAssumptionByTypeOfFinancialInstrumentAxis
= us-gaap_ResidentialMortgageMember

Impact on fair value of 10% adverse change

(2,703)us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOf10PercentAdverseChangeInDiscountRate
/ us-gaap_FairValueByAssetClassAxis
= bpop_PurchasedMortgageServicingRightsMSRMember
/ us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOfAdverseChangeInAssumptionByTypeOfFinancialInstrumentAxis
= us-gaap_ResidentialMortgageMember

(1,603)us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOf10PercentAdverseChangeInDiscountRate
/ us-gaap_FairValueByAssetClassAxis
= bpop_PurchasedMortgageServicingRightsMSRMember
/ us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOfAdverseChangeInAssumptionByTypeOfFinancialInstrumentAxis
= us-gaap_ResidentialMortgageMember

Impact on fair value of 20% adverse change

$ (4,224)us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOf20PercentAdverseChangeInDiscountRate
/ us-gaap_FairValueByAssetClassAxis
= bpop_PurchasedMortgageServicingRightsMSRMember
/ us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOfAdverseChangeInAssumptionByTypeOfFinancialInstrumentAxis
= us-gaap_ResidentialMortgageMember

$ (2,877)us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOf20PercentAdverseChangeInDiscountRate
/ us-gaap_FairValueByAssetClassAxis
= bpop_PurchasedMortgageServicingRightsMSRMember
/ us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOfAdverseChangeInAssumptionByTypeOfFinancialInstrumentAxis
= us-gaap_ResidentialMortgageMember

- Definition

The carrying amount (fair value) as of the balance sheet date of the transferor's interests in transferred financial assets (typically securitized receivables, generally not involved in the collection of principal) following transfer of significant portions of such financial instruments to other parties. Such interests could be ancillary cash flows and interest-only strips.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=13989330&loc=d3e107314-111719

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	debit
Period Type:	instant

- Definition

The hypothetical financial impact of a 10 percent adverse change of the discount rate on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=13989330&loc=d3e107314-111719

+ Details

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- Definition

The hypothetical financial impact of a 10 percent adverse change of prepayment speed on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=13989330&loc=d3e107314-111719

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- Definition

The hypothetical financial impact of a 20 percent adverse change of the discount rate on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=13989330&loc=d3e107314-111719

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- Definition

The hypothetical financial impact of a 20 percent adverse change of prepayment speed on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=13989330&loc=d3e107314-111719

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- Details

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

- Definition

Discount rate used to estimate the fair value of servicing assets and servicing liabilities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 50

-Section 50

-Paragraph 2

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=7882072&loc=d3e122596-111746

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- Definition

Estimated rate of prepayments of principal on servicing assets and servicing liabilities.

+ References

+ Details

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- Definition

Weighted average life of financial assets and financial liabilities, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

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