Repayments related to Trouble Debt Restructuring Loans.

No definition available.

Name:	fbp_FinancingReceivableModificationsTroubledDebtRestructuringsPaidOrPartialPaid
Namespace Prefix:	fbp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

Reflects the amount of the write-down related to a troubled debt restructuring.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554

+ Details

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

- Definition

Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953550-111524

+ Details

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

- Details

Name:	us-gaap_LoanRestructuringModificationNameAxis=us-gaap_EntityLoanModificationProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

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

- Details

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

LOANS HELD FOR INVESTMENT - Corporation's TDR Activity (Parenthetical) (Detail) - TDR - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable Modifications [Line Items]
Financing Receivable Modifications Troubled Debt Restructurings Paid Or Partial Paid	$ 52,724	$ 37,992	$ 136,709
Charge-offs post modification	(17,434)	$ (11,122)	$ (10,342)
Commercial Portfolio Segment [Member] \| Mortgage Receivable [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable Modifications Troubled Debt Restructurings Paid Or Partial Paid	92,400
Residential Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Charge-offs post modification	(12,500)
Residential Portfolio Segment [Member] \| Mortgage Receivable [Member]
Financing Receivable Modifications [Line Items]
Recorded Investment	29,900
Residential Portfolio Segment [Member] \| Bulk Sale Of Nonaccrual Loans [Member]
Financing Receivable Modifications [Line Items]
Recorded Investment	$ 52,500