ADVANCES FROM THE FEDERAL HOME LOAN BANK (FHLB) - Advances from FHLB Mature (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
ADVANCES FROM THE FEDERAL HOME LOAN BANK (FHLB) [Abstract]
Within one month	$ 425,000
Over one to five years	500,000
Total	$ 925,000	$ 675,000

Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank (FHLB), which are primarily used to cover shortages in the required reserve balance and liquidity shortages. The maturity period of these FHLB is withing one month of the reporting period.

No definition available.

Name:	fbp_FederalHomeLoanBankAdvancesMaturitiesDueWithinOneMonth
Namespace Prefix:	fbp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant