ADVANCES FROM THE FEDERAL HOME LOAN BANK (FHLB) - Advances from FHLB Mature (Detail) $ in Thousands	Dec. 31, 2021 USD ($)
Federal Home Loan Bank, Advances, Fixed Rate [Abstract]
Over six months to one year	$ 200,000

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 more than six months up to one year of the reporting period.

No definition available.

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