Classified and non-performing loans during the period. The amount consist of commercial and industrial loans, commercial mortgage and construction loans.

No definition available.

Name:	fbp_ClassifiedAndNonPerformingLoansSold
Namespace Prefix:	fbp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

LOAN PORTFOLIO - Loan Portfolio Held for Investment (Parenthetical) (Detail) (USD $)	1 Months Ended		3 Months Ended
	Jun. 21, 2013	Mar. 28, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013
Financial Information [Line Items]
Loans Transferred To Held For Sale			$ 181,600,000fbp_LoansTransferredToHeldForSale
Classified And Non Performing Loans Sold	203,800,000fbp_ClassifiedAndNonPerformingLoansSold	211,400,000fbp_ClassifiedAndNonPerformingLoansSold
CommercianLoansCollaterizedByRealEstate				$ 1,100,000,000	$ 1,200,000,000