FAIR VALUE - Additional Information (Detail) (USD $)	Sep. 30, 2014
Debt Instrument [Line Items]
Maximum amount of interest in brokered CD sold by broker	$ 250,000

Maximum amount of cash insured by the Federal Deposit Insurance Corporation.

No definition available.

Name:	fbp_FdicMaximumInsuredAmount
Namespace Prefix:	fbp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant