MONEY MARKET INVESTMENTS - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Money Market Investments [Abstract]
Cash pledged as collateral	$ 0	$ 8,800

Carrying amount as of the balance sheet date of cash and cash equivalents that have been pledged as collateral for borrowings.

No definition available.

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