OTHER BORROWINGS - Components of Other Borrowings (Parenthetical) (Detail) - Junior Subordinated Debt [Member] - London Interbank Offered Rate (LIBOR) [Member]	9 Months Ended
Sep. 30, 2020	Dec. 31, 2019
due June 17, 2034 [Member] \| Fbp Statutory Trust One [Member]
Subordinated Borrowing [Line Items]
Floating Interest rate on junior subordinated debentures	3.00%	4.65%
Callable step-rate notes rate	2.75%
due September 20, 2034 [Member] \| Fbp Statutory Trust Two [Member]
Subordinated Borrowing [Line Items]
Floating Interest rate on junior subordinated debentures	2.73%	4.41%
Callable step-rate notes rate	2.50%

The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant