FIRST BANCORP. (Holding Company Only) Financial Information - Statements of Financial Condition (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
ASSETS
Cash and due from banks	$ 1,203,791	$ 546,391	$ 642,440
Money market investments	97,692	97,708	97,853
Other assets	206,789	213,513
Total assets	14,096,406	12,611,266
Liabilities:
Other borrowings	184,150	184,150
Accounts payable and other liabilities	210,736	180,614
Total liabilities	11,881,572	10,383,193
Stockholders Equity	2,214,834	2,228,073	$ 2,152,976
Total liabilities and stockholders' equity	14,096,406	12,611,266
Holding Company [Member]
ASSETS
Cash and due from banks	15,558	16,895
Money market investments	6,211	6,211
Other investment securities	285	285
Other assets	803	509
Total assets	2,404,268	2,416,601
Liabilities:
Other borrowings	184,150	184,150
Accounts payable and other liabilities	5,284	4,378
Total liabilities	189,434	188,528
Stockholders Equity	2,214,834	2,228,073
Total liabilities and stockholders' equity	2,404,268	2,416,601
Holding Company [Member] | Investment in First Bank Puerto Rico, at equity [Member]
ASSETS
Equity Method Investments	2,346,208	2,362,182
Holding Company [Member] | Investment in First Bank Insurance Agency, at equity
ASSETS
Equity Method Investments	29,679	24,995
Holding Company [Member] | Fbp Statutory Trust One [Member]
ASSETS
Equity Method Investments	1,963	1,963
Holding Company [Member] | Fbp Statutory Trust Two [Member]
ASSETS
Equity Method Investments	$ 3,561	$ 3,561