FIRST BANCORP. (Holding Company Only) Financial Information - Statements of Financial Condition (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
ASSETS
Cash and due from banks	$ 1,694,066	$ 2,540,376	$ 1,515,232
Money market investments	2,183	2,682	2,932
Other assets	241,013	234,143
Total assets	19,929,037	20,785,275
Liabilities:
Other borrowings	183,762	183,762
Accounts payable and other liabilities	228,770	214,852
Liabilities	18,147,935	18,683,508
Stockholders Equity	1,781,102	2,101,767	$ 2,220,425
Total liabilities and stockholders' equity	19,929,037	20,785,275
Holding Company [Member]
ASSETS
Cash and due from banks	14,985	20,751
Other investment securities	285	285
Other assets	923	366
Total assets	1,971,666	2,293,724
Liabilities:
Other borrowings	183,762	183,762
Accounts payable and other liabilities	6,802	8,195
Liabilities	190,564	191,957
Stockholders Equity	1,781,102	2,101,767
Total liabilities and stockholders' equity	1,971,666	2,293,724
Holding Company [Member] | Firstbank Puerto Rico [Member]
ASSETS
Equity Method Investments	1,926,159	2,247,289
Holding Company [Member] | FirstBank Insurance Agency
ASSETS
Equity Method Investments	23,802	19,521
Holding Company [Member] | FBP Statutory Trust I [Member]
ASSETS
Equity Method Investments	1,951	1,951
Holding Company [Member] | FBP Statutory Trust II [Member]
ASSETS
Equity Method Investments	$ 3,561	$ 3,561