REGULATORY MATTERS, COMMITMENTS AND CONTINGENCIES (Tables)

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Corporations and its banking subsidiarys regulatory capital positions [Table Text Block]

The regulatory capital positions of the Corporation and FirstBank as of December 31, 2018 and 2017 were as follows:
	Regulatory Requirements
	Actual			For Capital Adequacy Purposes			To be Well-Capitalized-GeneralThresholds
	Amount		Ratio	Amount		Ratio	Amount		Ratio
(Dollars in thousands)
As of December 31, 2018
Total Capital (to
Risk-Weighted Assets)
First BanCorp.	$	2,118,940	24.00%	$	706,418	8.0%		N/A	N/A
FirstBank	$	2,075,894	23.51%	$	706,426	8.0%	$	883,032	10.0%
Common Equity Tier 1 Capital
(to Risk-Weighted Assets)
First BanCorp.	$	1,792,880	20.30%		397,360	4.5%		N/A	N/A
FirstBank	$	1,656,563	18.76%		397,365	4.5%		573,971	6.5%
Tier I Capital (to
Risk-Weighted Assets)
First BanCorp.	$	1,828,984	20.71%	$	529,814	6.0%		N/A	N/A
FirstBank	$	1,964,563	22.25%	$	529,819	6.0%	$	706,426	8.0%
Leverage ratio
First BanCorp.	$	1,828,984	15.37%	$	475,924	4.0%		N/A	N/A
FirstBank	$	1,964,563	16.53%	$	475,490	4.0%	$	594,362	5.0%
At December 31, 2017
Total Capital (to
Risk-Weighted Assets)
First BanCorp.	$	1,989,873	22.53%	$	706,432	8.0%		N/A	N/A
FirstBank	$	1,947,627	22.06%	$	706,218	8.0%	$	882,772	10.0%
Common Equity Tier 1 Capital
(to Risk-Weighted Assets)
First BanCorp.	$	1,674,164	18.96%	$	397,368	4.5%		N/A	N/A
FirstBank	$	1,562,431	17.70%	$	397,248	4.5%	$	573,802	6.5%
Tier I Capital (to
Risk-Weighted Assets)
First BanCorp.	$	1,675,282	18.97%	$	529,824	6.0%		N/A	N/A
FirstBank	$	1,835,445	20.79%	$	529,663	6.0%	$	706,218	8.0%
Leverage ratio
First BanCorp.	$	1,675,282	14.03%	$	477,643	4.0%		N/A	N/A
FirstBank	$	1,835,445	15.39%	$	477,056	4.0%	$	596,320	5.0%

Schedule of detail of commitments to extend credit, standby letters of credit and commitments to sell loans [Table Text Block]

The following table summarizes commitments to extend credit and standby letters of credit as of the indicated dates:
	December 31,
	2018		2017
(In thousands)
Financial instruments whose contract amounts represent credit risk:
Commitments to extend credit:
Construction undisbursed funds	$	160,905	$	77,649
Unused personal lines of credit		722,510		710,607
Commercial lines of credit		455,344		471,732
Commercial letters of credit		69,664		46,728
Standby letters of credit		2,865		2,691