LOANS HELD FOR INVESTMENT - Loan Modifications are Considered TDRs (Detail) - Entity Loan Modification Program [Member] $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) numberofcontracts	Mar. 31, 2019 USD ($) numberofcontracts
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	273	254
Pre-Modification Outstanding Recorded Investment	$ 23,683	$ 27,605
Post-Modification Outstanding Recorded Investment	$ 23,125	$ 25,459
Residential Portfolio Segment [Member] | Conventional Loan [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	32	29
Pre-Modification Outstanding Recorded Investment	$ 3,124	$ 3,178
Post-Modification Outstanding Recorded Investment	$ 2,560	$ 3,191
Commercial Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	0	1
Pre-Modification Outstanding Recorded Investment	$ 0	$ 12
Post-Modification Outstanding Recorded Investment	$ 0	$ 12
Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	3	4
Pre-Modification Outstanding Recorded Investment	$ 18,386	$ 107
Post-Modification Outstanding Recorded Investment	$ 18,386	$ 106
Commercial Portfolio Segment [Member] | Mortgage Receivable [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	2	3
Pre-Modification Outstanding Recorded Investment	$ 75	$ 22,510
Post-Modification Outstanding Recorded Investment	$ 81	$ 20,334
Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	81	62
Pre-Modification Outstanding Recorded Investment	$ 1,241	$ 947
Post-Modification Outstanding Recorded Investment	$ 1,235	$ 947
Consumer Portfolio Segment [Member] | Finance Leases [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	21	7
Pre-Modification Outstanding Recorded Investment	$ 284	$ 159
Post-Modification Outstanding Recorded Investment	$ 284	$ 159
Consumer Portfolio Segment [Member] | Personal Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	13	20
Pre-Modification Outstanding Recorded Investment	$ 113	$ 204
Post-Modification Outstanding Recorded Investment	$ 111	$ 204
Consumer Portfolio Segment [Member] | Other Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	64	99
Pre-Modification Outstanding Recorded Investment	$ 180	$ 320
Post-Modification Outstanding Recorded Investment	$ 188	$ 338
Consumer Portfolio Segment [Member] | Credit cards [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	57	29
Pre-Modification Outstanding Recorded Investment	$ 280	$ 168
Post-Modification Outstanding Recorded Investment	$ 280	$ 168
Puerto Rico and Virgin Islands regions [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	273	251
Pre-Modification Outstanding Recorded Investment	$ 23,683	$ 27,572
Post-Modification Outstanding Recorded Investment	$ 23,125	$ 25,426
Puerto Rico and Virgin Islands regions [Member] | Residential Portfolio Segment [Member] | Conventional Loan [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	32	29
Pre-Modification Outstanding Recorded Investment	$ 3,124	$ 3,178
Post-Modification Outstanding Recorded Investment	$ 2,560	$ 3,191
Puerto Rico and Virgin Islands regions [Member] | Commercial Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	0	1
Pre-Modification Outstanding Recorded Investment	$ 0	$ 12
Post-Modification Outstanding Recorded Investment	$ 0	$ 12
Puerto Rico and Virgin Islands regions [Member] | Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	3	4
Pre-Modification Outstanding Recorded Investment	$ 18,386	$ 107
Post-Modification Outstanding Recorded Investment	$ 18,386	$ 106
Puerto Rico and Virgin Islands regions [Member] | Commercial Portfolio Segment [Member] | Mortgage Receivable [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	2	3
Pre-Modification Outstanding Recorded Investment	$ 75	$ 22,510
Post-Modification Outstanding Recorded Investment	$ 81	$ 20,334
Puerto Rico and Virgin Islands regions [Member] | Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	81	59
Pre-Modification Outstanding Recorded Investment	$ 1,241	$ 914
Post-Modification Outstanding Recorded Investment	$ 1,235	$ 914
Puerto Rico and Virgin Islands regions [Member] | Consumer Portfolio Segment [Member] | Finance Leases [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	21	7
Pre-Modification Outstanding Recorded Investment	$ 284	$ 159
Post-Modification Outstanding Recorded Investment	$ 284	$ 159
Puerto Rico and Virgin Islands regions [Member] | Consumer Portfolio Segment [Member] | Personal Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	13	20
Pre-Modification Outstanding Recorded Investment	$ 113	$ 204
Post-Modification Outstanding Recorded Investment	$ 111	$ 204
Puerto Rico and Virgin Islands regions [Member] | Consumer Portfolio Segment [Member] | Other Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	64	99
Pre-Modification Outstanding Recorded Investment	$ 180	$ 320
Post-Modification Outstanding Recorded Investment	$ 188	$ 338
Puerto Rico and Virgin Islands regions [Member] | Consumer Portfolio Segment [Member] | Credit cards [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	57	29
Pre-Modification Outstanding Recorded Investment	$ 280	$ 168
Post-Modification Outstanding Recorded Investment	$ 280	$ 168
Florida region
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	0	3
Pre-Modification Outstanding Recorded Investment	$ 0	$ 33
Post-Modification Outstanding Recorded Investment	$ 0	$ 33
Florida region | Residential Portfolio Segment [Member] | Conventional Loan [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0
Florida region | Commercial Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0
Florida region | Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0
Florida region | Commercial Portfolio Segment [Member] | Mortgage Receivable [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0
Florida region | Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	0	3
Pre-Modification Outstanding Recorded Investment	$ 0	$ 33
Post-Modification Outstanding Recorded Investment	$ 0	$ 33
Florida region | Consumer Portfolio Segment [Member] | Finance Leases [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0
Florida region | Consumer Portfolio Segment [Member] | Personal Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0
Florida region | Consumer Portfolio Segment [Member] | Other Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0
Florida region | Consumer Portfolio Segment [Member] | Credit cards [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | numberofcontracts	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0