LOANS (Investment in Loans on Non-Accrual Status) (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	$ 49,139	$ 63,399
Non-accrual with no Allowance for Credit Loss	23,056	16,000
Total	72,195	79,399
Non-PCD
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	48,326	60,089
Non-accrual with no Allowance for Credit Loss	18,877	12,636
Total	67,203	72,725
PCD
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	813	3,310
Non-accrual with no Allowance for Credit Loss	4,179	3,364
Total	4,992	6,674
Commercial loans | Non-PCD
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	18,949	27,337
Non-accrual with no Allowance for Credit Loss	15,528	8,759
Total	34,477	36,096
Commercial loans | Non-PCD | Puerto Rico
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	6,446	8,113
Non-accrual with no Allowance for Credit Loss	15,528	8,759
Total	21,974	16,872
Commercial loans | Non-PCD | UNITED STATES
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	12,503	19,224
Non-accrual with no Allowance for Credit Loss	0	0
Total	12,503	19,224
Commercial loans | PCD | Puerto Rico
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	569	3,060
Non-accrual with no Allowance for Credit Loss	4,179	3,364
Total	4,748	6,424
Mortgage loans | Non-PCD
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	9,396	10,339
Non-accrual with no Allowance for Credit Loss	3,312	3,858
Total	12,708	14,197
Mortgage loans | PCD
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	244	250
Non-accrual with no Allowance for Credit Loss	0	0
Total	244	250
Consumer | Non-PCD
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	3,297	3,362
Non-accrual with no Allowance for Credit Loss	32	14
Total	3,329	3,376
Auto loans | Non-PCD
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	16,684	19,051
Non-accrual with no Allowance for Credit Loss	5	5
Total	16,689	19,056
Commercial secured by real estate: | Commercial loans | Non-PCD | Puerto Rico
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	4,789	3,553
Non-accrual with no Allowance for Credit Loss	12,865	7,929
Total	17,654	11,482
Commercial secured by real estate: | Commercial loans | PCD | Puerto Rico
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	569	3,060
Non-accrual with no Allowance for Credit Loss	3,468	2,417
Total	4,037	5,477
Other commercial and industrial | Commercial loans | Non-PCD | Puerto Rico
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	1,657	4,560
Non-accrual with no Allowance for Credit Loss	2,663	830
Total	4,320	5,390
Other commercial and industrial | Commercial loans | PCD | Puerto Rico
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	0	0
Non-accrual with no Allowance for Credit Loss	711	947
Total	711	947
Personal loans | Consumer | Non-PCD
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	2,564	2,741
Non-accrual with no Allowance for Credit Loss	32	14
Total	2,596	2,755
Credit lines | Consumer | Non-PCD
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	12	35
Non-accrual with no Allowance for Credit Loss	0	0
Total	12	35
Credit cards | Consumer | Non-PCD
Financing Receivable, Nonaccrual [Line Items]
Non-accrual with Allowance for Credit Loss	721	586
Non-accrual with no Allowance for Credit Loss	0	0
Total	$ 721	$ 586