LOANS HELD FOR INVESTMENT - Corporation's Nonaccrual Status and Loans 90 Days or More Still Accruing (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	$ 46,736
Nonaccrual Loans with ACL	158,353
Total Nonaccrual Loans	205,089	$ 210,668
Loans Past Due 90 days or more and Still Accruing	145,095	135,042
Interest Income Recognized on Nonaccrual Loans	2,029
Puerto Rico and Virgin Islands regions [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	43,591
Nonaccrual Loans with ACL	145,691
Total Nonaccrual Loans	189,282	196,383
Loans Past Due 90 days or more and Still Accruing	144,845	134,913
Interest Income Recognized on Nonaccrual Loans	1,653
Florida region [Member}
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	3,145
Nonaccrual Loans with ACL	12,662
Total Nonaccrual Loans	15,807	14,285
Loans Past Due 90 days or more and Still Accruing	250	129
Interest Income Recognized on Nonaccrual Loans	376
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	15,002
Nonaccrual Loans with ACL	110,365
Total Nonaccrual Loans	125,367	121,408
Loans Past Due 90 days or more and Still Accruing	38,834	40,208
Interest Income Recognized on Nonaccrual Loans	1,335
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member] | Puerto Rico and Virgin Islands regions [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	12,418
Nonaccrual Loans with ACL	98,527
Total Nonaccrual Loans	110,945	108,117
Loans Past Due 90 days or more and Still Accruing	38,834	40,208
Interest Income Recognized on Nonaccrual Loans	1,050
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member] | Florida region [Member}
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	2,584
Nonaccrual Loans with ACL	11,838
Total Nonaccrual Loans	14,422	13,291
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	285
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	0
Total Nonaccrual Loans	0	0
Loans Past Due 90 days or more and Still Accruing	99,243	81,140
Interest Income Recognized on Nonaccrual Loans	0
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member] | Puerto Rico and Virgin Islands regions [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	0
Total Nonaccrual Loans	0	0
Loans Past Due 90 days or more and Still Accruing	98,993	81,011
Interest Income Recognized on Nonaccrual Loans	0
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member] | Florida region [Member}
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	0
Total Nonaccrual Loans	0	0
Loans Past Due 90 days or more and Still Accruing	250	129
Interest Income Recognized on Nonaccrual Loans	0
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member}
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	15,385
Nonaccrual Loans with ACL	5,496
Total Nonaccrual Loans	20,881	18,773
Loans Past Due 90 days or more and Still Accruing	2,246	7,061
Interest Income Recognized on Nonaccrual Loans	157
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member} | Puerto Rico and Virgin Islands regions [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	14,824
Nonaccrual Loans with ACL	5,496
Total Nonaccrual Loans	20,320	18,458
Loans Past Due 90 days or more and Still Accruing	2,246	7,061
Interest Income Recognized on Nonaccrual Loans	86
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member} | Florida region [Member}
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	561
Nonaccrual Loans with ACL	0
Total Nonaccrual Loans	561	315
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	71
Commercial Portfolio Segment [Member] | Mortgage Receivable [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	11,777
Nonaccrual Loans with ACL	17,834
Total Nonaccrual Loans	29,611	40,076
Loans Past Due 90 days or more and Still Accruing	3,252	2,222
Interest Income Recognized on Nonaccrual Loans	194
Commercial Portfolio Segment [Member] | Mortgage Receivable [Member] | Puerto Rico and Virgin Islands regions [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	11,777
Nonaccrual Loans with ACL	17,834
Total Nonaccrual Loans	29,611	40,076
Loans Past Due 90 days or more and Still Accruing	3,252	2,222
Interest Income Recognized on Nonaccrual Loans	194
Commercial Portfolio Segment [Member] | Mortgage Receivable [Member] | Florida region [Member}
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	0
Total Nonaccrual Loans	0	0
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	0
Commercial Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	4,546
Nonaccrual Loans with ACL	8,425
Total Nonaccrual Loans	12,971	9,782
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	80
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Puerto Rico and Virgin Islands regions [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	4,546
Nonaccrual Loans with ACL	8,425
Total Nonaccrual Loans	12,971	9,782
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	80
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Florida region [Member}
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	0
Total Nonaccrual Loans	0	0
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	0
Consumer Portfolio Segment [Member] | Auto loans [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	26
Nonaccrual Loans with ACL	8,861
Total Nonaccrual Loans	8,887	12,220
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	176
Consumer Portfolio Segment [Member] | Auto loans [Member] | Puerto Rico and Virgin Islands regions [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	26
Nonaccrual Loans with ACL	8,638
Total Nonaccrual Loans	8,664	12,057
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	164
Consumer Portfolio Segment [Member] | Auto loans [Member] | Florida region [Member}
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	223
Total Nonaccrual Loans	223	163
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	12
Consumer Portfolio Segment [Member] | Finance Leases [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	1,466
Total Nonaccrual Loans	1,466	1,354
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	25
Consumer Portfolio Segment [Member] | Finance Leases [Member] | Puerto Rico and Virgin Islands regions [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	1,466
Total Nonaccrual Loans	1,466	1,354
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	25
Consumer Portfolio Segment [Member] | Finance Leases [Member] | Florida region [Member}
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	0
Total Nonaccrual Loans	0	0
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	0
Consumer Portfolio Segment [Member] | Personal Loans [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	1,623
Total Nonaccrual Loans	1,623	1,528
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	49
Consumer Portfolio Segment [Member] | Personal Loans [Member] | Puerto Rico and Virgin Islands regions [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	1,623
Total Nonaccrual Loans	1,623	1,523
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	49
Consumer Portfolio Segment [Member] | Personal Loans [Member] | Florida region [Member}
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	0
Total Nonaccrual Loans	0	5
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	0
Consumer Portfolio Segment [Member] | Credit Card Receivables [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	0
Total Nonaccrual Loans	0	0
Loans Past Due 90 days or more and Still Accruing	1,520	4,411
Interest Income Recognized on Nonaccrual Loans	0
Consumer Portfolio Segment [Member] | Credit Card Receivables [Member] | Puerto Rico and Virgin Islands regions [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	0
Total Nonaccrual Loans	0	0
Loans Past Due 90 days or more and Still Accruing	1,520	4,411
Interest Income Recognized on Nonaccrual Loans	0
Consumer Portfolio Segment [Member] | Credit Card Receivables [Member] | Florida region [Member}
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	0
Total Nonaccrual Loans	0	0
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	0
Consumer Portfolio Segment [Member] | Other Loans [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	4,283
Total Nonaccrual Loans	4,283	5,527
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	13
Consumer Portfolio Segment [Member] | Other Loans [Member] | Puerto Rico and Virgin Islands regions [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	3,682
Total Nonaccrual Loans	3,682	5,016
Loans Past Due 90 days or more and Still Accruing	0	0
Interest Income Recognized on Nonaccrual Loans	5
Consumer Portfolio Segment [Member] | Other Loans [Member] | Florida region [Member}
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual Loans with No ACL	0
Nonaccrual Loans with ACL	601
Total Nonaccrual Loans	601	511
Loans Past Due 90 days or more and Still Accruing	0	$ 0
Interest Income Recognized on Nonaccrual Loans	$ 8