LOANS HELD FOR INVESTMENT - Corporation's Residential Mortgage Loans By Origination Year Based on Accrual Status (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment	$ 11,577,985		$ 11,552,825
Financing Receivable, Allowance for Credit Loss, Writeoff	17,917	$ 12,715
Puerto Rico and Virgin Islands regions [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment	9,598,623		9,464,474
Florida region [Member}
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment	1,979,362		2,088,351
Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	38,091
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	253,914
Financing Receivable, Originated Two Years before Latest Fiscal Year	124,166
Financing Receivable, Originated Three Years before Latest Fiscal Year	63,419
Financing Receivable, Originated Four Years before Latest Fiscal Year	78,930
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	2,253,008
Financing Receivable, Revolving	0
Loans held for investment	2,811,528		2,847,290
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	0
Financing Receivable, Year Two, Originated, Fiscal Year Before Current Fiscal Year, Writeoff	0
Financing Receivable, Year Three, Originated, Two Years Before Current Fiscal Year, Writeoff	0
Financing Receivable, Year Four, Originated, Three Years Before Current Fiscal Year, Writeoff	3
Financing Receivable, Year Five, Originated, Four Years Before Current Fiscal Year, Writeoff	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff	980
Financing Receivable, Revolving, Writeoff	0
Financing Receivable, Allowance for Credit Loss, Writeoff	983	$ 2,528
Residential Portfolio Segment [Member] | Performing Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	38,091
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	253,914
Financing Receivable, Originated Two Years before Latest Fiscal Year	124,131
Financing Receivable, Originated Three Years before Latest Fiscal Year	63,419
Financing Receivable, Originated Four Years before Latest Fiscal Year	78,665
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	2,216,898
Financing Receivable, Revolving	0
Loans held for investment	2,775,118		2,804,518
Residential Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	35
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	265
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	36,110
Financing Receivable, Revolving	0
Loans held for investment	36,410		42,772
Residential Portfolio Segment [Member] | Puerto Rico and Virgin Islands regions [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	24,859
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	172,295
Financing Receivable, Originated Two Years before Latest Fiscal Year	75,175
Financing Receivable, Originated Three Years before Latest Fiscal Year	32,262
Financing Receivable, Originated Four Years before Latest Fiscal Year	49,262
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	2,027,929
Financing Receivable, Revolving	0
Loans held for investment	2,381,782		2,417,900
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	0
Financing Receivable, Year Two, Originated, Fiscal Year Before Current Fiscal Year, Writeoff	0
Financing Receivable, Year Three, Originated, Two Years Before Current Fiscal Year, Writeoff	0
Financing Receivable, Year Four, Originated, Three Years Before Current Fiscal Year, Writeoff	3
Financing Receivable, Year Five, Originated, Four Years Before Current Fiscal Year, Writeoff	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff	980
Financing Receivable, Revolving, Writeoff	0
Financing Receivable, Allowance for Credit Loss, Writeoff	983
Residential Portfolio Segment [Member] | Puerto Rico and Virgin Islands regions [Member] | Performing Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	24,859
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	172,295
Financing Receivable, Originated Two Years before Latest Fiscal Year	75,140
Financing Receivable, Originated Three Years before Latest Fiscal Year	32,262
Financing Receivable, Originated Four Years before Latest Fiscal Year	49,262
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,998,971
Financing Receivable, Revolving	0
Loans held for investment	2,352,789		2,382,429
Residential Portfolio Segment [Member] | Puerto Rico and Virgin Islands regions [Member] | Nonperforming Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	35
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	28,958
Financing Receivable, Revolving	0
Loans held for investment	28,993		35,471
Residential Portfolio Segment [Member] | Florida region [Member}
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	13,232
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	81,619
Financing Receivable, Originated Two Years before Latest Fiscal Year	48,991
Financing Receivable, Originated Three Years before Latest Fiscal Year	31,157
Financing Receivable, Originated Four Years before Latest Fiscal Year	29,668
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	225,079
Financing Receivable, Revolving	0
Loans held for investment	429,746		429,390
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	0
Financing Receivable, Year Two, Originated, Fiscal Year Before Current Fiscal Year, Writeoff	0
Financing Receivable, Year Three, Originated, Two Years Before Current Fiscal Year, Writeoff	0
Financing Receivable, Year Four, Originated, Three Years Before Current Fiscal Year, Writeoff	0
Financing Receivable, Year Five, Originated, Four Years Before Current Fiscal Year, Writeoff	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff	0
Financing Receivable, Revolving, Writeoff	0
Financing Receivable, Allowance for Credit Loss, Writeoff	0
Residential Portfolio Segment [Member] | Florida region [Member} | Performing Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	13,232
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	81,619
Financing Receivable, Originated Two Years before Latest Fiscal Year	48,991
Financing Receivable, Originated Three Years before Latest Fiscal Year	31,157
Financing Receivable, Originated Four Years before Latest Fiscal Year	29,403
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	217,927
Financing Receivable, Revolving	0
Loans held for investment	422,329		422,089
Residential Portfolio Segment [Member] | Florida region [Member} | Nonperforming Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	265
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	7,152
Financing Receivable, Revolving	0
Loans held for investment	7,417		7,301
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	696
Financing Receivable, Originated Two Years before Latest Fiscal Year	448
Financing Receivable, Originated Three Years before Latest Fiscal Year	765
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,557
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	108,103
Financing Receivable, Revolving	0
Loans held for investment	111,569		118,158
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member] | Performing Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	696
Financing Receivable, Originated Two Years before Latest Fiscal Year	448
Financing Receivable, Originated Three Years before Latest Fiscal Year	765
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,557
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	108,103
Financing Receivable, Revolving	0
Loans held for investment	111,569		118,158
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member] | Nonperforming Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans held for investment	0		0
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member] | Puerto Rico and Virgin Islands regions [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	696
Financing Receivable, Originated Two Years before Latest Fiscal Year	448
Financing Receivable, Originated Three Years before Latest Fiscal Year	765
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,557
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	107,368
Financing Receivable, Revolving	0
Loans held for investment	110,834		117,416
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member] | Puerto Rico and Virgin Islands regions [Member] | Performing Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	696
Financing Receivable, Originated Two Years before Latest Fiscal Year	448
Financing Receivable, Originated Three Years before Latest Fiscal Year	765
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,557
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	107,368
Financing Receivable, Revolving	0
Loans held for investment	110,834		117,416
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member] | Puerto Rico and Virgin Islands regions [Member] | Nonperforming Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans held for investment	0		0
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member] | Florida region [Member}
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	735
Financing Receivable, Revolving	0
Loans held for investment	735		742
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member] | Florida region [Member} | Performing Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	735
Financing Receivable, Revolving	0
Loans held for investment	735		742
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member] | Florida region [Member} | Nonperforming Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans held for investment	0		0
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	38,091
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	253,218
Financing Receivable, Originated Two Years before Latest Fiscal Year	123,718
Financing Receivable, Originated Three Years before Latest Fiscal Year	62,654
Financing Receivable, Originated Four Years before Latest Fiscal Year	77,373
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	2,144,905
Financing Receivable, Revolving	0
Loans held for investment	2,699,959		2,729,132
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member] | Performing Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	38,091
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	253,218
Financing Receivable, Originated Two Years before Latest Fiscal Year	123,683
Financing Receivable, Originated Three Years before Latest Fiscal Year	62,654
Financing Receivable, Originated Four Years before Latest Fiscal Year	77,108
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	2,108,795
Financing Receivable, Revolving	0
Loans held for investment	2,663,549		2,686,360
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member] | Nonperforming Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	35
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	265
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	36,110
Financing Receivable, Revolving	0
Loans held for investment	36,410		42,772
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member] | Puerto Rico and Virgin Islands regions [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	24,859
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	171,599
Financing Receivable, Originated Two Years before Latest Fiscal Year	74,727
Financing Receivable, Originated Three Years before Latest Fiscal Year	31,497
Financing Receivable, Originated Four Years before Latest Fiscal Year	47,705
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,920,561
Financing Receivable, Revolving	0
Loans held for investment	2,270,948		2,300,484
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member] | Puerto Rico and Virgin Islands regions [Member] | Performing Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	24,859
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	171,599
Financing Receivable, Originated Two Years before Latest Fiscal Year	74,692
Financing Receivable, Originated Three Years before Latest Fiscal Year	31,497
Financing Receivable, Originated Four Years before Latest Fiscal Year	47,705
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,891,603
Financing Receivable, Revolving	0
Loans held for investment	2,241,955		2,265,013
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member] | Puerto Rico and Virgin Islands regions [Member] | Nonperforming Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	35
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	28,958
Financing Receivable, Revolving	0
Loans held for investment	28,993		35,471
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member] | Florida region [Member}
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	13,232
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	81,619
Financing Receivable, Originated Two Years before Latest Fiscal Year	48,991
Financing Receivable, Originated Three Years before Latest Fiscal Year	31,157
Financing Receivable, Originated Four Years before Latest Fiscal Year	29,668
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	224,344
Financing Receivable, Revolving	0
Loans held for investment	429,011		428,648
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member] | Florida region [Member} | Performing Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	13,232
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	81,619
Financing Receivable, Originated Two Years before Latest Fiscal Year	48,991
Financing Receivable, Originated Three Years before Latest Fiscal Year	31,157
Financing Receivable, Originated Four Years before Latest Fiscal Year	29,403
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	217,192
Financing Receivable, Revolving	0
Loans held for investment	421,594		421,347
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member] | Florida region [Member} | Nonperforming Financial Instruments [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	265
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	7,152
Financing Receivable, Revolving	0
Loans held for investment	$ 7,417		$ 7,301