DEBT SECURITIES (Tables)	3 Months Ended
Mar. 31, 2026
Other Than Temporary Impairment Credit Losses Recognized In Earnings [Line Items]
ACL on Available-for-Sale Debt Securities [Table Text Block]	Quarter Ended March 31, 2026 2025 Private label MBS Puerto Rico Government Obligation Total Private label MBS Puerto Rico Government Obligation Total (In thousands) Beginning balance $ 445 $ 318 $ 763 $ 176 $ 345 $ 521 Provision for credit losses – expense (benefit) 98 (10) 88 - (5) (5) Net charge-offs (12) - (12) - - - ACL on available-for-sale debt securities $ 531 $ 308 $ 839 $ 176 $ 340 $ 516
ACL on Held-to-Maturity Debt Securities [Table Text Block]	Government Bonds Quarter Ended March 31, 2026 2025 (In thousands) Beginning balance $ 733 $ 802 Provision for credit losses - (benefit) expense (92) 41 ACL on held-to-maturity debt securities $ 641 $ 843
Available-for-Sale Securities [Member]
Other Than Temporary Impairment Credit Losses Recognized In Earnings [Line Items]
Investments Classified by Contractual Maturity Date [Table Text Block]	March 31, 2026 Amortized cost (1) Gross Unrealized ACL Fair Value (2) Weighted- Gains Losses average yield% (Dollars in thousands) U.S. Treasury securities: Due within one year $ 497,272 $ 2 $ 20 $ - $ 497,254 3.65 U.S. government-sponsored entities (“GSEs”) obligations: Due within one year 455,779 9 6,614 - 449,174 0.98 After 1 to 5 years 381,229 - 11,614 - 369,615 2.08 After 5 to 10 years 14,995 - 130 - 14,865 4.75 After 10 years 6,298 - 35 - 6,263 3.95 Puerto Rico government obligation: After 10 years (3) 2,655 - 738 308 1,609 - United States and Puerto Rico government obligations 1,358,228 11 19,151 308 1,338,780 2.32 Mortgage-backed securities (“MBS”): Residential MBS: U.S. Agencies MBS 2,408,684 1,360 259,497 - 2,150,547 1.89 U.S. Agencies collateralized mortgage obligations (“CMOs”) 1,017,683 2,196 41,833 - 978,046 4.10 Private label MBS 4,847 - 1,203 531 3,113 5.95 Total Residential MBS (4) 3,431,214 3,556 302,533 531 3,131,706 2.55 U.S. Agencies Commercial MBS (4) 233,449 299 35,537 - 198,211 2.42 Total MBS 3,664,663 3,855 338,070 531 3,329,917 2.54 Total available-for-sale debt securities $ 5,022,891 $ 3,866 $ 357,221 $ 839 $ 4,668,697 2.48 December 31, 2025 Amortized cost (1) Gross Unrealized ACL Fair value (2) Weighted- Gains Losses average yield% (Dollars in thousands) U.S. Treasury securities: Due within one year $ 497,159 $ 183 $ - $ - $ 497,342 3.85 U.S. GSEs’ obligations: Due within one year 402,352 17 4,659 - 397,710 0.92 After 1 to 5 years 500,025 5 16,114 - 483,916 1.45 After 5 to 10 years 14,996 - 11 - 14,985 4.75 After 10 years 6,547 - 46 - 6,501 3.97 Puerto Rico government obligation: After 10 years (3) 2,700 - 762 318 1,620 - United States and Puerto Rico government obligations 1,423,779 205 21,592 318 1,402,074 2.18 MBS: Residential MBS: U.S. Agencies MBS 2,401,704 2,360 256,589 - 2,147,475 1.80 U.S. Agencies CMOs 833,330 4,123 39,299 - 798,154 3.95 Private label MBS 5,072 - 1,361 445 3,266 5.92 Total Residential MBS (4) 3,240,106 6,483 297,249 445 2,948,895 2.36 U.S Agencies Commercial MBS (4) 238,097 508 35,542 - 203,063 2.42 Total MBS 3,478,203 6,991 332,791 445 3,151,958 2.36 Total available-for-sale debt securities $ 4,901,982 $ 7,196 $ 354,383 $ 763 $ 4,554,032 2.31 (1) Excludes accrued interest receivable on available-for-sale debt securities that totaled $ 11.4 million and $ 9.4 million as of March 31, 2026 and December 31, 2025, respectively, reported as part of accrued interest receivable on loans and investment securities in the consolidated statements of financial condition, and excluded from the estimate of credit losses. (2) Includes $ 226.4 million (amortized cost - $ 247.2 million) and $ 230.2 million (amortized cost - $ 251.0 million) as of March 31, 2026 and December 31, 2025, respectively, that was pledged at the FHLB as collateral for borrowings and letters of credit, as well as $ 2.4 billion (amortized cost - $ 2.6 billion) and $ 2.5 billion (amortized cost - $ 2.7 billion) as of March 31, 2026 and December 31, 2025, respectively, pledged as collateral for the uninsured portion of government deposits. The secured parties are not permitted to sell or repledge the collateral. (3) Consists of a residential pass-through MBS issued by the Puerto Rico Housing Finance Authority ("PRHFA") that is collateralized by certain second mortgages originated under a program launched by the Puerto Rico government in 2010 and is in nonaccrual status based on the delinquency status of the underlying second mortgage loans collateral. (4) The weighted-average remaining contractual life of residential MBS and commercial MBS was 16.9 years and 28.8 years, respectively, as of March 31, 2026, compared to 16.3 years and 29.1 years, respectively, as of December 31, 2025.
Investments Fair Value and Gross Unrealized Losses [Table Text Block]	As of March 31, 2026 Less than 12 months 12 months or more Total Unrealized Unrealized Unrealized Fair Value Losses Fair Value Losses Fair Value Losses (In thousands) U.S. Treasury and U.S. GSEs’ obligations $ 484,473 $ 874 $ 673,704 $ 17,539 $ 1,158,177 $ 18,413 Puerto Rico government obligation - - 1,609 738 (1) 1,609 738 MBS: Residential MBS: U.S. Agencies MBS 275,950 1,221 1,770,602 258,276 2,046,552 259,497 U.S. Agencies CMOs 423,478 1,895 163,247 39,938 586,725 41,833 Private label - - 3,113 1,203 (1) 3,113 1,203 U.S. Agencies Commercial MBS 10,570 58 136,084 35,479 146,654 35,537 $ 1,194,471 $ 4,048 $ 2,748,359 $ 353,173 $ 3,942,830 $ 357,221 (1) Unrealized losses do not include the credit loss component recorded as part of the ACL. As of March 31, 2026, the PRHFA bond and private label MBS had an ACL of $ 0.3 million and $ 0.5 million, respectively. As of December 31, 2025 Less than 12 months 12 months or more Total Unrealized Unrealized Unrealized Fair Value Losses Fair Value Losses Fair Value Losses (In thousands) U.S. Treasury and U.S. GSEs’ obligations $ 91,584 $ 100 $ 796,505 $ 20,730 $ 888,089 $ 20,830 Puerto Rico government obligation - - 1,620 762 (1) 1,620 762 MBS: Residential MBS: U.S. Agencies MBS 52,599 148 1,851,881 256,441 1,904,480 256,589 U.S. Agencies CMOs 74,773 402 170,490 38,897 245,263 39,299 Private label - - 3,266 1,361 (1) 3,266 1,361 U.S. Agencies Commercial MBS 2,810 150 138,412 35,392 141,222 35,542 $ 221,766 $ 800 $ 2,962,174 $ 353,583 $ 3,183,940 $ 354,383 (1) Unrealized losses do not include the credit loss component recorded as part of the ACL. As of December 31, 2025, the PRHFA bond and private label MBS had an ACL of $ 0.3 million and $0.5 million, respectively.
Held-to-Maturity Securities [Member]
Other Than Temporary Impairment Credit Losses Recognized In Earnings [Line Items]
Investments Classified by Contractual Maturity Date [Table Text Block]	March 31, 2026 Amortized cost (1) (2) Gross Unrecognized Fair value Weighted- Gains Losses ACL average yield% (Dollars in thousands) Government bonds: Due within one year $ 1,071 $ 20 $ 2 $ 1,089 $ 2 4.75 After 1 to 5 years 53,409 1,858 146 55,121 364 6.85 After 5 to 10 years 10,438 665 147 10,956 87 4.49 After 10 years 14,870 96 - 14,966 188 7.13 Total government bonds 79,788 2,639 295 82,132 641 6.57 MBS: Residential MBS: U.S. Agencies MBS 86,675 - 3,064 83,611 - 4.00 U.S. Agencies CMOs 21,146 - 541 20,605 - 3.40 Total Residential MBS (3) 107,821 - 3,605 104,216 - 3.89 U.S. Agencies Commercial MBS (3) 69,913 - 2,776 67,137 - 2.14 Total MBS 177,734 - 6,381 171,353 - 3.20 Total held-to-maturity debt securities $ 257,522 $ 2,639 $ 6,676 $ 253,485 $ 641 4.24 December 31, 2025 Amortized cost (1) (2) Gross Unrecognized Fair value Weighted- Gains Losses ACL average yield% (Dollars in thousands) Government bonds: Due within one year $ 1,044 $ 42 $ 3 $ 1,083 $ 2 4.94 After 1 to 5 years 54,611 1,921 131 56,401 437 7.05 After 5 to 10 years 10,376 653 159 10,870 95 4.78 After 10 years 14,870 22 6 14,886 199 7.46 Total government bonds 80,901 2,638 299 83,240 733 6.81 MBS: Residential MBS: U.S. Agencies MBS 89,798 - 2,245 87,553 - 3.99 U.S. Agencies CMOs 21,653 - 392 21,261 - 3.40 Total Residential MBS (3) 111,451 - 2,637 108,814 - 3.87 U.S. Agencies Commercial MBS (3) 72,944 - 2,943 70,001 - 2.13 Total MBS 184,395 - 5,580 178,815 - 3.19 Total held-to-maturity debt securities $ 265,296 $ 2,638 $ 5,879 $ 262,055 $ 733 4.29 (1) Excludes accrued interest receivable on held-to-maturity debt securities that totaled $ 1.8 million and $ 3.2 million as of March 31, 2026 and December 31, 2025, respectively, reported as part of accrued interest receivable on loans and investment securities in the consolidated statements of financial condition, and excluded from the estimate of credit losses. (2) Includes $ 136.9 million (fair value - $ 135.1 million) and $ 153.0 million (fair value - $ 150.9 million) as of March 31, 2026 and December 31, 2025, respectively, that serves as collateral for the uninsured portion of government deposits. The secured parties are not permitted to sell or repledge the collateral. (3) The weighted-average remaining contractual life of residential MBS and commercial MBS was 20.9 years and 11.6 years, respectively, as of March 31, 2026, compared to 21.0 years and 11.9 years, respectively, as of December 31, 2025.
Investments Fair Value and Gross Unrealized Losses [Table Text Block]	The following tables present the Corporation’s held-to-maturity debt securities’ fair value and gross unrecognized losses, aggregated by category and length of time that individual securities had been in a continuous unrecognized loss position, as of March 31, 2026 and December 31, 2025, including debt securities for which an ACL was recorded: As of March 31, 2026 Less than 12 months 12 months or more Total Unrecognized Unrecognized Unrecognized Fair Value Losses Fair Value Losses Fair Value Losses (In thousands) Government bonds $ - $ - $ 16,663 $ 295 $ 16,663 $ 295 MBS: Residential MBS: U.S. Agencies MBS 13,948 224 69,663 2,840 83,611 3,064 U.S. Agencies CMOs - - 20,605 541 20,605 541 U.S. Agencies Commercial MBS - - 67,137 2,776 67,137 2,776 Total held-to-maturity debt securities $ 13,948 $ 224 $ 174,068 $ 6,452 $ 188,016 $ 6,676 As of December 31, 2025 Less than 12 months 12 months or more Total Unrecognized Unrecognized Unrecognized Fair Value Losses Fair Value Losses Fair Value Losses (In thousands) Government bonds $ - $ - $ 21,460 $ 299 $ 21,460 $ 299 MBS: Residential MBS: U.S Agencies MBS - - 87,553 2,245 87,553 2,245 U.S. Agencies CMOs - - 21,261 392 21,261 392 U.S. Agencies Commercial MBS - - 70,001 2,943 70,001 2,943 Total held-to-maturity debt securities $ - $ - $ 200,275 $ 5,879 $ 200,275 $ 5,879

DEBT SECURITIES (Tables)

3 Months Ended

Mar. 31, 2026

Other Than Temporary Impairment Credit Losses Recognized In Earnings [Line Items]

ACL on Available-for-Sale Debt Securities [Table Text Block]

Quarter Ended March 31,

2026

2025

Private label

MBS

Puerto Rico

Government

Obligation

Total

Private label

MBS

Puerto Rico

Government

Obligation

Total

(In thousands)

Beginning balance

445

318

763

176

345

521

Provision for credit losses – expense (benefit)

(10)

(5)

Net charge-offs

(12)

ACL on available-for-sale debt securities

531

308

839

176

340

516

ACL on Held-to-Maturity Debt Securities [Table Text Block]

Government Bonds

Quarter Ended March 31,

2026

2025

(In thousands)

Beginning balance

733

802

Provision for credit losses - (benefit) expense

(92)

ACL on held-to-maturity debt securities

641

843

Available-for-Sale Securities [Member]

Other Than Temporary Impairment Credit Losses Recognized In Earnings [Line Items]

Investments Classified by Contractual Maturity Date [Table Text Block]

March 31, 2026

Amortized cost

(1)

Gross Unrealized

ACL

Fair Value

(2)

Weighted-

Gains

Losses

average yield%

(Dollars in thousands)

U.S. Treasury securities:

Due within one year

497,272

497,254

3.65

U.S. government-sponsored entities (“GSEs”) obligations:

Due within one year

455,779

6,614

449,174

0.98

After 1 to 5 years

381,229

11,614

369,615

2.08

After 5 to 10 years

14,995

130

14,865

4.75

After 10 years

6,298

6,263

3.95

Puerto Rico government obligation:

After 10 years

(3)

2,655

738

308

1,609

United States and Puerto Rico government obligations

1,358,228

19,151

308

1,338,780

2.32

Mortgage-backed securities (“MBS”):

Residential MBS:

U.S. Agencies MBS

2,408,684

1,360

259,497

2,150,547

1.89

U.S. Agencies collateralized mortgage

obligations (“CMOs”)

1,017,683

2,196

41,833

978,046

4.10

Private label MBS

4,847

1,203

531

3,113

5.95

Total Residential MBS

(4)

3,431,214

3,556

302,533

531

3,131,706

2.55

U.S. Agencies Commercial MBS

(4)

233,449

299

35,537

198,211

2.42

Total MBS

3,664,663

3,855

338,070

531

3,329,917

2.54

Total available-for-sale debt securities

5,022,891

3,866

357,221

839

4,668,697

2.48

December 31, 2025

Amortized cost

(1)

Gross Unrealized

ACL

Fair value

(2)

Weighted-

Gains

Losses

average yield%

(Dollars in thousands)

U.S. Treasury securities:

Due within one year

497,159

183

497,342

3.85

U.S. GSEs’ obligations:

Due within one year

402,352

4,659

397,710

0.92

After 1 to 5 years

500,025

16,114

483,916

1.45

After 5 to 10 years

14,996

14,985

4.75

After 10 years

6,547

6,501

3.97

Puerto Rico government obligation:

After 10 years

(3)

2,700

762

318

1,620

United States and Puerto Rico government obligations

1,423,779

205

21,592

318

1,402,074

2.18

MBS:

Residential MBS:

U.S. Agencies MBS

2,401,704

2,360

256,589

2,147,475

1.80

U.S. Agencies CMOs

833,330

4,123

39,299

798,154

3.95

Private label MBS

5,072

1,361

445

3,266

5.92

Total Residential MBS

(4)

3,240,106

6,483

297,249

445

2,948,895

2.36

U.S Agencies Commercial MBS

(4)

238,097

508

35,542

203,063

2.42

Total MBS

3,478,203

6,991

332,791

445

3,151,958

2.36

Total available-for-sale debt securities

4,901,982

7,196

354,383

763

4,554,032

2.31

(1)

Excludes accrued

interest receivable

on available-for-sale

debt securities

that totaled

11.4

million and

9.4

million as

of March

31, 2026

and December

31, 2025,

respectively,

reported

as part

of accrued

interest

receivable on loans and investment securities in the consolidated statements of financial condition, and excluded from the estimate of credit losses.

(2)

Includes $

226.4

million (amortized cost - $

247.2

million) and $

230.2

million (amortized cost - $

251.0

million) as of March 31,

2026 and December 31, 2025,

respectively, that was

pledged at the FHLB as

collateral for

borrowings and letters of credit, as well as $

2.4

billion (amortized cost - $

2.6

billion) and $

2.5

billion (amortized cost - $

2.7

billion) as of March 31, 2026 and December 31, 2025, respectively,

pledged as collateral for the

uninsured portion of government deposits. The secured parties are not permitted to sell or repledge the collateral.

(3)

Consists of a

residential pass-through MBS

issued by the

Puerto Rico Housing

Finance Authority ("PRHFA")

that is collateralized

by certain second

mortgages originated under

a program launched

by the Puerto

Rico

government in 2010 and is in nonaccrual status based on the delinquency status of the underlying second mortgage loans collateral.

(4)

The weighted-average remaining

contractual life of

residential MBS and

commercial MBS was

16.9

years and

28.8

years, respectively,

as of March

31, 2026, compared

16.3

years and

29.1

years, respectively,

as of

December 31, 2025.

Investments Fair Value and Gross Unrealized Losses [Table Text Block]

As of March 31, 2026

Less than 12 months

12 months or more

Total

Unrealized

Fair Value

Losses

Fair Value

Losses

Fair Value

Losses

(In thousands)

U.S. Treasury and U.S. GSEs’ obligations

484,473

874

673,704

17,539

1,158,177

18,413

Puerto Rico government obligation

1,609

738

(1)

1,609

738

MBS:

Residential MBS:

U.S. Agencies MBS

275,950

1,221

1,770,602

258,276

2,046,552

259,497

U.S. Agencies CMOs

423,478

1,895

163,247

39,938

586,725

41,833

Private label

3,113

1,203

(1)

3,113

1,203

U.S. Agencies Commercial MBS

10,570

136,084

35,479

146,654

35,537

1,194,471

4,048

2,748,359

353,173

3,942,830

357,221

(1)

Unrealized losses do not include the credit loss component recorded

as part of the ACL. As of March 31, 2026, the

PRHFA bond and private label MBS

had an ACL of $

0.3

million and

0.5

million, respectively.

As of December 31, 2025

Less than 12 months

12 months or more

Total

Unrealized

Fair Value

Losses

Fair Value

Losses

Fair Value

Losses

(In thousands)

U.S. Treasury and U.S. GSEs’ obligations

91,584

100

796,505

20,730

888,089

20,830

Puerto Rico government obligation

1,620

762

(1)

1,620

762

MBS:

Residential MBS:

U.S. Agencies MBS

52,599

148

1,851,881

256,441

1,904,480

256,589

U.S. Agencies CMOs

74,773

402

170,490

38,897

245,263

39,299

Private label

3,266

1,361

(1)

3,266

1,361

U.S. Agencies Commercial MBS

2,810

150

138,412

35,392

141,222

35,542

221,766

800

2,962,174

353,583

3,183,940

354,383

(1)

Unrealized losses do

not include the credit

loss component recorded

as part of the

ACL. As of December

31, 2025, the PRHFA

bond and private

label MBS had an

ACL of $

0.3

million

and $0.5 million, respectively.

Held-to-Maturity Securities [Member]

Other Than Temporary Impairment Credit Losses Recognized In Earnings [Line Items]

Investments Classified by Contractual Maturity Date [Table Text Block]

March 31, 2026

Amortized cost

(1) (2)

Gross Unrecognized

Fair value

Weighted-

Gains

Losses

ACL

average yield%

(Dollars in thousands)

Government bonds:

Due within one year

1,071

1,089

4.75

After 1 to 5 years

53,409

1,858

146

55,121

364

6.85

After 5 to 10 years

10,438

665

147

10,956

4.49

After 10 years

14,870

14,966

188

7.13

Total government bonds

79,788

2,639

295

82,132

641

6.57

MBS:

Residential MBS:

U.S. Agencies MBS

86,675

3,064

83,611

4.00

U.S. Agencies CMOs

21,146

541

20,605

3.40

Total Residential MBS

(3)

107,821

3,605

104,216

3.89

U.S. Agencies Commercial MBS

(3)

69,913

2,776

67,137

2.14

Total MBS

177,734

6,381

171,353

3.20

Total held-to-maturity debt securities

257,522

2,639

6,676

253,485

641

4.24

December 31, 2025

Amortized cost

(1) (2)

Gross Unrecognized

Fair value

Weighted-

Gains

Losses

ACL

average yield%

(Dollars in thousands)

Government bonds:

Due within one year

1,044

1,083

4.94

After 1 to 5 years

54,611

1,921

131

56,401

437

7.05

After 5 to 10 years

10,376

653

159

10,870

4.78

After 10 years

14,870

14,886

199

7.46

Total government bonds

80,901

2,638

299

83,240

733

6.81

MBS:

Residential MBS:

U.S. Agencies MBS

89,798

2,245

87,553

3.99

U.S. Agencies CMOs

21,653

392

21,261

3.40

Total Residential MBS

(3)

111,451

2,637

108,814

3.87

U.S. Agencies Commercial MBS

(3)

72,944

2,943

70,001

2.13

Total MBS

184,395

5,580

178,815

3.19

Total held-to-maturity debt securities

265,296

2,638

5,879

262,055

733

4.29

(1)

Excludes accrued interest receivable on held-to-maturity debt securities that totaled $

1.8

million and $

3.2

million as of March 31, 2026 and December 31, 2025, respectively, reported as part of accrued interest

receivable

on loans and investment securities in the consolidated statements of financial condition, and excluded from the estimate of credit losses.

(2)

Includes $

136.9

million (fair

value - $

135.1

million) and $

153.0

million (fair

value - $

150.9

million) as of

March 31,

2026 and December

31, 2025, respectively,

that serves as

collateral for

the uninsured portion

government deposits. The secured parties are not permitted to sell or repledge the collateral.

(3)

The weighted-average remaining contractual

life of residential MBS

and commercial MBS was

20.9

years and

11.6

years, respectively, as

of March 31,

2026, compared to

21.0

years and

11.9

years, respectively, as

December 31,

2025.

Investments Fair Value and Gross Unrealized Losses [Table Text Block]

The

following

tables

present

the

Corporation’s

held-to-maturity

debt

securities’

fair

value

and

gross

unrecognized

losses,

aggregated by

category and length

of time that

individual securities had

been in a

continuous unrecognized

loss position, as

of March

31, 2026 and December 31, 2025, including debt securities for which

an ACL was recorded:

As of March 31, 2026

Less than 12 months

12 months or more

Total

Unrecognized

Fair Value

Losses

Fair Value

Losses

Fair Value

Losses

(In thousands)

Government bonds

16,663

295

16,663

295

MBS:

Residential MBS:

U.S. Agencies MBS

13,948

224

69,663

2,840

83,611

3,064

U.S. Agencies CMOs

20,605

541

20,605

541

U.S. Agencies Commercial MBS

67,137

2,776

67,137

2,776

Total held-to-maturity debt securities

13,948

224

174,068

6,452

188,016

6,676

As of December 31, 2025

Less than 12 months

12 months or more

Total

Unrecognized

Fair Value

Losses

Fair Value

Losses

Fair Value

Losses

(In thousands)

Government bonds

21,460

299

21,460

299

MBS:

Residential MBS:

U.S Agencies MBS

87,553

2,245

87,553

2,245

U.S. Agencies CMOs

21,261

392

21,261

392

U.S. Agencies Commercial MBS

70,001

2,943

70,001

2,943

Total held-to-maturity debt securities

200,275

5,879

200,275

5,879