REVENUE FROM CONTRACTS WITH CUSTOMERS (Tables)	9 Months Ended
REVENUE FROM CONTRACTS WITH CUSTOMERS (Tables)	Sep. 30, 2025
REVENUE FROM CONTRACTS WITH CUSTOMERS [Abstract]
Disaggregation of Revenue [Table Text Block]	Quarter ended September 30, 2025 Mortgage Banking Consumer (Retail) Banking Commercial and Corporate Treasury and Investments United States Operations Virgin Islands Operations Total (In thousands) Net interest income (loss) (1) $ 17,636 $ 147,907 $ 44,076 $ (30,957) $ 22,517 $ 16,737 $ 217,916 Service charges and fees on deposit accounts - 7,419 1,506 - 142 744 9,811 Insurance commission income - 2,430 - - 65 123 2,618 Card and processing income - 10,347 221 - 23 1,091 11,682 Other service charges and fees 20 1,695 32 - 289 123 2,159 Not in scope of ASC Topic 606 (1) 3,395 439 139 33 479 39 4,524 Total non-interest income 3,415 22,330 1,898 33 998 2,120 30,794 Total Revenue (Loss) $ 21,051 $ 170,237 $ 45,974 $ (30,924) $ 23,515 $ 18,857 $ 248,710 Quarter ended September 30, 2024 Mortgage Banking Consumer (Retail) Banking Commercial and Corporate Treasury and Investments United States Operations Virgin Islands Operations Total (In thousands) Net interest income (loss) (1) $ 18,409 $ 140,014 $ 40,124 $ (31,262) $ 19,447 $ 15,332 $ 202,064 Service charges and fees on deposit accounts - 7,833 949 - 149 753 9,684 Insurance commission income - 2,824 - - 75 104 3,003 Card and processing income - 10,219 221 - 10 1,318 11,768 Other service charges and fees 54 1,649 173 - 698 157 2,731 Not in scope of ASC Topic 606 (1) 3,353 1,387 328 250 27 (29) 5,316 Total non-interest income 3,407 23,912 1,671 250 959 2,303 32,502 Total Revenue (Loss) $ 21,816 $ 163,926 $ 41,795 $ (31,012) $ 20,406 $ 17,635 $ 234,566 Nine-Month Period Ended September 30, 2025 Mortgage Banking Consumer (Retail) Banking Commercial and Corporate Treasury and Investments United States Operations Virgin Islands Operations Total (In thousands) Net interest income (loss) (1) $ 52,892 $ 436,824 $ 128,941 $ (85,746) $ 63,748 $ 49,513 $ 646,172 Service charges and fees on deposit accounts - 22,099 4,434 - 431 2,243 29,207 Insurance commission income - 10,310 - - 158 493 10,961 Card and processing income - 30,172 854 - 76 3,935 35,037 Other service charges and fees 54 4,996 73 - 856 393 6,372 Not in scope of ASC Topic 606 (1) 10,441 3,310 689 203 1,193 65 15,901 Total non-interest income 10,495 70,887 6,050 203 2,714 7,129 97,478 Total Revenue (Loss) $ 63,387 $ 507,711 $ 134,991 $ (85,543) $ 66,462 $ 56,642 $ 743,650 Nine-Month Period Ended September 30, 2024 Mortgage Banking Consumer (Retail) Banking Commercial and Corporate Treasury and Investments United States Operations Virgin Islands Operations Total (In thousands) Net interest income (loss) (1) $ 54,740 $ 409,005 $ 116,219 $ (83,018) $ 56,392 $ 44,874 $ 598,212 Service charges and fees on deposit accounts - 23,117 3,228 - 452 2,274 29,071 Insurance commission income - 10,621 - - 161 514 11,296 Card and processing income - 29,706 671 - 119 4,107 34,603 Other service charges and fees 153 5,218 514 - 1,932 451 8,268 Not in scope of ASC Topic 606 (1) 9,981 4,103 659 483 47 12 15,285 Total non-interest income 10,134 72,765 5,072 483 2,711 7,358 98,523 Total Revenue (Loss) $ 64,874 $ 481,770 $ 121,291 $ (82,535) $ 59,103 $ 52,232 $ 696,735 (1) Most of the Corporation’s revenue is not within the scope of ASC Topic 606. The guidance explicitly excludes net interest income from financial assets and liabilities, as well as other non-interest income from loans, leases, investment securities and derivative financial instruments.