REVENUE FROM CONTRACTS WITH CUSTOMERS (Tables)	9 Months Ended
REVENUE FROM CONTRACTS WITH CUSTOMERS (Tables)	Sep. 30, 2023
REVENUE FROM CONTRACTS WITH CUSTOMERS [Abstract]
Disaggregation of Revenue [Table Text Block]	Quarter ended September 30,2023 Mortgage Banking Consumer (Retail) Banking Commercial and Corporate Treasury and Investments United States Operations Virgin Islands Operations Total (In thousands) Net interest income (1) $ 18,279 $ 147,066 $ 13,212 $ (4,055) $ 19,749 $ 5,477 $ 199,728 Service charges and fees on deposit accounts - 5,286 3,406 - 155 705 9,552 Insurance commissions - 2,596 - - 68 126 2,790 Merchant-related income - 2,156 - - 19 319 2,494 Credit and debit card fees - 7,826 24 - 4 493 8,347 Other service charges and fees 50 1,262 853 - 615 163 2,943 Not in scope of ASC Topic 606 (1) 2,971 1,044 185 (3) (14) (13) 4,170 Total non-interest income 3,021 20,170 4,468 (3) 847 1,793 30,296 Total Revenue $ 21,300 $ 167,236 $ 17,680 $ (4,058) $ 20,596 $ 7,270 $ 230,024 Quarter ended September 30,2022 Mortgage Banking Consumer (Retail) Banking Commercial and Corporate Treasury and Investments United States Operations Virgin Islands Operations Total (In thousands) Net interest income (1) $ 24,338 $ 118,408 $ 22,861 $ 14,827 $ 21,494 $ 5,982 $ 207,910 Service charges and fees on deposit accounts - 5,744 3,169 - 151 756 9,820 Insurance commissions - 2,485 - - 16 123 2,624 Merchant-related income - 1,458 347 - 32 330 2,167 Credit and debit card fees - 7,209 21 - (2) 439 7,667 Other service charges and fees 85 1,228 340 - 595 195 2,443 Not in scope of ASC Topic 606 (1) 3,648 997 399 33 (19) (86) 4,972 Total non-interest income 3,733 19,121 4,276 33 773 1,757 29,693 Total Revenue $ 28,071 $ 137,529 $ 27,137 $ 14,860 $ 22,267 $ 7,739 $ 237,603 Nine-Month Period Ended September 30,2023 Mortgage Banking Consumer (Retail) Banking Commercial and Corporate Treasury and Investments United States Operations Virgin Islands Operations Total (In thousands) Net interest income (1) $ 61,427 $ 427,407 $ 41,085 $ (7,502) $ 60,369 $ 17,642 $ 600,428 Service charges and fees on deposit accounts - 15,859 9,886 - 492 2,143 28,380 Insurance commissions - 9,700 - - 175 509 10,384 Merchant-related income - 6,454 - - 87 1,172 7,713 Credit and debit card fees - 23,581 74 - 16 1,510 25,181 Other service charges and fees 244 3,922 2,801 - 1,858 714 9,539 Not in scope of ASC Topic 606 (1) 8,913 2,909 4,027 1,837 221 (19) 17,888 Total non-interest income 9,157 62,425 16,788 1,837 2,849 6,029 99,085 Total Revenue $ 70,584 $ 489,832 $ 57,873 $ (5,665) $ 63,218 $ 23,671 $ 699,513 Nine-Month Period Ended September 30,2022 Mortgage Banking Consumer (Retail) Banking Commercial and Corporate Treasury and Investments United States Operations Virgin Islands Operations Total (In thousands) Net interest income (1) $ 76,452 $ 310,351 $ 94,655 $ 33,702 $ 56,664 $ 17,896 $ 589,720 Service charges and fees on deposit accounts - 16,778 9,214 - 446 2,211 28,649 Insurance commissions - 10,176 - - 65 604 10,845 Merchant-related income - 4,991 1,101 - 54 1,046 7,192 Credit and debit card fees - 21,271 58 - (6) 1,298 22,621 Other service charges and fees 287 4,404 2,329 - 1,579 509 9,108 Not in scope of ASC Topic 606 (1) 12,865 1,747 576 (130) 57 (38) 15,077 Total non-interest income 13,152 59,367 13,278 (130) 2,195 5,630 93,492 Total Revenue $ 89,604 $ 369,718 $ 107,933 $ 33,572 $ 58,859 $ 23,526 $ 683,212 (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.
Activity of Contract Liabilities [Table Text Block]	Quarter Ended September 30, Nine-Month Period Ended September 30, 2023 2022 2023 2022 (In thousands) Beginning balance $ 608 $ 1,049 $ 841 $ 1,443 Revenue recognized (81) (104) (314) (498) Ending balance $ 527 $ 945 $ 527 $ 945