Quarterly report [Sections 13 or 15(d)]

SECURITIES AND OTHER INVESTMENTS (Amortized Cost, Gross Unrealized Gains and Losses, and Estimated Fair Values of Investment Securities) (Details)

v3.25.1
SECURITIES AND OTHER INVESTMENTS (Amortized Cost, Gross Unrealized Gains and Losses, and Estimated Fair Values of Investment Securities) (Details) - USD ($)
$ in Thousands
Mar. 31, 2025
Dec. 31, 2024
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]    
Total AFS securities $ 2,865,872 $ 2,844,763
Gross Unrealized Gains 5,508 3,378
Gross Unrealized (Losses) (387,545) (405,975)
Total AFS securities, Estimated Fair Value 2,483,835 2,442,166
US Government Agencies Debt Securities [Member]    
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]    
Total AFS securities 65,428 65,650
Gross Unrealized Gains 680 390
Gross Unrealized (Losses) (13) (27)
Total AFS securities, Estimated Fair Value 66,095 66,013
US States and Political Subdivisions Debt Securities [Member]    
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]    
Total AFS securities 593,973 597,956
Gross Unrealized Gains 125 84
Gross Unrealized (Losses) (137,728) (129,703)
Total AFS securities, Estimated Fair Value 456,370 468,337
Corporate Bond Securities [Member]    
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]    
Total AFS securities 245,806 253,526
Gross Unrealized Gains 558 505
Gross Unrealized (Losses) (7,534) (9,319)
Total AFS securities, Estimated Fair Value 238,830 244,712
Commercial Mortgage-Backed Securities [Member]    
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]    
Total AFS securities 356,209 347,501
Gross Unrealized Gains 758 352
Gross Unrealized (Losses) (43,533) (46,788)
Total AFS securities, Estimated Fair Value 313,434 301,065
Commercial Mortgage-Backed Securities [Member] | Agency Securities [Member]    
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]    
Total AFS securities 288,399 285,949
Gross Unrealized Gains 668 348
Gross Unrealized (Losses) (41,610) (44,678)
Total AFS securities, Estimated Fair Value 247,457 241,619
Commercial Mortgage-Backed Securities [Member] | Non-agency    
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]    
Total AFS securities 67,810 61,552
Gross Unrealized Gains 90 4
Gross Unrealized (Losses) (1,923) (2,110)
Total AFS securities, Estimated Fair Value 65,977 59,446
Residential Mortgage-Backed Securities [Member]    
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]    
Total AFS securities 1,602,571 1,578,270
Gross Unrealized Gains 3,387 2,047
Gross Unrealized (Losses) (198,737) (220,138)
Total AFS securities, Estimated Fair Value 1,407,221 1,360,179
Residential Mortgage-Backed Securities [Member] | Agency Securities [Member]    
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]    
Total AFS securities 1,506,416 1,478,648
Gross Unrealized Gains 2,917 1,375
Gross Unrealized (Losses) (195,677) (216,754)
Total AFS securities, Estimated Fair Value 1,313,656 1,263,269
Residential Mortgage-Backed Securities [Member] | Non-agency    
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]    
Total AFS securities 96,155 99,622
Gross Unrealized Gains 470 672
Gross Unrealized (Losses) (3,060) (3,384)
Total AFS securities, Estimated Fair Value 93,565 96,910
Collateralized Securities, Other [Member]    
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]    
Total AFS securities 1,885 1,860
Gross Unrealized Gains 0 0
Gross Unrealized (Losses) 0 0
Total AFS securities, Estimated Fair Value $ 1,885 $ 1,860