SECURITIES AND OTHER INVESTMENTS (Amortized Cost, Gross Unrealized Gains and Losses, and Estimated Fair Values of Investment Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]
Total AFS securities	$ 4,489,998	$ 2,844,763
Gross Unrealized Gains	19,804	3,378
Gross Unrealized (Losses)	(315,501)	(405,975)
Total AFS securities, Estimated Fair Value	4,194,301	2,442,166
US Government Agencies Debt Securities [Member]
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]
Total AFS securities	103,335	65,650
Gross Unrealized Gains	681	390
Gross Unrealized (Losses)	(14)	(27)
Total AFS securities, Estimated Fair Value	104,002	66,013
US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]
Total AFS securities	589,194	597,956
Gross Unrealized Gains	178	84
Gross Unrealized (Losses)	(101,487)	(129,703)
Total AFS securities, Estimated Fair Value	487,885	468,337
Corporate Bond Securities [Member]
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]
Total AFS securities	221,432	253,526
Gross Unrealized Gains	709	505
Gross Unrealized (Losses)	(4,207)	(9,319)
Total AFS securities, Estimated Fair Value	217,934	244,712
Commercial Mortgage-Backed Securities [Member]
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]
Total AFS securities	469,414	347,501
Gross Unrealized Gains	1,463	352
Gross Unrealized (Losses)	(41,711)	(46,788)
Total AFS securities, Estimated Fair Value	429,166	301,065
Commercial Mortgage-Backed Securities [Member] | Agency Securities [Member]
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]
Total AFS securities	354,405	285,949
Gross Unrealized Gains	1,276	348
Gross Unrealized (Losses)	(39,806)	(44,678)
Total AFS securities, Estimated Fair Value	315,875	241,619
Commercial Mortgage-Backed Securities [Member] | Non-agency
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]
Total AFS securities	115,009	61,552
Gross Unrealized Gains	187	4
Gross Unrealized (Losses)	(1,905)	(2,110)
Total AFS securities, Estimated Fair Value	113,291	59,446
Residential Mortgage-Backed Securities [Member]
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]
Total AFS securities	3,104,667	1,578,270
Gross Unrealized Gains	16,773	2,047
Gross Unrealized (Losses)	(168,082)	(220,138)
Total AFS securities, Estimated Fair Value	2,953,358	1,360,179
Residential Mortgage-Backed Securities [Member] | Agency Securities [Member]
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]
Total AFS securities	2,942,900	1,478,648
Gross Unrealized Gains	15,838	1,375
Gross Unrealized (Losses)	(165,524)	(216,754)
Total AFS securities, Estimated Fair Value	2,793,214	1,263,269
Residential Mortgage-Backed Securities [Member] | Non-agency
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]
Total AFS securities	161,767	99,622
Gross Unrealized Gains	935	672
Gross Unrealized (Losses)	(2,558)	(3,384)
Total AFS securities, Estimated Fair Value	160,144	96,910
Collateralized Securities, Other [Member]
Debt Securities, Available-for-sale Securities, Amortized Cost Basis [Abstract]
Total AFS securities	1,956	1,860
Gross Unrealized Gains	0	0
Gross Unrealized (Losses)	0	0
Total AFS securities, Estimated Fair Value	$ 1,956	$ 1,860