SECURITIES - Available-for-sale (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Securities available-for-sale:
Amortized Cost	$ 965,341	$ 995,709
Gross Unrealized Gains	291	56
Gross Unrealized Losses	(106,416)	(109,525)
Fair Value	859,216	886,240
Agency notes
Securities available-for-sale:
Amortized Cost	10,000	10,000
Gross Unrealized Losses	(591)	(629)
Fair Value	9,409	9,371
Treasury securities
Securities available-for-sale:
Amortized Cost	238,622	245,877
Gross Unrealized Losses	(10,451)	(11,687)
Fair Value	228,171	234,190
Corporate securities
Securities available-for-sale:
Amortized Cost	169,954	174,978
Gross Unrealized Gains	255
Gross Unrealized Losses	(19,964)	(23,808)
Fair Value	150,245	151,170
Pass-through MBS issued by GSEs
Securities available-for-sale:
Amortized Cost	221,666	230,253
Gross Unrealized Gains	16	10
Gross Unrealized Losses	(25,806)	(24,978)
Fair Value	195,876	205,285
Agency CMOs
Securities available-for-sale:
Amortized Cost	297,445	305,860
Gross Unrealized Gains	20	46
Gross Unrealized Losses	(47,625)	(46,491)
Fair Value	249,840	259,415
State and municipal obligations
Securities available-for-sale:
Amortized Cost	27,654	28,741
Gross Unrealized Losses	(1,979)	(1,932)
Fair Value	$ 25,675	$ 26,809