MARKETABLE SECURITIES - Investments Classified by Contractual Maturity Date (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Amortized Cost
Due within one year	$ 0
Due after one year through five years	11,063
Due after five years through ten years	18,880
Due after ten years	3,186
Available-for-sale debt securities, amortized cost basis	193,121	$ 208,165
Estimated Fair Value
Due within one year	0
Due after one year through five years	10,578
Due after five years through ten years	17,063
Due after ten years	3,402
Available-for-sale debt securities, estimated fair value	173,744	188,927
Held to Maturity Amortized Cost
Due within one year	74,980
Due after one year through five years	70,556
Due after five years through ten years	86,353
Due after ten years	73,214
Held to Maturity debt securities, amortized cost	476,105	509,008
Held to Maturity Estimated Fair Value
Due within one year	73,848
Due after one year through five years	69,126
Due after five years through ten years	83,208
Due after ten years	68,935
Held to maturity debt securities, estimated fair value	444,304	475,068
Mortgage-backed securities
Amortized Cost
Available-for-sale debt securities, amortized cost basis	139,187
Available-for-sale debt securities, amortized cost basis	139,187	145,896
Estimated Fair Value
Available-for-sale debt securities, estimated fair value	123,578
Available-for-sale debt securities, estimated fair value	123,578	130,341
Held to Maturity Amortized Cost
Held to Maturity debt securities, amortized cost	130,138
Held to Maturity debt securities, amortized cost	130,138	132,693
Held to Maturity Estimated Fair Value
Held to maturity debt securities, estimated fair value	115,412
Held to maturity debt securities, estimated fair value	115,412	117,985
Collateralized mortgage obligations
Amortized Cost
Available-for-sale debt securities, amortized cost basis	20,805
Available-for-sale debt securities, amortized cost basis	20,805	21,981
Estimated Fair Value
Available-for-sale debt securities, estimated fair value	19,123
Available-for-sale debt securities, estimated fair value	19,123	20,157
Held to Maturity Amortized Cost
Held to Maturity debt securities, amortized cost	40,864
Held to Maturity debt securities, amortized cost	40,864	41,759
Held to Maturity Estimated Fair Value
Held to maturity debt securities, estimated fair value	33,775
Held to maturity debt securities, estimated fair value	$ 33,775	$ 34,334