SECURITIES AVAILABLE FOR SALE - Summary of Securities Available for Sale (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Investment Holdings [Line Items]
Amortized Cost	$ 613,642	$ 655,888
Gross Unrealized Gains	20,345	11,205
Gross Unrealized Losses	(7,646)	(3,863)
Available for sale securities	626,341	663,230
US Government-sponsored enterprises
Investment Holdings [Line Items]
Amortized Cost	284,925	319,064
Gross Unrealized Gains	11,349	4,985
Gross Unrealized Losses	(617)	(2,080)
Available for sale securities	295,657	321,969
US Government agency
Investment Holdings [Line Items]
Amortized Cost	98,059	98,568
Gross Unrealized Gains	3,801	1,640
Gross Unrealized Losses	(191)	(547)
Available for sale securities	101,669	99,661
Private label
Investment Holdings [Line Items]
Amortized Cost	20,209	20,212
Gross Unrealized Gains	62	68
Gross Unrealized Losses	(1,772)	(747)
Available for sale securities	18,499	19,533
Obligations of states and political subdivisions thereof
Investment Holdings [Line Items]
Amortized Cost	134,258	139,240
Gross Unrealized Gains	3,636	3,034
Gross Unrealized Losses	(315)	(268)
Available for sale securities	137,579	142,006
Corporate bonds
Investment Holdings [Line Items]
Amortized Cost	76,191	78,804
Gross Unrealized Gains	1,497	1,478
Gross Unrealized Losses	(4,751)	(221)
Available for sale securities	$ 72,937	$ 80,061

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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