MARKETABLE SECURITIES - Schedule of Amortized Cost and Fair Value of Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Available for sale:
Available-for-sale debt securities, amortized cost basis	$ 227,200	$ 239,945
Gross Unrealized Gain	2,649	127
Gross Unrealized Loss	1,135	7,097
Estimated Fair Value	228,714	232,975
Held to maturity:
Amortized Cost	158,915	163,164
Gross Unrealized Gains	4,289	1,258
Gross Unrealized Losses	232	1,622
Estimated Fair Value	162,972	162,800
Corporate bonds
Available for sale:
Available-for-sale debt securities, amortized cost basis	19,705	19,743
Gross Unrealized Gain	387	0
Gross Unrealized Loss	0	789
Estimated Fair Value	20,092	18,954
Mortgage-backed securities
Available for sale:
Available-for-sale debt securities, amortized cost basis	91,782	93,083
Gross Unrealized Gain	595	52
Gross Unrealized Loss	1,098	3,676
Estimated Fair Value	91,279	89,459
Held to maturity:
Amortized Cost	15,832	17,163
Gross Unrealized Gains	163	54
Gross Unrealized Losses	187	500
Estimated Fair Value	15,808	16,717
Collateralized mortgage obligations
Available for sale:
Available-for-sale debt securities, amortized cost basis	100,007	111,341
Gross Unrealized Gain	1,241	0
Gross Unrealized Loss	37	2,372
Estimated Fair Value	101,211	108,969
Held to maturity:
Amortized Cost	3,243	4,059
Gross Unrealized Gains	104	48
Gross Unrealized Losses	0	28
Estimated Fair Value	3,347	4,079
Municipal securities
Available for sale:
Available-for-sale debt securities, amortized cost basis	15,706	15,778
Gross Unrealized Gain	426	75
Gross Unrealized Loss	0	260
Estimated Fair Value	16,132	15,593
Held to maturity:
Amortized Cost	139,840	141,942
Gross Unrealized Gains	4,022	1,156
Gross Unrealized Losses	45	1,094
Estimated Fair Value	$ 143,817	$ 142,004

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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