MARKETABLE SECURITIES - Schedule of Amortized Cost and Fair Value of Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Available for sale:
Available-for-sale debt securities, amortized cost basis	$ 218,599	$ 239,945
Gross Unrealized Gain	3,334	127
Gross Unrealized Loss	588	7,097
Estimated Fair Value	221,345	232,975
Held to maturity:
Amortized Cost	156,925	163,164
Gross Unrealized Gains	5,291	1,258
Gross Unrealized Losses	51	1,622
Estimated Fair Value	162,165	162,800
Corporate bonds
Available for sale:
Available-for-sale debt securities, amortized cost basis	19,686	19,743
Gross Unrealized Gain	533	0
Gross Unrealized Loss	0	789
Estimated Fair Value	20,219	18,954
Mortgage-backed securities
Available for sale:
Available-for-sale debt securities, amortized cost basis	87,946	93,083
Gross Unrealized Gain	676	52
Gross Unrealized Loss	555	3,676
Estimated Fair Value	88,067	89,459
Held to maturity:
Amortized Cost	15,119	17,163
Gross Unrealized Gains	188	54
Gross Unrealized Losses	43	500
Estimated Fair Value	15,264	16,717
Collateralized mortgage obligations
Available for sale:
Available-for-sale debt securities, amortized cost basis	95,297	111,341
Gross Unrealized Gain	1,522	0
Gross Unrealized Loss	33	2,372
Estimated Fair Value	96,786	108,969
Held to maturity:
Amortized Cost	2,930	4,059
Gross Unrealized Gains	118	48
Gross Unrealized Losses	0	28
Estimated Fair Value	3,048	4,079
Municipal securities
Available for sale:
Available-for-sale debt securities, amortized cost basis	15,670	15,778
Gross Unrealized Gain	603	75
Gross Unrealized Loss	0	260
Estimated Fair Value	16,273	15,593
Held to maturity:
Amortized Cost	138,876	141,942
Gross Unrealized Gains	4,985	1,156
Gross Unrealized Losses	8	1,094
Estimated Fair Value	$ 143,853	$ 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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