INVESTMENTS (Summary of Amortized Cost and Fair Value of Debt and Equity Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt securities - available-for-sale:
Amortized Cost of Cost	$ 343,619	$ 473,126
Debt securities, at fair value	349,299	488,210
Debt Securities
Debt securities - available-for-sale:
Amortized Cost of Cost	343,619	473,126
Gross Unrealized Gains	7,625	15,218
Gross Unrealized Losses	1,945	134
Debt securities, at fair value	349,299	488,210
United States government obligations and authorities
Debt securities - available-for-sale:
Amortized Cost of Cost	94,569	169,947
Gross Unrealized Gains	1,019	1,866
Gross Unrealized Losses	459	38
Debt securities, at fair value	95,129	171,775
Obligations of states and political subdivisions
Debt securities - available-for-sale:
Amortized Cost of Cost	19,970	21,560
Gross Unrealized Gains	554	704
Gross Unrealized Losses	68	0
Debt securities, at fair value	20,456	22,264
Corporate securities
Debt securities - available-for-sale:
Amortized Cost of Cost	198,574	254,618
Gross Unrealized Gains	5,679	11,989
Gross Unrealized Losses	1,331	79
Debt securities, at fair value	202,922	266,528
International securities
Debt securities - available-for-sale:
Amortized Cost of Cost	30,506	27,001
Gross Unrealized Gains	373	659
Gross Unrealized Losses	87	17
Debt securities, at fair value	$ 30,792	$ 27,643

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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Amount 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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