Debt Securities - Schedule of Available for Sale Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Available-for-sale Securities
Amortized Cost	$ 871,660	$ 780,061
Gross Unrealized Gains	16,068	8,359
Gross Unrealized Losses	5,869	2,443
Allowance for Credit Loss related to Debt Securities	0
Debt securities available for sale at fair value	881,859	785,977
U.S. Government agencies and corporations
Schedule of Available-for-sale Securities
Amortized Cost	421	439
Gross Unrealized Gains	10	2
Gross Unrealized Losses	0	0
Allowance for Credit Loss related to Debt Securities	0
Debt securities available for sale at fair value	431	441
State and political subdivisions
Schedule of Available-for-sale Securities
Amortized Cost	283,087	253,750
Gross Unrealized Gains	4,499	3,803
Gross Unrealized Losses	1,209	348
Allowance for Credit Loss related to Debt Securities	0
Debt securities available for sale at fair value	286,377	257,205
Mortgage-backed securities
Schedule of Available-for-sale Securities
Amortized Cost	41,191	43,009
Gross Unrealized Gains	1,412	536
Gross Unrealized Losses	2	15
Allowance for Credit Loss related to Debt Securities	0
Debt securities available for sale at fair value	42,601	43,530
Collateralized mortgage obligations
Schedule of Available-for-sale Securities
Amortized Cost	301,287	293,911
Gross Unrealized Gains	6,804	1,000
Gross Unrealized Losses	1,231	1,965
Allowance for Credit Loss related to Debt Securities	0
Debt securities available for sale at fair value	306,860	292,946
Corporate debt securities
Schedule of Available-for-sale Securities
Amortized Cost	245,674	188,952
Gross Unrealized Gains	3,343	3,018
Gross Unrealized Losses	3,427	115
Allowance for Credit Loss related to Debt Securities	0
Debt securities available for sale at fair value	$ 245,590	$ 191,855

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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Amount of allowance for credit loss 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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