Investment Securities Summary of Amortized Cost and Estimated Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 355,890	$ 323,809
Unrealized Gains	5,565	578
Unrealized Losses	(935)	(6,971)
Fair Value (Estimated)	360,520	317,416
Securities to be held to maturity, cost and FMV [Abstract]
Amortized Cost	281,606	255,663
Unrealized Gains	5,590	1,382
Unrealized Losses	(151)	(6,145)
Fair Value (Estimated)	287,045	250,900
Restricted equity securities
Federal Home Loan Bank Stock	7,945	10,549
Federal Reserve Bank Stock	1,037	1,037
Restricted equity securities	8,982	11,586
U.S. Government-sponsored agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	7,500	5,000
Unrealized Gains	0	7
Unrealized Losses	(102)	0
Fair Value (Estimated)	7,398	5,007
Securities to be held to maturity, cost and FMV [Abstract]
Amortized Cost	32,840	11,155
Unrealized Gains	47	0
Unrealized Losses	(26)	(472)
Fair Value (Estimated)	32,861	10,683
Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	323,277	313,854
Unrealized Gains	4,173	571
Unrealized Losses	(833)	(6,732)
Fair Value (Estimated)	326,617	307,693
Securities to be held to maturity, cost and FMV [Abstract]
Amortized Cost	14,431	18,250
Unrealized Gains	450	336
Unrealized Losses	(16)	(255)
Fair Value (Estimated)	14,865	18,331
State and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	25,113	4,955
Unrealized Gains	1,392	0
Unrealized Losses	0	(239)
Fair Value (Estimated)	26,505	4,716
Securities to be held to maturity, cost and FMV [Abstract]
Amortized Cost	219,585	221,958
Unrealized Gains	4,936	1,046
Unrealized Losses	(109)	(5,418)
Fair Value (Estimated)	224,412	217,586
Corporate securities
Securities to be held to maturity, cost and FMV [Abstract]
Amortized Cost	14,750	4,300
Unrealized Gains	157	0
Unrealized Losses	0	0
Fair Value (Estimated)	$ 14,907	$ 4,300

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