Securities Available-for-Sale - Revenue and General Obligation Bonds by Location (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 592,378	$ 569,942
Fair Market Value	600,799	560,479
States and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	181,900	140,181
Fair Market Value	188,265	140,534
General Obligation Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	156,039	116,291
Fair Market Value	161,587	116,633
General Obligation Bonds [Member] | Texas [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	59,439	36,331
Fair Market Value	61,519	36,199
General Obligation Bonds [Member] | California [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	23,882	26,928
Fair Market Value	25,030	27,357
General Obligation Bonds [Member] | Washington [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	23,392	16,036
Fair Market Value	24,313	16,062
General Obligation Bonds [Member] | Ohio [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	7,144	8,639
Fair Market Value	7,271	8,601
General Obligation Bonds [Member] | Other [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	42,182	28,357
Fair Market Value	43,454	28,414
Revenue Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	25,861	23,890
Fair Market Value	26,678	23,901
Revenue Bonds [Member] | Texas [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	6,035	7,526
Fair Market Value	6,298	7,506
Revenue Bonds [Member] | California [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	365	367
Fair Market Value	380	374
Revenue Bonds [Member] | Washington [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,737	1,751
Fair Market Value	1,856	1,780
Revenue Bonds [Member] | Ohio [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,069
Fair Market Value	2,066
Revenue Bonds [Member] | Other [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	15,655	14,246
Fair Market Value	$ 16,078	$ 14,241