Loans and Leases Held for Investment and Credit Quality - Schedule of Troubled Debt Restructurings (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) SecurityLoan	Dec. 31, 2018 USD ($) SecurityLoan	Dec. 31, 2017 USD ($) SecurityLoan
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan	11	11	3
Recorded Investment at period end | $	$ 15,642	$ 19,413	$ 1,229
Interest Only Period
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan	1	1
Recorded Investment at period end | $	$ 348	$ 634
Interest Only Period | Construction & Development | Healthcare
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan		1
Recorded Investment at period end | $		$ 634
Interest Only Period | Commercial & Industrial | Other Industries
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan	1
Recorded Investment at period end | $	$ 348
Rate Concession
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan	1
Recorded Investment at period end | $	$ 87
Rate Concession | Commercial & Industrial | Agricultural
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan	1
Recorded Investment at period end | $	$ 87
Interest Only and Rate Concession
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan		4
Recorded Investment at period end | $		$ 10,240
Interest Only and Rate Concession | Commercial Land | Agricultural
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan		4
Recorded Investment at period end | $		$ 10,240
Extended Maturity
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan	1	2
Recorded Investment at period end | $	$ 1,566	$ 3,073
Extended Maturity | Construction & Development | Agricultural
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan		1
Recorded Investment at period end | $		$ 3,067
Extended Maturity | Commercial Land | Agricultural
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan	1	1
Recorded Investment at period end | $	$ 1,566	$ 6
Payment Deferral and Extended Amortization
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan		1	1
Recorded Investment at period end | $		$ 608	$ 1,102
Payment Deferral and Extended Amortization | Commercial & Industrial | Independent Pharmacies
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan			1
Recorded Investment at period end | $			$ 1,102
Payment Deferral and Extended Amortization | Commercial Land | Agricultural
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan		1
Recorded Investment at period end | $		$ 608
Extended Amortization and Rate Concession
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan	4	3
Recorded Investment at period end | $	$ 7,525	$ 4,858
Extended Amortization and Rate Concession | Construction & Development | Agricultural
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan		1
Recorded Investment at period end | $		$ 1,872
Extended Amortization and Rate Concession | Commercial & Industrial | Registered Investment Advisors
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan		1
Recorded Investment at period end | $		$ 1,254
Extended Amortization and Rate Concession | Commercial Land | Agricultural
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan	4
Recorded Investment at period end | $	$ 7,525
Extended Amortization and Rate Concession | Commercial Real Estate | Agricultural
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan		1
Recorded Investment at period end | $		$ 1,732
Payment Deferral
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan	2		2
Recorded Investment at period end | $	$ 2,415		$ 127
Payment Deferral | Commercial & Industrial | Healthcare
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan	1
Recorded Investment at period end | $	$ 574
Payment Deferral | Commercial & Industrial | Veterinary Industry
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan			2
Recorded Investment at period end | $			$ 127
Payment Deferral | Commercial Real Estate | Healthcare
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan	1
Recorded Investment at period end | $	$ 1,841
Payment Deferral And Rate Concession
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan	2
Recorded Investment at period end | $	$ 3,701
Payment Deferral And Rate Concession | Commercial Real Estate | Other Industries
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | SecurityLoan	2
Recorded Investment at period end | $	$ 3,701