Loans and Allowance for Loan Losses - Internal Risk Summary Narrative (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020 USD ($) loan property	Jun. 30, 2019	Dec. 31, 2019 USD ($)
Classes of the loan portfolio summarized by credit quality indicators:
Total Loans	$ 1,496,761		$ 1,374,235
Special Mention
Classes of the loan portfolio summarized by credit quality indicators:
Total loans excluding loans acquired and PCI loans	74,800		25,200
Increase (decrease) in loans	$ 49,600
Increase in loans (as a percentage)		197.00%
Number of loans | loan	6
Loan chargeoff expense	$ 1,800
Special Mention | The First State Bank
Classes of the loan portfolio summarized by credit quality indicators:
Total Loans	182
Special Mention | Other Loan Relationships
Classes of the loan portfolio summarized by credit quality indicators:
Loans outstanding	1,900
Substandard
Classes of the loan portfolio summarized by credit quality indicators:
Total loans excluding loans acquired and PCI loans	23,900		18,600
Increase (decrease) in loans	$ 5,300
Increase in loans (as a percentage)	29.00%
Number of loans | loan	12
Substandard | The First State Bank
Classes of the loan portfolio summarized by credit quality indicators:
Total Loans	$ 130
Substandard | Other Loan Relationships
Classes of the loan portfolio summarized by credit quality indicators:
Loans outstanding	1,900
Substandard | Risk Grade Downgrade
Classes of the loan portfolio summarized by credit quality indicators:
Loans outstanding	967
Commercial Loan Portfolio
Classes of the loan portfolio summarized by credit quality indicators:
Total Loans	$ 1,127,792		1,063,828
Commercial Loan Portfolio | Special Mention | Commercial Loan Relationship One
Classes of the loan portfolio summarized by credit quality indicators:
Number of loans | loan	2
Loans outstanding	$ 30,800
Number of hotel properties | property	6
Commercial Loan Portfolio | Special Mention | Commercial Loan Relationship Two
Classes of the loan portfolio summarized by credit quality indicators:
Number of loans | loan	2
Loans outstanding	$ 30,000
Number of real estate projects | loan	3
Commercial Loan Portfolio | Special Mention | Commercial Loan Relationship Three
Classes of the loan portfolio summarized by credit quality indicators:
Loans outstanding	$ 3,400
Commercial Loan Portfolio | Special Mention | Commercial Loan Relationship Four
Classes of the loan portfolio summarized by credit quality indicators:
Loans outstanding	2,200
Commercial Loan Portfolio | Special Mention | Loan Relationship Five
Classes of the loan portfolio summarized by credit quality indicators:
Loans outstanding	$ 11,700
Commercial Loan Portfolio | Special Mention | Other Loan Relationships
Classes of the loan portfolio summarized by credit quality indicators:
Number of loans | loan	2
Commercial Loan Portfolio | Special Mention | Risk Grade Downgrade
Classes of the loan portfolio summarized by credit quality indicators:
Loans outstanding	$ 66,400
Commercial Loan Portfolio | Substandard
Classes of the loan portfolio summarized by credit quality indicators:
Increase (decrease) in loans	$ 537
Number of loans | loan	2
Commercial Loan Portfolio | Substandard | Commercial Loan Relationship One
Classes of the loan portfolio summarized by credit quality indicators:
Loans outstanding	$ 4,800
Commercial Loan Portfolio | Substandard | Risk Grade Downgrade
Classes of the loan portfolio summarized by credit quality indicators:
Increase (decrease) in loans	(1,800)
Loans outstanding	6,700
Residential Real Estate
Classes of the loan portfolio summarized by credit quality indicators:
Total Loans	279,626		$ 271,604
Residential Real Estate | Substandard | Risk Grade Downgrade
Classes of the loan portfolio summarized by credit quality indicators:
Loans outstanding	$ 451