Business Combinations (Additional Information) (Details) $ / shares in Units, $ in Thousands	Jul. 01, 2019 USD ($) office $ / shares shares	Jun. 30, 2020 USD ($) office	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jun. 30, 2019 USD ($)	Jun. 28, 2019 $ / shares	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Business Acquisition [Line Items]
Number of banking offices | office		74
Assets		$ 4,851,051		$ 4,397,672
Equity		594,674	$ 583,540	573,820	$ 499,411		$ 479,187	$ 458,640
Goodwill		$ 121,956		$ 121,306
Citizens First
Business Acquisition [Line Items]
Direct acquisition costs	$ 3,300
Goodwill	17,739
Intangible assets	4,547
Non-deductible goodwill for tax purposes	$ 17,700
Cash portion, cash per share for common stock converted (USD per share) | $ / shares	$ 5.80
Number of the Company's common stock for each share converted (in shares) | shares	0.6629
Shares of common stock issued for acquisition (in shares) | shares	1,664,000
Aggregate amount of cash consideration paid	$ 15,500
Citizens First | Acquired Non-impaired Loans
Business Acquisition [Line Items]
Fair value of non-impaired loans and customers receivables acquired	349,900
Unpaid principal balance non-impaired loans and customers receivables acquired	353,300
Citizens First | CFB 401(k) Plan Shares
Business Acquisition [Line Items]
Cash portion, cash per share for common stock converted (USD per share) | $ / shares						$ 25.77
Additional cash per share for common stock converted (USD per share) | $ / shares						$ 5.80
Citizens First | Core Deposits
Business Acquisition [Line Items]
Intangible assets	$ 4,500
Weighted average useful live of acquired intangibles	8 years
Citizens First
Business Acquisition [Line Items]
Number of banking offices | office	8
Assets	$ 456,000
Equity	$ 49,800