Employee Benefit Plans (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) plan shares	Dec. 31, 2020 USD ($) shares
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, cost recognized	$ 1,300	$ 1,100
Number of stock option plans | plan	1
Deferred tax benefit from stock options exercised	$ 13	$ 18
Shares vested (in shares) | shares	0	0
Stock Options [Member]
Defined Benefit Plan Disclosure [Line Items]
Options, exercises in period, intrinsic value	$ 233	$ 190
Options, outstanding, intrinsic value	792
Options, exercisable, intrinsic value	1,400
Proceeds from options exercised	205
Stock Appreciation Rights (SARs) [Member]
Defined Benefit Plan Disclosure [Line Items]
Share-based compensation expense	$ 256	$ 51
Granted (in shares) | shares	22,000	18,000
Exercise of options | shares	34,000
Restricted Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Share-based compensation expense	$ 693	$ 482
Unrecognized compensation cost	$ 1,400
Unrecognized compensation costs, period for recognition	2 years 5 months 15 days
Grant-date fair value	$ 154
Vested (in shares) | shares	7,185
2015 Stock Incentive Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Rights issued (in shares) | shares	18,401
Rights available for grant (in shares) | shares	1,830,260
Cornerstone Bancshares, Inc. Long-Term Incentive Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Rights issued (in shares) | shares	19,250
Cornerstone Non-Qualified Plan Options [Member]
Defined Benefit Plan Disclosure [Line Items]
Rights issued (in shares) | shares	39,750
Capstone Stock Option Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Rights issued (in shares) | shares	2,266
401 (k) Matching Range One [Member] | Deferred Salary Reduction Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	100.00%
Employer matching contribution, percent of employees gross pay	3.00%
401 (k) Matching Range Two [Member] | Deferred Salary Reduction Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	50.00%
Employer matching contribution, percent of employees gross pay	2.00%