Regulatory Matters (Regulatory Capital Levels) (Details) $ in Thousands	Sep. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
SmartFinancial, Inc. [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital (to Risk-Weighted Assets), Actual Amount	$ 449,546	$ 425,957
Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	380,272	360,608
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	380,272	360,608
Tier 1 Capital (to Average Assets), Actual Amount	$ 380,272	$ 360,608
Total Capital (to Risk-Weighted Assets), Actual Ratio (as a percent)	0.1190	0.1140
Tier 1 Capital (to Risk-Weighted Assets), Actual Ratio (as a percent)	0.1007	0.0965
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Ration (as percent)	0.1007	0.0965
Tier 1 Capital (to Average Assets), Actual Ratio (as a percent)	0.0813	0.0795
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	$ 302,100	$ 298,966
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	226,575	224,224
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	169,931	168,168
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Amount	$ 187,074	$ 181,387
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio (as a percent)	0.0800	0.0800
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio (as a percent)	0.0600	0.0600
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio (as a percent)	0.0450	0.0450
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Ratio (as a percent)	0.0400	0.0400
Smart Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital (to Risk-Weighted Assets), Actual Amount	$ 447,326	$ 426,947
Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	420,130	403,613
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	420,130	403,613
Tier 1 Capital (to Average Assets), Actual Amount	$ 420,130	$ 403,613
Total Capital (to Risk-Weighted Assets), Actual Ratio (as a percent)	0.1187	0.1144
Tier 1 Capital (to Risk-Weighted Assets), Actual Ratio (as a percent)	0.1115	0.1082
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Ration (as percent)	0.1115	0.1082
Tier 1 Capital (to Average Assets), Actual Ratio (as a percent)	0.0900	0.0890
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	$ 301,538	$ 298,476
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	226,153	223,857
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	169,615	167,892
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Amount	$ 186,792	$ 181,383
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio (as a percent)	0.0800	0.0800
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio (as a percent)	0.0600	0.0600
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio (as a percent)	0.0450	0.0450
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Ratio (as a percent)	0.0400	0.0400
Total Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	$ 376,922	$ 373,094
Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	301,538	298,476
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	244,999	242,511
Tier 1 Capital (to Average Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	$ 233,490	$ 226,729
Total Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio (as a percent)	0.1000	0.1000
Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio (as a percent)	0.0800	0.0800
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio (as a percent)	0.0650	0.0650
Tier 1 Capital (to Average Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio (as a percent)	0.0500	0.0500