Regulatory Matters (Regulatory Capital Levels) (Details) $ in Thousands	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
SmartFinancial, Inc. [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital (to Risk-Weighted Assets), Actual Amount	$ 456,659	$ 448,050
Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	393,088	385,795
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	393,088	385,795
Tier 1 Capital (to Average Assets), Actual Amount	$ 393,088	$ 385,795
Total Capital (to Risk-Weighted Assets), Actual Ratio (as a percent)	0.1185	0.1180
Tier 1 Capital (to Risk-Weighted Assets), Actual Ratio (as a percent)	0.1020	0.1016
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Ration (as percent)	0.1020	0.1016
Tier 1 Capital (to Average Assets), Actual Ratio (as a percent)	0.0823	0.0827
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	$ 308,231	$ 303,658
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	231,173	227,744
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	173,380	170,808
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Amount	$ 191,043	$ 186,672
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	$ 462,143	$ 456,134
Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	432,268	427,559
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	432,268	427,559
Tier 1 Capital (to Average Assets), Actual Amount	$ 432,268	$ 427,559
Total Capital (to Risk-Weighted Assets), Actual Ratio (as a percent)	0.1200	0.1202
Tier 1 Capital (to Risk-Weighted Assets), Actual Ratio (as a percent)	0.1123	0.1126
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Ration (as percent)	0.1123	0.1126
Tier 1 Capital (to Average Assets), Actual Ratio (as a percent)	0.0907	0.0918
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	$ 307,991	$ 303,680
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	230,993	227,760
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	173,245	170,820
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Amount	$ 190,725	$ 186,363
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	$ 384,989	$ 379,600
Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	307,991	303,680
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	250,243	246,740
Tier 1 Capital (to Average Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	$ 238,406	$ 232,954
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