Regulatory Matters (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio	8.00%
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio	6.00%
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio	4.50%
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Ratio	4.00%
Total Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio	10.00%
Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio	8.00%
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio	6.50%
Tier 1 Capital (to Average Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio	5.00%
SmartFinancial, Inc. [Member]
Total Capital (to Risk-Weighted Assets), Actual Amount	$ 99,616
Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	95,253
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	83,253
Tier 1 Capital (to Average Assets), Actual Amount	$ 95,253
Total Capital (to Risk-Weighted Assets), Actual Ratio	12.32%
Tier 1 Capital (to Risk-Weighted Assets), Actual Ratio	11.78%
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Ratio	10.30%
Tier 1 Capital (to Average Assets), Actual Ratio	9.45%
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	$ 64,668
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	48,501
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	36,376
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Amount	$ 40,307
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio	8.00%
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio	6.00%
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio	4.50%
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Ratio	4.00%
Total Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	$ 80,835
Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	64,668
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	52,543
Tier 1 Capital (to Average Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	$ 50,383
Total Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio	10.00%
Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio	8.00%
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio	6.50%
Tier 1 Capital (to Average Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio	5.00%
Comerstone Community Bank [Member]
Total Capital (to Risk-Weighted Assets), Actual Amount	$ 40,227
Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	39,717
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	39,717
Tier 1 Capital (to Average Assets), Actual Amount	$ 39,717
Total Capital (to Risk-Weighted Assets), Actual Ratio	11.69%
Tier 1 Capital (to Risk-Weighted Assets), Actual Ratio	11.53%
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Ratio	11.53%
Tier 1 Capital (to Average Assets), Actual Ratio	9.05%
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	$ 27,559
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	20,669
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	15,502
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Amount	$ 17,550
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio	8.00%
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio	6.00%
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio	4.50%
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Ratio	4.00%
Total Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	$ 34,449
Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	27,559
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	22,392
Tier 1 Capital (to Average Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	$ 21,938
Total Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio	10.00%
Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio	8.00%
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio	6.50%
Tier 1 Capital (to Average Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio	5.00%
Smart Bank [Member]
Total Capital (to Risk-Weighted Assets), Actual Amount	$ 60,349	$ 59,088
Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	56,546	55,457
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	56,546
Tier 1 Capital (to Average Assets), Actual Amount	$ 56,546	$ 55,457
Total Capital (to Risk-Weighted Assets), Actual Ratio	13.03%	14.73%
Tier 1 Capital (to Risk-Weighted Assets), Actual Ratio	12.21%	13.83%
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Ratio	12.21%
Tier 1 Capital (to Average Assets), Actual Ratio	10.05%	10.83%
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	$ 37,057	$ 32,085
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	27,793	16,042
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	20,845
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Amount	$ 22,501	$ 20,475
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio	8.00%	8.00%
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio	6.00%	4.00%
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio	4.50%
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Ratio	4.00%	4.00%
Total Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	$ 46,322	$ 40,106
Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	37,057	24,064
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	30,109
Tier 1 Capital (to Average Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	$ 28,126	$ 25,594
Total Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio	8.00%	6.00%
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio	6.50%
Tier 1 Capital (to Average Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio	5.00%	5.00%