Commitments and Contingencies (Details) $ in Millions	Dec. 31, 2016 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Commitments to extend credit	$ 145.3
Standby letters of credit, issued by the Company	$ 3.2

Contractual amount for all off-balance sheet commitments.

No definition available.

Name:	smbk_OutstandingOffBalanceSheetRisksAmountLiability
Namespace Prefix:	smbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant