Commitments and Contingent Liabilities (Details) $ in Millions	Mar. 31, 2016 USD ($)
Commitments to extend credit	$ 127.8
Standby letters of credit	$ 2.9

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