Commitments and Contingencies (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments to extend credit	$ 669,770	$ 476,841
Standby letters of credit	$ 17,868	$ 5,261

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