Loans and Allowance for Loan Losses - Summary of Individually Impaired Loans by Class of Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Financing Receivable, Impaired [Line Items]
With no related allowance recorded unpaid principal balance	$ 21,286	$ 19,512
With an related allowance recorded unpaid principal balance	899	997
Unpaid Principal Balance	22,185	20,509
With no related allowance recorded investment	16,689	14,925
With an related allowance recorded, recorded investment	884	985
Recorded Investment	17,573	15,910
Related Allowance	852	748
Commercial, Industrial and Agricultural
Financing Receivable, Impaired [Line Items]
With no related allowance recorded unpaid principal balance	1,294	1,400
With an related allowance recorded unpaid principal balance	859	859
With no related allowance recorded investment	245	367
With an related allowance recorded, recorded investment	847	847
Related Allowance	847	717
Real Estate \| 1-4 Family Residential
Financing Receivable, Impaired [Line Items]
With no related allowance recorded unpaid principal balance	2,490	3,034
With an related allowance recorded unpaid principal balance	0	104
With no related allowance recorded investment	2,072	2,473
With an related allowance recorded, recorded investment	0	104
Related Allowance	0	18
Real Estate \| 1-4 Family HELOC
Financing Receivable, Impaired [Line Items]
With no related allowance recorded unpaid principal balance	311	130
With an related allowance recorded unpaid principal balance	0	0
With no related allowance recorded investment	298	124
With an related allowance recorded, recorded investment	0	0
Related Allowance	0	0
Real Estate \| Multi-family and Commercial
Financing Receivable, Impaired [Line Items]
With no related allowance recorded unpaid principal balance	6,856	4,549
With an related allowance recorded unpaid principal balance	0	0
With no related allowance recorded investment	5,407	3,161
With an related allowance recorded, recorded investment	0	0
Related Allowance	0	0
Real Estate \| Construction, Land Development and Farmland
Financing Receivable, Impaired [Line Items]
With no related allowance recorded unpaid principal balance	6,619	6,809
With an related allowance recorded unpaid principal balance	0	0
With no related allowance recorded investment	6,234	6,452
With an related allowance recorded, recorded investment	0	0
Related Allowance	0	0
Consumer
Financing Receivable, Impaired [Line Items]
With no related allowance recorded unpaid principal balance	3,716	3,590
With an related allowance recorded unpaid principal balance	40	34
With no related allowance recorded investment	2,433	2,348
With an related allowance recorded, recorded investment	37	34
Related Allowance	$ 5	$ 13

Reliant Bancorp, Inc. 10-Q