Loans and Allowance - Summary of Troubled Debt Restructurings by Modification Type (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification	$ 164	$ 125	$ 253	$ 416
Term Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification	0		0	97
Rate Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification	0	91	89	180
Combination
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification	164	34	164	139
Residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification	164	125	253	339
Residential | Term Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification			0	37
Residential | Rate Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification	0	91	89	163
Residential | Combination
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification	$ 164	$ 34	$ 164	139
Home equity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification				70
Home equity | Term Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification				60
Home equity | Rate Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification				10
Home equity | Combination
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification				0
Individuals' loans for household and other personal expenditures
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification				7
Individuals' loans for household and other personal expenditures | Term Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification				0
Individuals' loans for household and other personal expenditures | Rate Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification				7
Individuals' loans for household and other personal expenditures | Combination
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modification				$ 0