Fair Value Measurements - Textual (Details) $ in Thousands	3 Months Ended
	Sep. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets and other real estate owned	$ 22,664	$ 32,118
Impaired loan, related allowance	459	338
Collateral dependent
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loan, related allowance	$ 2,738	2,195
Commercial Real Estate | Discount Rate | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input (as percent)	0.10
Commercial Real Estate | Discount Rate | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input (as percent)	0.40
Residential Real Estate | Discount Rate | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input (as percent)	0.10
Residential Real Estate | Discount Rate | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input (as percent)	0.40
Foreclosed Assets Not Covered By FDIC Loss Share
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets and other real estate owned	$ 22,700	$ 32,100
Ratings of Substandard or worse
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Threshold value for performing impairment testing on loans	$ 1,500