Fair Value Measurements - Significant Unobservable Inputs (Level 3) Used in Valuation of Assets and Liabilities Measured at Fair Value on Non-Recurring Basis (Details) - Level 3 $ in Thousands	Sep. 30, 2018 USD ($)
Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Fair Value	$ 14,207
OREO
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Fair Value	$ 4,162
Measurement Input, Price Volatility | Minimum | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Debt instrument, measurement input	0.04
Measurement Input, Price Volatility | Minimum | OREO
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
OREO, measurement input	0.04
Measurement Input, Price Volatility | Maximum | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Debt instrument, measurement input	0.10
Measurement Input, Price Volatility | Maximum | OREO
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
OREO, measurement input	0.10