Fair Value Measurements - Significant Unobservable Inputs (Level 3) Used in Valuation of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Trust preferred securities $ in Thousands	Sep. 30, 2018 USD ($)
Significant unobservable inputs (Level 3) used in the valuation of assets and liabilities measured at fair value on a recurring basis
Fair Value	$ 10,304
Measurement Input, Price Volatility | Minimum
Significant unobservable inputs (Level 3) used in the valuation of assets and liabilities measured at fair value on a recurring basis
Range of Inputs	0.00
Measurement Input, Price Volatility | Maximum
Significant unobservable inputs (Level 3) used in the valuation of assets and liabilities measured at fair value on a recurring basis
Range of Inputs	1.00