Fair Value Measurement, Key Methods and Assumptions Used (Details) - Selling Costs [Member]	Dec. 31, 2018	Dec. 31, 2017
Collateral, Market, Income, Enterprise, Liquidation and Discounted Cash Flows [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Abstract]
Impaired loans, measurement input	0.06	0.06
Collateral, Market, Income, Enterprise, Liquidation and Discounted Cash Flows [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Abstract]
Impaired loans, measurement input	0.1	0.1
Collateral [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Abstract]
Other real estate owned, measurement input	0.06	0.06
Collateral [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Abstract]
Other real estate owned, measurement input	0.1	0.1