Fair Value Measurement (Fair Value Inputs, Assets, Quantitative Information) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Impaired Loan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Techniques	Appraisal of collateral	Appraisal of collateral
Fair Value Disclosure, Unobservable Input Range	Appraisal adjustments	Appraisal adjustments
Impaired Loan [Member] | Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 1,015	$ 4,935
Impaired Loan [Member] | Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 1,015	$ 4,935
Foreclosed Assets Held for Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Techniques	Appraisal of collateral	Appraisal of collateral
Fair Value Disclosure, Unobservable Input Range	Appraisal adjustments	Appraisal adjustments
Foreclosed Assets Held for Sale [Member] | Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 168	$ 581
Foreclosed Assets Held for Sale [Member] | Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 168	$ 581
Minimum [Member] | Discount Rate [Member] | Appraisal of Collateral [Member] | Impaired Loan [Member] | Unobservable Input - Appraisal Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	26.00%	6.00%
Minimum [Member] | Discount Rate [Member] | Appraisal of Collateral [Member] | Foreclosed Assets Held for Sale [Member] | Unobservable Input - Appraisal Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	17.00%	0.00%
Maximum [Member] | Discount Rate [Member] | Appraisal of Collateral [Member] | Impaired Loan [Member] | Unobservable Input - Appraisal Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	100.00%	51.00%
Maximum [Member] | Discount Rate [Member] | Appraisal of Collateral [Member] | Foreclosed Assets Held for Sale [Member] | Unobservable Input - Appraisal Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	17.00%	0.00%
Weighted Average [Member] | Discount Rate [Member] | Appraisal of Collateral [Member] | Impaired Loan [Member] | Unobservable Input - Appraisal Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	36.00%	28.00%
Weighted Average [Member] | Discount Rate [Member] | Appraisal of Collateral [Member] | Foreclosed Assets Held for Sale [Member] | Unobservable Input - Appraisal Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	27.00%	0.00%