Loans And Allowance for Credit Losses (Collateral-Dependent Loans) (Details) - Commercial Portfolio Segment [Member] $ in Thousands	Mar. 31, 2020 USD ($)
Financing Receivable, Credit Quality Indicator [Line Items]
Collateral Dependent Loans, Amortized Cost	$ 7,560
Business [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Collateral Dependent Loans, Business, Amortized Cost	7,020
Real Estate - Business [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Collateral Dependent Loans, Business Real Estate, Amortized Cost	540
Business Assets
Financing Receivable, Credit Quality Indicator [Line Items]
Collateral Dependent Loans, Amortized Cost	149
Business Assets | Business [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Collateral Dependent Loans, Business, Amortized Cost	149
Business Assets | Real Estate - Business [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Collateral Dependent Loans, Business Real Estate, Amortized Cost	0
Future Revenue Streams
Financing Receivable, Credit Quality Indicator [Line Items]
Collateral Dependent Loans, Amortized Cost	3,996
Future Revenue Streams | Business [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Collateral Dependent Loans, Business, Amortized Cost	3,996
Future Revenue Streams | Real Estate - Business [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Collateral Dependent Loans, Business Real Estate, Amortized Cost	0
Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Collateral Dependent Loans, Amortized Cost	540
Real Estate | Business [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Collateral Dependent Loans, Business, Amortized Cost	0
Real Estate | Real Estate - Business [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Collateral Dependent Loans, Business Real Estate, Amortized Cost	540
Energy Service
Financing Receivable, Credit Quality Indicator [Line Items]
Collateral Dependent Loans, Amortized Cost	2,876
Energy Service | Business [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Collateral Dependent Loans, Business, Amortized Cost	2,876
Energy Service | Real Estate - Business [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Collateral Dependent Loans, Business Real Estate, Amortized Cost	$ 0