Derivative Instruments (Derivative Assets Offset in The Consolidated Balance Sheets) (Details) - Interest Rate Swap $ in Thousands	Mar. 31, 2018 USD ($)
Customer Counterparties Loan Interest Rate Swap Assets [Member] | Non-hedging interest rate derivatives:
Offsetting Assets [Line Items]
Gross amounts of recognized assets	$ 2,039
Net Amounts of Assets presented in the Statement of Financial Position	2,039
Fair Value of collateral	2,039
Total Gross amounts not offset in the statement of financial position including applicable netting agreement and fair value of collateral	2,039
Net Amount	0
Financial Institution Counterparties Loan Interest Rate Swap Asset [Member] | Non-hedging interest rate derivatives:
Offsetting Assets [Line Items]
Gross amounts of recognized assets	19,620
Net Amounts of Assets presented in the Statement of Financial Position	19,620
Fair Value of collateral	0
Total Gross amounts not offset in the statement of financial position including applicable netting agreement and fair value of collateral	0
Net Amount	19,620
Financial Institution Counterparties Loan Interest Rate Swap Asset [Member] | Derivatives designated as hedges of fair value:
Offsetting Assets [Line Items]
Gross amounts of recognized assets	93
Net Amounts of Assets presented in the Statement of Financial Position	93
Fair Value of collateral	70
Total Gross amounts not offset in the statement of financial position including applicable netting agreement and fair value of collateral	70
Net Amount	$ 23