Commitments and Contingencies (Summary of Contractual and Notional Amounts of Financial Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Home Equity Line of Credit [Member]
Financial Instruments [Line Items]
Contractual amounts of financial instrument	$ 454,225	$ 464,701
Commercial And Commercial Real Estate [Member]
Financial Instruments [Line Items]
Contractual amounts of financial instrument	83,103	94,791
Mortgage Loan Commitments [Member]
Financial Instruments [Line Items]
Contractual amounts of financial instrument	17,795	16,256
Letter of Credit [Member]
Financial Instruments [Line Items]
Contractual amounts of financial instrument	2,580	4,468
Other Commitments [Member]
Financial Instruments [Line Items]
Contractual amounts of financial instrument	432	433
Customer loan swaps
Financial Instruments [Line Items]
Notional amount of derivative	532,526	285,888
Forward-Starting Interest Rate Swap [Member]
Financial Instruments [Line Items]
Notional amount of derivative	50,000	50,000
Interest rate swaps
Financial Instruments [Line Items]
Notional amount of derivative	43,000	43,000
Interest Rate Lock Commitments [Member]
Financial Instruments [Line Items]
Notional amount of derivative	15,249	20,735
Forward Contracts [Member]
Financial Instruments [Line Items]
Notional amount of derivative	$ 15,125	$ 0