Commitments and Contingencies (Financial Instruments with Off Balance Sheet Risk) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Interest Rate Commitments [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional Amount	$ 112,083	$ 49,712
Commitments to sell mortgage loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional Amount	155,901	87,498
Interest rate swaps with customers [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional Amount	446,268	302,142
Mirror swaps with counterparties [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional Amount	446,268	302,142
Risk participation-in agreement [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional Amount	21,474	21,474
Commitments to extend credit on commerical loans [Member] | Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract amount	374,689	360,795
Commitments to extend credit on home equity lines [Member] | Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract amount	227,656	219,427
Commitments to extend credit on other loans [Member] | Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract amount	50,670	44,164
Commitments to extend credit on standby letters of credit [Member] | Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract amount	5,648	5,629
Not Designated as Hedging Instrument [Member] | Interest rate swaps with customers [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional Amount	446,300	302,100
Not Designated as Hedging Instrument [Member] | Mirror swaps with counterparties [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional Amount	446,268	302,142
Not Designated as Hedging Instrument [Member] | Risk participation-in agreement [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional Amount	$ 21,500	$ 21,500