Derivatives and Hedging Activities (Narrative) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Derivative [Line Items]
Term of written loan commitments, days	60
Default assumptions percentage	100.00%
Credit derivative, maximum exposure, undiscounted	$ 7,100
Government Agency Issued Bonds or MBS
Derivative [Line Items]
Collateral posted against derivative liabilities	55,900	$ 47,200	$ 45,600
Designated as Hedging Instrument | Interest Rate Swap
Derivative [Line Items]
Derivative asset, notional amount	$ 250,000	$ 250,000	$ 250,000	$ 250,000
Minimum | Equity Swap
Derivative [Line Items]
Maturity of credit risk derivatives	2 years
Minimum | Credit Risk Contract
Derivative [Line Items]
Maturity of credit risk derivatives	1 year
Maximum | Equity Swap
Derivative [Line Items]
Maturity of credit risk derivatives	7 years
Maximum | Credit Risk Contract
Derivative [Line Items]
Maturity of credit risk derivatives	9 years