Derivatives and Hedging Activities (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) instrument	Dec. 31, 2016 USD ($) instrument
Derivative [Line Items]
Derivative instruments in accumulated other comprehensive income reclassified to interest expense	$ 81
Derivative liabilities	746
Collateral against obligations	$ 1,300
Derivatives Not Designated as a Hedging Instruments [Member] | Interest rate products [Member]
Derivative [Line Items]
Number of derivative instruments held (in instrument) | instrument	40	36
Derivative notional amount	$ 629,100	$ 582,200
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Number of outstanding derivatives | instrument	1
Derivative liability, notional amount	$ 40,000