Derivatives and Hedging Activities (Derivative Financial Instruments included in OCI and Current Earnings) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Gain in OCI on derivatives (effective portion), net of tax	$ 290	$ (292)	$ (500)	$ (667)
Derivatives designated as hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain in OCI on derivatives (effective portion), net of tax	674	132	653	596
Loss reclassified from OCI into interest expense (effective portion)	(648)	(715)	(1,949)	(2,130)
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	0	0
Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Other income	61	213	444	72
Interest Expense [Member] | Derivatives designated as hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	0	0
Other expense | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Other income	(42)	39	71	56
Changes in fair value of mortgage derivatives | Derivatives designated as hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	0	0
Changes in fair value of mortgage derivatives | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Other income	(12)	0	(46)	(51)
Total | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Mortgage banking income	$ 115	$ 174	$ 419	$ 67