Derivatives and Hedging Activities (Derivative Financial Instruments included in OCI and Current Earnings) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent	$ 215	$ 89
Derivatives designated as hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified from OCI into interest income or interest expense (effective portion)	90	(93)
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	8	37
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	9	(7)
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	(13)	(6)
Total | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Mortgage banking income	12	50
Derivatives designated as hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent	$ 215	$ 89