Derivatives and Hedging Activities (Derivative Financial Instruments included in OCI and Current Earnings) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Derivatives designated as hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain reclassified from OCI into interest income or interest expense (effective portion)	$ 424	$ 90
Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Other income	71	8
Other expense | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Other income	13	9
Changes in fair value of mortgage derivatives | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Other income	(1)	(13)
Total | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Mortgage banking income	59	12
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	$ 3,285	$ 215