Derivative Financial Instruments (Derivatives in Cash Flow Hedging Relationships, Effect in Statements of Changes in Shareholders' Equity and Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income, Net of Tax (Effective Portion)	$ (52)	$ (257)	$ 244
Other Comprehensive Income (Loss) [Member] | Interest rate swaps [Member] | Cash Flow Hedge [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income, Net of Tax (Effective Portion)	358	(224)	288
Other Comprehensive Income (Loss) [Member] | Interest rate caps [Member] | Cash Flow Hedge [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income, Net of Tax (Effective Portion)	(64)	(33)	(44)
Other Comprehensive Income (Loss) [Member] | Interest rate floors [Member] | Cash Flow Hedge [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income, Net of Tax (Effective Portion)	$ (346)	$ 0	$ 0