Derivative Financial Instruments (Derivatives in Cash Flow Hedging Relationships, Effect in Statements of Income and Changes in Shareholders' Equity) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income (Effective Portion)	$ 889	$ 98
Interest rate caps [Member] | Cash Flow Hedge [Member] | Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income (Effective Portion)	38	(33)
Interest rate swaps [Member] | Cash Flow Hedge [Member] | Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income (Effective Portion)	839	131
Interest rate floors [Member] | Cash Flow Hedge [Member] | Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income (Effective Portion)	$ 12	$ 0