Financial Derivatives (Schedule of Effect of Derivative Instruments on the Statement of Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Location of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	Interest Expense	Interest Expense
Location of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	Other income (expense)	Other income (expense)
Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion)	$ 0	$ 0
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in OCI net of tax on (Effective Portion)	120	139
Other Income (Expense) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	$ (180)	$ (181)