Derivative Financial Instruments Derivative Financial Instruments (Schedule of Other Derivatives Not Designated as Hedging Instruments) (Details) (Interest Expense [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 79	$ 0