Derivatives (Offsetting Derivatives Liabilities) (Details) (Interest Rate Swap [Member], USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Interest Rate Swap [Member]
Derivative Liabilities
Derivative Liabilities, Gross Amounts of Recognized Liabilities	$ 8,893	$ 22,048
Derivative Liabilities, Gross Amounts Offset in the Statement of Financial Position	0	0
Derivatives Liabilities, Net Amounts of Liabilities presented in the Statement of Financial Position	8,893	22,048
Derivative Liability, Fair Value, Amount Not Offset Against Collateral [Abstract]
Derivative Liabilities, Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	(2,303)	(16)
Derivative Liabilities, Gross Amounts Not Offset in the Statement of Financial Position, Collateral Posted	(4,068)	(22,032)
Derivative Liabilities, Net Amount	$ 2,522	$ 0