Derivatives (Offsetting Derivatives Liabilities) (Details) (Interest Rate Swap [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Interest Rate Swap [Member]
Derivative Liabilities
Derivative Liabilities, Gross Amounts of Recognized Liabilities	$ 40,101	$ 28,158
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	40,101	28,158
Derivative Liability, Fair Value, Amount Not Offset Against Collateral [Abstract]
Derivative Liabilities, Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	(131)
Derivative Liabilities, Gross Amounts Not Offset in the Statement of Financial Position, Collateral Posted	(40,101)	(28,027)
Derivative Liabilities, Net Amount	$ 0	$ 0