Derivative Financial Instruments, Offsetting Derivative Assets and Liabilities (Details) (Interest Rate Swap [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Interest Rate Swap [Member]
Offsetting Derivative Assets [Abstract]
Gross Amounts of Recognized Assets, Offsetting of Derivative Assets	$ 3,025	$ 7,431
Gross Amounts Offset in the Statement of Financial Position, Offsetting of Derivative Assets	0	0
Net Amounts of Assets presented in the Statement of Financial Position, Offsetting of Derivative Assets	3,025	7,431
Financial Instruments, Gross Amounts Not Offset in the Statement of Financial Position, Offsetting of Derivative Assets	(347)	(967)
Cash Collateral Received, Gross Amounts Not Offset in the Statement of Financial Position, Offsetting of Derivative Assets	0	(1,920)
Net Amount, Offsetting of Derivative Assets	2,678	4,544
Offsetting Derivative Liabilities [Abstract]
Gross Amounts of Recognized Liabilities, Offsetting of Derivative Liabilities	2,813	4,628
Gross Amounts Offset in the Statement of Financial Position, Offsetting of Derivative Liabilities	0	0
Net Amounts of Liabilities presented in the Statement of Financial Position, Offsetting of Derivative Liabilities	2,813	4,628
Financial Instruments, Gross Amounts Not Offset in the Statement of Financial Position, Offsetting of Derivative Liabilities	(347)	(967)
Cash Collateral Posted, Gross Amounts Not Offset in the Statement of Financial Position, Offsetting of Derivative Liabilities	0	0
Net Amount, Offsetting of Derivative Liabilities	$ 2,466	$ 3,661