Derivative Financial Instruments (Details 4) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Offsetting of financial liabilities and derivative liabilities
Gross Amounts of Recognized Liabilities	$ 134,592	$ 128,324
Gross Amounts Offset in the Statement of Financial Position	534	617
Net Amounts of Liabilities Presented in the Statement of Financial Position	134,058	127,707
Gross amounts not offset in the Statement of Financial Position
Financial Instruments	124,339	117,620
Cash Collateral Pledged	9,032	8,409
Net Amount	687	1,678
Repurchase agreements
Offsetting of financial liabilities and derivative liabilities
Gross Amounts of Recognized Liabilities	124,339	117,620
Net Amounts of Liabilities Presented in the Statement of Financial Position	124,339	117,620
Gross amounts not offset in the Statement of Financial Position
Financial Instruments	124,339	117,620
Interest rate swaps
Offsetting of financial liabilities and derivative liabilities
Gross Amounts of Recognized Liabilities	10,253	10,704
Gross Amounts Offset in the Statement of Financial Position	534	617
Net Amounts of Liabilities Presented in the Statement of Financial Position	9,719	10,087
Gross amounts not offset in the Statement of Financial Position
Cash Collateral Pledged	9,032	8,409
Net Amount	$ 687	$ 1,678