Derivative Financial Instruments (Details 4) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Offsetting of financial liabilities and derivative liabilities
Gross Amounts of Recognized Liabilities	$ 129,370	$ 155,124
Gross Amounts Offset in the Statement of Financial Position	18	27
Net Amounts of Liabilities Presented in the Statement of Financial Position	129,352	155,097
Gross amounts Not Offset in the Statement of Financial Position
Financial Instruments	123,913	149,835
Cash Collateral Pledged	365	2,705
Net Amount	5,074	2,557
Interest rate swaps
Offsetting of financial liabilities and derivative liabilities
Gross Amounts of Recognized Liabilities	5,457	5,289
Gross Amounts Offset in the Statement of Financial Position	18	27
Net Amounts of Liabilities Presented in the Statement of Financial Position	5,439	5,262
Gross amounts Not Offset in the Statement of Financial Position
Cash Collateral Pledged	365	2,705
Net Amount	5,074	2,557
Repurchase agreements
Offsetting of financial liabilities and derivative liabilities
Gross Amounts of Recognized Liabilities	123,913	149,835
Net Amounts of Liabilities Presented in the Statement of Financial Position	123,913	149,835
Gross amounts Not Offset in the Statement of Financial Position
Financial Instruments	$ 123,913	$ 149,835