Securities Sold Under Agreements To Repurchase And Collateral Pledged By Counterparties (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Securities Sold Under Agreements To Repurchase [Abstract]
Gross amounts of recognized liabilities	$ 341,998		$ 332,329
Gross amounts offset in the statement of Condition	0		0
Net amounts of liabilities presented in the Statement of Condition	341,998	$ 338,133	332,329
Offsetting securities purchased under agreements to resell	(1,632)		(2,909)
Securities Collateral	(340,047)		(329,420)
Net amount	$ 319		$ 0