Derivative Liabilities and Collateral Pledged (Details) - USD ($)		Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Derivative [Line Items]
Gross amounts of recognized liabilities		$ 109,815,000	$ 119,239,000	$ 138,336,000
Derivative Liabilities not subject to master netting agreements		9,600,000		10,000,000
Derivatives, Interest Rate Contracts | Subject to Master Netting Agreements
Derivative [Line Items]
Gross amounts of recognized liabilities	[1]	100,191,000		128,293,000
Gross amounts offset in the Statement of Condition	[1]	0		0
Net amounts of liabilities presented in the Statement of Condition	[1],[2]	100,191,000		128,293,000
Derivative assets available for offset	[1]	(15,750,000)		(26,475,000)
Collateral pledged	[1]	(68,775,000)		(88,935,000)
Net amount	[1]	$ 15,666,000		$ 12,883,000

[1] 2015 and 2014 are comprised entirely of interest rate derivative contracts.

[2] In cluded in Derivative l iabilities on the Consolidated Condensed Statements of Condition. As of June 30 , 201 5 and 201 4 , $ 9 . 6 million and $ 10.0 million, respectively, of derivative liabilities (primarily fixed income forward contracts) have been excluded from these tables because they are generally not subject to master netting or similar agreements.