Derivative Liabilities and Collateral Pledged (Details) (USD $)	Jun. 30, 2013		Dec. 31, 2012	Jun. 30, 2012
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Gross amounts of recognized liabilities	$ 198,489,000		$ 202,269,000	$ 235,490,000
Derivative Liabilities not subject to master netting agreements	36,800,000			9,800,000
Subject to Master Netting Agreements
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Gross amounts of recognized liabilities	161,720,000	[1]		225,635,000	[1]
Gross amounts offset in the Statement of Condition	0			0
Net amounts of liabilities presented in the Statement of Condition	161,720,000	[1],[2]		225,635,000	[1],[2]
Derivative assets available for offset	(37,505,000)			(34,481,000)
Collateral pledged	(116,510,000)			(186,720,000)
Net amount	7,705,000			4,434,000
Interest Rate Contract [Member] | Subject to Master Netting Agreements
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Gross amounts of recognized liabilities	161,300,000			224,500,000
Net amounts of liabilities presented in the Statement of Condition	161,300,000			224,500,000
Forwards And Futures [Member] | Subject to Master Netting Agreements
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Gross amounts of recognized liabilities	500,000			1,100,000
Net amounts of liabilities presented in the Statement of Condition	$ 500,000			$ 1,100,000

[1] 2013 includes $161.3 million of interest rate derivative contracts and $.5 million of forwards and futures contracts. 2012 includes $224.5 million of interest rate derivative contracts and $1.1 million of forwards and futures contracts.

[2] Included in Derivative Liabilities on the Consolidated Condensed Statements of Condition. As of June 30, 2013 and 2012, $36.8 million and $9.8 million, respectively, of derivative liabilities (primarily capital markets forward contracts) have been excluded from these tables because they are generally not subject to master netting or similar agreements.