Derivative Liabilities and Collateral Pledged (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012	Sep. 30, 2012
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Gross amounts of recognized liabilities	$ 165,918,000		$ 202,269,000	$ 225,084,000
Derivative Liabilities not subject to master netting agreements	12,500,000			14,800,000
Subject to Master Netting Agreements
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Gross amounts of recognized liabilities	153,403,000	[1]		210,320,000	[1]
Gross amounts offset in the Statement of Condition	0			0
Net amounts of liabilities presented in the Statement of Condition	153,403,000	[1],[2]		210,320,000	[1],[2]
Derivative assets available for offset	(36,770,000)			(20,218,000)
Collateral pledged	(109,079,000)			(185,230,000)
Net amount	7,554,000			4,872,000
Interest Rate Contract [Member] | Subject to Master Netting Agreements
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Gross amounts of recognized liabilities	153,400,000			210,300,000
Net amounts of liabilities presented in the Statement of Condition	$ 153,400,000			$ 210,300,000

[1] 2013 and 2012 includes $153.4 million and $210.3 million, respectively, of interest rate derivative contracts.

[2] Included in Derivative Liabilities on the Consolidated Condensed Statements of Condition. As of September 30, 2013 and 2012, $12.5 million and $14.8 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.