Derivative Liabilities and Collateral Pledged (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013	Mar. 31, 2013
Derivative Line Items
Gross amounts of recognized liabilities	$ 137,863,000		$ 154,280,000	$ 199,999,000
Derivative Liabilities not subject to master netting agreements	7,700,000			18,600,000
Subject to Master Netting Agreements
Derivative Line Items
Gross amounts of recognized liabilities	130,180,000	[1]		181,362,000	[1]
Gross amounts offset in the Statement of Condition	0			0
Net amounts of liabilities presented in the Statement of Condition	130,180,000	[1],[2]		181,362,000	[1],[2]
Derivative assets available for offset	(33,495,000)			(22,582,000)
Collateral pledged	(91,331,000)			(153,870,000)
Net amount	5,354,000			4,910,000
Interest Rate Contract [Member] | Subject to Master Netting Agreements
Derivative Line Items
Gross amounts of recognized liabilities	130,180,000			181,362,000
Net amounts of liabilities presented in the Statement of Condition	$ 130,180,000			$ 181,362,000

[1] 2014 and 2013 are comprised entirely of interest rate derivative contracts.

[2] Included in Derivative Liabilities on the Consolidated Condensed Statements of Condition. As of March 31, 2014 and 2013, $7.7 million and $18.6 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.