Offsetting Assets and Liabilties - Offsetting of Liabilties (Details) (Repurchase Agreements [Member], USD $)	Mar. 31, 2015	Dec. 31, 2014
Repurchase Agreements [Member]
Offsetting Liabilities [Line Items]
Gross Amount Of Recognized Liabilties	$ 106,294,000	$ 109,964,000
Gross Amount Of Liabilties Offset In The Balance Sheet	0	0
Net Amount Of Liabilities Presented In The Balance Sheet	106,294,000	109,964,000
Gross Amount Of Financial Instruments Posted Not Offset in Balance Sheet	(106,058,000)	(109,706,000)
Gross Amounts Of Cash Posted Not Offset In Balance Sheet	(236,000)	(258,000)
Net Amount Of Liabilities	$ 0	$ 0