Annual report pursuant to Section 13 and 15(d)

Derivative Instruments and Hedging Activities Interest Rate Sensitive Assets/Liabilities (Details)

v2.4.0.6
Derivative Instruments and Hedging Activities Interest Rate Sensitive Assets/Liabilities (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Derivatives, Fair Value [Line Items]    
Available-for-sale Securities, Interest-only $ 77,342 $ 48,372
Agency To-be-Announced Securities, Notional Amount, Long 1,753,000 275,000
Agency To-be-Announced Securities, Notional Amount, Short 800,000 850,000
Agency To-be-Announced Securities, Fair Value, Asset 1,917 2,664
Agency To-be-Announced Securities, Fair Value, Liability $ (239) $ (5,652)