Annual report pursuant to Section 13 and 15(d)

Repurchase Agreements Schedule of Repurchase Agreements by Maturity (Details)

v2.4.0.6
Repurchase Agreements Schedule of Repurchase Agreements by Maturity (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2011
Dec. 31, 2010
Assets Sold under Agreements to Repurchase [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability $ 6,660,148 $ 1,169,803
Maturity up to 30 days [Member]
    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability 1,967,009 197,286
Maturity 30 to 59 Days [Member]
    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability 1,263,060 211,556
Maturity 60 to 89 Days [Member]
    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability 1,096,410 117,621
Maturity 90 to 119 Days [Member]
    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability 359,171 152,433
Maturity 120 to 364 days [Member]
    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability 923,248 292,157
Maturity on Demand [Member]
    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability 1,001,250 198,750
Maturity Over One Year [Member]
    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability $ 50,000 $ 0