Quarterly report pursuant to Section 13 or 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
Jun. 30, 2012
Dec. 31, 2011
Assets Sold under Agreements to Repurchase [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability $ 10,438,441 $ 6,660,148
Maturity up to 30 days [Member]
    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability 3,167,682 1,967,009
Maturity 30 to 59 Days [Member]
    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability 2,326,103 1,263,060
Maturity 60 to 89 Days [Member]
    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability 1,692,465 1,096,410
Maturity 90 to 119 Days [Member]
    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability 730,244 359,171
Maturity 120 to 364 days [Member]
    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability 1,395,702 923,248
Maturity on Demand [Member]
    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability 997,500 1,001,250
Maturity Over One Year [Member]
    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability $ 128,745 $ 50,000