Annual report pursuant to Section 13 and 15(d)

Schedule of Available-for-sale Securities Reconciliation (Details)

v2.4.0.6
Schedule of Available-for-sale Securities Reconciliation (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Gross Unrealized Gains $ 724,696 $ 120,745
Available-for-sale Securities, Gross Unrealized Losses 28,238 179,461
Available-for-sale securities, at fair value 13,666,954 6,249,252
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Face Value 11,934,492 5,692,754
Available-for-sale Securities, Unamortized Premium 749,252 279,640
Available-for-sale Securities, Designated Credit Reserve 0 0
Available-for-sale Securities, Net, Unamortized (1,929,811) (1,008,780)
Available-for-sale Securities, Amortized Cost Basis 10,753,933 4,963,614
Available-for-sale Securities, Gross Unrealized Gains 276,293 108,864
Available-for-sale Securities, Gross Unrealized Losses (18,123) (19,321)
Available-for-sale securities, at fair value 11,012,103 5,053,157
Mortgage-backed Securities, Issued by Private Enterprises [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Face Value 4,503,999 2,667,929
Available-for-sale Securities, Unamortized Premium 0 0
Available-for-sale Securities, Designated Credit Reserve (1,290,946) (782,606)
Available-for-sale Securities, Net, Unamortized (996,490) (540,969)
Available-for-sale Securities, Amortized Cost Basis 2,216,563 1,344,354
Available-for-sale Securities, Gross Unrealized Gains 448,403 11,881
Available-for-sale Securities, Gross Unrealized Losses (10,115) (160,140)
Available-for-sale securities, at fair value 2,654,851 1,196,095
Collateralized Mortgage Backed Securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Face Value 16,438,491 8,360,683
Available-for-sale Securities, Unamortized Premium 749,252 279,640
Available-for-sale Securities, Designated Credit Reserve (1,290,946) (782,606)
Available-for-sale Securities, Net, Unamortized (2,926,301) (1,549,749)
Available-for-sale Securities, Amortized Cost Basis 12,970,496 6,307,968
Available-for-sale Securities, Gross Unrealized Gains 724,696 120,745
Available-for-sale Securities, Gross Unrealized Losses (28,238) (179,461)
Available-for-sale securities, at fair value $ 13,666,954 $ 6,249,252