Quarterly report pursuant to Section 13 or 15(d)

Available-for-sale Securities Classified by Rate Type (Details)

v2.4.0.8
Available-for-sale Securities Classified by Rate Type (Details) (USD $)
In Thousands, unless otherwise specified
Sep. 30, 2014
Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Adjustable Rate $ 2,635,890 $ 3,409,699
Available-for-sale Securities, Fixed Rate 10,062,018 8,847,028
Available-for-sale securities, at fair value 12,697,908 12,256,727
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Adjustable Rate 132,157 1,006,621
Available-for-sale Securities, Fixed Rate 9,566,255 8,490,788
Available-for-sale securities, at fair value 9,698,412 9,497,409
Mortgage-backed Securities, Issued by Private Enterprises [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Adjustable Rate 2,503,733 2,403,078
Available-for-sale Securities, Fixed Rate 495,763 356,240
Available-for-sale securities, at fair value $ 2,999,496 $ 2,759,318