Annual report pursuant to Section 13 and 15(d)

Schedule of Unrealized Loss on Investments (Details)

v2.4.0.6
Schedule of Unrealized Loss on Investments (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2011
Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]    
Available-for-Sale Securities, Number of Positions 854 373
Assets Sold under Agreements to Repurchase, Market Value $ 7,457,095 $ 1,357,264
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value 1,277,120 310,445
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses (175,348) (7,183)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value 15,608 1,405
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses (4,113) (1,009)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value 1,292,728 311,850
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses $ (179,461) $ (8,192)
Available-for-Sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Number of Positions 264 108
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Number of Positions 20 5