XML 45 R56.htm IDEA: XBRL DOCUMENT v2.4.0.6
Losses and Loss Expense Reserve - Summary of Rollforward of RMBS Subrogation, by Estimation Approach (Detail) (USD $)
In Thousands, unless otherwise specified
 9 Months Ended
Sep. 30, 2012
Transactions
Summary Of Rollforward Of Subrogation By Estimation Approach [Line Items]  
December 31, 2011 $ 2,720,266
Additional transactions reviewed   
Additional adverse sample loans reviewed   
Adverse loans repurchased by the sponsor 35
All other changes (31,434)
Discounted RMBS subrogation (gross of reinsurance) at September 30, 2012 2,688,867
Number of transaction removed from the Adverse Sample subrogation population 2
Random Samples [Member]
  
Summary Of Rollforward Of Subrogation By Estimation Approach [Line Items]  
December 31, 2011 1,262,794
Additional transactions reviewed   
Additional adverse sample loans reviewed   
All other changes (82,077)
Discounted RMBS subrogation (gross of reinsurance) at September 30, 2012 1,180,717
Discounted RMBS subrogation (gross of reinsurance) at December 31, 2011 16
Discounted RMBS subrogation (gross of reinsurance) at September 30, 2012 16
Adverse Samples [Member]
  
Summary Of Rollforward Of Subrogation By Estimation Approach [Line Items]  
December 31, 2011 1,457,472
Additional transactions reviewed   
Additional adverse sample loans reviewed   
Adverse loans repurchased by the sponsor 35
All other changes 50,643
Discounted RMBS subrogation (gross of reinsurance) at September 30, 2012 $ 1,508,150
Discounted RMBS subrogation (gross of reinsurance) at December 31, 2011 30
All other changes (2)
Discounted RMBS subrogation (gross of reinsurance) at September 30, 2012 28