XML 76 R62.htm IDEA: XBRL DOCUMENT v3.8.0.1
Loss And Loss Adjustment Expense Reserves (Schedule Of Losses And Loss Adjustment Expenses) (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Loss And Loss Adjustment Expense Reserves [Line Items]      
Policyholder Benefits And Claims Incurred Net $ 683 $ 220 $ 123
U S Public Finance Insurance [Member]      
Loss And Loss Adjustment Expense Reserves [Line Items]      
Policyholder Benefits And Claims Incurred Net 499 74 5
Second-Lien RMBS [Member]      
Loss And Loss Adjustment Expense Reserves [Line Items]      
Policyholder Benefits And Claims Incurred Net 62 121 63
First-Lien RMBS [Member]      
Loss And Loss Adjustment Expense Reserves [Line Items]      
Policyholder Benefits And Claims Incurred Net 92 41 34
CDOs [Member]      
Loss And Loss Adjustment Expense Reserves [Line Items]      
Policyholder Benefits And Claims Incurred Net 10 (32) 29
Other [Member]      
Loss And Loss Adjustment Expense Reserves [Line Items]      
Policyholder Benefits And Claims Incurred Net [1] $ 20 $ 16 $ (8)
[1]
Includes non-U.S. public finance and other issues.