XML 161 R98.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Investments - Summary of Net Investment Income (Detail) - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Dec. 31, 2019
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Investment [Line Items]                        
Net Realized and Unrealized Gain (Loss) on Trading Securities                   $ 24 $ (3) $ 18
Trading Securities, Realized Gain (Loss)                   7 1 5
Fixed income securities                   265 337  
Investment expense                 $ (6) (7) (8)  
Securities available-for-sale and short-term                 196 271 338  
Net investment income $ 42 $ 45 $ 86 $ 55 $ 37 $ 58 $ 67 $ 110 227 273 361  
Gains (losses) on securities held as of reporting date [Member]                        
Investment [Line Items]                        
Other Investments Income                   17 (4) $ 13
Available-for-sale Securities [Member]                        
Investment [Line Items]                        
Fixed income securities                 183      
Short-term Investments [Member]                        
Investment [Line Items]                        
Fixed income securities                 17 11 8  
Financing Receivable [Member]                        
Investment [Line Items]                        
Fixed income securities                 1 1 1  
Other Investments [Member]                        
Investment [Line Items]                        
Fixed income securities                 $ 32 $ 2 $ 23