XML 67 R50.htm IDEA: XBRL DOCUMENT v3.21.1
Investments (Fair Value Below Amortized Cost of Gross Unrealized Losses for Fixed Maturity and Equity Securities) (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2021
Dec. 31, 2020
Gross unrealized losses with number of securities [Line Items]    
Document Period End Date Mar. 31, 2021  
Gross Unrealized Losses $ 490 $ 197
% of Total 100.00% 100.00%
Less than 20%    
Gross unrealized losses with number of securities [Line Items]    
Gross Unrealized Losses $ 427 $ 133
% of Total 87.20% 67.50%
20% or more for less than six months    
Gross unrealized losses with number of securities [Line Items]    
Gross Unrealized Losses $ 28 $ 42
% of Total 5.70% 21.30%
20% or more for six months or greater    
Gross unrealized losses with number of securities [Line Items]    
Gross Unrealized Losses $ 35 $ 22
% of Total 7.10% 11.20%