XML 88 R66.htm IDEA: XBRL DOCUMENT v3.20.4
Investments (Schedule Of Available-For-Sale Securities Whose Value Is Below Amortized Cost) (Details)
$ in Millions
Dec. 31, 2020
USD ($)
security
Dec. 31, 2019
USD ($)
security
Schedule of Available-for-sale Securities [Line Items]    
Fair Value - Nine months or greater, but less than twelve months $ 4,808 $ 5,673
Fair Value - Twelve months or greater 1,068 1,848
Fair Value - Total 5,876 7,521
Gross Unrealized Losses - Nine months or greater, but less than twelve months 117 73
Gross Unrealized Losses - Twelve months or greater 81 170
Gross Unrealized Losses - Total $ 198 $ 243
Number of Securities - Total | security 802 895
Fair Value Decline, Greater Than 20% [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Fair Value - Less than six months $ 63 $ 15
Fair Value - Six months or greater, but less than nine months 2 10
Fair Value - Nine months or greater, but less than twelve months 23  
Fair Value - Twelve months or greater 30 132
Fair Value - Total 118 157
Gross Unrealized Losses - Less than six months 23 5
Gross Unrealized Losses - Six months or greater, but less than nine months 1 3
Gross Unrealized Losses - Nine months or greater, but less than twelve months 7  
Gross Unrealized Losses - Twelve months or greater 11 76
Gross Unrealized Losses - Total $ 42 $ 84
Number of Securities - Less than six months | security 14 7
Number of Securities - Six months or greater, but less than nine months | security 4 4
Number of Securities - Nine months or greater, but less than twelve months | security 14  
Number of Securities - Twelve months or greater | security 20 31
Number of Securities - Total | security 52 42