XML 65 R52.htm IDEA: XBRL DOCUMENT v3.21.2
Fair Value Measurements - Investment Maturities (Details) - Fair Value - USD ($)
$ in Millions
Sep. 30, 2021
Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Less than 1 year $ 3 $ 2
1 - 5 years 28 22
5 - 10 years 14 23
Greater than 10 years 48 54
Total investments at fair value $ 93 $ 101