v3.22.0.1
Financial Instruments (Gross Unrealized Losses and Fair Values for Investments in Unrealized Loss Position) (Details) - USD ($)
$ in Millions
Dec. 31, 2021
Dec. 31, 2020
Investments, Unrealized Loss Position [Line Items]    
Less than 12 Months, Fair Value $ 67,082 $ 8,444
Less than 12 Months, Unrealized Loss (494) (15)
12 Months or Greater, Fair Value 622 245
12 Months or Greater, Unrealized Loss (13) (2)
Total Fair Value 67,704 8,689
Total Unrealized Loss (507) (17)
Government bonds    
Investments, Unrealized Loss Position [Line Items]    
Less than 12 Months, Fair Value 32,843 5,516
Less than 12 Months, Unrealized Loss (236) (9)
12 Months or Greater, Fair Value 71 3
12 Months or Greater, Unrealized Loss (2) 0
Total Fair Value 32,914 5,519
Total Unrealized Loss (238) (9)
Corporate debt securities    
Investments, Unrealized Loss Position [Line Items]    
Less than 12 Months, Fair Value 22,737 1,999
Less than 12 Months, Unrealized Loss (152) (1)
12 Months or Greater, Fair Value 303 0
12 Months or Greater, Unrealized Loss (5) 0
Total Fair Value 23,040 1,999
Total Unrealized Loss (157) (1)
Mortgage-backed and asset-backed securities    
Investments, Unrealized Loss Position [Line Items]    
Less than 12 Months, Fair Value 11,502 929
Less than 12 Months, Unrealized Loss (106) (5)
12 Months or Greater, Fair Value 248 242
12 Months or Greater, Unrealized Loss (6) (2)
Total Fair Value 11,750 1,171
Total Unrealized Loss $ (112) $ (7)