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Investments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
Investments (Details) - USD ($) $ in Millions	Oct. 02, 2021	Sep. 26, 2020	Oct. 02, 2021	Sep. 26, 2020	Dec. 31, 2020
Investments
Total trading short-term investments	$ 1,516		$ 1,516		$ 1,465
Change in unrealized gains (losses) on trading securities	(9)	$ 53	7	$ (45)
Long term investments	144		144		87
Denominated in foreign currencies
Investments
Total trading short-term investments	51		51		29
Domestic debt securities
Investments
Fair Value	724		724		496
Domestic equity securities
Investments
Fair Value	446		446		702
Foreign equity securities
Investments
Fair Value	192		192		133
Foreign debt securities
Investments
Fair Value	124		124		68
Money market funds held in trading accounts
Investments
Fair Value	9		9		47
Other trading investments
Investments
Fair Value	$ 21		$ 21		$ 19