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Investments (Details) - USD ($) $ in Millions	3 Months Ended
Investments (Details) - USD ($) $ in Millions	Mar. 28, 2020	Mar. 30, 2019	Dec. 31, 2019
Investments
Total trading short-term investments	$ 1,125		$ 1,434
Change in unrealized gains (losses) on trading securities	(236)	$ 104
Domestic equity securities
Investments
Fair Value	473		706
Domestic debt securities
Investments
Fair Value	360		409
Domestic debt securities \| Denominated in Euros
Investments
Fair Value	13		13
Foreign equity securities
Investments
Fair Value	147		189
Foreign equity securities \| Denominated in foreign currencies
Investments
Fair Value	47		62
Foreign equity securities \| Denominated in Euros
Investments
Fair Value	23		32
Foreign equity securities \| Denominated in Japanese Yen
Investments
Fair Value	10		12
Foreign equity securities \| Denominated in British pounds
Investments
Fair Value	5		8
Foreign equity securities \| Denominated in other foreign currencies
Investments
Fair Value	9		10
Foreign debt securities
Investments
Fair Value	54		43
High yield securities
Investments
Fair Value	51		56
Money market funds held in trading accounts
Investments
Fair Value	23		12
Collateralized loan obligations
Investments
Fair Value	13		15
Other trading securities
Investments
Fair Value	$ 4		$ 4