Lines of Credit and Long-Term Debt - Summary of long-term debt (Details) - USD ($) $ in Millions	Sep. 25, 2018	Dec. 31, 2020	Dec. 31, 2019	Sep. 24, 2018
Notes Payable and Long Term Debt
Total long-term debt at face value		$ 763	$ 793
Current maturities of long-term debt and unamortized discount		(56)	(63)
Long-term debt, less current maturities		707	730
Term Loans Due 2027-2028
Notes Payable and Long Term Debt
Total long-term debt at face value		714	$ 691
Term Loan Due 2027
Notes Payable and Long Term Debt
Face amount		$ 30
Interest rate (as a percent)		1.00%
Term loan due 2028
Notes Payable and Long Term Debt
Face amount	$ 700
Proceeds from issuance of debt	$ 220
Effective interest rate (as a percent)		1.77%	3.42%
Term loan due 2022
Notes Payable and Long Term Debt
Face amount				$ 500
Foreign subsidiary obligations
Notes Payable and Long Term Debt
Total long-term debt at face value		$ 49	$ 102
Foreign subsidiary obligations | Denominated in Euros
Notes Payable and Long Term Debt
Total long-term debt at face value		$ 46