Revenue (Narrative) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
	Oct. 01, 2021	Oct. 01, 2021	Oct. 02, 2020	Oct. 01, 2021	Oct. 02, 2020	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue, OTLs and STLs		$ 125	$ 119	$ 359	$ 356
Revenue, remaining performance obligation	$ 3,700	3,700		3,700
Revenue, remaining performance obligation, expected satisfaction in next 12 months, percent	50.00%
Revenue, remaining performance obligation, expected satisfaction in subsequent 12 months, percent	25.00%
Contract with customer, assets, net	$ 88	88		88		$ 65
Contract with customer, liabilities	$ 1,800	$ 1,800		1,800		$ 1,400
Contract with customer, liabilities, revenue recognized				$ 963	$ 537