Unbilled Receivables - Additional Information (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2020 USD ($) progress_payment	Mar. 29, 2020 USD ($) progress_payment	Jun. 28, 2020 progress_payment	Sep. 27, 2020 USD ($)	Dec. 31, 2019 USD ($)
Contracts In Process [Line Items]
Net unbilled receivables				$ 8,143	$ 7,857
Large International Wheel Armored Vehicle | Combat Systems
Contracts In Process [Line Items]
Net unbilled receivables				$ 2,500	$ 2,900
Number of progress payments received | progress_payment	1	1	2
Progress payments received	$ 500	$ 500