Revenue - Impact of Adjustments in Contract Estimates (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 27, 2020	Sep. 29, 2019	Sep. 27, 2020	Sep. 29, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	$ 9,431	$ 9,761	$ 27,444	$ 28,577
Operating Earnings	1,084	1,216	2,866	3,320
Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	126	95	270	263
Operating Earnings	$ 84	$ 81	$ 169	$ 220
Diluted earnings per share (in dollars per share)	$ 0.23	$ 0.22	$ 0.46	$ 0.60