OTHER - Changes in Estimates and Backlog (Details) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended		9 Months Ended
	Apr. 30, 2019 satellite	Feb. 28, 2019 satellite	Sep. 29, 2019 USD ($) program $ / shares	Sep. 30, 2018 USD ($) $ / shares	Sep. 29, 2019 USD ($) program satellite $ / shares	Sep. 30, 2018 USD ($) $ / shares
Change in Accounting Estimate [Line Items]
Performance obligation satisfied in previous period			$ 495	$ 595	$ 1,700	$ 1,600
Number of satellites launched or to be launched | satellite	1	1			3
Ground Based Radar
Change in Accounting Estimate [Line Items]
Cumulative losses on development			195		$ 195
LM 2100 Project
Change in Accounting Estimate [Line Items]
Cumulative losses on development			410		410
Warrior Capability Sustainment Program
Change in Accounting Estimate [Line Items]
Cumulative losses on development			140		140
Contracts Accounted for under Percentage of Completion
Change in Accounting Estimate [Line Items]
Increase in operating profit due to profit rate adjustments			480	545	1,500	1,400
Increase in net earnings due to profit rate adjustments			$ 379	$ 431	$ 1,200	$ 1,100
Increase in diluted earnings per common share due to profit rate adjustments (in dollars per share) | $ / shares			$ 1.33	$ 1.50	$ 4.07	$ 3.93
Space
Change in Accounting Estimate [Line Items]
Number of commercial satellite programs with performance issues | program			2		2