PENSION AND OTHER POSTRETIREMENT BENEFITS - Additional Information (Details) - USD ($)	6 Months Ended	12 Months Ended
	Dec. 31, 2019	Jun. 28, 2019	Jun. 29, 2018	Jun. 30, 2017	Jun. 25, 2028	Jun. 25, 2027	Dec. 31, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Matching contributions charged to expense		$ 85,000,000	$ 83,000,000	$ 80,000,000
Fair value of plan assets		5,159,000,000	5,305,000,000	5,133,000,000
Projected benefit obligation		6,344,000,000	6,007,000,000	6,405,000,000
Accumulated benefit obligation for all defined benefit pension plans		$ 6,100,000,000
Per capita cost of healthcare assumed for next fiscal year, pre-age 65		7.35%
Per capita cost of healthcare assumed for next fiscal year, post-age 65		6.85%
Voluntary contributions by employer to pension plan		$ 5,000,000	302,000,000
Hedge funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plans, future unfunded commitments on NAV equity funds investments		$ 0	0
Minimum redemption notice period permitted on NAV equity funds investments		90 days
Private equity funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plans, future unfunded commitments on NAV equity funds investments		$ 355,000,000	246,000,000
Forecast
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Per capita cost of healthcare assumed for next fiscal year, pre-age 65	7.00%
Per capita cost of healthcare assumed for next fiscal year, post-age 65	6.55%
Ultimate per capita cost of healthcare assumed (percent)						4.75%
Per capita cost of healthcare assumed for next fiscal year (percent)					4.75%
Pension
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets		4,958,000,000	5,098,000,000	4,921,000,000
Projected benefit obligation		$ 6,123,000,000	$ 5,774,000,000	$ 6,140,000,000
Discount rate (percent)		3.35%	4.05%
Expected return on plan assets		7.66%	7.66%	7.65%
Voluntary contributions by employer to pension plan		$ 3,000,000	$ 303,000,000
Pension | Forecast
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected return on plan assets	7.67%
United States
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets		4,400,000,000
Projected benefit obligation		$ 5,500,000,000
Cash balance benefit percentage							1.00%
Percentage of total projected benefit obligation (percent)		90.27%
Discount rate (percent)		3.37%
Expected return on plan assets		7.75%
United States | Forecast
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected return on plan assets	7.75%
United States | Pension
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Voluntary contributions by employer to pension plan			$ 300,000,000	$ 400,000,000
United States | Pension | Harris U.S. Qualified Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Anticipated contributions to qualified pension plans		$ 2,000,000
United States | Pension | L3 U.S. Qualified Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Anticipated contributions to qualified pension plans		$ 23,000,000
Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage match of the employee contribution		2.00%
Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage match of the employee contribution		6.00%