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SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details) $ / shares in Units, engineer in Thousands, $ in Millions		12 Months Ended
	Jun. 29, 2019 employee country	Jun. 28, 2019 USD ($) employee engineer site country $ / shares	Jun. 29, 2018 USD ($) $ / shares	Jun. 30, 2017 USD ($) $ / shares	Sep. 27, 2019 USD ($)
Change in Accounting Estimate [Line Items]
Number of countries in which entity operates \| country		100
Number of employees \| employee		18,200
Number of engineers and scientists \| engineer		8
Amortization period for contract costs		1 year
Threshold for separate line item reporting of total current assets or total assets in Consolidated Balance Sheets		5.00%	5.00%
Threshold for separate line item reporting of total current liabilities or total liabilities in Consolidated Balance Sheet		5.00%	5.00%
Revenue recognized from performance obligations satisfied in previous periods		$ 59	$ 43	$ 45
Total number of sites for existence of future environment liabilities \| site		60
Number of sites owned by the company \| site		5
Number of sites associated with former graphics or semiconductor locations \| site		47
Treatment or disposal sites not owned by the company that contain hazardous substances allegedly attributable to the company from past operations \| site		8
Accrual for environment loss contingencies		$ 99
Fair value of environmental liabilities		93
Other environmental liabilities		6
Contracts Accounted for under Percentage of Completion
Change in Accounting Estimate [Line Items]
Operating income (loss)		17	(19)	$ (1)
Operating income (loss), after tax		$ 13	$ (13)
Operating income (loss), per diluted share (in dollars per share) \| $ / shares		$ 0.10	$ (0.11)	$ (0.01)
L3Harris \| Subsequent Event
Change in Accounting Estimate [Line Items]
Number of countries in which entity operates \| country	130
Number of employees \| employee	50,000
Fixed exchange conversion ratio per share	1.30
L3Harris \| Discontinued Operations, Disposed of by Sale \| Harris Night Vision \| Communication Systems \| Subsequent Event \| Forecast
Change in Accounting Estimate [Line Items]
Cash proceeds from divestiture of business					$ 350
L3Harris \| Former Harris Shareholders \| Subsequent Event
Change in Accounting Estimate [Line Items]
Percentage of voting interests acquired	54.00%
L3Harris \| Former L3 Shareholders \| Subsequent Event
Change in Accounting Estimate [Line Items]
Percentage of voting interests acquired	46.00%