TRANSITION PERIOD COMPARATIVE DATA (UNAUDITED) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	6 Months Ended		12 Months Ended
	Jan. 03, 2020	Dec. 28, 2018	Jun. 28, 2019	Jun. 29, 2018	Jun. 30, 2017
Condensed Financial Information Disclosure [Abstract]
Revenue from product sales and services	$ 9,263	$ 3,208	$ 6,801	$ 6,168	$ 5,897
Cost of product sales and services	(6,726)	(2,105)	(4,467)	(4,066)	(3,854)
Engineering, selling and administrative expenses	(1,927)	(583)	(1,242)	(1,182)	(1,150)
Gain on sale of business	229	0	0	0	(14)
Non-operating income	192	94	188	156	166
Interest income	12	1	2	2	2
Interest expense	(135)	(87)	(169)	(170)	(172)
Income from continuing operations before income taxes	908	528	1,113	908	889
Income taxes	(73)	(87)	(160)	(206)	(261)
Income from continuing operations	835	441	953	702	628
Discontinued operations, net of income taxes	(1)	(3)	(4)	(3)	(85)
Net income	834	438	949	699	543
Noncontrolling interests, net of income taxes	(12)	0	0	0	0
Net income attributable to L3Harris Technologies, Inc.	$ 822	$ 438	$ 949	$ 699	$ 543
Basic
Continuing operations (in dollars per share)	$ 3.72	$ 3.74	$ 8.06	$ 5.90	$ 5.11
Discontinued operations (in dollars per share)	0	(0.03)	(0.03)	(0.02)	(0.69)
Total basic net income per common share (in dollars per share)	3.72	3.71	8.03	5.88	4.42
Diluted
Continuing operations (in dollars per share)	3.68	3.66	7.89	5.78	5.04
Discontinued operations (in dollars per share)	(0.01)	(0.02)	(0.03)	(0.02)	(0.68)
Diluted (in dollars per share)	$ 3.67	$ 3.64	$ 7.86	$ 5.76	$ 4.36
Basic weighted average common shares outstanding (in shares)	221.2	117.8	118.0	118.6	122.6
Diluted weighted average common shares outstanding (in shares)	223.7	120.3	120.5	121.1	124.3