CONDENSED CONSOLIDATED STATEMENT OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Income Statement [Abstract]
Revenue from product sales and services	$ 4,668	$ 4,445	$ 9,235	$ 9,071
Cost of product sales and services	(3,251)	(3,175)	(6,464)	(6,473)
Engineering, selling and administrative expenses	(891)	(855)	(1,692)	(1,667)
Business divestiture-related gains (losses)	180	(49)	165	(52)
Impairment of goodwill and other assets	(145)	(70)	(207)	(394)
Non-operating income	86	105	203	200
Interest expense, net	(65)	(65)	(131)	(128)
Income from continuing operations before income taxes	582	336	1,109	557
Income taxes	(169)	(58)	(229)	(84)
Income from continuing operations	413	278	880	473
Discontinued operations, net of income taxes	0	0	(1)	(1)
Net income	413	278	879	472
Noncontrolling interests, net of income taxes	0	5	2	28
Net income attributable to L3Harris Technologies, Inc.	413	283	881	500
Amounts attributable to L3Harris Technologies, Inc. common shareholders
Income from continuing operations	413	283	882	501
Discontinued operations, net of income taxes	$ 0	$ 0	$ (1)	$ (1)
Basic
Continuing operations (in dollars per share)	$ 2.03	$ 1.31	$ 4.29	$ 2.31
Discontinued operations (in dollars per share)	0	0	0	(0.01)
Basic (in dollars per share)	2.03	1.31	4.29	2.30
Diluted
Continuing operations (in dollars per share)	2.01	1.30	4.26	2.29
Discontinued operations (in dollars per share)	0	0	(0.01)	(0.01)
Diluted (in dollars per share)	$ 2.01	$ 1.30	$ 4.25	$ 2.28
Basic weighted average common shares outstanding (in shares)	203.6	215.9	205.2	216.7
Diluted weighted average common shares outstanding (in shares)	205.6	217.8	207.1	218.7