CONDENSED CONSOLIDATED STATEMENT OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2021	Oct. 02, 2020	Oct. 01, 2021	Oct. 02, 2020
Income Statement [Abstract]
Revenue from product sales and services	$ 4,229	$ 4,463	$ 13,464	$ 13,534
Cost of product sales and services	(2,921)	(3,152)	(9,385)	(9,625)
Engineering, selling and administrative expenses	(793)	(817)	(2,485)	(2,484)
Business divestiture-related gains (losses)	27	(10)	192	(62)
Impairment of goodwill and other assets	0	0	(207)	(394)
Non-operating income	111	96	314	296
Interest expense, net	(67)	(62)	(198)	(190)
Income from continuing operations before income taxes	586	518	1,695	1,075
Income taxes	(107)	(87)	(336)	(171)
Income from continuing operations	479	431	1,359	904
Discontinued operations, net of income taxes	0	(1)	(1)	(2)
Net income	479	430	1,358	902
Noncontrolling interests, net of income taxes	2	(4)	4	24
Net income attributable to L3Harris Technologies, Inc.	481	426	1,362	926
Amounts attributable to L3Harris Technologies, Inc. common shareholders
Income from continuing operations	481	427	1,363	928
Discontinued operations, net of income taxes	0	(1)	(1)	(2)
Net income attributable to L3Harris Technologies, Inc.	$ 481	$ 426	$ 1,362	$ 926
Basic
Continuing operations (in dollars per share)	$ 2.41	$ 2.00	$ 6.70	$ 4.31
Discontinued operations (in dollars per share)	0	0	0	(0.01)
Basic (in dollars per share)	2.41	2.00	6.70	4.30
Diluted
Continuing operations (in dollars per share)	2.39	1.99	6.64	4.27
Discontinued operations (in dollars per share)	0	(0.01)	0	(0.01)
Diluted (in dollars per share)	$ 2.39	$ 1.98	$ 6.64	$ 4.26
Basic weighted average common shares outstanding (in shares)	199.5	213.4	203.3	215.5
Diluted weighted average common shares outstanding (in shares)	201.6	215.1	205.2	217.3