CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2021	Oct. 02, 2020	Oct. 01, 2021	Oct. 02, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 479	$ 430	$ 1,358	$ 902
Other comprehensive income (loss):
Foreign currency translation (loss) gain, net of income taxes	(34)	32	(37)	(28)
Net unrealized (loss) gain on hedging derivatives, net of income taxes	(7)	5	0	(55)
Net unrecognized gain on postretirement obligations, net of income taxes	576	0	574	0
Other comprehensive income (loss) recognized during the period	535	37	537	(83)
Reclassification adjustments for (gains) losses included in net income	(3)	(3)	(1)	1
Other comprehensive income (loss), net of income taxes	532	34	536	(82)
Total comprehensive income	1,011	464	1,894	820
Comprehensive loss (income) attributable to noncontrolling interests	2	(4)	4	24
Total comprehensive income attributable to L3Harris Technologies, Inc.	$ 1,013	$ 460	$ 1,898	$ 844