CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 02, 2020	Sep. 27, 2019	Oct. 02, 2020	Sep. 27, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 430	$ 435	$ 902	$ 946
Other comprehensive income (loss):
Foreign currency translation gain (loss), net of income taxes	32	(25)	(28)	(24)
Net unrealized gain (loss) on hedging derivatives, net of income taxes	5	(38)	(55)	(57)
Net unrecognized loss on postretirement obligations, net of income taxes	0	0	0	(478)
Other comprehensive income (loss) recognized during the period	37	(63)	(83)	(559)
Less: reclassification adjustments for (gains) losses included in net income	(3)	14	1	14
Other comprehensive loss	34	(49)	(82)	(545)
Total comprehensive income	464	386	820	401
Comprehensive (income) loss attributable to noncontrolling interests	(4)	(6)	24	(6)
Total comprehensive income attributable to L3Harris Technologies, Inc.	$ 460	$ 380	$ 844	$ 395