CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jan. 03, 2020	Jan. 01, 2021	Jun. 28, 2019	Jun. 29, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 834	$ 1,086	$ 949	$ 699
Other comprehensive (loss) income:
Foreign currency translation gain (loss), net of income taxes	25	16	(7)	15
Net unrealized (loss) gain on hedging derivatives, net of income taxes	(17)	(31)	(18)	1
Net unrecognized (loss) gain on postretirement obligations, net of income taxes	178	(313)	(480)	93
Other comprehensive (loss) income, recognized during the period	186	(328)	(505)	109
Less: reclassification adjustments for (gains) losses included in net income	13	(3)	0	0
Other comprehensive income	199	(331)	(505)	109
Total comprehensive income	1,033	755	444	808
Comprehensive loss (income) attributable to noncontrolling interests	(12)	33	0	0
Total comprehensive income attributable to L3Harris Technologies, Inc.	$ 1,021	$ 788	$ 444	$ 808