UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017
Statement of Comprehensive Income [Abstract]
Net income		$ 208	$ 25	$ 795	$ 400
Other comprehensive income (loss):
Foreign currency translation adjustments		(3)	49	(42)	120
Unrealized gains (losses) on hedging instruments (1)	[1]	2	6	(9)	6
Pension and postretirement benefit plans:
Amortization of net loss and prior service cost previously recognized (2)	[2]	12	8	39	27
Total other comprehensive income (loss)		11	63	(12)	153
Comprehensive income		219	88	783	553
Comprehensive income attributable to noncontrolling interests		(6)	(3)	(15)	(12)
Comprehensive income attributable to L3		$ 213	$ 85	$ 768	$ 541

[1] Net of income taxes of $1 million and $2 million for the quarterly periods ended September 28, 2018 and September 29, 2017, respectively, and net of income tax benefit of $2 million and net of income taxes of $2 million for the year-to-date periods ended September 28, 2018 and September 29, 2017, respectively.

[2] Net of income taxes of $4 million and $5 million for the quarterly periods ended September 28, 2018 and September 29, 2017, respectively, and net of income taxes of $12 million and $16 million for the year-to-date periods ended September 28, 2018 and September 29, 2017, respectively.