CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Total net sales	$ 10,244	$ 9,573	$ 9,210
Operating costs and expenses:
Cost of sales	(9,138)	(8,542)	(8,252)
General and administrative expenses	(1,601)	(1,520)	(1,287)
Total operating costs and expenses	(9,138)	(8,542)	(8,252)
Gain on sale of the Crestview Aerospace and TCS businesses	42	0	0
Merger and acquisition related expenses	(28)	0	0
Operating income	1,120	1,031	958
Interest expense	(164)	(169)	(164)
Interest and other income, net	37	9	17
Debt retirement charges	(69)	0	(7)
Income from continuing operations before income taxes	924	871	804
Provision for income taxes	(103)	(102)	(171)
Income from continuing operations	821	769	633
Income (loss) from discontinued operations, net of income taxes	205	(76)	91
Net income	1,026	693	724
Net income from continuing operations attributable to noncontrolling interests	(21)	(16)	(14)
Net income attributable to L3	$ 1,005	$ 677	$ 710
Basic earnings (loss) per share attributable to common shareholders:
Continuing operations (in dollars per share)	$ 10.19	$ 9.65	$ 7.99
Discontinued operations (in dollars per share)	2.61	(0.97)	1.18
Basic earnings (loss) per share (in dollars per share)	12.80	8.68	9.17
Diluted earnings (loss) per share attributable to common shareholders:
Continuing operations (in dollars per share)	10.05	9.46	7.86
Discontinued operations (in dollars per share)	2.58	(0.95)	1.15
Diluted earnings (loss) per share (in dollars per share)	12.63	8.51	9.01
Cash dividends declared per common share (in dollars per share)	$ 3.2	$ 3	$ 2.8
Weighted average common shares outstanding:
Basic (in shares)	78.5	78.0	77.4
Diluted (in shares)	79.6	79.6	78.8
Product [Member]
Total net sales	$ 7,165	$ 6,733	$ 6,453
Operating costs and expenses:
Cost of sales	(5,345)	(4,967)	(4,879)
Service [Member]
Total net sales	3,079	2,840	2,757
Operating costs and expenses:
Cost of sales	$ (2,192)	$ (2,055)	$ (2,086)