Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 23, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Allowances for billed receivables	$ 13	$ 15
L-3 Communications Holdings, Inc. [Member]
Class of Stock [Line Items]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares outstanding	77,355,596	78,133,763
Treasury stock (at cost), shares	82,052,903	79,375,063
L-3 Communications Corporation [Member]
Class of Stock [Line Items]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100	100
Common stock, shares issued	100	100
Common stock, shares outstanding	100	100