Condensed Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 27, 2013		Sep. 28, 2012		Sep. 27, 2013		Sep. 28, 2012
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 208		$ 194		$ 588		$ 605
Other comprehensive income:
Foreign currency translation adjustments	34		46		(18)		28
Unrealized gains (losses) on hedging instruments	3	[1]	2	[1]	(1)	[1]	4	[1]
Pension and postretirement benefit plans:
Amortization of net loss and prior service cost previously recognized	13	[2]	9	[2]	40	[2]	31	[2]
Total other comprehensive income:	50		57		21		63
Comprehensive income	258		251		609		668
Comprehensive income attributable to noncontrolling interests	(4)		(2)		(6)		(7)
Comprehensive income attributable to L-3	$ 254		$ 249		$ 603		$ 661

[1] Amounts are net of income taxes of $2 and $1 million for the quarterly periods ended September 27, 2013 and September 28, 2012, respectively, and income tax benefits of $1 million and income taxes of $2 million for the year-to-date periods ended September 27, 2013 and September 28, 2012, respectively.

[2] Amounts are net of income taxes of $7 million and $8 million for the quarterly periods ended September 27, 2013 and September 28, 2012, respectively, and $23 million and $20 million for the year-to-date periods ended September 27, 2013 and September 28, 2012, respectively.