Financial Information of L-3 Communications and Its Subsidiaries - Condensed Combining Statements of Equity (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended							12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Common Stock [Member]	Dec. 31, 2012 Common Stock [Member]	Dec. 31, 2011 Common Stock [Member]	Dec. 31, 2010 Common Stock [Member]	Dec. 31, 2013 Retained Earnings [Member]	Dec. 31, 2012 Retained Earnings [Member]	Dec. 31, 2011 Retained Earnings [Member]	Dec. 31, 2013 L-3 Communications Corporation [Member]	Dec. 31, 2012 L-3 Communications Corporation [Member]	Dec. 31, 2011 L-3 Communications Corporation [Member]	Dec. 31, 2013 L-3 Communications Corporation [Member] Common Stock [Member]	Dec. 31, 2012 L-3 Communications Corporation [Member] Common Stock [Member]	Dec. 31, 2011 L-3 Communications Corporation [Member] Common Stock [Member]	Dec. 31, 2013 L-3 Communications Corporation [Member] Additional Paid-in Capital [Member]	Dec. 31, 2012 L-3 Communications Corporation [Member] Additional Paid-in Capital [Member]	Dec. 31, 2011 L-3 Communications Corporation [Member] Additional Paid-in Capital [Member]	Dec. 31, 2013 L-3 Communications Corporation [Member] Treasury Stock [Member]	Dec. 31, 2012 L-3 Communications Corporation [Member] Treasury Stock [Member]	Dec. 31, 2011 L-3 Communications Corporation [Member] Treasury Stock [Member]	Dec. 31, 2013 L-3 Communications Corporation [Member] Retained Earnings [Member]	Dec. 31, 2012 L-3 Communications Corporation [Member] Retained Earnings [Member]	Dec. 31, 2011 L-3 Communications Corporation [Member] Retained Earnings [Member]	Dec. 31, 2013 L-3 Communications Corporation [Member] Accumulated Other Comprehensive Loss [Member]	Dec. 31, 2012 L-3 Communications Corporation [Member] Accumulated Other Comprehensive Loss [Member]	Dec. 31, 2011 L-3 Communications Corporation [Member] Accumulated Other Comprehensive Loss [Member]
Condensed Financial Statements, Captions [Line Items]
Beginning Balance											$ 5,451	$ 6,644	$ 6,771				$ 5,314	$ 5,064	$ 4,801				$ 687	$ 2,034	$ 2,226	$ (550)	$ (454)	$ (256)
Beginning Balance, Shares				85.8	90.4	99.0	108.6							100.0	100.0	100.0
Net income attributable to L-3	760	794	970					751	784	958	751	784	958										751	784	958
Contributions from L-3 Holdings											339	250	263				339	250	263
Dividends to L-3 Holdings											(997)	(1,064)	(1,157)										(997)	(1,064)	(1,157)
Comprehensive gain (loss)	440	(96)	(198)								440	(96)	(198)													440	(96)	(198)
Net change of equity due to spin-off of Engility												(1,063)												(1,063)
Other											(3)	(4)	7										(3)	(4)	7
Ending Balance											$ 5,981	$ 5,451	$ 6,644				$ 5,653	$ 5,314	$ 5,064				$ 438	$ 687	$ 2,034	$ (110)	$ (550)	$ (454)
Ending Balance, Shares				85.8	90.4	99.0	108.6							100.0	100.0	100.0