Debt - Components of Long-Term Debt and Reconciliation to Carrying Amount of Long-Term Debt (Parenthetical) (Detail) (USD $)	Dec. 31, 2012	Feb. 03, 2012	Dec. 31, 2011
Debt Instrument [Line Items]
Total aggregate borrowings under revolving credit facility	$ 1,000,000,000	$ 1,000,000,000
Available borrowings under revolving credit facility			997,000,000
Outstanding letters of credit	1,000,000		3,000,000
CODES due 2035 [Member]
Debt Instrument [Line Items]
Interest rate on senior notes	3.00%
L-3 Communications Corporation's [Member]
Debt Instrument [Line Items]
Outstanding letters of credit
L-3 Communications Corporation's [Member] | 3.95% Senior Notes due 2016 [Member]
Debt Instrument [Line Items]
Interest rate on senior notes	3.95%		3.95%
L-3 Communications Corporation's [Member] | 5.20% Senior Notes due 2019 [Member]
Debt Instrument [Line Items]
Interest rate on senior notes	5.20%		5.20%
L-3 Communications Corporation's [Member] | 4.75% Senior Notes due 2020 [Member]
Debt Instrument [Line Items]
Interest rate on senior notes	4.75%		4.75%
L-3 Communications Corporation's [Member] | 4.95% Senior Notes due 2021 [Member]
Debt Instrument [Line Items]
Interest rate on senior notes	4.95%		4.95%
L-3 Communications Corporation's [Member] | 6 3/8% Senior Subordinated Notes due October 15, 2015 [Member]
Debt Instrument [Line Items]
Interest rate on senior notes	6.375%		6.375%
L-3 Communications Holdings Inc. [Member] | CODES due 2035 [Member]
Debt Instrument [Line Items]
Interest rate on senior notes	3.00%		3.00%