Components of Debt and Reconciliation to Carrying Amount of Long-Term Debt (Detail) (USD $) In Millions, unless otherwise specified	Sep. 28, 2012		Dec. 31, 2011
Debt Instrument [Line Items]
Borrowings under Amended and Restated Revolving Credit Facility	$ 3
L-3 Holdings (Parent) [Member]
Debt Instrument [Line Items]
3% Convertible Contingent Debt Securities due 2035	689	[1]	689	[1]
Principal amount of long-term debt	3,889		4,139
Less: Unamortized discounts	(11)		(14)
Carrying amount of long-term debt	3,878		4,125
L-3 Communications [Member]
Debt Instrument [Line Items]
Borrowings under Amended and Restated Revolving Credit Facility		[2]		[2]
3.95% Senior Notes due 2016	500		500
5.20% Senior Notes due 2019	1,000		1,000
4.75% Senior Notes due 2020	800		800
4.95% Senior Notes due 2021	650		650
6 3/8% Senior Subordinated Notes due 2015	250		500
Subtotal	$ 3,200		$ 3,450

[1] Under select conditions, including if L-3 Holdings common stock price is more than 120% (currently $110.60) of the then current conversion price (currently $92.17) for a specified period, the conversion feature of the CODES will require L-3 Holdings, upon conversion, to pay the holders of the CODES the principal amount in cash, and if the settlement amount exceeds the principal amount, the excess will be settled in cash or stock or a combination thereof, at the Company's option. At the current conversion price of $92.17, the aggregate consideration to be delivered upon conversion would be determined based on 7.5 million shares of L-3 Holdings' common stock. See Note 10 to the audited consolidated financial statements for the year ended December 31, 2011, included in the Company's Annual Report on Form 10-K for additional information regarding the CODES, including conditions for conversion. L-3 Holdings' closing stock price on November 2, 2012 was $75.85 per share. Through February 1, 2011, the effective interest rate on the CODES was 6.33%. Interest expense related to both the contractual coupon interest and amortization of the discount on the liability component. The Company amortized the discount on the liability component of the CODES through February 1, 2011 which was the first date that the holders of the CODES had a contractual right to require L-3 Holdings to repurchase the CODES. Interest expense for the CODES after February 1, 2011 relates only to the contractual coupon interest. Interest expense recognized was $5 million each for the third quarter ended September 28, 2012 and September 30, 2011, and $15 million and $17 million for the year-to-date periods ended September 28, 2012 and September 30, 2011, respectively, a portion of which was allocated to discontinued operations. The carrying amount of the equity component (conversion feature) of the CODES was $64 million at September 28, 2012 and December 31, 2011.

[2] The Company's three-year revolving credit facility, which was amended and restated on February 3, 2012 and matures on February 3, 2017, provides for total aggregate borrowings of up to $1 billion. At September 28, 2012, available borrowings under the Amended and Restated Revolving Credit Facility were $997 million after reductions for outstanding letters of credit of $3 million.