Debt - Components of Debt and Reconciliation to Carrying Amount of Long-Term Debt (Detail) (USD $) In Millions, unless otherwise specified	Sep. 26, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
3% Convertible Contingent Debt Securities due 2035 (CODES)		$ 689
L-3 Communications Corporation [Member]
Debt Instrument [Line Items]
Borrowings under Amended and Restated Revolving Credit Facility
3.95% Senior Notes due 2016	500	500
1.50% Senior Notes due 2017	350
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
3.95% Senior Notes due 2024	650
Subtotal	3,950	2,950
L-3 Communications Holdings, Inc. [Member]
Debt Instrument [Line Items]
3% Convertible Contingent Debt Securities due 2035 (CODES)		689
Principal amount of long-term debt	3,950	3,639
Unamortized discounts	(12)	(9)
Carrying amount of long-term debt	$ 3,938	$ 3,630

Long Term Debt Maturities Repayments Of Principal In Year Seven

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Long Term Debt Maturities Repayments Of Principal In Year Six

+ References

No definition available.

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Amount of long-term debt maturing in year ten following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed of determinable prices and dates.

+ References

No definition available.

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- Definition

Long term debt noncurrent subtotal.

+ References

No definition available.

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- Definition

Including the current and noncurrent portions, the carrying value of convertible subordinated debt, as of the balance sheet date, initially scheduled to be repaid after one year or beyond the normal operating cycle if longer. This form of debt can be exchanged for a specified amount of another security, typically the entity's common stock, at the option of the issuer or the holder, and places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Name Regulation S-X (SX)

-Number 210

-Section 02

-Article 5

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Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

+ References

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-Name Regulation S-X (SX)

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- Definition

The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

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- Definition

Amount borrowed under the credit facility as of the balance sheet date.

+ References

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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- Definition

Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the fifth fiscal year following the latest fiscal year.

+ References

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Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the third fiscal year following the latest fiscal year.

+ References

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Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the second fiscal year following the latest fiscal year.

+ References

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