Description of Business	6 Months Ended
Jun. 28, 2013
Accounting Policies [Abstract]
Description of Business	1. Description of Business L-3 Communications Holdings, Inc. derives all of its operating income and cash flows from its wholly-owned subsidiary, L-3 Communications Corporation (L-3 Communications). L-3 Communications Holdings, Inc. (L-3 Holdings and, together with its subsidiaries, referred to herein as L-3 or the Company) is a prime contractor in Intelligence, Surveillance and Reconnaissance (ISR) systems, Command, Control, Communications (C³) systems, platform and logistics solutions for aircrafts, maritime vessels and ground vehicles, and national security solutions. L-3 is also a leading provider of a broad range of electronic systems used on military and commercial platforms. The Company’s customers include the United States (U.S.) Department of Defense (DoD) and its prime contractors, U.S. Government intelligence agencies, the U.S. Department of Homeland Security (DHS), U.S. Department of State (DoS), allied international governments, and domestic and international commercial customers. The Company has the following four reportable segments: (1) C³ISR, (2) Electronic Systems, (3) Platform & Logistics Solutions (P&LS) and (4) National Security Solutions (NSS). Financial information with respect to each of the Company’s segments is included in Note 21. C³ISR provides products and services for the global ISR market, C³ systems, networked communication systems and secure communications products. The Company believes that these products and services are critical elements for a substantial number of major command, control and communication, intelligence gathering and space systems. These products and services are used to connect a variety of airborne, space, ground and sea-based communication systems and are used in the transmission, processing, recording, monitoring, and dissemination functions of these communication systems. Electronic Systems provides a broad range of products and services, including components, products, subsystems and systems and related services to military and commercial customers in several niche markets across several business areas. These business areas include microwave, power & control systems, marine systems international, sensor systems, simulation & training, aviation products, precision engagement, warrior systems, security & detection, space & propulsion, undersea warfare and marine services. P&LS provides modernization, upgrades and sustainment, maintenance and logistics support solutions for military and various government aircraft and other platforms. The Company sells these services primarily to the DoD, the Canadian Department of National Defence and other allied international governments. NSS provides a full range of cyber security, intelligence, enterprise information technology (IT) and security solutions services to the DoD, U.S. Government intelligence agencies, federal civilian agencies and allied international governments.

1. Description of Business

L-3 Communications Holdings, Inc. derives all of its operating income and cash flows from its wholly-owned subsidiary, L-3 Communications Corporation (L-3 Communications). L-3 Communications Holdings, Inc. (L-3 Holdings and, together with its subsidiaries, referred to herein as L-3 or the Company) is a prime contractor in Intelligence, Surveillance and Reconnaissance (ISR) systems, Command, Control, Communications (C³) systems, platform and logistics solutions for aircrafts, maritime vessels and ground vehicles, and national security solutions. L-3 is also a leading provider of a broad range of electronic systems used on military and commercial platforms. The Company’s customers include the United States (U.S.) Department of Defense (DoD) and its prime contractors, U.S. Government intelligence agencies, the U.S. Department of Homeland Security (DHS), U.S. Department of State (DoS), allied international governments, and domestic and international commercial customers.

The Company has the following four reportable segments: (1) C³ISR, (2) Electronic Systems, (3) Platform & Logistics Solutions (P&LS) and (4) National Security Solutions (NSS). Financial information with respect to each of the Company’s segments is included in Note 21. C³ISR provides products and services for the global ISR market, C³ systems, networked communication systems and secure communications products. The Company believes that these products and services are critical elements for a substantial number of major command, control and communication, intelligence gathering and space systems. These products and services are used to connect a variety of airborne, space, ground and sea-based communication systems and are used in the transmission, processing, recording, monitoring, and dissemination functions of these communication systems. Electronic Systems provides a broad range of products and services, including components, products, subsystems and systems and related services to military and commercial customers in several niche markets across several business areas. These business areas include microwave, power & control systems, marine systems international, sensor systems, simulation & training, aviation products, precision engagement, warrior systems, security & detection, space & propulsion, undersea warfare and marine services. P&LS provides modernization, upgrades and sustainment, maintenance and logistics support solutions for military and various government aircraft and other platforms. The Company sells these services primarily to the DoD, the Canadian Department of National Defence and other allied international governments. NSS provides a full range of cyber security, intelligence, enterprise information technology (IT) and security solutions services to the DoD, U.S. Government intelligence agencies, federal civilian agencies and allied international governments.