Description of Business	12 Months Ended
Dec. 31, 2012
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, aircraft modernization and sustainment of 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 foreign governments, and domestic and foreign commercial customers. On July 17, 2012, L-3 completed the spin-off of its subsidiary, Engility Holdings, Inc. (Engility) to L-3’s shareholders. The spin-off was a tax-free distribution to L-3 shareholders for U.S. federal tax purposes, except for cash received in lieu of fractional shares. L-3 shareholders of record on July 16, 2012 (the record date) received one share of Engility common stock for every six shares of L-3 common stock held on the record date. Engility began trading as an independent publicly traded company on the New York Stock Exchange on July 18, 2012. As a result of the spin-off, the assets, liabilities, non-controlling interest, results of operations and cash flows of the Engility businesses have been classified as discontinued operations for all periods presented. References to financial data are to the Company’s continuing operations, unless specifically noted. See Note 4 for additional information. The Company has the following four reportable segments: (1) Electronic Systems, (2) C³ISR, (3) Aircraft Modernization and Maintenance (AM&M), and (4) National Security Solutions (NSS). Financial information with respect to each of the Company’s segments is included in Note 22. 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, including microwave, power & control systems, sensor systems, simulation & training, aviation products, precision engagement, warrior systems, security & detection, space & propulsion, undersea warfare and marine services. C³ISR provides products and services for the global ISR (intelligence, surveillance and reconnaissance) market, C3 systems, networked communications 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. AM&M provides modernization, upgrades and sustainment, maintenance and logistics support services for military and various government aircraft and other platforms. The Company sells these services primarily to the DoD, the Canadian Department of Defense and other allied foreign 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 foreign 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, aircraft modernization and sustainment of 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 foreign governments, and domestic and foreign commercial customers.

On July 17, 2012, L-3 completed the spin-off of its subsidiary, Engility Holdings, Inc. (Engility) to L-3’s shareholders. The spin-off was a tax-free distribution to L-3 shareholders for U.S. federal tax purposes, except for cash received in lieu of fractional shares. L-3 shareholders of record on July 16, 2012 (the record date) received one share of Engility common stock for every six shares of L-3 common stock held on the record date. Engility began trading as an independent publicly traded company on the New York Stock Exchange on July 18, 2012. As a result of the spin-off, the assets, liabilities, non-controlling interest, results of operations and cash flows of the Engility businesses have been classified as discontinued operations for all periods presented. References to financial data are to the Company’s continuing operations, unless specifically noted. See Note 4 for additional information.

The Company has the following four reportable segments: (1) Electronic Systems, (2) C³ISR, (3) Aircraft Modernization and Maintenance (AM&M), and (4) National Security Solutions (NSS). Financial information with respect to each of the Company’s segments is included in Note 22. 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, including microwave, power & control systems, sensor systems, simulation & training, aviation products, precision engagement, warrior systems, security & detection, space & propulsion, undersea warfare and marine services. C³ISR provides products and services for the global ISR (intelligence, surveillance and reconnaissance) market, C3 systems, networked communications 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. AM&M provides modernization, upgrades and sustainment, maintenance and logistics support services for military and various government aircraft and other platforms. The Company sells these services primarily to the DoD, the Canadian Department of Defense and other allied foreign 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 foreign governments.