Description of Business	9 Months Ended
Sep. 23, 2016
Organization, Consolidation and Presentation of Financial Statements [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, aircraft sustainment (including modifications, logistics and maintenance), simulation and training, night vision and image intensification equipment, and security and detection systems. L-3 is also a leading provider of a broad range of communication and electronic systems and products 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), foreign governments, and domestic and international commercial customers. On December 7, 2015, the Company entered into a definitive agreement to sell its National Security Solutions (NSS) business to CACI International Inc. The transaction was completed on February 1, 2016. NSS provides cybersecurity solutions, high-performance computing, enterprise IT services, analytics and intelligence analysis to the DoD, U.S. Government intelligence agencies, federal civilian agencies and foreign governments. In accordance with Accounting Standards Update (ASU) 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity, the assets and liabilities and results of operations of NSS are reported as discontinued operations for all periods presented. Accordingly, all references made to financial data in this Quarterly Report on Form 10-Q are to the Company’s continuing operations, unless specifically noted. See Note 5 for additional information. The Company has the following three reportable segments: (1) Electronic Systems, (2) Aerospace Systems and (3) Communication Systems. Electronic Systems provides a broad range of components, products, subsystems, systems, and related services for military and commercial customers in several niche markets across several business areas. These business areas include precision engagement & training, sensor systems, power & propulsion systems, aviation products & security systems, warrior systems and advanced programs. Aerospace Systems delivers integrated solutions for the global ISR market and provides modernization, upgrade, sustainment, and maintenance and logistics support for a wide variety of aircraft and ground systems. Communication Systems delivers products and services for the global communications market, specializing in strategic and tactical airborne, space, ground and sea-based communication systems. Financial information with respect to the Company’s segments is included in Note 22 to the unaudited condensed consolidated financial statements and in Note 21 to the audited consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015.

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, aircraft sustainment (including modifications, logistics and maintenance), simulation and training, night vision and image intensification equipment, and security and detection systems. L-3 is also a leading provider of a broad range of communication and electronic systems and products 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), foreign governments, and domestic and international commercial customers.

On December 7, 2015, the Company entered into a definitive agreement to sell its National Security Solutions (NSS) business to CACI International Inc. The transaction was completed on February 1, 2016. NSS provides cybersecurity solutions, high-performance computing, enterprise IT services, analytics and intelligence analysis to the DoD, U.S. Government intelligence agencies, federal civilian agencies and foreign governments. In accordance with Accounting Standards Update (ASU) 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity, the assets and liabilities and results of operations of NSS are reported as discontinued operations for all periods presented. Accordingly, all references made to financial data in this Quarterly Report on Form 10-Q are to the Company’s continuing operations, unless specifically noted. See Note 5 for additional information.

The Company has the following three reportable segments: (1) Electronic Systems, (2) Aerospace Systems and (3) Communication Systems. Electronic Systems provides a broad range of components, products, subsystems, systems, and related services for military and commercial customers in several niche markets across several business areas. These business areas include precision engagement & training, sensor systems, power & propulsion systems, aviation products & security systems, warrior systems and advanced programs. Aerospace Systems delivers integrated solutions for the global ISR market and provides modernization, upgrade, sustainment, and maintenance and logistics support for a wide variety of aircraft and ground systems. Communication Systems delivers products and services for the global communications market, specializing in strategic and tactical airborne, space, ground and sea-based communication systems.

Financial information with respect to the Company’s segments is included in Note 22 to the unaudited condensed consolidated financial statements and in Note 21 to the audited consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015.