Description of Business	9 Months Ended
Sep. 29, 2017
Description of Business [Abstract]
Description of Business	1. Description of Business L3 Technologies, Inc. (L3 Technologies Inc. and, together with its subsidiaries, referred to herein as L3 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. L3 is also a leading provider of a broad range of communication, electronic and sensor systems used on military, homeland security 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. At December 31, 2016, the Company had the following three reportable segments: (1) Electronic Systems, (2) Aerospace Systems and (3) Communication Systems. Effective March 1, 2017, the Company realigned its Electronic Systems segment, which was separated into two segments named: (1) Electronic Systems and (2) Sensor Systems. Accordingly, the Company’s current structure consists of the following four segments: (1) Electronic Systems, (2) Aerospace Systems, (3) Communication Systems and (4) Sensor Systems. The Company has reported its segment results for all periods presented under the realigned business segments for the prior year to be consistent with the current presentation. Electronic Systems provides a broad range of products and services for military and commercial customers in several niche markets across several business areas. The Electronic System business areas are Precision Engagement Systems, Power & Propulsion Systems, Aviation Products, Security & Detection Systems and Total Training Solutions. Aerospace Systems delivers integrated solutions for the global ISR market and provides engineering, modernization, upgrade, sustainment, and maintenance and logistics support for a wide variety of aircraft and ground systems. Aerospace Systems sells these products and services primarily to the DoD and select foreign governments. During the third quarter of 2017, the Company restructured the businesses within its Aerospace Systems segment to streamline operations by consolidating most of the Aircraft Systems sector into the ISR Systems sector, which has been renamed. The restructured Aerospace Systems business areas are Advanced Systems, MAS, Mission Integration and Vertex Aerospace. Communication Systems delivers products and services for the global communications market, specializing in strategic and tactical space, airborne, ground and sea-based communication systems. Communication Systems sells these products and services primarily to the DoD and select foreign governments. The Communications Systems business areas are Broadband Communication Systems, Advanced Communications and Space & Power Systems. Sensor Systems provides diverse sensor technologies for the land, sea, air, space and cyber domains to military and commercial customers. During the third quarter of 2017, the Company realigned the business areas within its Sensor Systems segment. The realigned Sensor Systems business areas are Advanced Programs & BD, Space & Sensor Systems, Airborne Turrets, Intelligence & Mission Systems, Maritime Sensor Systems and Warrior Sensor Systems. 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 provided 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 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. 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, 2016.

1. Description of Business

L3 Technologies, Inc. (L3 Technologies Inc. and, together with its subsidiaries, referred to herein as L3 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. L3 is also a leading provider of a broad range of communication, electronic and sensor systems used on military, homeland security 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.

At December 31, 2016, the Company had the following three reportable segments: (1) Electronic Systems, (2) Aerospace Systems and (3) Communication Systems. Effective March 1, 2017, the Company realigned its Electronic Systems segment, which was separated into two segments named: (1) Electronic Systems and (2) Sensor Systems. Accordingly, the Company’s current structure consists of the following four segments: (1) Electronic Systems, (2) Aerospace Systems, (3) Communication Systems and (4) Sensor Systems. The Company has reported its segment results for all periods presented under the realigned business segments for the prior year to be consistent with the current presentation.

Electronic Systems provides a broad range of products and services for military and commercial customers in several niche markets across several business areas. The Electronic System business areas are Precision Engagement Systems, Power & Propulsion Systems, Aviation Products, Security & Detection Systems and Total Training Solutions.

Aerospace Systems delivers integrated solutions for the global ISR market and provides engineering, modernization, upgrade, sustainment, and maintenance and logistics support for a wide variety of aircraft and ground systems. Aerospace Systems sells these products and services primarily to the DoD and select foreign governments. During the third quarter of 2017, the Company restructured the businesses within its Aerospace Systems segment to streamline operations by consolidating most of the Aircraft Systems sector into the ISR Systems sector, which has been renamed. The restructured Aerospace Systems business areas are Advanced Systems, MAS, Mission Integration and Vertex Aerospace.

Communication Systems delivers products and services for the global communications market, specializing in strategic and tactical space, airborne, ground and sea-based communication systems. Communication Systems sells these products and services primarily to the DoD and select foreign governments. The Communications Systems business areas are Broadband Communication Systems, Advanced Communications and Space & Power Systems.

Sensor Systems provides diverse sensor technologies for the land, sea, air, space and cyber domains to military and commercial customers. During the third quarter of 2017, the Company realigned the business areas within its Sensor Systems segment. The realigned Sensor Systems business areas are Advanced Programs & BD, Space & Sensor Systems, Airborne Turrets, Intelligence & Mission Systems, Maritime Sensor Systems and Warrior Sensor Systems.

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 provided 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 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.

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, 2016.