Description of Business	9 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Description of Business	Description of BusinessMercury Systems, Inc. (the “Company” or “Mercury”) is a leading commercial provider of secure sensor and safety-critical mission processing subsystems. Optimized for customer and mission success, its solutions power a wide variety of critical aerospace, defense and intelligence programs. Headquartered in Andover, Massachusetts, it is pioneering a next-generation defense electronics business model specifically designed to meet the industry's current and emerging technology and business needs. The Company delivers affordable innovative solutions, rapid time-to-value and service and support to its defense prime contractor customers. The Company's products and solutions have been deployed in more than 300 programs with over 25 different defense prime contractors. Key programs include Aegis, Patriot, Surface Electronic Warfare Improvement Program (“SEWIP”), Gorgon Stare, Predator, F-35, Reaper, F-16 SABR, E2D Hawkeye, Paveway, Filthy Buzzard, PGK, ProVision, P1, AIDEWS, CDS, and WIN-T. The Company's organizational structure allows it to deliver capabilities that combine technology building blocks and deep domain expertise in the aerospace and defense sector.