v3.3.1.900
Document and Entity Information - shares
9 Months Ended
Mar. 31, 2016
Apr. 30, 2016
Document Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Mar. 31, 2016  
Document Fiscal Year Focus 2016  
Document Fiscal Period Focus Q3  
Trading Symbol MRCY  
Entity Registrant Name MERCURY SYSTEMS INC  
Entity Central Index Key 0001049521  
Current Fiscal Year End Date --06-30  
Entity Filer Category Accelerated Filer  
Entity Common Stock, Shares Outstanding   40,028,735