Cover Page - USD ($) $ in Millions	12 Months Ended
	Jul. 01, 2022	Jul. 31, 2022	Dec. 31, 2021
Entity Listings [Line Items]
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Jul. 01, 2022
Entity File Number	0-23599
Entity Registrant Name	MERCURY SYSTEMS, INC
Entity Incorporation, State or Country Code	MA
Entity Tax Identification Number	04-2741391
Entity Address, Address Line One	50 Minuteman Road
Entity Address, City or Town	Andover
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01810
City Area Code	978
Local Phone Number	256-1300
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 3,100.0
Entity Common Stock, Shares Outstanding		57,676,669
ICFR Auditor Attestation Flag	false
Entity Central Index Key	0001049521
Current Fiscal Year End Date	--07-01
Amendment Flag	false
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Common Stock
Entity Listings [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	MRCY
Security Exchange Name	NASDAQ
Preferred Class A
Entity Listings [Line Items]
Title of 12(b) Security	Preferred Stock Purchase Rights
Trading Symbol	N/A
Security Exchange Name	NASDAQ