Document and Entity Information - shares	3 Months Ended
	Sep. 30, 2018	Nov. 05, 2018
Document Documentand Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Trading Symbol	MTRX
Entity Registrant Name	MATRIX SERVICE CO
Entity Central Index Key	0000866273
Current Fiscal Year End Date	--06-30
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		27,071,755