Acquisitions (Details) - USD ($) $ / shares in Units, $ in Thousands			9 Months Ended
	Feb. 01, 2016	Dec. 21, 2013	Mar. 31, 2014	Mar. 31, 2013	Jun. 30, 2016	Jun. 30, 2015	Sep. 30, 2014	Aug. 22, 2014	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
Business Acquisition [Line Items]
Goodwill					$ 78,293	$ 71,518			$ 69,837		$ 30,836
Pro Forma Information:
Revenues			$ 1,397,706	$ 1,096,267
Net income attributable to Matrix Service Company			$ 38,786	$ 28,444
Basic earnings per common share (in dollars per share)			$ 1.48	$ 1.10
Diluted earnings per common share (in dollars per share)			$ 1.44	$ 1.08
Baillie Tank Equipment, Ltd. [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	$ 13,049
Current assets	5,574
Property, plant and equipment	4,347
Goodwill	6,942
Other intangible assets	720
Other assets	233
Total assets acquired	17,816
Current liabilities	1,581
Deferred income taxes	329
Long-term debt	1,858
Other liabilities	407
Net assets acquired	13,641
Cash acquired	$ 592
HDB, Inc. [Member]
Business Acquisition [Line Items]
Current assets								$ 1,645
Property, plant and equipment								1,001
Tax deductible goodwill								3,065
Other intangible assets								900
Total assets acquired								6,611
Current liabilities								1,060
Net assets acquired							$ 5,600	$ 5,551
Kvaerner North American Construction [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred		$ 51,607
Current assets		83,575
Property, plant and equipment		11,377
Goodwill		39,295								$ 39,295
Tax deductible goodwill		30,700
Other intangible assets		24,009
Total assets acquired		158,256
Current liabilities		68,115
Deferred income taxes		1,179
Noncontrolling interest of consolidated joint venture		700
Net assets acquired		88,262								$ 88,262
Cash acquired		$ 36,655