Acquisitions (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended			0 Months Ended	3 Months Ended		6 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2013	Dec. 31, 2013 Matrix NAC	Dec. 31, 2013 Matrix NAC	Dec. 31, 2012 Matrix NAC	Dec. 31, 2013 Matrix NAC	Dec. 31, 2012 Matrix NAC	Dec. 31, 2013 Pelichem
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition									Dec. 21, 2013		Dec. 31, 2012
Business Acquisition, Percentage of Voting Interests Acquired						100.00%	100.00%		100.00%
Business Acquisition, Name of Acquired Entity			Kvaerner North American Construction, Ltd. and substantially all of the assets of Kvaerner North American Construction, Inc
Business Combination, Consideration Transferred									$ 88,100,000
Goodwill	67,122,000		67,122,000		30,836,000	36,311,000	36,311,000		36,311,000		2,247,000
Tax deductible goodwill						28,500,000	28,500,000		28,500,000
Noncontrolling Interest, Description									The Joint Venture was formed by Kvaerner North American Construction, Inc. and an engineering firm to engineer and construct a combined cycle power plant in Dover, Delaware.
Noncontrolling Interest, Ownership Percentage by Parent						65.00%	65.00%		65.00%
mtrx_JointVentureValue						2,000,000	2,000,000		2,000,000
mtrx_ControllingInterestOfJointVenture,Value						1,300,000	1,300,000		1,300,000
Noncontrolling interest of consolidated joint venture					0	700,000	700,000		700,000
mtrx_JointVentureAssetValue,Total						27,700,000	27,700,000		27,700,000
mtrx_JointVentureAssetValue,Cash						17,600,000	17,600,000		17,600,000
mtrx_JointVentureAssetValue,Receivables						10,100,000	10,100,000		10,100,000
mtrx_JointVentureLiabilityValue,Total						25,800,000	25,800,000		25,800,000
mtrx_JointVentureLiabilityValue,BillingsInExcessOfCostsAndEstimatedEarnings						20,900,000	20,900,000		20,900,000
mtrx_JointVentureLiabilityValue,Payables						4,900,000	4,900,000		4,900,000
Revenues	310,998,000	221,436,000	537,215,000	431,044,000		5,400,000
Operating income	14,817,000	8,772,000	25,579,000	16,696,000		0
Business Combination, Acquisition Related Costs									2,000,000
Amortization Expense							1,100,000	1,100,000	2,100,000	2,100,000
Depreciation Expense							600,000	600,000	1,200,000	1,200,000
Acquisition related costs							(2,000,000)	0	(2,000,000)	2,000,000
Interest Income							$ (600,000)		$ (600,000)