Business Acquisitions, Goodwill and Other Intangible Assets - Narrative (Details) - USD ($) shares in Thousands, $ in Thousands			1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Nov. 30, 2015	Sep. 29, 2014	Dec. 25, 2015	Dec. 25, 2015	Dec. 26, 2014	Dec. 25, 2015	Dec. 26, 2014	Jun. 30, 2015	Sep. 25, 2015
Business Acquisition [Line Items]
Goodwill			$ 101,697	$ 101,697		$ 101,697		$ 37,024
Amortization period of identifiable intangible assets								6 years
Gross revenue				157,743	$ 143,228	293,202	$ 266,253
Net service revenue				111,382	99,838	211,545	192,457
Segment profit (loss)				6,698	6,866	14,371	12,858
Amortization of Intangible Assets				1,076	1,014	$ 1,916	1,728
NOVA Safety & Environmental
Business Acquisition [Line Items]
Goodwill					3,683		3,683
Cash paid		$ 7,198
Second cash payment		2,092
Estimated net working capital adjustment		560
Additions for fiscal year 2015 acquisitions		1,500							$ 893
Second cash payment		2,600
Cash paid out of escrow		$ 508
Shares issued in business acquisition (in shares)		50
Shares issued in business acquisition, value		$ 323
Total identifiable intangible assets					$ 3,622		$ 3,622
Pipeline Services
Business Acquisition [Line Items]
Goodwill	$ 64,673
Purchase price	127,455
Cash paid	119,955
Cash on hand	355
Second cash payment	7,500
Total identifiable intangible assets	44,500
Customer relationships and backlog | Pipeline Services
Business Acquisition [Line Items]
Amortization period of identifiable intangible assets						6 years
Total identifiable intangible assets	43,500
Internally developed software | Pipeline Services
Business Acquisition [Line Items]
Intangible asset, useful life						5 years
Amortization period of identifiable intangible assets						3 years
Total identifiable intangible assets	$ 1,000
Customer relationships
Business Acquisition [Line Items]
Amortization period of identifiable intangible assets								6 years
Minimum | Customer relationships and backlog | Pipeline Services
Business Acquisition [Line Items]
Intangible asset, useful life						1 year
Maximum | Customer relationships and backlog | Pipeline Services
Business Acquisition [Line Items]
Intangible asset, useful life						15 years
Pipeline Services
Business Acquisition [Line Items]
Goodwill			64,673	$ 64,673		$ 64,673		$ 0
Gross revenue			8,017
Net service revenue			5,986
Segment profit (loss)			$ (1,161)