Operating Segments - Segment Summary (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 30, 2016 USD ($)	Dec. 25, 2015 USD ($)	Dec. 30, 2016 USD ($) segment	Dec. 25, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments (in segments) | segment			4
Gross revenue	$ 198,662	$ 157,743	$ 379,513	$ 293,202
Net service revenue	127,356	111,382	251,661	211,545
Segment profit (loss)	7,036	6,698	12,993	14,371
Total [Member]
Segment Reporting Information [Line Items]
Gross revenue	196,947	156,289	377,428	291,338
Net service revenue	126,563	110,913	250,527	210,378
Segment profit (loss)	23,626	20,389	46,324	40,575
Depreciation	1,545	1,522	3,122	2,707
Amortization	2,491	900	5,080	1,566
Energy
Segment Reporting Information [Line Items]
Gross revenue	67,860	48,040	124,854	87,276
Net service revenue	40,288	39,794	77,388	74,132
Segment profit (loss)	9,501	9,470	17,468	16,782
Depreciation	438	492	881	956
Amortization	245	298	493	599
Environmental
Segment Reporting Information [Line Items]
Gross revenue	80,162	77,925	154,098	153,768
Net service revenue	50,325	51,424	99,219	102,988
Segment profit (loss)	9,184	9,548	18,236	19,529
Depreciation	657	638	1,301	1,262
Amortization	254	300	528	665
Infrastructure
Segment Reporting Information [Line Items]
Gross revenue	21,442	22,307	44,355	42,277
Net service revenue	14,618	13,709	31,249	27,272
Segment profit (loss)	3,474	2,532	7,782	5,425
Depreciation	139	125	277	222
Amortization	0	0	0	0
Oil & Gas
Segment Reporting Information [Line Items]
Gross revenue	27,483	8,017	54,121	8,017
Net service revenue	21,332	5,986	42,671	5,986
Segment profit (loss)	1,467	(1,161)		(1,161)
Depreciation	311	267	663	267
Amortization	$ 1,992	$ 302	$ 4,059	$ 302