Operating Segments - Segment Detail (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Dec. 27, 2013	Dec. 28, 2012	Dec. 27, 2013	Dec. 28, 2012
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	$ 122,592	$ 104,470	$ 229,166	$ 212,756
Net service revenue	91,131	75,254	172,383	150,470
Operating income (loss)	5,195	4,399	9,449	9,005
Corporate shared services(2)	(11,021)	(8,864)	(21,236)	(17,789)
Allocated Share-based Compensation Expense	(1,243)	(984)	(2,398)	(1,893)
Depreciation and amortization	(2,250)	(1,593)	(4,426)	(3,131)
Interest expense	(38)	(80)	(130)	(192)
Income from operations before taxes	5,157	4,319	9,319	8,813
Operating Segments
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	122,607	104,700	227,981	211,558
Net service revenue	90,902	75,064	170,655	149,329
Operating income (loss)	18,083	14,816	34,341	29,798
Depreciation and amortization	(1,626)	(1,024)	(3,168)	(2,020)
Reconciling Items
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	(15)	(230)	1,185	1,198
Net service revenue	229	190	1,728	1,141
Depreciation and amortization	(624)	(569)	(1,258)	(1,111)
Energy
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	40,106	31,618	73,570	63,792
Net service revenue	34,893	25,872	63,707	51,515
Operating income (loss)	7,301	5,646	11,405	11,646
Depreciation and amortization	(792)	(360)	(1,550)	(693)
Environmental
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	66,420	58,940	121,942	117,539
Net service revenue	44,560	39,493	82,921	76,869
Operating income (loss)	8,764	7,819	18,111	14,734
Depreciation and amortization	(726)	(537)	(1,406)	(1,078)
Infrastructure
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	16,081	14,142	32,469	30,227
Net service revenue	11,449	9,699	24,027	20,945
Operating income (loss)	2,018	1,351	4,825	3,418
Depreciation and amortization	$ (108)	$ (127)	$ (212)	$ (249)