Operating Segments - Segment Detail (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 28, 2014	Mar. 29, 2013	Mar. 28, 2014	Mar. 29, 2013
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	$ 120,836	$ 109,806	$ 350,002	$ 322,562
Net service revenue	88,081	83,044	260,464	233,514
Operating income (loss)	2,511	3,392	11,960	12,397
Corporate shared services(2)	(12,895)	(10,424)	(34,131)	(28,213)
Allocated Share-based Compensation Expense	(1,115)	(892)	(3,513)	(2,785)
Depreciation and amortization	(2,161)	(1,828)	(6,587)	(4,959)
Interest expense	(22)	(78)	(152)	(270)
Income from operations before taxes	2,489	3,314	11,808	12,127
Operating Segments
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	119,453	108,963	347,434	320,521
Net service revenue	86,974	82,172	257,629	231,501
Operating income (loss)	17,108	15,226	51,449	45,024
Depreciation and amortization	(1,574)	(1,310)	(4,742)	(3,330)
Reconciling Items
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	1,383	843	2,568	2,041
Net service revenue	1,107	872	2,835	2,013
Depreciation and amortization	(587)	(518)	(1,845)	(1,629)
Energy
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	44,480	34,505	118,050	98,297
Net service revenue	34,632	29,145	98,339	80,660
Operating income (loss)	7,908	5,185	19,313	16,831
Depreciation and amortization	(835)	(564)	(2,385)	(1,257)
Environmental
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	60,750	59,664	182,692	177,203
Net service revenue	41,939	41,423	124,860	118,292
Operating income (loss)	7,787	7,253	25,898	21,987
Depreciation and amortization	(633)	(651)	(2,039)	(1,729)
Infrastructure
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	14,223	14,794	46,692	45,021
Net service revenue	10,403	11,604	34,430	32,549
Operating income (loss)	1,413	2,788	6,238	6,206
Depreciation and amortization	$ (106)	$ (95)	$ (318)	$ (344)