Operating Segments - Segment Detail (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jun. 30, 2014	Mar. 28, 2014	Dec. 27, 2013	Sep. 27, 2013	Jun. 30, 2013	Mar. 29, 2013	Dec. 28, 2012	Sep. 28, 2012	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	$ 125,675	$ 120,836	$ 122,592	$ 106,574	$ 118,955	$ 109,806	$ 104,470	$ 108,286	$ 475,677	$ 441,517	$ 419,959
Net service revenue	94,492	88,081	91,131	81,252	86,889	83,044	75,254	75,216	354,956	320,403	301,780
Operating income (loss)	8,961	2,511	5,195	4,254	6,164	3,392	4,399	4,606	20,921	18,561	29,956
Corporate shared services(2)									(42,549)	(38,174)	(35,903)	[1]
Arena Towers litigation expense (reversal)									0	0	11,061
Allocated Share-based Compensation Expense									(4,658)	(3,832)	(6,550)
Depreciation and amortization									(8,800)	(6,903)	(5,508)
Interest expense									(169)	(337)	(668)
Income (loss) from operations before taxes and equity in earnings	8,944	2,489	5,157	4,162	6,097	3,314	4,319	4,494	20,752	18,224	29,288
Operating Segments
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other									469,846	438,949	417,020
Net service revenue									350,276	317,250	298,562
Operating income (loss)									70,546	62,760	63,210
Depreciation and amortization									(6,382)	(4,710)	(3,646)
Reconciling Items
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other									5,831	2,568	2,939	[2]
Net service revenue									4,680	3,153	3,218	[2]
Depreciation and amortization									(2,418)	(2,193)	(1,862)
Energy
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other									160,651	138,189	125,219
Net service revenue									132,795	109,815	96,018
Operating income (loss)									26,468	23,261	23,517
Depreciation and amortization									(3,253)	(1,868)	(1,171)
Environmental
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other									245,944	240,820	235,089
Net service revenue									170,506	163,217	159,016
Operating income (loss)									35,324	30,836	31,955
Depreciation and amortization									(2,703)	(2,397)	(1,996)
Infrastructure
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other									63,251	59,940	56,712
Net service revenue									46,975	44,218	43,528
Operating income (loss)									8,754	8,663	7,738
Depreciation and amortization									$ (426)	$ (445)	$ (479)

[1] Corporate shared services consists of centrally managed functions in the following areas: accounting, treasury, information technology, legal, human resources, marketing, internal audit and executive management such as the CEO and various executives. These costs and other items of a general corporate nature are not allocated to the Company's three operating segments.

[2] Amounts represent certain unallocated corporate amounts not considered in the CODM's evaluation of operating segment performance.