Operating Segments - Segment Summary (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Sep. 26, 2014 segment	Sep. 27, 2013
Segment Reporting Information [Line Items]
Number of operating segments (in segments)	3
Sales Revenue, Services, Other	$ 123,025	$ 106,574
Net service revenue	92,619	81,252
Segment profit	5,992	4,254
Depreciation and amortization	2,265	2,176
Total [Member]
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	124,060	105,374
Net service revenue	94,002	79,753
Segment profit	18,058	16,258
Depreciation and amortization	1,664	1,542
Energy
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	38,035	33,464
Net service revenue	33,213	28,814
Segment profit	5,641	4,104
Depreciation and amortization	839	758
Environmental
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	68,194	55,522
Net service revenue	47,656	38,361
Segment profit	10,158	9,347
Depreciation and amortization	712	680
Infrastructure
Segment Reporting Information [Line Items]
Sales Revenue, Services, Other	17,831	16,388
Net service revenue	13,133	12,578
Segment profit	2,259	2,807
Depreciation and amortization	$ 113	$ 104

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

+ Details

Name:	us-gaap_DepreciationDepletionAndAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfOperatingSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The net result for the period of deducting operating expenses from operating revenues.

+ References

No definition available.

+ Details

Name:	us-gaap_OperatingIncomeLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Aggregate revenue during the period for services rendered in the normal course of business (before deducting allowances and discounts) which are not otherwise defined in the taxonomy.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1(d))

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

+ Details

Name:	us-gaap_SalesRevenueServicesGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Aggregate revenue during the period from services rendered in the normal course of business, after deducting allowances and discounts.

+ References

+ Details

Name:	us-gaap_SalesRevenueServicesNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration