Goodwill and Intangible Assets - Goodwill (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Goodwill
Goodwill	$ 127,226	$ 124,161
West
Goodwill
Goodwill	45,239	45,239
East
Goodwill
Goodwill	40,150	42,866
Energy
Goodwill
Goodwill	41,837	36,056
Rockford \| West
Goodwill
Goodwill	32,079	32,079
Q3 Contracting \| West
Goodwill
Goodwill	13,160	13,160
JCG \| East
Goodwill
Goodwill	40,150	42,866
PES \| Energy
Goodwill
Goodwill	28,463	28,463
Aevenia \| Energy
Goodwill
Goodwill	10,933	5,152
OnQuest Canada, ULC \| Energy
Goodwill
Goodwill	$ 2,441	$ 2,441

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=64834752&loc=SL49117168-202975

Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant