Business Combinations (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended								3 Months Ended	6 Months Ended		3 Months Ended		0 Months Ended		0 Months Ended		0 Months Ended		0 Months Ended	6 Months Ended	0 Months Ended		0 Months Ended	6 Months Ended		6 Months Ended				6 Months Ended		0 Months Ended			0 Months Ended	1 Months Ended	6 Months Ended			6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 Customer relationship Minimum	Jun. 30, 2013 Customer relationship Maximum	Jun. 30, 2013 Tradename Minimum	Jun. 30, 2013 Tradename Maximum	Jun. 30, 2013 Non-compete agreements Minimum	Jun. 30, 2013 Non-compete agreements Maximum	Jun. 30, 2013 FSSI item	Jun. 30, 2013 FSSI item	Mar. 11, 2013 FSSI	Jun. 30, 2013 FSSI Revisions	Mar. 11, 2013 FSSI 2013 earnout target	Mar. 11, 2013 FSSI 2013 earnout target Minimum	Mar. 11, 2013 FSSI 2014 earnout target	Mar. 11, 2013 FSSI 2014 earnout target Minimum	Mar. 11, 2013 FSSI 2015 earnout target	Mar. 11, 2013 FSSI 2015 earnout target Minimum	Mar. 11, 2013 FSSI Customer relationship	Mar. 11, 2013 FSSI Non-competition and non-solicitation agreement with a key employee	Jun. 30, 2013 FSSI Non-competition and non-solicitation agreement with a key employee	Mar. 11, 2013 FSSI Tradename	Jun. 30, 2013 FSSI Non-compete agreements Income approach	Mar. 12, 2012 Sprint	Jun. 30, 2013 Sprint	Jun. 30, 2013 Sprint 2012 earnout target	Jun. 30, 2013 Sprint 2012 earnout target Minimum	Jun. 30, 2013 Sprint 2013 earnout target	Dec. 31, 2012 Sprint 2013 earnout target	Mar. 12, 2012 Sprint 2013 earnout target	Jun. 30, 2013 Sprint 2013 earnout target Minimum	May 30, 2012 Silva	Sep. 28, 2012 Saxon item	Jun. 30, 2013 Saxon	Dec. 31, 2012 Saxon	Sep. 28, 2012 Saxon Minimum	Jan. 31, 2013 Q3 Contracting	Jun. 30, 2013 Q3 Contracting	Dec. 31, 2012 Q3 Contracting	Nov. 17, 2012 Q3 Contracting	Jun. 30, 2013 Q3 Contracting Earnout target period from November 18, 2012 through December 31, 2013	Jun. 30, 2013 Q3 Contracting Earnout target period from November 18, 2012 through December 31, 2013 Minimum	Jun. 30, 2013 Q3 Contracting 2014 earnout target	Jun. 30, 2013 Q3 Contracting 2014 earnout target Minimum
Business combinations
Cash consideration													$ 1,675																						$ 550							$ 48,116
Cash consideration paid	1,025	35,131	1,025	35,131							650	650	1,025													21,197
Number of future potential payments based on agreed upon contingencies											3	3
Cash payable																						1,000
Potential contingent consideration															500		500		500									4,000		4,000					2,500								3,750		3,750
Pretax income threshold for measuring financial performance																553		2,502		4,227									7,000				7,750					4,000						17,700		19,000
Contingent consideration											721	721	702																	3,205	3,020	2,745			1,950	2,184	2,028			7,862	7,490
Period of employment, non-competition and non-solicitation agreement with a key employee																						5 years
Amortization period of agreement					5 years	15 years	3 years	10 years	2 years	5 years													5 years
Revenues	445,013	337,436	855,008	629,009							2,990	3,473
Gross Profit	59,537	44,004	105,633	81,600							183	311
Decrease in the fair value of the contingent consideration			(10,161)	(2,871)										136
Increases in intangible assets														800
Decrease in goodwill														936
Small tools inventory received in acquisition													302
Property, plant and equipment received in acquisition													448
Accounts payable received in acquisition													1,060
Intangible assets																					950	1,000		550	100
Estimated useful life of intangible assets																								5 years
Goodwill													1,087
Total consideration													2,377													28,377								14,090	4,929							55,994
Company common stock as a part of consideration																										980																430
Number of shares of common stock issued																										62,052	62,052												29,273	29,273
Earnout consideration																										6,200																7,448
Bank note as part of consideration																																			2,429
Number of targets for payment of contingent cash consideration																																			2
EBITDA threshold for measuring financial performance, case two																																						4,750						19,000		22,000
Additional potential contingent consideration																																											$ 1,250		$ 1,250
Amortization period of goodwill and other intangible assets for income tax purposes												15 years