Acquisitions (Details) (USD $) In Thousands, unless otherwise specified	Feb. 04, 2011 Morgan Southern	May 31, 2011 Bruenger	Aug. 01, 2011 James Brooks	Aug. 31, 2011 Prime	Feb. 24, 2012 CTL	Apr. 19, 2012 D&E	Jun. 04, 2012 CTW	Aug. 01, 2012 R&M	Aug. 10, 2012 EFS	Nov. 05, 2012 Central Cal	Nov. 12, 2012 A&A	Dec. 21, 2012 DCT
Schedule of allocated purchase price paid to fair value of acquired net assets for acquisitions
Accounts receivable	$ 4,854	$ 1,948	$ 777	$ 8,149	$ 744	$ 1,798	$ 1,652	$ 3,722	$ 1,588	$ 2,079	$ 3,243	$ 589
Other current assets	842	718	36	496	19	518	0	352	37	2	298	14
Property and equipment	1,041	11,234	319	3,996	95	4,023	736	5,654	1,925	1,666	18,288	0
Goodwill	15,019	4,182	7,944	90,654	6,434	8,211	9,223	20,164	12,050	6,688	12,361	2,325
Customer relationships intangible assets	500	0	0	9,400	80	721	725	1,829	558	140	0	0
Other noncurrent assets	356	300	161	100	1	169	0	0	65	156	230	3
Accounts payable and other liabilities	(3,256)	(7,772)	(1,675)	(16,033)	(1,215)	(4,082)	(4,739)	(7,511)	(6,224)	(6,922)	(10,345)	(1,913)
Total	$ 19,356	$ 10,610	$ 7,562	$ 96,762	$ 6,158	$ 11,358	$ 7,597	$ 24,210	$ 9,999	$ 3,809	$ 24,075	$ 1,018

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The total purchase price of the acquired entity. This includes cash paid to equity interest holders of the acquired entity, fair value of debt and equity securities issued to equity holders of the acquired entity, and transaction costs paid to third parties to consummate the acquisition.

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The amount of acquisition cost of a business combination allocated to prepaid expenses and other current assets. Does not include amounts allocated to cash and cash equivalents, marketable securities, receivables, inventory, and assets not to be used.

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The amount of acquisition cost of a business combination allocated to receivables.

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The amount of acquisition cost of a business combination allocated to current liabilities of the acquired entity.

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Amount of goodwill arising from a business combination, which is the excess of the cost of the acquired entity over the amounts assigned to assets acquired and liabilities assumed.

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

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Amount of acquisition cost of a business combination allocated to assets, excluding financial assets and goodwill, lacking physical substance.

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Amount of acquisition cost of a business combination allocated to other noncurrent assets not separately disclosed.

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The amount of acquisition cost of a business combination allocated to property, plant and equipment to be used in ongoing operations.

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