Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amounts	$ 95,775	$ 96,618
Accumulated Amortization	(51,590)	(48,526)
Net Carrying Amounts	44,185	48,092
Customer relationships
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amounts	82,558	82,478
Accumulated Amortization	(44,175)	(40,946)
Net Carrying Amounts	38,383	41,532
Non-compete agreements
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amounts	1,232	1,536
Accumulated Amortization	(502)	(735)
Net Carrying Amounts	730	801
Customer backlog
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amounts	859	1,535
Accumulated Amortization	(377)	(736)
Net Carrying Amounts	482	799
Trade name
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amounts	70	140
Accumulated Amortization	(41)	(76)
Net Carrying Amounts	29	64
Internally developed software
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amounts	11,056	10,929
Accumulated Amortization	(6,495)	(6,033)
Net Carrying Amounts	$ 4,561	$ 4,896

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 928
-SubTopic 340
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6473545&loc=d3e61844-108004

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
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- References

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- Definition

Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
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-Topic 350
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-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16212-109274

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