Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amounts	$ 124,066	$ 95,841
Accumulated Amortization	(56,719)	(57,888)
Net Carrying Amounts	67,347	37,953
Customer relationships
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amounts	98,926	82,431
Accumulated Amortization	(43,958)	(49,716)
Net Carrying Amounts	54,968	32,715
Non-compete agreements
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amounts	1,498	1,264
Accumulated Amortization	(794)	(601)
Net Carrying Amounts	704	663
Customer backlog
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amounts	9,020	1,102
Accumulated Amortization	(2,983)	(987)
Net Carrying Amounts	6,037	115
Trade name
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amounts	411	60
Accumulated Amortization	(157)	(37)
Net Carrying Amounts	254	23
Developed software
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amounts	14,211	10,984
Accumulated Amortization	(8,827)	(6,547)
Net Carrying Amounts	$ 5,384	$ 4,437