Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Intangible Assets, Net [Abstract]
Gross Carrying Amount	$ 123,740	$ 95,841
Accumulated Amortization	(60,169)	(57,888)
Net Carrying Amount	63,571	37,953
Customer Relationships [Member]
Intangible Assets, Net [Abstract]
Gross Carrying Amount	97,497	82,431
Accumulated Amortization	(44,185)	(49,716)
Net Carrying Amount	53,312	32,715
Noncompete Agreements [Member]
Intangible Assets, Net [Abstract]
Gross Carrying Amount	1,479	1,264
Accumulated Amortization	(831)	(601)
Net Carrying Amount	648	663
Customer Backlog [Member]
Intangible Assets, Net [Abstract]
Gross Carrying Amount	10,353	1,102
Accumulated Amortization	(5,941)	(987)
Net Carrying Amount	4,412	115
Trade Names [Member]
Intangible Assets, Net [Abstract]
Gross Carrying Amount	449	60
Accumulated Amortization	(281)	(37)
Net Carrying Amount	168	23
Software Development [Member]
Intangible Assets, Net [Abstract]
Gross Carrying Amount	13,962	10,984
Accumulated Amortization	(8,931)	(6,547)
Net Carrying Amount	$ 5,031	$ 4,437