Goodwill and Identifiable Intangible Assets, Net - Identifiable Intangible Assets, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Identifiable Intangible Assets, Net
Gross Book Value	$ 477,667	$ 366,987
Accumulated Amortization	(172,886)	(135,180)
Future amortization expense of identifiable intangible assets
2022	46,505
2023	34,532
2024	32,343
2025	30,156
2026	29,312
Thereafter	131,933
Total	$ 304,781
Customer Relationships
Identifiable Intangible Assets, Net
Estimated Useful Lives in Years	7 years 7 months 6 days
Gross Book Value	$ 330,572	255,692
Accumulated Amortization	$ (130,098)	(103,919)
Customer Relationships | Minimum
Identifiable Intangible Assets, Net
Estimated Useful Lives in Years	7 years 7 months 6 days
Backlog
Identifiable Intangible Assets, Net
Estimated Useful Lives in Years	1 year 1 month 6 days
Gross Book Value	$ 32,300	19,800
Accumulated Amortization	$ (20,091)	(12,600)
Backlog | Minimum
Identifiable Intangible Assets, Net
Estimated Useful Lives in Years	1 year 1 month 6 days
Trade Name
Identifiable Intangible Assets, Net
Estimated Useful Lives in Years	19 years 7 months 6 days
Gross Book Value	$ 114,795	91,495
Accumulated Amortization	$ (22,697)	$ (18,661)
Trade Name | Minimum
Identifiable Intangible Assets, Net
Estimated Useful Lives in Years	19 years 7 months 6 days
Customer Relationships Noncompete Agreements and Tradenames | Minimum
Identifiable Intangible Assets, Net
Estimated Useful Lives in Years	1 year
Customer Relationships Noncompete Agreements and Tradenames | Maximum
Identifiable Intangible Assets, Net
Estimated Useful Lives in Years	25 years