Goodwill and Intangible Assets - Gross Carrying Amounts and Accumulated Amortization (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets
Total intangible assets, gross	$ 185,318	$ 177,336
Total accumulated amortization	(56,994)	(47,740)
Total intangible assets, net	$ 128,324	129,596
Customer relationships
Finite-Lived Intangible Assets
Estimated useful life	10 years 1 month 6 days
Total intangible assets, gross	$ 154,894	149,420
Total accumulated amortization	$ (45,548)	(38,270)
Technology, including internally developed software
Finite-Lived Intangible Assets
Estimated useful life	6 years 8 months 12 days
Total intangible assets, gross	$ 24,399	21,892
Total accumulated amortization	$ (7,727)	(6,153)
Backlog
Finite-Lived Intangible Assets
Estimated useful life	4 years
Total intangible assets, gross	$ 3,100	3,100
Total accumulated amortization	$ (3,100)	(2,842)
Covenants not to compete
Finite-Lived Intangible Assets
Estimated useful life	4 years 8 months 12 days
Total intangible assets, gross	$ 425	424
Total accumulated amortization	$ (397)	(337)
Trade Names
Finite-Lived Intangible Assets
Estimated useful life	15 years
Total intangible assets, gross	$ 2,500	2,500
Total accumulated amortization	$ (222)	$ (138)