Business Acquisitions - Summary of Elements of Purchase Price of Acquisitions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Cash	$ 59,486	$ 175,450	$ 87,285
Common Stock	8,320	25,000	4,047
Other Purchase Price Component Current	11,928	(1,889)	1,450
Other Purchase Price Component Long Term		100
Contingent Consideration Current	2,801	34,661
Contingent Consideration Long Term	4,603	10,543
Contingent Consideration			5,401
Total Purchase Price	87,138	243,865	98,183
MSE Group
Business Acquisition [Line Items]
Cash	9,082
Common Stock	2,271
Other Purchase Price Component Current	10,701
Contingent Consideration Current	1,551
Contingent Consideration Long Term	253
Total Purchase Price	23,858
EI
Business Acquisition [Line Items]
Cash	20,721
Common Stock	2,274
Other Purchase Price Component Current	(63)
Total Purchase Price	22,932
All Other 2021 Acquisitions
Business Acquisition [Line Items]
Cash	29,683
Common Stock	3,775
Other Purchase Price Component Current	1,290
Contingent Consideration Current	1,250
Contingent Consideration Long Term	4,350
Total Purchase Price	$ 40,348
CTEH
Business Acquisition [Line Items]
Cash		175,000
Common Stock		25,000
Other Purchase Price Component Current		(1,939)
Contingent Consideration Current		34,451
Contingent Consideration Long Term		10,543
Total Purchase Price		243,055
All Other 2020 Acquisitions
Business Acquisition [Line Items]
Cash		450
Other Purchase Price Component Current		50
Other Purchase Price Component Long Term		100
Contingent Consideration Current		210
Total Purchase Price		$ 810
ECT2
Business Acquisition [Line Items]
Cash			54,037
Other Purchase Price Component Current			(220)
Total Purchase Price			53,817
All Other 2019 Acquisitions
Business Acquisition [Line Items]
Cash			33,248
Common Stock			4,047
Other Purchase Price Component Current			1,670
Contingent Consideration			5,401
Total Purchase Price			$ 44,366