Business Acquisitions - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Apr. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Aug. 31, 2019	Jul. 31, 2019	Jun. 30, 2019	Apr. 30, 2019	Mar. 31, 2019	Nov. 30, 2018	Oct. 31, 2018	Mar. 31, 2018	Feb. 01, 2018	Jan. 31, 2018
Business Acquisition [Line Items]
Transaction costs related to business combinations		$ 4,300,000	$ 2,400,000	$ 1,200,000
Number of common stock shares issued in connection with business acquisition		791,139	150,439	264,582
Revenue			$ 23,200,000
Pre-tax income (loss)			2,400,000
Revenues from discontinued service lines		$ 3,800,000	$ 18,400,000	$ 19,800,000
Customer Relationships
Business Acquisition [Line Items]
Weighted average useful lives for acquired intangible assets			9 years 6 months
Trade Names
Business Acquisition [Line Items]
Weighted average useful lives for acquired intangible assets			1 year 6 months
Covenants Not to Compete
Business Acquisition [Line Items]
Weighted average useful lives for acquired intangible assets			4 years
Proprietary Software
Business Acquisition [Line Items]
Weighted average useful lives for acquired intangible assets			3 years
Patent
Business Acquisition [Line Items]
Weighted average useful lives for acquired intangible assets			16 years
CTEH
Business Acquisition [Line Items]
Percentage of interests acquired	100.00%
Revenue		82,400
Pre-tax income (loss)		$ 11,700
CTEH | External Proprietary Software
Business Acquisition [Line Items]
Weighted average useful lives for acquired intangible assets	5 years
CTEH | Customer Relationships
Business Acquisition [Line Items]
Weighted average useful lives for acquired intangible assets	15 years
CTEH | Trade Names
Business Acquisition [Line Items]
Weighted average useful lives for acquired intangible assets	5 years
CTEH | Covenants Not to Compete
Business Acquisition [Line Items]
Weighted average useful lives for acquired intangible assets	5 years
CTEH | Proprietary Software
Business Acquisition [Line Items]
Weighted average useful lives for acquired intangible assets	3 years
CTEH | Covenants Not to Compete Other Acquisitions
Business Acquisition [Line Items]
Weighted average useful lives for acquired intangible assets	4 years
CTEH | 2020 Earn Out
Business Acquisition [Line Items]
Business combination, contingent consideration arrangements, basis for amount		CTEH first year earnout is to be calculated at twelve times CTEH’s 2020 EBITDA (as defined in the purchase agreement) in excess of $18.3 million, with a maximum first year earn-out payment of $50.0 million, which is expected to be fully achieved.
Business combination, contingent consideration arrangements, description		The 2020 earn out was initially payable 100.0% in common stock, but as a result of the completion of the Company’s IPO (Note 1), 50.0% of any 2020 earnout payment may be paid in cash at the Company’s election.
Business combination, minimum EBITDA for contingent consideration arrangements		$ 18,300,000
Business combination, earn-out payment, maximum		$ 50,000,000
Percentage of earn out payable in common stock		100.00%
Percentage of earn out payable in cash, as result of completing of IPO		50.00%
Percentage of earn out payable in cash, as a result of completion of IPO, at company's election		50.00%
Percentage of earn out payable in shares, as a result of completion of IPO, at company's election		50.00%
CTEH | 2021 Earn Out
Business Acquisition [Line Items]
Business combination, contingent consideration arrangements, basis for amount		The second year earn-out is to be calculated at ten times CTEH’s 2021 EBITDA in excess of actual 2020 EBITDA (with actual 2020 EBITDA subject to a minimum of $18.3 million and a maximum of $22.5 million), with a maximum second year earn-out payment of $30.0 million.
Business combination, contingent consideration arrangements, description		The Company expects to pay 50.0% of the 2020 earn-out in cash and 50.0% in shares of common stock. The 2021 earn out, if any, is payable 100.0% in cash.
Business combination, earn-out payment, maximum		$ 30,000,000
Percentage of earn out payable in cash		100.00%
CTEH | Minimum | 2020 Earn Out
Business Acquisition [Line Items]
Business combination, actual EBITDA		$ 18,300,000
CTEH | Maximum [Member] | 2020 Earn Out
Business Acquisition [Line Items]
Business combination, actual EBITDA		$ 22,500,000
CTEH | Convertible And Redeemable Series A-2 Preferred Stock
Business Acquisition [Line Items]
Number of common stock shares issued in connection with business acquisition			791,139	791,139
Golden
Business Acquisition [Line Items]
Percentage of interests acquired									100.00%
TES
Business Acquisition [Line Items]
Percentage of interests acquired								100.00%
TESUS
Business Acquisition [Line Items]
Percentage of interests acquired								100.00%
AWS
Business Acquisition [Line Items]
Percentage of interests acquired							100.00%
LEHDER
Business Acquisition [Line Items]
Percentage of interests acquired						100.00%
ECT2
Business Acquisition [Line Items]
Percentage of interests acquired					100.00%
Revenue			$ 11,300,000
Pre-tax income (loss)			$ 1,200,000
Advanced Geo Services Corp
Business Acquisition [Line Items]
Percentage of interests acquired														100.00%
Streamline Environmental Inc
Business Acquisition [Line Items]
Percentage of interests acquired													100.00%
Leymaster Environmental Consulting L L C
Business Acquisition [Line Items]
Percentage of interests acquired												100.00%
Analytical Environmental Services Corp
Business Acquisition [Line Items]
Percentage of interests acquired											100.00%
Environmental Planning Specialists Inc
Business Acquisition [Line Items]
Percentage of interests acquired										100.00%