Commitments and Contingencies - Narrative (Details)		1 Months Ended	3 Months Ended		6 Months Ended
	Apr. 28, 2023 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2023 USD ($) project	Jun. 30, 2022	Jun. 30, 2023 USD ($) project customer	Jun. 30, 2022	Dec. 31, 2022 USD ($)
Loss Contingencies [Line Items]
Line of credit facility, letters of credit issued			$ 128,200,000		$ 128,200,000		$ 166,700,000
Cash and cash equivalents			119,905,000		119,905,000		370,592,000
Indemnities, accrued project close-out liabilities			20,000,000		$ 20,000,000		40,000,000
Number of customers | customer					1,305
Workers' Compensation, General and Automobile Policies | Self-Insurance
Loss Contingencies [Line Items]
Self-insurance reserve			196,000,000		$ 196,000,000		176,700,000
Workers' Compensation, General and Automobile Policies | Self-Insurance | Other Long-Term Liabilities
Loss Contingencies [Line Items]
Self-insurance reserve, non-current			123,900,000		123,900,000		109,300,000
Employee Group Medical Claims | Self-Insurance
Loss Contingencies [Line Items]
Self-insurance reserve			4,400,000		4,400,000		4,100,000
Corporate Joint Venture
Loss Contingencies [Line Items]
Cash and cash equivalents			$ 23,200,000		$ 23,200,000		25,700,000
Corporate Joint Venture | Joint Ventures That Provide Electrical Transmission Infrastructure Services | Minimum
Loss Contingencies [Line Items]
Proportionately consolidated non-controlled joint venture, ownership percentage			85.00%		85.00%
Corporate Joint Venture | Joint Ventures That Provide Electrical Transmission Infrastructure Services | Maximum
Loss Contingencies [Line Items]
Proportionately consolidated non-controlled joint venture, ownership percentage			90.00%		90.00%
Corporate Joint Venture | Joint Venture Civil Construction Project
Loss Contingencies [Line Items]
Number of joint ventures | project			4		4
Corporate Joint Venture | Joint Venture Civil Construction Project | Minimum
Loss Contingencies [Line Items]
Proportionately consolidated non-controlled joint venture, ownership percentage			25.00%		25.00%
Corporate Joint Venture | Joint Venture Civil Construction Project | Maximum
Loss Contingencies [Line Items]
Proportionately consolidated non-controlled joint venture, ownership percentage			50.00%		50.00%
Corporate Joint Venture | Joint Venture, Pipeline Project
Loss Contingencies [Line Items]
Proportionately consolidated non-controlled joint venture, ownership percentage			49.00%		49.00%
Number of joint ventures | project			1		1
Contractual Joint Venture
Loss Contingencies [Line Items]
Payments for project financing					$ 500,000
Captive Insurance Company
Loss Contingencies [Line Items]
Cash and cash equivalents			$ 900,000		900,000		1,100,000
Performance and Payment Bonds
Loss Contingencies [Line Items]
Bonded projects, estimated costs to complete			1,789,700,000		1,789,700,000		1,739,900,000
Commercial and/or Financial Standby | Workers' Compensation, General and Automobile Policies | Self-Insurance
Loss Contingencies [Line Items]
Line of credit facility, letters of credit issued			56,400,000		56,400,000		95,600,000
Surety Bonds | Workers' Compensation | Self-Insurance
Loss Contingencies [Line Items]
Guarantor obligations, maximum exposure, undiscounted			148,600,000		148,600,000		110,900,000
Subsidiaries | Performance and Payment Bonds
Loss Contingencies [Line Items]
Guarantor obligations, maximum exposure, undiscounted			5,389,200,000		5,389,200,000		4,855,500,000
Subsidiaries | Performance and Payment Bonds | Corporate Joint Venture
Loss Contingencies [Line Items]
Guarantor obligations, maximum exposure, undiscounted			$ 357,900,000		$ 357,900,000		115,800,000
Revenue Benchmark | Customer Concentration Risk | Ten Largest Customers
Loss Contingencies [Line Items]
Concentration risk, percentage of total			35.00%	42.00%	36.00%	43.00%
Infrastructure Energy Alternatives, Inc. | Commitments And Contingencies Concentration Risk
Loss Contingencies [Line Items]
Attorney fee percentage	0.45
Silicon Ranch Corporation, LLC | Litigation Settlement, Benchmark | Commitments And Contingencies Concentration Risk
Loss Contingencies [Line Items]
Concentration risk, percentage of total	30.00%
IEA | Pension
Loss Contingencies [Line Items]
Multiemployer plans, withdrawal obligation, monthly payment amount			$ 10,000
Withdrawal liability			$ 1,900,000		$ 1,900,000		$ 1,900,000
IEA | Litigation Settlement, Benchmark | Commitments And Contingencies Concentration Risk
Loss Contingencies [Line Items]
Concentration risk, percentage of total	40.00%
IEA Constructors, LLC | Litigation Settlement, Benchmark | Commitments And Contingencies Concentration Risk
Loss Contingencies [Line Items]
Concentration risk, percentage of total	30.00%
Silicon Ranch Corporation, LLC Matter
Loss Contingencies [Line Items]
Damages sought	$ 1,000,000
Silicon Ranch Corporation, LLC Matter | H&L Farms
Loss Contingencies [Line Items]
Payments to acquire land		$ 3,300,000
Silicon Ranch Corporation, LLC Matter | Infrastructure Energy Alternatives, Inc.
Loss Contingencies [Line Items]
Compensatory damages awarded to plaintiffs	4,500,000
Remediation costs	1,500,000
Silicon Ranch Corporation, LLC Matter | Silicon Ranch Corporation, LLC
Loss Contingencies [Line Items]
Punitive damages	25,000,000
Silicon Ranch Corporation, LLC Matter | Infrastructure Energy Alternatives, Inc. And IEA Constructors, LLC
Loss Contingencies [Line Items]
Punitive damages	50,000,000
Reduction in punitive damages	$ 250,000