Acquisitions - Additional Information (Details) $ in Thousands		1 Months Ended		12 Months Ended
	Oct. 13, 2021 USD ($) shares	Jan. 31, 2023 USD ($) business shares	Jul. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) business shares	Dec. 31, 2020 USD ($) shares
Business Acquisition [Line Items]
Fair value of contingent consideration liability				$ 148,517	$ 143,073
Purchase price allocation adjustments				66,416	(1,791)
Goodwill expected to be deductible for income tax purposes				12,200	1,490,000	$ 72,600
Cash payment for contingent consideration liabilities				$ 1,600	$ 300	$ 76,000
Shares transferred in settlement of contingent consideration liabilities (in shares) | shares						4,277
Level 3 | Recurring | Volatility factors | Valuation, Market Approach
Business Acquisition [Line Items]
Contingent consideration liability, measurement input					0.50
Minimum | Level 3 | Recurring | Volatility factors | Valuation, Market Approach
Business Acquisition [Line Items]
Contingent consideration liability, measurement input				0.350
Minimum | Level 3 | Recurring | Weighted average cost of capital | Valuation, Market Approach
Business Acquisition [Line Items]
Contingent consideration liability, measurement input				0.145	0.165
Minimum | Level 3 | Recurring | Discount rates | Valuation, Market Approach
Business Acquisition [Line Items]
Contingent consideration liability, measurement input				0.0171	0.0004
Maximum | Level 3 | Recurring | Volatility factors | Valuation, Market Approach
Business Acquisition [Line Items]
Contingent consideration liability, measurement input				0.500
Maximum | Level 3 | Recurring | Weighted average cost of capital | Valuation, Market Approach
Business Acquisition [Line Items]
Contingent consideration liability, measurement input				0.175	0.170
Maximum | Level 3 | Recurring | Discount rates | Valuation, Market Approach
Business Acquisition [Line Items]
Contingent consideration liability, measurement input				0.0630	0.0218
Weighted Average | Level 3 | Recurring | Volatility factors | Valuation, Market Approach
Business Acquisition [Line Items]
Contingent consideration liability, measurement input				0.425	0.50
Weighted Average | Level 3 | Recurring | Weighted average cost of capital | Valuation, Market Approach
Business Acquisition [Line Items]
Contingent consideration liability, measurement input				0.160	0.168
Weighted Average | Level 3 | Recurring | Discount rates | Valuation, Market Approach
Business Acquisition [Line Items]
Contingent consideration liability, measurement input				0.045	0.014
Renewable Energy Infrastructure Solutions
Business Acquisition [Line Items]
Purchase price allocation adjustments				$ 64,874	$ 0
Construction Contracting Services Business Acquisition
Business Acquisition [Line Items]
Aggregate cash consideration paid			$ 22,000
Post-acquisition period, financial performance objectives			5 years
Value of Quanta common stock issued				0
Fair value of contingent consideration liability				2,600
Cash consideration				21,990
Blattner
Business Acquisition [Line Items]
Aggregate cash consideration paid	$ 2,430,000
Post-acquisition period, financial performance objectives	3 years
Contingent consideration payments (up to)	$ 300,000
Number of shares granted for acquired companies (in shares) | shares	3,326,955
Value of Quanta common stock issued	$ 345,400				345,422
Fair value of contingent consideration liability				134,500	125,632
Cash consideration					$ 2,434,877
Businesses That Provide Electric Power Construction Services In The United States
Business Acquisition [Line Items]
Number of businesses acquired | business					3
All Others
Business Acquisition [Line Items]
Number of shares granted for acquired companies (in shares) | shares					187,093
Value of Quanta common stock issued					$ 16,922
Fair value of contingent consideration liability					0
Cash consideration					328,155
2020 Acquisitions
Business Acquisition [Line Items]
Number of shares granted for acquired companies (in shares) | shares						1,334,469
Value of Quanta common stock issued						$ 57,100
Cash consideration						$ 359,600
Contingent consideration financial target term						5 years
Revenues included in consolidated results of operations						$ 133,500
Income from continuing operations before income taxes included in consolidated results of operations						(1,300)
Amortization expense						6,400
Acquisition-related costs						$ 17,500
All Acquisitions
Business Acquisition [Line Items]
Contingent consideration payments (up to)				326,600
Acquisitions 2022
Business Acquisition [Line Items]
Revenues included in consolidated results of operations				15,500
Income from continuing operations before income taxes included in consolidated results of operations				2,000
Amortization expense				(1,400)
Acquisition-related costs				$ 600
2021 Acquisitions
Business Acquisition [Line Items]
Revenues included in consolidated results of operations					499,600
Income from continuing operations before income taxes included in consolidated results of operations					(71,600)
Amortization expense					80,300
Acquisition-related costs					$ 41,500
Businesses That Provide Various Services In The United States | Subsequent Event
Business Acquisition [Line Items]
Aggregate cash consideration paid		$ 465,000
Number of shares granted for acquired companies (in shares) | shares		1,018,952
Value of Quanta common stock issued		$ 123,500
Number of businesses acquired | business		3