v3.26.3
Stock-Based Compensation - Grant Date Fair Value for Awards of Performance Units Inputs (Details) - Performance Stock Units (PSUs) to be settled in Common Stock - $ / shares
9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Valuation date price based on closing prices of Quanta common stock on February 26,2026 and April 10, 2026 for 2026 and February 27,2025 for 2025 (in usd per share)   $ 259.26
Expected volatility (in percent)   34.00%
Risk-free interest rate (in percent)   4.05%
Term in years   2 years 10 months 2 days
Minimum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Valuation date price based on closing prices of Quanta common stock on February 26,2026 and April 10, 2026 for 2026 and February 27,2025 for 2025 (in usd per share) $ 565.05  
Expected volatility (in percent) 35.00%  
Risk-free interest rate (in percent) 3.45%  
Term in years 2 years 10 months 6 days  
Maximum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Valuation date price based on closing prices of Quanta common stock on February 26,2026 and April 10, 2026 for 2026 and February 27,2025 for 2025 (in usd per share) $ 611.39  
Expected volatility (in percent) 37.00%  
Risk-free interest rate (in percent) 4.43%  
Term in years 4 years 8 months 23 days