v3.26.1
Earnings Per Share - Schedule of Computation of Basic and Diluted EPS (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Mar. 31, 2026
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2026
Jun. 30, 2025
Numerator—basic:            
Net loss $ (34,564) $ 17,394 $ (3,869) $ (19,139) $ (17,170) $ (23,008)
Less: Net loss attributable to noncontrolling interests (6,723)   $ 1,401   (5,423) $ 3,475
Net loss attributable to Legence—basic $ (27,841)       $ (11,747)  
Denominator—basic:            
Weighted-average Class A Common Stock outstanding—basic (in shares) 76,032       71,616  
Loss per share—basic (in usd per share) $ (0.37)       $ (0.16)  
Numerator—diluted:            
Net loss attributable to Class A Common Stockholders—basic $ (27,841)       $ (11,747)  
Effect of assumed exchange of LGN B Units 0       (10,873)  
Effect of exchange of LGN B Units related to exercise of underwriters' overallotment option and Subsequent Secondary Offering 0       (1,810)  
Net loss attributable to Class A Common Stockholders—diluted $ (27,841)       $ (24,430)  
Denominator—diluted:            
Weighted-average Class A Common Stock outstanding—basic (in shares) 76,032       71,616  
Effect of assumed exchange of LGN B Units (in shares) 0       31,171  
Effect of exchange of LGN B Units related to exercise of underwriters' overallotment option and Subsequent Secondary Offering (in shares) 0       5,189  
Weighted-average Class A Common Stock outstanding—diluted (in shares) 76,032       107,976  
Loss per share—diluted (in usd per share) $ (0.37)       $ (0.23)