v3.26.1
Earnings (Loss) Per Share - Calculation of Basic and Diluted Net Loss Per Share (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Numerator    
Net loss $ (2,190) $ (3,307)
Less: Net loss attributable to noncontrolling interests (1,735) (2,117)
Net loss attributable to Viant Technology Inc. (455) (1,190)
Add back: Reallocation of net loss attributable to noncontrolling interest from the assumed exchange of RSUs and NQSOs for Class A common stock 0 0
Income tax benefit (expense) from the assumed exchange of dilutive securities for Class A common stock 0 0
Net loss attributable to Viant Technology, Inc.—diluted $ (2,190) $ (1,190)
Weighted-average shares of Class A common stock outstanding:    
Weighted-average shares of Class A common stock outstanding—basic (shares) 17,827,000 16,439,000
Weighted-average shares of Class A common stock outstanding—diluted (shares) 63,452,000 16,439,000
Basic (USD per share) $ (0.03) $ (0.07)
Diluted (USD per share) $ (0.03) $ (0.07)
Anti-dilutive shares excluded from loss per share of Class A common stock—diluted:    
Total shares excluded from loss per share of Class A common stock—diluted (shares) 11,282,000 57,034,000
Class A Common Stock    
Weighted-average shares of Class A common stock outstanding:    
Weighted-average shares of Class A common stock outstanding—basic (shares) 17,827,000 16,439,000
Weighted-average shares of Class A common stock outstanding—diluted (shares) 63,452,000 16,439,000
Class B Common Stock    
Anti-dilutive shares excluded from loss per share of Class A common stock—diluted:    
Total shares excluded from loss per share of Class A common stock—diluted (shares) 45,625,000 46,720,000
Restricted Stock Units    
Anti-dilutive shares excluded from loss per share of Class A common stock—diluted:    
Total shares excluded from loss per share of Class A common stock—diluted (shares) 6,504,000 5,415,000
Restricted Stock Units | Class A Common Stock    
Anti-dilutive shares excluded from loss per share of Class A common stock—diluted:    
Total shares excluded from loss per share of Class A common stock—diluted (shares) 0 0
Nonqualified Stock Options    
Anti-dilutive shares excluded from loss per share of Class A common stock—diluted:    
Total shares excluded from loss per share of Class A common stock—diluted (shares) 4,291,000 4,899,000
Nonqualified Stock Options | Class A Common Stock    
Anti-dilutive shares excluded from loss per share of Class A common stock—diluted:    
Total shares excluded from loss per share of Class A common stock—diluted (shares) 0 0
Performance Shares    
Anti-dilutive shares excluded from loss per share of Class A common stock—diluted:    
Total shares excluded from loss per share of Class A common stock—diluted (shares) 487,000 0
Performance Shares | Class A Common Stock    
Anti-dilutive shares excluded from loss per share of Class A common stock—diluted:    
Total shares excluded from loss per share of Class A common stock—diluted (shares) 0 0