v3.26.1
Noncontrolling Interests - Summary Ownership of Viant Technology LLC (Details) - Viant Technology LLC - shares
6 Months Ended 9 Months Ended
Jun. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Minority Interest [Line Items]      
Units Owned (shares) 66,454,762 63,310,414  
Units Owned, Noncontrolling Interest (shares) 45,402,216 45,717,216  
Ownership percentage by non-controlling interests 68.30%   72.20%
Ownership Percentage 100.00%   100.00%
Viant Technology Inc.      
Minority Interest [Line Items]      
Units Owned (shares) 21,052,546 17,593,198  
Ownership percentage by Viant Technology Inc. 31.70%   27.80%