v3.26.1
Redeemable Non-controlling Interest - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Redeemable Noncontrolling Interest [Line Items]          
Accrued annual recurring compensation to redeemable non-controlling shareholders $ 2.1 $ 2.4 $ 4.3 $ 4.8  
DPLTA [Member]          
Redeemable Noncontrolling Interest [Line Items]          
Accrued annual recurring compensation to redeemable non-controlling shareholders $ 2.1   $ 4.3   $ 9.3
Adtran Networks [Member]          
Redeemable Noncontrolling Interest [Line Items]          
Equity ownership percentage 28.10%   28.10%   29.20%