Redeemable Non-controlling Interest - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Redeemable Noncontrolling Interest [Line Items]
Accrued annual recurring compensation to redeemable non-controlling shareholders	$ 2.2	$ 2.4
DPLTA [Member]
Redeemable Noncontrolling Interest [Line Items]
Accrued annual recurring compensation to redeemable non-controlling shareholders	$ 2.2		$ 9.3
Adtran Networks [Member]
Redeemable Noncontrolling Interest [Line Items]
Equity ownership percentage	28.80%		29.20%