Goodwill - Summary of Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Goodwill [Line Items]
Goodwill, Beginning balance	$ 358,150	$ 386,459
Goodwill impairment	(295,298)	(37,500)
Correction of goodwill from business combination with Adtran Networks		4,735
Foreign currency translation adjustments	(9,934)	9,191
Goodwill, Ending balance	52,918	358,150
As Previously Reported [Member]
Goodwill [Line Items]
Goodwill, Beginning balance	353,415	381,724
Goodwill, Ending balance	52,918	353,415
Network Solutions [Member]
Goodwill [Line Items]
Goodwill, Beginning balance	301,766	303,015
Goodwill impairment	(295,298)
Correction of goodwill from business combination with Adtran Networks		4,735
Correction of a purchase allocation adjustment		(9,662)
Foreign currency translation adjustments	(6,468)	8,413
Goodwill, Ending balance	0	301,766
Network Solutions [Member] | As Previously Reported [Member]
Goodwill [Line Items]
Goodwill, Beginning balance		298,280
Services & Support [Member]
Goodwill [Line Items]
Goodwill, Beginning balance	56,384	83,444
Goodwill impairment		(37,500)
Correction of a purchase allocation adjustment		9,662
Foreign currency translation adjustments	(3,466)	778
Goodwill, Ending balance	$ 52,918	56,384
Services & Support [Member] | As Previously Reported [Member]
Goodwill [Line Items]
Goodwill, Beginning balance		$ 83,444