Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended							6 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Jun. 30, 2024	Sep. 30, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Statement of Comprehensive Income [Abstract]
Net Loss	$ (43,704)	$ (30,966)	$ (47,162)	$ (328,235)	$ (800)	$ (100)	$ (0)	$ (375,397)	$ (406,363)	$ (450,067)	$ (261,906)	$ (8,888)
Other Comprehensive (Loss) Income, net of tax
Net unrealized gain (loss) on available-for-sale securities				0							454	(284)
Defined benefit plan adjustments	1,437	109	(7)	(60)				(67)	42	1,479	(1,490)	4,597
Foreign currency translation (loss) gain	(37,344)	18,802	(1,442)	(17,773)				(19,215)	(411)	(37,755)	22,822	53,396
Other Comprehensive (Loss) Income, net of tax	(35,907)	18,911	(1,449)	(17,833)				(19,282)	(369)	(36,276)	21,786	57,709
Comprehensive Loss, net of tax	(79,611)	(12,055)	(48,611)	(346,068)				(394,679)	(406,732)	(486,343)	(240,120)	48,821
Less: Comprehensive Income attributable to non-controlling interest	2,407	2,382	2,504	2,531				5,035	7,417	9,824	7,328	12,818
Comprehensive Loss attributable to ADTRAN Holdings, Inc., net of tax	$ (82,018)	$ (14,437)	$ (51,115)	$ (348,599)				$ (399,714)	$ (414,149)	$ (496,167)	$ (247,448)	$ 36,003