Condensed Consolidated Statements of Changes in Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Adtran Networks SE [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Adtran Networks SE [Member]	Retained Deficit [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income [Member]
Beginning Balance at Dec. 31, 2024	$ 126,951		$ 795	$ 808,913		$ (688,813)	$ (5,198)	$ 11,254
Beginning Balance, Shares at Dec. 31, 2024			79,483
Net (loss) income	(8,948)					(8,948)
Annual recurring compensation earned	(2,319)					(2,319)
Other comprehensive income (loss), net of tax	20,378							20,378
Deferred compensation adjustments, net of tax	38			(52)			90
ADTRAN RSUs and restricted stock vested	(1,170)		$ 4			(1,174)
ADTRAN RSUs and restricted stock vested, Shares			373
ADTRAN Stock options exercised	756		$ 1			755
ADTRAN Stock options exercised, Shares			113
Redemption of redeemable non-controlling interest	(3)					(3)
ADTRAN Stock-based compensation expense	2,062	$ 1,148		2,062	$ 1,148
Ending Balance at Mar. 31, 2025	138,893		$ 800	812,071		(700,502)	(5,108)	31,632
Ending Balance, Shares at Mar. 31, 2025			79,969
Beginning Balance at Dec. 31, 2025	$ 145,830		$ 802	801,269		(730,010)	(5,108)	78,877
Beginning Balance, Shares at Dec. 31, 2025	80,188		80,188
Net (loss) income	$ 930					930
Annual recurring compensation earned	(2,251)					(2,251)
Other comprehensive income (loss), net of tax	(8,831)							(8,831)
Dividends accrued on unvested restricted stock units	(7)					(7)
Deferred compensation adjustments, net of tax	36			(57)			93
ADTRAN RSUs and restricted stock vested	(1,671)		$ 4			(1,675)
ADTRAN RSUs and restricted stock vested, Shares			398
ADTRAN Stock options exercised	1,369		$ 2			1,367
ADTRAN Stock options exercised, Shares			217
Redemption of redeemable non-controlling interest	301					301
ADTRAN Stock-based compensation expense	1,819			1,819
Ending Balance at Mar. 31, 2026	$ 137,525		$ 808	$ 803,031		$ (731,345)	$ (5,015)	$ 70,046
Ending Balance, Shares at Mar. 31, 2026	80,803		80,803