Business Combination - Additional Information (Details) $ / shares in Units, $ in Thousands			3 Months Ended		9 Months Ended
	Jul. 15, 2022 USD ($) $ / shares shares	Aug. 30, 2021 USD ($) $ / shares shares	Sep. 30, 2022 USD ($) $ / shares shares	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) $ / shares shares	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($) $ / shares shares	Aug. 30, 2021 € / shares shares
Business Acquisition [Line Items]
Common stock, par value | $ / shares		$ 0.01	$ 0.01		$ 0.01		$ 0.01
Exchange offer settled date	Jul. 15, 2022
Common stock, shares outstanding | shares			77,619,000		77,619,000		49,063,000
Common stock, reserved for future issuance | shares	28,000,000.0	27,994,595						27,994,595
Goodwill			$ 357,869		$ 357,869		$ 6,968
Net revenue			340,709	$ 138,081	667,265	$ 408,846
Net loss attributable to ADTRAN Holdings, Inc.			(41,934)	(10,427)	(40,918)	(4,445)
Net loss attributable to non-controlling interest			(2,925)		(2,925)
Network Solutions [Member]
Business Acquisition [Line Items]
Goodwill			270,916		270,916		6,568
Net revenue			304,940	120,767	599,306	360,025
Services & Support [Member]
Business Acquisition [Line Items]
Goodwill			86,953		86,953		$ 400
Net revenue			35,769	17,314	67,959	48,821
Common Stock [Member]
Business Acquisition [Line Items]
Percentage of common stock exchanged		64.00%
ADVA Optical Networking SE [Member]
Business Acquisition [Line Items]
Business combination date of agreement		Aug. 30, 2021
Common stock, shares outstanding | shares		33,957,538						33,957,538
Percentage of outstanding bearer shares		65.43%
Fair value of stock options assumed		$ 12,800
Goodwill	$ 359,157		359,200		359,200
Accounts receivable	114,659
Other receivables	1,457
Unpaid principal balance of account receivable	118,500
Unpaid principal balance of other receivable	1,500
Fair value of noncontrolling interest	316,415
Net revenue	163,800
Net loss attributable to ADTRAN Holdings, Inc.	$ 8,400
Net loss attributable to non-controlling interest			(2,900)		(2,900)
Shares held by noncontrolling interest | shares		17,941,496						17,941,496
Closing share price | (per share)	$ 20.20	$ 17.64						€ 17.58
Currency conversion rate	1.00318
ADVA Optical Networking SE [Member] | Selling, General and Administrative Expense [Member]
Business Acquisition [Line Items]
Transaction costs incurred					25,200
Transaction costs related to the business combination			$ 10,600	$ 5,100	13,300	$ 6,400
Estimated additional transaction costs to be incurred					$ 1,100
ADVA Optical Networking SE [Member] | Network Solutions [Member]
Business Acquisition [Line Items]
Goodwill	$ 270,600
ADVA Optical Networking SE [Member] | Services & Support [Member]
Business Acquisition [Line Items]
Goodwill	$ 88,600
ADVA Optical Networking SE [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Number of shares issuable for each share of acquired entity | shares		0.8244
Percentage of common stock exchanged		36.00%