Subsequent Events	9 Months Ended
Sep. 30, 2022
Subsequent Events [Abstract]
Subsequent Events	21. SUBSEQUENT EVENTS Dividend Approval On November 7, 2022, the Company announced that its Board of Directors declared a quarterly cash dividend of $0.09 per common share to be paid to the Company’s stockholders of record as of the close of business on November 22, 2022. The payment date will be December 6, 2022 in the aggregate amount of approximately $7.0 million. Assumed ADVA Options Pursuant to the Business Combination which closed on July 15, 2022, ADVA stock option holders were entitled to have their ADVA stock options assumed by ADTRAN Holdings, Inc. (applying the exchange ratio in the Business Combination Agreement), thereafter representing options to acquire stock of ADTRAN Holdings, Inc. The period in which such options could be assumed ended July 22, 2022. However, that period was subsequently extended and a total of 0.1 million shares of ADTRAN Holdings, Inc. stock are subject to additional assumed ADVA options. The fair value of the stock options assumed by ADTRAN Holdings, Inc. will be estimated using a Black-Scholes model. The valuation of this component of consideration is not yet complete. Approval of Proposed Domination and Profit and Loss Transfer Agreement On October 18, 2022, the Board of Directors of the Company and the management board of ADVA, agreed on a final draft of a domination and profit and loss transfer agreement (the “DPLTA”) between the Company, as the controlling company, and ADVA, as the controlled company. The parties’ execution of the DPLTA remains subject to the approval of the DPLTA by shareholders of ADVA with 75% of the votes cast in an extraordinary general meeting, which is scheduled to be held on November 30, 2022. The Company currently holds 33,957,538 shares of ADVA, representing 65.35% of ADVA’s outstanding shares as of September 30, 2022. Subject to the approval of the DPLTA shareholders and the subsequent registration of the DPLTA with the commercial register of the local court at ADVA’s registered offices, the Company will offer, at the election of each shareholder of ADVA (other than the Company), (i) to acquire the shares of such shareholder for a compensation (Abfindung) of EUR 17.21 per share pursuant to Sec. 305 German Stock Corporation Akt (Aktiengesetz, “AktG”), or (ii) to pay such shareholder a fixed annual recurring compensation payment (Ausgleichszahlung) pursuant to Sec. 304 AktG in an amount of EUR 0.59 (EUR 0.52 net under the current taxation regime), subject to adjustment prior to execution of the DPLTA due to changes in interest rates and borrowing costs prior to November 30, 2022, which is the reference date for the valuation of ADVA shares ("Annual Recurring Compensation"). The amount of the Annual Recurring Compensation payment of EUR 0.59 (EUR 0.52 net) is determined on the basis of a rounded annuity interest rate (Verrentungszinssatz) of 3.00% and still subject to an adjustment in case of a change of interest rates and borrowing costs prior to November 30, 2022 which is the reference date for the valuation. An increase of borrowing costs could lead to an increase of the Annual Recurring Compensation payment. The potential increase ranges from EUR 0.62 (EUR 0.54 net), if the annuity interest rate is increased by 25 basis points to 3.25%, up to an Annual Recurring Compensation payment at the amount of EUR 1.00 (EUR 0.87 net), if the annuity interest rate is increased by 250 basis points to 5.50%. Board Approval Purchase of ADVA Common Stock On October 18, 2022, the Company's Board of Directors authorized the Company to purchase additional shares of ADVA through open market purchases not to exceed 15,346,544 shares. Foreign Currency Hedging Agreement On November 3, 2022, the Company entered into a Euro/U.S. dollar cross-currency swap arrangement (the “Swap”) with Wells Fargo Bank, N.A. (the “Hedge Counterparty”). The Swap, which is governed by the provisions of an ISDA Master Agreement (including schedules thereto and transaction confirmations that supplement such agreement) entered into between the Company and the Hedge Counterparty, enable the Company to convert a portion of its Euro denominated payment obligations under the proposed DPLTA into U.S. Dollars. Under the Swap, the Company will exchange an aggregate notional amount of $160.0 million U.S. dollars for Euros at a daily fixed forward rate ranging from $0.98286 to $1.03290. The aggregate amount of $160.0 million will be divided into eight quarterly tranches of $20.0 million. The Company, at its sole discretion, may exchange all or part of each tranche on any given day within the applicable quarter; provided, however, that it must exchange the full tranche by the end of such quarter. The Swap may be accelerated or terminated early for a number of reasons, including but not limited to (i) non-payment by the Company or the Hedge Counterparty, (ii) breach of representation or warranty or covenant by either party or (iii) insolvency or bankruptcy of either party.

Subsequent Events

9 Months Ended

Sep. 30, 2022

21. SUBSEQUENT EVENTS

Dividend Approval

On November 7, 2022, the Company announced that its Board of Directors declared a quarterly cash dividend of $0.09 per common share to be paid to the Company’s stockholders of record as of the close of business on November 22, 2022. The payment date will be December 6, 2022 in the aggregate amount of approximately $7.0 million.

Assumed ADVA Options

Pursuant to the Business Combination which closed on July 15, 2022, ADVA stock option holders were entitled to have their ADVA stock options assumed by ADTRAN Holdings, Inc. (applying the exchange ratio in the Business Combination Agreement), thereafter representing options to acquire stock of ADTRAN Holdings, Inc. The period in which such options could be assumed ended July 22, 2022. However, that period was subsequently extended and a total of 0.1 million shares of ADTRAN Holdings, Inc. stock are subject to additional assumed ADVA options. The fair value of the stock options assumed by ADTRAN Holdings, Inc. will be estimated using a Black-Scholes model. The valuation of this component of consideration is not yet complete.

Approval of Proposed Domination and Profit and Loss Transfer Agreement

On October 18, 2022, the Board of Directors of the Company and the management board of ADVA, agreed on a final draft of a domination and profit and loss transfer agreement (the “DPLTA”) between the Company, as the controlling company, and ADVA, as the controlled company. The parties’ execution of the DPLTA remains subject to the approval of the DPLTA by shareholders of ADVA with 75% of the votes cast in an extraordinary general meeting, which is scheduled to be held on November 30, 2022. The Company currently holds 33,957,538 shares of ADVA, representing 65.35% of ADVA’s outstanding shares as of September 30, 2022.

Subject to the approval of the DPLTA shareholders and the subsequent registration of the DPLTA with the commercial register of the local court at ADVA’s registered offices, the Company will offer, at the election of each shareholder of ADVA (other than the Company), (i) to acquire the shares of such shareholder for a compensation (Abfindung) of EUR 17.21 per share pursuant to Sec. 305 German Stock Corporation Akt (Aktiengesetz, “AktG”), or (ii) to pay such shareholder a fixed annual recurring compensation payment (Ausgleichszahlung) pursuant to Sec. 304 AktG in an amount of EUR 0.59 (EUR 0.52 net under the current taxation regime), subject to adjustment prior to execution of the DPLTA due to changes in interest rates and borrowing costs prior to November 30, 2022, which is the reference date for the valuation of ADVA shares ("Annual Recurring Compensation").

The amount of the Annual Recurring Compensation payment of EUR 0.59 (EUR 0.52 net) is determined on the basis of a rounded annuity interest rate (Verrentungszinssatz) of 3.00% and still subject to an adjustment in case of a change of interest rates and borrowing costs prior to November 30, 2022 which is the reference date for the valuation. An increase of borrowing costs could lead to an increase of the Annual Recurring Compensation payment. The potential increase ranges from EUR 0.62 (EUR 0.54 net), if the annuity interest rate is increased by 25 basis points to 3.25%, up to an Annual Recurring Compensation payment at the amount of EUR 1.00 (EUR 0.87 net), if the annuity interest rate is increased by 250 basis points to 5.50%.

Board Approval Purchase of ADVA Common Stock

On October 18, 2022, the Company's Board of Directors authorized the Company to purchase additional shares of ADVA through open market purchases not to exceed 15,346,544 shares.

Foreign Currency Hedging Agreement

On November 3, 2022, the Company entered into a Euro/U.S. dollar cross-currency swap arrangement (the “Swap”) with Wells Fargo Bank, N.A. (the “Hedge Counterparty”). The Swap, which is governed by the provisions of an ISDA Master Agreement (including schedules thereto and transaction confirmations that supplement such agreement) entered into between the Company and the Hedge Counterparty, enable the Company to convert a portion of its Euro denominated payment obligations under the proposed DPLTA into U.S. Dollars. Under the Swap, the Company will exchange an aggregate notional amount of $160.0 million U.S. dollars for Euros at a daily fixed forward rate ranging from $0.98286 to $1.03290. The aggregate amount of $160.0 million will be divided into eight quarterly tranches of $20.0 million. The Company, at its sole discretion, may exchange all or part of each tranche on any given day within the applicable quarter; provided, however, that it must exchange the full tranche by the end of such quarter. The Swap may be accelerated or terminated early for a number of reasons, including but not limited to (i) non-payment by the Company or the Hedge Counterparty, (ii) breach of representation or warranty or covenant by either party or (iii) insolvency or bankruptcy of either party.