Subsequent Events	12 Months Ended
Dec. 31, 2023
Subsequent Events [Abstract]
Subsequent Events	Note 24 – Subsequent Events Third Amendment to Wells Fargo Credit Agreement On March 12, 2024, the Company, its wholly-owned direct subsidiary, ADTRAN, Inc. (the “Borrower”), the lenders party thereto and Wells Fargo Bank, National Association, as administrative agent (the “Administrative Agent”), entered into a Third Amendment to Credit Agreement (the “Third Amendment”), which amends that certain Credit Agreement, dated as of July 18, 2022 (as amended or otherwise modified, including by the Third Amendment, the “Credit Agreement”), by and among the Borrower, the Company, the lenders party thereto and the Administrative Agent. The Third Amendment, among other things, amends the definition of “Consolidated Funded Indebtedness” (which is used in the calculation of the Consolidated Total Net Leverage Ratio and the Consolidated Senior Secured Net Leverage Ratio) to exclude obligations of the Company and its subsidiaries under certain factoring arrangements when calculated for the fiscal quarters ending March 31, 2024 and June 30, 2024. Second Amendment to Wells Fargo Credit Agreement On January 16, 2024, the Company, its wholly-owned direct subsidiary, ADTRAN, Inc. (the “Borrower”), the lenders party thereto and Wells Fargo Bank, National Association, as administrative agent (the “Administrative Agent”), entered into a Second Amendment to Credit Agreement and First Amendment to Collateral Agreement (the “Second Amendment”), which amends (i) that certain Credit Agreement, dated as of July 18, 2022 (as amended or otherwise modified, including by the Second Amendment, the “Credit Agreement”), by and among the Borrower, the Company, the lenders party thereto and the Administrative Agent and (ii) that certain Collateral Agreement, dated as of July 18, 2022, by and among the Borrower, the Company and the Administrative Agent. Capitalized terms used in this Note 24 and not otherwise defined herein have the meanings assigned to them in the Second Amendment or the Credit Agreement, as applicable. The Second Amendment, among other things, provides the Company and its subsidiaries with additional covenant headroom from (and including) the fourth quarter of 2023 through and including the third quarter of 2024 (the “Covenant Relief Period”) and revises and/or adds certain other financial covenants. The full set of financial covenants includes the following: • As of the last day of any fiscal quarter, commencing with the fiscal quarter ended December 31, 2023, the Consolidated Total Net Leverage Ratio may not exceed 5.00x. • As of the last day of any fiscal quarter, commencing with the fiscal quarter ended December 31, 2023, the Consolidated Senior Secured Net Leverage Ratio may not exceed: • In the event of the purchase by the Company of at least sixty percent (60%) of the outstanding shares of Adtran Networks SE not owned by the Company as of August 9, 2023 that have been tendered (such event, a “Springing Covenant Event” and the fiscal quarter in which the Springing Covenant Event Occurs and the three consecutive quarterly test periods thereafter, the “Springing Covenant Period”), the following covenant levels: • First fiscal quarter ending after a Springing Covenant Event: 4.00x • Second fiscal quarter ending after a Springing Covenant Event: 3.75x • Third and fourth fiscal quarters ending after a Springing Covenant Event: 3.50x • If the Company or any of its subsidiaries incurs certain unsecured Indebtedness in excess of $50,000,000 in connection with a transaction that is a Springing Covenant Event or during a Springing Covenant Period, the Consolidated Senor Secured Net Leverage Ratio covenant will step down to 3.50x at the time of such incurrence. • If a Springing Covenant Period is not in effect, the following covenant levels: • From December 31, 2023 through and including March 31, 2024: 3.25x. • From April 1, 2024 through and including June 30, 2024: 3.50x. • From July 1, 2024 and thereafter: 3.25x. • As of the last day of any fiscal quarter, commencing with the fiscal quarter ended December 31, 2023, the Consolidated Fixed Charge Coverage Ratio may not exceed 1.25x. • During the Covenant Relief Period or a Springing Covenant Period, as of the last day of any fiscal quarter (i) cash and cash equivalents of the Credit Parties must be at least $50.0 million and (ii) cash and cash equivalents of the Company and its subsidiaries must be at least $75.0 million. The Credit Agreement is guaranteed by certain domestic subsidiaries of the Company, and the Company is also required to add certain additional domestic and international subsidiaries as guarantors under the Credit Agreement (such existing and new guarantors, collectively, the “Guarantors”). In addition to the guarantees provided by the Guarantors, the Guarantors have granted (or will grant) security interests in favor of the Administrative Agent over substantially all tangible and intangible assets, and the Borrower will grant mortgages in favor of the Administrative Agent over certain owned real estate assets. The Credit Agreement continues to provide for revolving borrowings of up to $400.0 million in aggregate principal amount, as well as an additional $50.0 million delayed draw term loan tranche that would be available upon a Springing Covenant Event. It also continues to permit the Company to prepay any or all of the outstanding loans or to reduce the commitments under the Credit Agreement subject to certain limitations and minimum payment thresholds. During the Covenant Relief Period, the Company is not permitted to make certain dividend payments to the Company's Stockholders or certain other Restricted Payments. However, the Company is permitted to make the Recurring Compensation Payment to each Adtran Networks shareholder (other than the Company), pursuant to the terms of the DPLTA. See Note 20 for additional information. Furthermore, the Credit Agreement continues to contain customary affirmative and negative covenants, including incurrence covenants and certain other limitations on the ability of the Company and the Company’s subsidiaries to incur additional debt, guarantee other obligations, grant liens on assets, make investments, dispose of assets, make restricted payments, engage in mergers or consolidations, engage in transactions with affiliates, modify its organizational documents, and enter into certain restrictive agreements. The negative covenants are subject to various exceptions and carveouts; however, certain of the exceptions and carveouts are not permitted to be used during the Covenant Relief Period. It also contains customary events of default, such as misrepresentation and a default in the performance or observance of any covenant (subject to customary cure periods and materiality thresholds). Upon the occurrence and during the continuance of an event of default, the Administrative Agent is entitled to take various actions, including the acceleration of all amounts due under the Credit Agreement. Upon the effective date of the Second Amendment, (A) the applicable commitment fee increased to 0.25% per annum, (B) for any revolving credit loan that is a Term SOFR Loan, the applicable margin rate increased to 3.15% per annum, (C) for any revolving credit loan that is a Eurocurrency Rate Loan, the applicable margin rate increased to 3.25% per annum, (D) for any revolving credit loan that is a Base Rate Loan (including any Swingline Loan), the applicable margin rate increased to 2.15% per annum, (E) for any Delayed Draw Term Loan that is a Term SOFR Loan, the applicable margin rate increased to 3.40% per annum and (F)_for any Delayed Draw Term Loan that is a Base Rate Loan, the applicable margin rate increased to 2.40% per annum. The aforementioned increases in the commitment fee and margin rates continues to the first date when each of the following conditions have been met (the period during which such increases are in place is hereinafter referred to as the “Applicable Margin Interest Period”): (a) the Covenant Relief Period has ended, (b) since the Second Amendment effective date, we have repaid the revolving credit outstanding borrowings by a principal amount of at least $75.0 million, (c) we have reduced the aggregate revolving credit commitment to an amount no greater than $300.0 million and (d) we are in compliance with all financial covenants based on the financial statements for the most recently completed reference period. In addition, (x) if on or prior to December 31, 2024 we have not reduced the aggregate revolving credit commitment to $340.0 million or less, the applicable margin for all loans shall be increased by 1.00% per annum, and (y) if on or prior to June 30, 2025 we have not reduced the aggregate revolving credit commitment to $300.0 million or less, the applicable margin for all loans shall be increased by 1.00% per annum.

On March 12, 2024, the Company, its wholly-owned direct subsidiary, ADTRAN, Inc. (the “Borrower”), the lenders party thereto and Wells Fargo Bank, National Association, as administrative agent (the “Administrative Agent”), entered into a Third Amendment to Credit Agreement (the “Third Amendment”), which amends that certain Credit Agreement, dated as of July 18, 2022 (as amended or otherwise modified, including by the Third Amendment, the “Credit Agreement”), by and among the Borrower, the Company, the lenders party thereto and the Administrative Agent.

The Third Amendment, among other things, amends the definition of “Consolidated Funded Indebtedness” (which is used in the calculation of the Consolidated Total Net Leverage Ratio and the Consolidated Senior Secured Net Leverage Ratio) to exclude obligations of the Company and its subsidiaries under certain factoring arrangements when calculated for the fiscal quarters ending March 31, 2024 and June 30, 2024.

On January 16, 2024, the Company, its wholly-owned direct subsidiary, ADTRAN, Inc. (the “Borrower”), the lenders party thereto and Wells Fargo Bank, National Association, as administrative agent (the “Administrative Agent”), entered into a Second Amendment to Credit Agreement and First Amendment to Collateral Agreement (the “Second Amendment”), which amends (i) that certain Credit Agreement, dated as of July 18, 2022 (as amended or otherwise modified, including by the Second Amendment, the “Credit Agreement”), by and among the Borrower, the Company, the lenders party thereto and the Administrative Agent and (ii) that certain Collateral Agreement, dated as of July 18, 2022, by and among the Borrower, the Company and the Administrative Agent. Capitalized terms used in this Note 24 and not otherwise defined herein have the meanings assigned to them in the Second Amendment or the Credit Agreement, as applicable. The Second Amendment, among other things, provides the Company and its subsidiaries with additional covenant headroom from (and including) the fourth quarter of 2023 through and including the third quarter of 2024 (the “Covenant Relief Period”) and revises and/or adds certain other financial covenants. The full set of financial covenants includes the following:

•

As of the last day of any fiscal quarter, commencing with the fiscal quarter ended December 31, 2023, the Consolidated Total Net Leverage Ratio may not exceed 5.00x.

•

As of the last day of any fiscal quarter, commencing with the fiscal quarter ended December 31, 2023, the Consolidated Senior Secured Net Leverage Ratio may not exceed:

•

In the event of the purchase by the Company of at least sixty percent (60%) of the outstanding shares of Adtran Networks SE not owned by the Company as of August 9, 2023 that have been tendered (such event, a “Springing Covenant Event” and the fiscal quarter in which the Springing Covenant Event Occurs and the three consecutive quarterly test periods thereafter, the “Springing Covenant Period”), the following covenant levels:

•

If the Company or any of its subsidiaries incurs certain unsecured Indebtedness in excess of $50,000,000 in connection with a transaction that is a Springing Covenant Event or during a Springing Covenant Period, the Consolidated Senor Secured Net Leverage Ratio covenant will step down to 3.50x at the time of such incurrence.

•

As of the last day of any fiscal quarter, commencing with the fiscal quarter ended December 31, 2023, the Consolidated Fixed Charge Coverage Ratio may not exceed 1.25x.

•

During the Covenant Relief Period or a Springing Covenant Period, as of the last day of any fiscal quarter (i) cash and cash equivalents of the Credit Parties must be at least $50.0 million and (ii) cash and cash equivalents of the Company and its subsidiaries must be at least $75.0 million.

The Credit Agreement is guaranteed by certain domestic subsidiaries of the Company, and the Company is also required to add certain additional domestic and international subsidiaries as guarantors under the Credit Agreement (such existing and new guarantors, collectively, the “Guarantors”). In addition to the guarantees provided by the Guarantors, the Guarantors have granted (or will grant) security interests in favor of the Administrative Agent over substantially all tangible and intangible assets, and the Borrower will grant mortgages in favor of the Administrative Agent over certain owned real estate assets.

The Credit Agreement continues to provide for revolving borrowings of up to $400.0 million in aggregate principal amount, as well as an additional $50.0 million delayed draw term loan tranche that would be available upon a Springing Covenant Event. It also continues to permit the Company to prepay any or all of the outstanding loans or to reduce the commitments under the Credit Agreement subject to certain limitations and minimum payment thresholds.

During the Covenant Relief Period, the Company is not permitted to make certain dividend payments to the Company's Stockholders or certain other Restricted Payments. However, the Company is permitted to make the Recurring Compensation Payment to each Adtran Networks shareholder (other than the Company), pursuant to the terms of the DPLTA. See Note 20 for additional information.

Furthermore, the Credit Agreement continues to contain customary affirmative and negative covenants, including incurrence covenants and certain other limitations on the ability of the Company and the Company’s subsidiaries to incur additional debt, guarantee other obligations, grant liens on assets, make investments, dispose of assets, make restricted payments, engage in mergers or consolidations, engage in transactions with affiliates, modify its organizational documents, and enter into certain restrictive agreements. The negative covenants are subject to various exceptions and carveouts; however, certain of the exceptions and carveouts are not permitted to be used during the Covenant Relief Period. It also contains customary events of default, such as misrepresentation and a default in the performance or observance of any covenant (subject to customary cure periods and materiality thresholds). Upon the occurrence and during the continuance of an event of default, the Administrative Agent is entitled to take various actions, including the acceleration of all amounts due under the Credit Agreement.

Upon the effective date of the Second Amendment, (A) the applicable commitment fee increased to 0.25% per annum, (B) for any revolving credit loan that is a Term SOFR Loan, the applicable margin rate increased to 3.15% per annum, (C) for any revolving credit loan that is a Eurocurrency Rate Loan, the applicable margin rate increased to 3.25% per annum, (D) for any revolving credit loan that is a Base Rate Loan (including any Swingline Loan), the applicable margin rate increased to 2.15% per annum, (E) for any Delayed Draw Term Loan that is a Term SOFR Loan, the applicable margin rate increased to 3.40% per annum and (F)_for any Delayed Draw Term Loan that is a Base Rate Loan, the applicable margin rate increased to 2.40% per annum. The aforementioned increases in the commitment fee and margin rates continues to the first date when each of the following conditions have been met (the period during which such increases are in place is hereinafter referred to as the “Applicable Margin Interest Period”): (a) the Covenant Relief Period has ended, (b) since the Second Amendment effective date, we have repaid the revolving credit outstanding borrowings by a principal amount of at least $75.0 million, (c) we have reduced the aggregate revolving credit commitment to an amount no greater than $300.0 million and (d) we are in compliance with all financial covenants based on the financial statements for the most recently completed reference period.

In addition, (x) if on or prior to December 31, 2024 we have not reduced the aggregate revolving credit commitment to $340.0 million or less, the applicable margin for all loans shall be increased by 1.00% per annum, and (y) if on or prior to June 30, 2025 we have not reduced the aggregate revolving credit commitment to $300.0 million or less, the applicable margin for all loans shall be increased by 1.00% per annum.