XML 55 R39.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Stock-Based Compensation (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2024
Stock-Based Compensation Expense Related to Stock Options, PSUs, RSUs and Restricted Stock | The following table summarizes stock-based compensation expense related to stock options, PSUs, RSUs and restricted stock for the years ended December 31, 2024, 2023 and 2022:
(In thousands) |  | 2024 |  |  | 2023 |  |  | 2022 |
Stock-based compensation expense included in cost of revenue |  | $ | 1,142 |  |  | $ | 1,293 |  |  | $ | 2,876 |
Selling, general and administrative expenses |  |  | 10,412 |  |  |  | 10,701 |  |  |  | 20,844 |
Research and development expenses |  |  | 3,788 |  |  |  | 4,022 |  |  |  | 4,602 |
Stock-based compensation expense included in operating expenses |  |  | 14,200 |  |  |  | 14,723 |  |  |  | 25,446 |
Total stock-based compensation expense |  |  | 15,342 |  |  |  | 16,016 |  |  |  | 28,322 |
Tax benefit for expense associated with non-qualified stock options, PSUs, RSUs and restricted stock |  |  | (2,102 | ) |  |  | (3,837 | ) |  |  | (5,152 | )
Total stock-based compensation expense, net of tax |  | $ | 13,240 |  |  | $ | 12,179 |  |  | $ | 23,170 |
Summary of PSUs, RSUs and Restricted Stock Outstanding | The following table is a summary of our PSUs, RSUs and restricted stock outstanding as of December 31, 2023 and 2024 and the changes that occurred during 2024:
|  | Number of shares (In thousands) |  |  | Weighted Average Grant Date Fair Value (Per Share) |
Unvested PSUs, RSUs and restricted stock outstanding, December 31, 2023 |  |  | 1,942 |  |  | $ | 17.46 |
PSUs, RSUs and restricted stock granted |  |  | 1,097 |  |  | $ | 7.85 |
PSUs, RSUs and restricted stock vested |  |  | (575 | ) |  | $ | 18.76 |
PSUs, RSUs and restricted stock forfeited |  |  | (129 | ) |  | $ | 14.20 |
Unvested PSUs, RSUs and restricted stock outstanding, December 31, 2024 |  |  | 2,335 |  |  | $ | 13.22 |
Summary of Stock Options Outstanding | The following table is a summary of stock options outstanding as of December 31, 2024 and 2023 and the changes that occurred during 2024:
|  | Number of Options (In thousands) |  |  | Weighted Average Exercise Price (Per share) |  |  | Weighted Average Remaining Contractual Life in Years |  |  | Aggregate Intrinsic Value (In thousands) |
Stock options outstanding, December 31, 2023 |  |  | 3,894 |  |  | $ | 10.32 |  |  |  | 5.25 |  |  | $ | 3,087 |
Stock options exercised |  |  | (139 | ) |  | $ | 5.93 |  |  |  |  |  |  |
Stock options forfeited |  |  | (202 | ) |  | $ | 6.78 |  |  |  |  |  |  |
Stock options expired |  |  | (609 | ) |  | $ | 14.69 |  |  |  |  |  |  |
Stock options outstanding, December 31, 2024 |  |  | 2,944 |  |  | $ | 9.86 |  |  |  | 4.98 |  |  | $ | 3,762 |
Stock options exercisable, December 31, 2024 |  |  | 1,465 |  |  | $ | 8.73 |  |  |  | 4.18 |  |  | $ | 1,960 |
Stock Options Outstanding | The following table further describes our stock options outstanding as of December 31, 2024:
|  | Options Outstanding |  |  | Options Exercisable |
Range of Exercise Prices (Per Share) |  | Options Outstanding at December 31, 2024 (In thousands) |  |  | Weighted Average Remaining Contractual Life in Years |  |  | Weighted Average Exercise Price (Per Share) |  |  | Options Exercisable at December 31, 2024 (In thousands) |  |  | Weighted Average Exercise Price |
$5.23 – $5.23 |  |  | 1,131 |  |  |  | 8.87 |  |  | $ | 5.23 |  |  |  | 550 |  |  | $ | 5.23 |
$5.24 – $8.58 |  |  | 431 |  |  |  | 1.85 |  |  | $ | 7.86 |  |  |  | 431 |  |  | $ | 7.86 |
$8.59 – $12.17 |  |  | 696 |  |  |  | 2.81 |  |  | $ | 11.57 |  |  |  | 155 |  |  | $ | 9.49 |
$12.18 – $15.33 |  |  | 378 |  |  |  | 1.23 |  |  | $ | 15.33 |  |  |  | 329 |  |  | $ | 15.33 |
$15.34 – $19.08 |  |  | 308 |  |  |  | 4.37 |  |  | $ | 19.08 |  |  |  | — |  |  | $ | — |
|  |  | 2,944 |  |  |  |  |  |  |  |  |  | 1,465 |  |  |  |
Summary of Weighted-Average Assumptions and Value of Options Granted | The weighted-average estimated fair value of stock options granted to employees during the years ended December 31, 2023 was $2.99 per share with the following weighted-average assumptions:
|  | 2023 |
Expected volatility | $ |  | 51.78 | %
Risk-free interest rate |  |  | 4.13 | %
Expected dividend yield |  |  | — |
Expected life (in years) |  |  | 5.8 | %
Market-Based PSUs [Member] |
Summary of Weighted-Average Assumptions and Value of Options Granted | The following table details the significant assumptions that impact the fair value estimate of the market-based PSUs:
|  | 2024 |  |  | 2023 |  |  | 2022 |
Estimated fair value per share |  | $ | 8.29 |  |  | $ | 19.26 |  |  | $ | 24.01 |
Expected volatility |  |  | 51.34 | % |  |  | 51.52 | % |  |  | 45.77 | %
Risk-free interest rate |  |  | 4.12 | % |  |  | 3.93 | % |  |  | 4.28 | %
Expected dividend yield |  |  | — |  |  |  | 2.55 | % |  |  | 1.76 | %

X
- Definition Schedule of share based compensation performance stock units restricted stock units and restricted stock activity. + References No definition available. + Details
Name: | adtn_ScheduleOfShareBasedCompensationPerformanceStockUnitsRestrictedStockUnitsAndRestrictedStockActivityTableTextBlock
Namespace Prefix: | adtn_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of allocation of amount expensed and capitalized for award under share-based payment arrangement to statement of income or comprehensive income and statement of financial position. Includes, but is not limited to, corresponding line item in financial statement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of option exercise prices, by grouped ranges, including the upper and lower limits of the price range, the number of shares under option, weighted average exercise price and remaining contractual option terms. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure for stock option plans. Includes, but is not limited to, outstanding awards at beginning and end of year, grants, exercises, forfeitures, and weighted-average grant date fair value. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (d) -SubTopic 10 -Topic 718 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (e) -SubTopic 10 -Topic 718 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the significant assumptions used during the year to estimate the fair value of stock options, including, but not limited to: (a) expected term of share options and similar instruments, (b) expected volatility of the entity's shares, (c) expected dividends, (d) risk-free rate(s), and (e) discount for post-vesting restrictions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 718 -SubTopic 10 -Subparagraph (f)(2) -Name Accounting Standards Codification -Paragraph 2 -Section 50 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AwardTypeAxis=adtn_MarketBasedPerformanceStockUnitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |