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Summary of Significant Accounting Policies - Additional Information (Detail) $ / shares in Units, € in Thousands, $ in Thousands | 3 Months Ended | 6 Months Ended |  |  |
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Jun. 30, 2025 EUR (€) shares | Jun. 30, 2025 USD ($) shares | Jun. 30, 2024 EUR (€) shares | Jun. 30, 2024 USD ($) $ / shares shares | Jun. 30, 2025 EUR (€) shares | Jun. 30, 2025 USD ($) shares | Jun. 30, 2024 EUR (€) shares | Jun. 30, 2024 USD ($) $ / shares shares | Jun. 30, 2025 USD ($) | Sep. 30, 2024 USD ($) | Oct. 18, 2022 shares
Summary Of Significant Accounting Policy [Line Items] |  |  |  |  |  |  |  |  |  |  |
Percentage of guaranteed interest rate | 5.00% |  |  |  | 5.00% |  |  |  | 5.00% |  |
Percentage of guaranteed interest rate plus a variable component | 2.27% |  |  |  | 2.27% |  |  |  | 2.27% |  |
Aggregate exit compensation payments obligation including guaranteed interest | € 326,800 |  |  |  | € 326,800 |  |  |  | $ 385,200 |  |
Expire date of exit compensation |  |  |  |  | Mar. 16, 2023 | Mar. 16, 2023 |  |  |  |  |
Annual recurring compensation obligation |  |  |  |  | € 8,500 | $ 10,000 |  |  |  |  |
Accrued annual recurring compensation obligation | $ |  | $ 2,400 |  | $ 2,500 |  | $ 4,800 |  | $ 5,000 |  |  |
Number of shares tendered | 900 | 900 |  |  | 900 | 900 |  |  |  |  |
Exit compensation payments | € 16,900 | $ 19,400 |  |  | € 16,900 | $ 19,400 |  |  |  |  |
Wells Fargo Credit Agreement [Member] |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policy [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net leverage ratio |  |  |  |  | 0.0325 | 0.0325 |  |  |  |  |
Wells Fargo Credit Agreement [Member] | Acorn HoldCo, Inc., [Member] |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policy [Line Items] |  |  |  |  |  |  |  |  |  |  |
Available for future borrowings | $ |  |  |  |  |  |  |  |  | 156,500 | $ 156,500 |
Credit agreement current borrowing capacity | $ |  |  |  |  |  |  |  |  | $ 66,800 | $ 66,800 |
Maximum [Member] | Wells Fargo Credit Agreement [Member] |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policy [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net leverage ratio |  |  |  |  | 0.05 | 0.05 |  |  |  |  |
Maximum [Member] | Wells Fargo Credit Agreement [Member] | First Quarter Ending Springing Covenant Period [Member] |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policy [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net leverage ratio |  |  |  |  | 0.04 | 0.04 |  |  |  |  |
Minimum [Member] | Wells Fargo Credit Agreement [Member] |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policy [Line Items] |  |  |  |  |  |  |  |  |  |  |
Fixed charge coverage ratio |  |  |  |  | 0.0125 | 0.0125 |  |  |  |  |
Minimum [Member] | Wells Fargo Credit Agreement [Member] | Third And Fourth Quarters Ending Springing Covenant Event [Member] |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policy [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net leverage ratio |  |  |  |  | 0.035 | 0.035 |  |  |  |  |
Adtran Networks [Member] |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policy [Line Items] |  |  |  |  |  |  |  |  |  |  |
Annual recurring compensation payment per share | $ / shares |  |  |  | $ 0.52 |  |  |  | $ 0.52 |  |  |
Accrued liability per share | $ / shares |  |  |  | $ 0.59 |  |  |  |  |  |  |
Number of shares tendered | 900,000 | 900,000 | 1,000,000 | 1,000,000 | 900,000 | 900,000 | 1,000,000 | 1,000,000 |  |  |
Exit compensation payments | € 16,900 | $ 19,400 | € 19 | $ 20 | € 16,900 | $ 19,400 | € 23 | $ 25 |  |  |
Adtran Networks [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policy [Line Items] |  |  |  |  |  |  |  |  |  |  |
Number of additional shares authorized to purchase |  |  |  |  |  |  |  |  |  |  | 15,346,544
Number of shares tendered |  |  | 1,000 | 1,000 |  |  | 1,000 | 1,000 |  |  |

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