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Income taxes: (Tables) | 12 Months Ended
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Dec. 31, 2025
Income taxes: |
Schedule of the components of (loss) income before income taxes | The components of (loss) income before income taxes consist of the following (in thousands):
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Years Ended December 31,
​ | ​ ​ ​ | 2025 | ​ ​ ​ | 2024 | ​ ​ ​ | 2023
Domestic | ​ | $ | (244,571) | ​ | $ | (257,523) | ​ | $ | 1,217,084
Foreign | ​ | ​ | (394) | ​ | ​ | (2,126) | ​ | ​ | 2,393
Total (loss) income before income taxes | ​ | $ | (244,965) | ​ | $ | (259,649) | ​ | $ | 1,219,477
Schedule of income tax benefit (expense) | The income tax benefit (expense) is comprised of the following (in thousands):
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Years Ended December 31,
​ | ​ ​ ​ | 2025 | ​ ​ ​ | 2024 | ​ ​ ​ | 2023
Current: | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Federal | ​ | $ | — | ​ | $ | — | ​ | $ | (3,638)
State | ​ | ​ | (1,161) | ​ | ​ | 4,620 | ​ | ​ | (11,868)
Foreign | ​ | ​ | (649) | ​ | ​ | (351) | ​ | ​ | (203)
Deferred: | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Federal | ​ | ​ | 47,887 | ​ | ​ | 54,859 | ​ | ​ | 53,393
State | ​ | ​ | 17,894 | ​ | ​ | (3,143) | ​ | ​ | 16,086
Foreign | ​ | ​ | (1,180) | ​ | ​ | (410) | ​ | ​ | 194
Total income tax benefit (expense) | ​ | $ | 62,791 | ​ | $ | 55,575 | ​ | $ | 53,964
Schedule of net deferred tax assets | Our consolidated temporary differences comprising our net deferred tax assets are as follows (in thousands): ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | December 31,
​ | ​ ​ ​ | 2025 | ​ ​ ​ | 2024
Deferred Tax Assets: | ​ | ​ | ​ | ​ | ​ | ​
Net operating loss carry-forwards | ​ | $ | 290,219 | ​ | $ | 236,346
Interest expense limitation | ​ | ​ | 86,577 | ​ | ​ | 66,386
Accrued liabilities and other | ​ | ​ | 550 | ​ | ​ | 8,584
Operating leases | ​ | ​ | 87,029 | ​ | ​ | 98,261
Total gross deferred tax assets | ​ | ​ | 464,375 | ​ | ​ | 409,577
Valuation allowance | ​ | ​ | (148,055) | ​ | ​ | (131,773)
​ | ​ | ​ | 316,320 | ​ | ​ | 277,804
Deferred Tax Liabilities: | ​ | ​ | ​ | ​ | ​ | ​
Property & equipment | ​ | ​ | 298,991 | ​ | ​ | 308,254
Intangibles | ​ | ​ | 116,087 | ​ | ​ | 113,596
Deferred consideration – IP Transit Services Agreement | ​ | ​ | 43,261 | ​ | ​ | 63,070
Investment in foreign subsidiaries | ​ | ​ | 107,267 | ​ | ​ | 95,974
Right-of-use assets | ​ | ​ | 84,008 | ​ | ​ | 95,176
Gross deferred tax liabilities | ​ | ​ | 649,614 | ​ | ​ | 676,070
Net deferred tax liabilities | ​ | $ | 333,294 | ​ | $ | 398,266
Schedule of reconciliation of the Federal statutory income taxes to the amounts reported in the financial statements | The following is a reconciliation of the Federal statutory income taxes to the amounts reported in the financial statements for the years ended December 31, 2023 and 2024 (in thousands), prior to the adoption of ASU 2023-09. ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | December 31, | ​ | December 31,
​ | ​ ​ ​ | 2024 | ​ ​ ​ | 2023
Federal income tax expense at statutory rates | ​ | $ | 54,381 | ​ | $ | (256,086)
Effect of: | ​ | ​ | ​ | ​ | ​ | ​
State income taxes, net of federal benefit | ​ |  | 1,587 | ​ | ​ | 3,722
Impact of foreign operations | ​ |  | (1,602) | ​ | ​ | 868
Non-deductible expenses | ​ |  | (2,713) | ​ | ​ | (2,783)
Bargain purchase gain - Cogent Fiber Business acquisition | ​ | ​ | 4,662 | ​ | ​ | 295,351
Tax effect of TCJA from foreign earnings | ​ |  | — | ​ | ​ | (490)
Changes in valuation allowance | ​ |  | (740) | ​ | ​ | 13,382
Income tax benefit (expense) | ​ | $ | 55,575 | ​ | $ | 53,964
​ The following is a tabular rate reconciliation disaggregated into specified categories with certain reconciling items further broken out by nature and jurisdiction to the extent those items exceed a specified threshold as defined under ASU 2023-09 for the year ended December 31, 2025 (in thousands). ​
​ | ​ | ​ | ​ | ​ | ​
​ | ​ ​ ​ | December 31, 2025
Benefit for income taxes at U.S. federal statutory rate | ​ | $ | 51,476 | % | 21.0
Effect of: | ​ |  | ​ | ​ | ​
U.S. State and local income taxes, net of federal benefit * | ​ |  | 17,114 | ​ | 7.1
Foreign tax effects | ​ |  | (2,004) | ​ | (0.5)
Effect of cross-border tax laws | ​ |  | (1,565) | ​ | (1.0)
Non-deductible expenses | ​ |  | (2,230) | ​ | (1.0)
Total tax benefit and effective tax rate | ​ | $ | 62,791 | % | 25.6
*State taxes in California, Kansas and Illinois for 2025 make up the majority (greater than 50%) of the tax effect in this category.
Schedule of income tax paid, net of refunds | The following is a detail of cash paid for income taxes (net of any refunds) for the year ended December 31, 2025 by jurisdiction under ASU 2023-09 (in thousands): ​
​ | ​ | ​ | ​
​ | ​ ​ ​ | December 31,
​ | ​ | 2025
U.S. Federal | ​ | $ | 1,122
U.S. State and local | ​ | ​ | ​
State of California | ​ | ​ | (865)
State of Texas | ​ |  | 347
State of Georgia | ​ |  | (376)
New York City | ​ |  | (899)
Other jurisdictions | ​ |  | (392)
Foreign jurisdictions | ​ | ​ | 404
Total income taxes paid (refunded) | ​ | $ | (659)
​

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- Definition Tabular disclosure of the components of income tax expense attributable to continuing operations for each year presented including, but not limited to: current tax expense (benefit), deferred tax expense (benefit), investment tax credits, government grants, the benefits of operating loss carryforwards, tax expense that results from allocating certain tax benefits either directly to contributed capital or to reduce goodwill or other noncurrent intangible assets of an acquired entity, adjustments of a deferred tax liability or asset for enacted changes in tax laws or rates or a change in the tax status of the entity, and adjustments of the beginning-of-the-year balances of a valuation allowance because of a change in circumstances that causes a change in judgment about the realizability of the related deferred tax asset in future years. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482685/740-10-50-9 + Details
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- Definition Tabular disclosure of the components of net deferred tax asset or liability recognized in an entity's statement of financial position, including the following: the total of all deferred tax liabilities, the total of all deferred tax assets, the total valuation allowance recognized for deferred tax assets. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482685/740-10-50-2 + Details
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- Definition Tabular disclosure of the reconciliation using percentage or dollar amounts of the reported amount of income tax expense attributable to continuing operations for the year to the amount of income tax expense that would result from applying domestic federal statutory tax rates to pretax income from continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 231 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482663/740-10-55-231 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 12A -Publisher FASB -URI https://asc.fasb.org/1943274/2147482685/740-10-50-12A Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 12 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482685/740-10-50-12 + Details
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