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Long-term debt: (Details) - USD ($) $ in Thousands |  |  |  |  |  | 1 Months Ended | 3 Months Ended | 6 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Jun. 04, 2025 | Apr. 11, 2025 | Jun. 15, 2024 | Jun. 11, 2024 | May 02, 2024 | May 31, 2025 | Nov. 30, 2024 | May 31, 2024 | Jun. 30, 2025 | Jun. 30, 2025 | Oct. 31, 2024 | Jun. 30, 2024 | Apr. 30, 2024 | Jun. 17, 2025 | Dec. 31, 2024
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from issuance of secured debt |  | $ 170,500 |  |  |  |  |  |  |  |  |  |  |  |  |
Loss on debt extinguishment and redemption - 2026 notes | $ 5,600 |  |  |  |  |  |  |  | $ 5,606 | $ 5,606 |  |  |  |  |
Lease payments |  |  |  |  |  |  |  |  |  | 16,523 |  | $ 42,131 |  |  |
Debt Instrument, Restricted Value |  | 72,600 |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Unrestricted Value |  | $ 97,900 |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate swap |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair value of interest rate swaps |  |  |  |  |  |  |  |  | 13,600 | 13,600 |  |  |  |  | $ 4,000
Interest rate swap | Restricted cash |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Margin deposits |  |  |  |  |  |  |  |  | 13,600 | 13,600 |  |  |  |  |
Interest rate swap | Unrestricted cash |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Margin deposits |  |  |  |  |  |  |  |  | 200 | 200 |  |  |  |  |
Interest rate swap | Accrued and other current liabilities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair value of interest rate swaps |  |  |  |  |  |  |  |  | 22,300 | 22,300 |  |  |  |  | 13,800
Interest rate swap | Other long-term liabilities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair value of interest rate swaps |  |  |  |  |  |  |  |  | 18,300 | $ 18,300 |  |  |  |  | $ 13,800
SOFR | Interest rate swap |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate (as a percent) |  |  |  |  |  |  |  |  |  | 3.50% |  |  |  |  |
Payment of debt in Installments |  |  |  |  |  | $ 9,700 | $ 12,100 |  |  |  |  |  |  |  |
Net proceeds |  |  |  |  |  | $ 9,700 |  |  |  |  | $ 12,100 |  | $ 12,100 |  |
Payment made to counter party |  |  |  |  |  |  |  | $ 12,100 |  |  |  |  |  |  |
2027 Mirror Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount |  |  |  | $ 300,000 |  |  |  |  | $ 300,000 | $ 300,000 |  |  |  |  |
Interest rate (as a percent) |  |  |  | 7.00% |  |  |  |  |  |  |  |  |  |  |
Proceeds from issuance of secured debt |  |  |  |  |  |  |  |  |  | $ 291,900 |  |  |  |  |
Percentage of face value |  |  |  |  |  |  |  |  | 98.50% | 98.50% |  |  |  |  |
Lease payments |  |  |  |  |  |  |  |  |  | $ 114,600 |  |  |  |  |
Maturity date |  |  |  | Jun. 15, 2027 |  |  |  |  |  |  |  |  |  |  |
Minimum percentage of principal amount entitled for redemption |  |  |  | 90.00% |  |  |  |  |  |  |  |  |  |  |
2027 Mirror Notes | Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of principal amount considered as default debt |  |  |  | 25.00% |  |  |  |  |  |  |  |  |  |  |
2027 Mirror Notes | Redemption of some or all the notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Redemption price percentage of principal amount redeemed |  |  | 103.50% |  |  |  |  |  |  |  |  |  |  |  |
2027 Mirror Notes | If certain events have occurred |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repurchase price, percentage |  |  |  | 101.00% |  |  |  |  |  |  |  |  |  |  |
2027 Mirror Notes | If certain events have not occurred |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repurchase price in cash, percentage |  |  |  | 100.00% |  |  |  |  |  |  |  |  |  |  |
2027 Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount |  |  |  |  |  |  |  |  | $ 450,000 | $ 450,000 |  |  |  |  |
Interest rate (as a percent) |  |  |  |  |  |  |  |  | 7.00% | 7.00% |  |  |  |  |
2026 Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate (as a percent) |  |  |  |  |  |  |  |  | 3.50% | 3.50% |  |  |  |  |
Aggregate Principal amount | 500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of net proceeds from offering | 507,300 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of settlement payment | 5,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of accrued interest redeemed | $ 2,200 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Redemption value |  |  |  |  |  |  |  |  |  | $ 500,000 |  |  |  |  |
Secured IPv4 notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from issuance of secured debt |  |  |  |  |  |  |  |  |  | 170,479 |  | 198,420 |  |  |
Debt costs |  |  |  |  |  |  |  |  |  | 4,000 |  | $ 7,600 |  |  |
Secured IPv4 Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount |  |  |  |  | $ 380,400 |  |  |  |  |  |  |  |  |  |
Senior secured 2032 notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount |  |  |  |  |  |  |  |  | $ 600,000 | $ 600,000 |  |  |  | $ 600,000 |
Interest rate (as a percent) |  |  |  |  |  |  |  |  | 6.50% | 6.50% |  |  |  | 6.50% |
Proceeds from issuance of secured debt |  |  |  |  |  |  |  |  |  | $ 597,842 |  |  |  |  |
Debt costs |  |  |  |  |  |  |  |  |  | $ 2,200 |  |  |  |  |
Repurchase price in cash, percentage |  |  |  |  |  |  |  |  |  | 100.00% |  |  |  |  |
Minimum percentage of principal amount entitled for redemption |  |  |  |  |  |  |  |  |  | 90.00% |  |  |  |  |
Senior secured 2032 notes | Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of principal amount considered as default debt |  |  |  |  |  |  |  |  | 25.00% | 25.00% |  |  |  |  |
Senior secured 2032 notes | Redemption of some or all the notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repurchase price, percentage |  |  |  |  |  |  |  |  |  | 100.00% |  |  |  |  |
Senior secured 2032 notes | Issuers may redeem up to 40% of notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Redemption price percentage |  |  |  |  |  |  |  |  |  | 106.50% |  |  |  |  |
Repurchase price, percentage |  |  |  |  |  |  |  |  |  | 40.00% |  |  |  |  |
Senior secured 2032 notes | Redemption after July 1, 2028 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repurchase price, percentage |  |  |  |  |  |  |  |  |  | 103.25% |  |  |  |  |
Senior secured 2032 notes | Change in control accompanied by certain rating events |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repurchase price, percentage |  |  |  |  |  |  |  |  |  | 101.00% |  |  |  |  |
Existing IPv4 Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount |  |  |  |  | $ 206,000 |  |  |  | $ 206,000 | $ 206,000 |  |  |  |  |
Interest rate (as a percent) |  |  |  |  | 7.924% |  |  |  | 7.924% | 7.924% |  |  |  |  |
Proceeds from issuance of secured debt |  |  |  |  | $ 198,400 |  |  |  |  |  |  |  |  |  |
Maturity date |  |  |  |  | May 31, 2054 |  |  |  |  |  |  |  |  |  |
Percentage Of Noteholders Voting Rights To Amend Covenants |  | 50.00% |  |  |  |  |  |  |  |  |  |  |  |  |
Additional interest accrued on percentage of principal amount |  |  |  |  | 5.00% |  |  |  |  |  |  |  |  |  |
Existing IPv4 Notes | Base Rate [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  |  |  |  |  |  |  |  | 5.00% |  |  |  |  |
Existing IPv4 Notes | US Treasury (UST) Interest Rate [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  |  |  |  |  |  |  |  | 3.40% |  |  |  |  |
IPv4 New Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount |  | $ 174,400 |  |  |  |  |  |  | $ 174,400 | $ 174,400 |  |  |  |  |
Interest rate (as a percent) |  | 6.646% |  |  |  |  |  |  | 6.646% | 6.646% |  |  |  |  |
Maturity date |  | Apr. 30, 2055 |  |  |  |  |  |  |  |  |  |  |  |  |
Additional interest accrued on percentage of principal amount |  | 5.00% |  |  |  |  |  |  |  |  |  |  |  |  |
IPv4 New Notes | Base Rate [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  | 5.00% |  |  |  |  |  |  |  |  |  |  |  |  |
IPv4 New Notes | US Treasury (UST) Interest Rate [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  | 3.00% |  |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition Percentage of outstanding long-term debt or borrowing associated with any securities or credit agreement for which there has been a default in principal, interest, sinking fund, or redemption provisions, or any breach of covenant that existed at the end of the period and subsequently has not been cured. + References No definition available. + Details
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