Description of the business and summary of significant accounting policies: - Lessor Accounting and Leases (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash paid for amounts included in the measurement of lease liabilities
Amortization of right-of-use assets	$ 48,370	$ 64,698	$ 28,915
Interest expense on finance lease liabilities	40,352	34,940	23,317
Operating lease cost	98,521	92,763	18,331
Total lease costs	187,243	192,401	70,563
Operating cash flows from finance leases	(37,829)	(33,080)	(23,317)
Operating cash flows from operating leases	(102,649)	(93,924)	(18,836)
Financing cash flows from finance leases		(77,362)	(45,472)
Right-of-use assets obtained in exchange for new finance lease liabilities	241,193	232,468	107,875
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 12,614	$ 13,682	$ 11,168
Weighted-average remaining lease term - finance leases (in years)	17 years 1 month 6 days	11 years 6 months	13 years 6 months
Weighted-average remaining lease term - operating leases (in years)	10 years 10 months 24 days	12 years 2 months 12 days	16 years 7 months 6 days
Weighted-average discount rate - finance leases	8.10%	7.60%	8.60%
Weighted-average discount rate - operating leases	7.80%	8.10%	5.40%
Finance leases-fiber lease agreements
Initial terms (in years)	20 years
Additional finance lease future payments due	$ 184,300
Future minimum payments under these operating lease agreements
2024	65,584
2025	60,803
2026	57,429
2027	54,957
2028	45,777
Thereafter	246,763
Total minimum lease obligations	531,313
Less-amounts representing interest	(172,137)
Present value of minimum lease obligations	359,176
Current maturities	(57,172)	$ (67,962)
Lease obligations, net of current maturities	302,004	330,095
Future minimum payments under these finance lease agreements
2024	63,299
2025	58,328
2026	58,361
2027	57,402
2028	56,357
Thereafter	715,349
Total minimum lease obligations	1,009,096
Less-amounts representing interest	(470,710)
Present value of minimum lease obligations	538,386
Current maturities	(21,225)	(64,594)
Lease obligations, net of current maturities	$ 517,161	$ 419,921
Minimum
Finance leases-fiber lease agreements
Initial terms (in years)	15 years
Future minimum payments under these operating lease agreements
Right to use specified fibers (in years)	20 years
Maximum
Finance leases-fiber lease agreements
Initial terms (in years)	20 years
Future minimum payments under these operating lease agreements
Right to use specified fibers (in years)	25 years

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