Description of the business: - Leases (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2025
Cash paid for amounts included in the measurement of lease liabilities
Amortization of right-of-use assets	$ 13,553	$ 13,975	$ 27,089	$ 27,891
Interest expense on finance lease liabilities	12,472	12,509	24,985	23,615
Operating lease cost	18,169	18,569	35,816	36,013
Total lease costs	$ 44,194	$ 45,053	87,890	87,519
Operating cash flows from finance leases			(28,276)	(22,650)
Operating cash flows from operating leases			(37,084)	(35,790)
Financing cash flows from finance leases			(23,007)	(16,523)
Right-of-use assets obtained in exchange for new finance lease liabilities			52,102	79,076
Right-of-use assets obtained in exchange for new operating lease liabilities			$ 1,765	$ 15,105
Weighted-average remaining lease term - finance leases (in years)	16 years 9 months 18 days	17 years 1 month 6 days	16 years 9 months 18 days	17 years 1 month 6 days
Weighted-average remaining lease term - operating leases (in years)	11 years 4 months 24 days	11 years 3 months 18 days	11 years 4 months 24 days	11 years 3 months 18 days
Weighted-average discount rate - finance leases	8.30%	8.10%	8.30%	8.10%
Weighted-average discount rate - operating leases	7.20%	7.60%	7.20%	7.60%
Finance leases-fiber lease agreements
Initial terms (in years)	20 years		20 years
Additional finance lease future payments due	$ 96,700		$ 96,700
Future minimum payments under these operating lease agreements
2027	60,082		60,082
2028	57,534		57,534
2029	55,440		55,440
2030	34,482		34,482
2031	27,688		27,688
Thereafter	220,283		220,283
Total minimum lease obligations	455,509		455,509
Less-amounts representing interest	(146,033)		(146,033)
Present value of minimum lease obligations	309,476		309,476
Current maturities	(53,102)		(53,102)		$ (54,576)
Lease obligations, net of current maturities	256,374		256,374		269,753
Future minimum payments under these finance lease agreements
2027	70,239		70,239
2028	69,157		69,157
2029	67,913		67,913
2030	67,537		67,537
2031	67,426		67,426
Thereafter	827,320		827,320
Total minimum lease obligations	1,169,592		1,169,592
Less-amounts representing interest	(539,382)		(539,382)
Present value of minimum lease obligations	630,210		630,210
Current maturities	(21,171)		(21,171)		(26,112)
Lease obligations, net of current maturities	$ 609,039		$ 609,039		$ 597,239
Minimum
Finance leases-fiber lease agreements
Initial terms (in years)	15 years		15 years
Maximum
Finance leases-fiber lease agreements
Initial terms (in years)	20 years		20 years

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