Commitments and contingencies: (Tables)

12 Months Ended

Dec. 31, 2016

Commitments and contingencies:

Schedule of future minimum annual payments under capital leases-fiber lease agreements

The future minimum payments (principal and interest) under these agreements are as follows (in thousands):

For the year ending December 31,
2017	$	21,161
2018		19,846
2019		19,609
2020		19,593
2021		19,137
Thereafter		199,798
Total minimum lease obligations		299,144
Less—amounts representing interest		(157,183	)
Present value of minimum lease obligations		141,961
Current maturities		(6,626	)
Capital lease obligations, net of current maturities	$	135,335

Schedule of future minimum annual payments under operating leases and building access agreements

Future minimum annual payments under these arrangements are as follows (in thousands):

For the year ending December 31,
2017	$	33,125
2018		24,455
2019		21,320
2020		18,050
2021		14,896
Thereafter		44,264
	$	156,110