Accrued and other liabilities: (Tables)

12 Months Ended

Dec. 31, 2017

Accrued and other liabilities:

Schedule of accrued and other current liabilities

        Accrued and other current liabilities consist of the following (in thousands):

	December 31,
	2017		2016
Operating accruals	$	25,278	$	24,356
Deferred revenue—current portion		4,758		4,334
Payroll and benefits		5,139		4,170
Taxes—non-income based		2,360		4,037
Interest		10,412		10,252
Total	$	47,947	$	47,149