CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income	$ 6,784	$ 4,136
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	19,788	18,538
Amortization of debt discount and premium	370	280
Equity-based compensation expense (net of amounts capitalized)	3,784	2,647
Gains - equipment transactions and other, net	(484)	(2,172)
Deferred income taxes	2,623	3,229
Changes in operating assets and liabilities:
Accounts receivable	1,355	43
Prepaid expenses and other current assets	(1,213)	(1,067)
Accounts payable, accrued liabilities and other long-term liabilities	(2,005)	(1,660)
Deposits and other assets	(823)	(460)
Net cash provided by operating activities	30,179	23,514
Cash flows from investing activities:
Purchases of property and equipment	(14,905)	(12,249)
Net cash used in investing activities	(14,905)	(12,249)
Cash flows from financing activities:
Dividends paid	(22,819)	(18,999)
Proceeds from exercises of stock options	297	300
Principal payments on installment payment agreement	(1,965)	(218)
Principal payments of capital lease obligations	(2,304)	(3,854)
Net cash used in financing activities	(26,791)	(22,771)
Effect of exchange rates changes on cash	532	383
Net decrease in cash and cash equivalents	(10,985)	(11,123)
Cash and cash equivalents, beginning of period	247,011	274,319
Cash and cash equivalents, end of period	236,026	263,196
Supplemental disclosure of non-cash financing activities:
Non-cash component of network equipment obtained in exchange transactions	117	2,124
PP&E obtained for installment payment agreement	2,566	3,307
Capital lease obligations incurred	$ 3,616	$ 5,957