Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:
Net income	$ 9,181	$ 13,753
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion	8,381	7,629
Amortization of deferred financing costs	129	129
Deferred income tax expense	4,952	8,849
Amortization of stock based compensation	1,710	1,254
Provision for doubtful accounts, service credits and other	597	833
Adjustment of non-cash transaction taxes	(229)	(251)
Loss/(Gain) on disposals of property and equipment	3	167
Changes in assets and liabilities:
Accounts receivable	(5,478)	2,812
Prepaid expenses and other assets	850	(367)
Accounts payable and accrued liabilities	(3,076)	(7,578)
Deferred revenue	1,331	(4,088)
Net cash provided by operating activities	18,351	23,142
Cash flows from investing activities:
Purchase of property and equipment	(5,036)	(5,268)
Proceeds from disposals of property and equipment	59	9
Net cash used in investing activities	(4,977)	(5,259)
Cash flows from financing activities:
Cash dividends to stockholders	(5,414)	(6,900)
Net cash used in financing activities	(5,414)	(6,900)
Net increase/(decrease) in cash and cash equivalents	7,960	10,983
Cash and cash equivalents, beginning of period	89,075	61,046
Cash and cash equivalents, end of period	97,035	72,029
Supplemental disclosure:
Interest paid	3	6
Income taxes paid	$ 884	$ 831