Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash flows from operating activities
Net income	$ 27,770	$ 23,831
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization of property and equipment	14,137	13,983
Amortization of other intangible assets	1,220	571
Loss on asset disposals and impairments of property and equipment	733	1,221
Deferred income taxes	(1,687)	(706)
Equity in net income of affiliate	(3,035)	(2,921)
Distributions from affiliate	4,300	4,050
Bad debt expense	860	930
Non-cash share-based compensation	4,377	3,831
Changes in operating assets and liabilities
Trade accounts receivable	722	327
Prepaid expenses and other assets	(548)	2,705
Accounts payable	(1,319)	250
Accrued expenses and other current liabilities	(10,770)	(6,998)
Deferred revenue	15,227	11,267
Other noncurrent liabilities	1,667	2,010
Net cash provided by operating activities	53,654	54,351
Cash flows from investing activities
Additions to property and equipment	(10,627)	(14,182)
Net cash used in investing activities	(10,627)	(14,182)
Cash flows from financing activities
Proceeds from stock option exercises and stock purchase plan	3,311	2,046
Stock repurchases	(50,025)
Dividends paid to stockholders	(5,454)	(5,408)
Tax benefits realized from share-based awards	554	484
Debt borrowings		5,000
Debt repayments		(53,000)
Net cash used in financing activities	(51,614)	(50,878)
Effect of exchange rate changes on cash and cash equivalents	(55)	(1)
Net change in cash and cash equivalents	(8,642)	(10,710)
Cash and cash equivalents at beginning of period	19,715	18,925
Cash and cash equivalents at end of period	$ 11,073	$ 8,215