CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
Current assets:
Cash and cash equivalents	$ 168,721	$ 246,342	$ 174,458
Restricted cash	612	601	720
Accounts receivable, net	119,529	77,313	89,425
Deferred income taxes	25,687	44,547	19,284
Prepaid expenses and other current assets	18,952	16,162	18,331
Total current assets	333,501	384,965	302,218
Property and equipment, net	174,394	189,890	194,253
Deferred income taxes	54,657	56,112	39,499
Other assets	46,409	41,263	49,080
Total assets	608,961	672,230	585,050
Current liabilities:
Accounts payable	61,468	63,304	76,358
Accrued compensation and benefits	20,113	21,023	19,729
Other current liabilities	51,285	86,722	19,910
Deferred revenue	132,246	135,900	119,089
Total current liabilities	265,112	306,949	235,086
Long-term debt	60,000	140,000	140,000
Other liabilities	82,852	98,327	78,189
Total liabilities	407,964	545,276	453,275
Shareholders' equity:
Preferred stock, $.01 par value, 5,000,000 shares authorized, none issued	0	0	0
Common stock, $.01 par value, 300,000,000 shares authorized, 37,068,904 issued	371	371	371
Capital surplus	206,714	206,703	203,095
Retained earnings	1,030,002	959,072	968,545
Accumulated other comprehensive (loss)	(7,715)	(7,930)	(8,970)
Treasury stock, 13,698,990, 13,744,395 and 13,744,474 shares, at cost	(1,028,375)	(1,031,262)	(1,031,266)
Total shareholders' equity	200,997	126,954	131,775
Total liabilities and shareholders' equity	$ 608,961	$ 672,230	$ 585,050