Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current Assets:
Cash and cash equivalents	$ 70,700	$ 98,810
Marketable investments (Note 2)	86,961	134,876
Accounts receivable, net	37,009	74,623
Deferred commissions	8,408	9,410
Prepaid expenses and other current assets	18,645	18,978
Total current assets	221,723	336,697
Long-term marketable investments (Note 2)	9,092	8,970
Property and equipment, net	41,058	46,300
Goodwill	79,493	78,954
Intangible assets, net	6,296	7,920
Other assets	11,166	8,809
Total assets	368,828	487,650
Current Liabilities:
Accounts payable	918	772
Accrued expenses and other current liabilities	25,184	30,078
Deferred revenue	125,787	150,495
Total current liabilities	151,889	181,345
Non-current liabilities	8,972	9,433
Total liabilities	160,861	190,778
Commitments
Stockholders' Equity (Note 6):
Preferred stock, $.01 par value Authorized - 500 shares, issued and outstanding - none
Common stock, $.01 par value Authorized - 125,000 shares Issued - 20,389 and 31,451 as of September 30, 2013 and December 31, 2012, respectively Outstanding - 19,896 and 22,293 as of September 30, 2013 and December 31, 2012, respectively	204	315
Additional paid-in capital	105,396	389,362
Retained earnings	118,814	117,450
Treasury stock - 493 and 9,158 as of September 30, 2013 and December 31, 2012, respectively, at cost	(17,071)	(210,843)
Accumulated other comprehensive income	624	588
Total stockholders' equity	207,967	296,872
Total liabilities and stockholders' equity	$ 368,828	$ 487,650