Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current Assets:
Cash and cash equivalents	$ 80,900	$ 81,047
Marketable investments (Note 3)	147,757	136,991
Accounts receivable, net	44,149	81,378
Deferred commissions	7,890	12,010
Prepaid expenses and other current assets	21,279	25,935
Total current assets	301,975	337,361
Long-term marketable investments (Note 3)	9,789	9,565
Property and equipment, net	48,312	50,448
Goodwill	78,211	71,543
Intangible assets, net	8,517	10,317
Other assets	17,902	8,344
Total assets	464,706	487,578
Current Liabilities:
Accounts payable	933	1,223
Accrued expenses and other current liabilities	25,270	30,153
Deferred revenue	124,857	147,887
Total current liabilities	151,060	179,263
Non-current liabilities	17,499	17,580
Total liabilities	168,559	196,843
Commitments
Stockholders' Equity (Note 7):
Preferred stock, $.01 par value, Authorized - 500 shares, issued and outstanding - none
Common stock, $.01 par value Authorized - 125,000 shares, Issued - 31,338 and 30,962 as of September 30, 2012 and December 31, 2011, respectively Outstanding- 22,303 and 22,747 as of September 30, 2012 and December 31, 2011, respectively	313	310
Additional paid-in capital	385,873	373,591
Retained earnings	116,504	104,662
Treasury stock- 9,035 and 8,215 as of September 30, 2012 and December 31, 2011, respectively, at cost	(207,187)	(181,000)
Accumulated other comprehensive income (loss)	644	(6,828)
Total stockholders' equity	296,147	290,735
Total liabilities and stockholders' equity	$ 464,706	$ 487,578