Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 298,519	$ 280,740
Short-term investments, available-for-sale	530,758	453,976
Accounts receivable, net of allowances of $4,960 and $5,354 at March 31, 2014 and December 31, 2013, respectively	510,862	654,821
Inventories, net	12,537	14,107
Prepaid expenses and other current assets	138,389	110,981
Current portion of deferred tax assets, net	47,836	48,470
Total current assets	1,538,901	1,563,095
Long-term investments, available-for-sale	998,831	855,700
Property and equipment, net	336,740	338,996
Goodwill	1,783,090	1,768,949
Other intangible assets, net	487,771	509,595
Long-term portion of deferred tax assets, net	70,779	115,418
Other assets	53,361	60,496
Total assets	5,269,473	5,212,249
Current liabilities:
Accounts payable	76,661	78,452
Accrued expenses and other current liabilities	271,840	257,606
Income taxes payable	8,458	29,322
Current portion of deferred revenues	1,092,577	1,098,681
Total current liabilities	1,449,536	1,464,061
Long-term portion of deferred revenues	318,226	313,059
Other liabilities	87,694	115,322
Commitments and contingencies
Stockholders' equity:
Preferred stock at $.01 par value: 5,000 shares authorized, none issued and outstanding	0	0
Common stock at $.001 par value: 1,000,000 shares authorized; 292,798 and 291,078 shares issued and outstanding at March 31, 2014 and December 31, 2013, respectively	293	291
Additional paid-in capital	4,034,515	3,974,297
Retained earnings	2,959,480	2,903,541
Accumulated other comprehensive income	4,250	4,951
Stockholders' equity before treasury stock	6,998,538	6,883,080
Less - common stock in treasury, at cost (108,158 and 107,789 shares at March 31, 2014 and December 31, 2013, respectively)	(3,584,521)	(3,563,273)
Total stockholders' equity	3,414,017	3,319,807
Total liabilities and equity	$ 5,269,473	$ 5,212,249