Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
CURRENT ASSETS:
Cash and cash equivalents	$ 262,670	$ 270,408
Short-term investments	610,728	479,141
Accounts receivable (net of allowance for doubtful accounts of $6,250 and $3,774 at June 30, 2013 and December 31, 2012, respectively)	203,585	203,607
Deferred commissions	29,710	30,232
Prepaid expenses	26,785	14,344
Other current assets	30,672	21,065
Total current assets	1,164,150	1,018,797
Property and equipment, net	292,715	186,677
Goodwill	150,831	115,214
Intangible assets, net	38,284	32,780
Other assets	41,980	28,862
TOTAL ASSETS	1,687,960	1,382,330
CURRENT LIABILITIES:
Accounts payable	74,605	53,559
Accrued liabilities	106,118	104,077
Deferred revenue	331,187	257,743
Total current liabilities	511,910	415,379
DEFERRED TAX LIABILITIES	22,905	27,717
OTHER LONG TERM LIABILITIES	42,128	30,810
Total liabilities	576,943	473,906
COMMITMENTS AND CONTINGENCIES (Note 10)
STOCKHOLDERS’ EQUITY (Note 11):
Additional paid-in capital	1,055,870	879,303
Accumulated other comprehensive income (loss)	(64)	260
Accumulated earnings	55,200	28,850
Total stockholders’ equity	1,111,017	908,424
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	1,687,960	1,382,330
Common Stock Class A And Class B
STOCKHOLDERS’ EQUITY (Note 11):
Class A and Class B common stock	$ 11	$ 11