Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 116,976	$ 68,088
Restricted cash	37	45
Short-term investments	139,485
Accounts receivable, net	55,924	44,860
Current portion of deferred commissions	12,236	6,087
Prepaid expenses and other current assets	5,675	9,883
Current portion of deferred tax assets	1,544	1,544
Total current assets	331,877	130,507
Deferred commissions, less current portion	9,734	4,597
Property and equipment, net	39,086	20,695
Other assets	1,507	524
Total assets	382,204	156,323
Current liabilities:
Accounts payable	5,680	9,411
Accrued expenses and other current liabilities	32,038	25,608
Current portion of deferred revenue	128,970	91,087
Current portion of deferred rent		455
Total current liabilities	166,688	126,561
Deferred revenue, less current portion	18,976	13,549
Deferred rent, less current portion	433	2,935
Other long-term liabilities	4,839	2,532
Total liabilities	190,936	145,577
Convertible preferred stock		68,172
Stockholders' equity (deficit):
Common stock	123	22
Additional paid-in capital	286,376	9,793
Accumulated other comprehensive income	326	899
Accumulated deficit	(95,557)	(68,140)
Total stockholders' equity (deficit)	191,268	(57,426)
Total liabilities, convertible preferred stock and stockholders' equity (deficit)	$ 382,204	$ 156,323