Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
OPERATING ACTIVITIES:
Net income	$ 22,616	$ 4,989
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	25,806	14,882
Provision (benefit) for doubtful accounts and sales returns	1,314	(63)
Stock-based compensation	33,939	12,626
Excess income tax benefit from stock-based compensation	(12,556)	(2,257)
Changes in operating assets and liabilities:
Accounts receivable	(8,849)	(5,508)
Deferred commissions	(642)	(437)
Prepaid expenses and other assets	(9,398)	(9,575)
Accounts payable and other liabilities	(3,498)	10,672
Income taxes, net	(4,248)	2,867
Deferred revenue	59,345	35,019
Net cash provided by operating activities	103,829	63,215
INVESTING ACTIVITIES:
Purchases of property and equipment	(44,283)	(22,087)
Purchases of investments	(158,210)	(63,312)
Sales of investments	59,031	0
Maturities of investments	11,230	22,365
Payments for intangible assets and acquisitions, net of cash acquired	(226)	(7,603)
Changes in deposits and restricted cash	(55)	(2,054)
Net cash used in investing activities	(132,513)	(72,691)
FINANCING ACTIVITIES:
Proceeds from issuance of common stock from employee stock options	12,057	9,677
Proceeds from early exercise of employee stock options	16	48
Excess income tax benefit from stock-based compensation	12,556	2,257
Repurchase of common stock	0	(12)
Net cash provided by financing activities	24,629	11,970
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	(1,414)	706
CHANGE IN CASH AND CASH EQUIVALENTS	(5,469)	3,200
CASH AND CASH EQUIVALENTS—Beginning of period	270,408	339,048
CASH AND CASH EQUIVALENTS—End of period	264,939	342,248
SUPPLEMENTAL DISCLOSURES OF NONCASH INVESTING AND FINANCING ACTIVITIES:
Purchases of property and equipment recorded in accounts payable and accrued liabilities	28,071	11,418
Vesting of early exercised stock options	$ 291	$ 772