Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Operating activities:
Net income (loss)	$ (85,351)	$ 16,758
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	29,398	17,847
Stock-based expense	133,851	14,506
Accretion and amortization on marketable securities	2,836	868
Loss from sale of property and equipment	12
Deferred income taxes	(1,286)
Changes in operating assets and liabilities:
Accounts receivable, net	(5,617)	(21,791)
Income tax receivable	14,242	14,661
Other assets	(4,818)	4,346
Accounts payable	(283)	5,074
Deferred revenue	8,192	43,708
Other liabilities	(12,359)	7,680
Net cash provided by operating activities	78,817	103,657
Investing activities:
Purchases of marketable securities	(964,741)	(272,418)
Sales of marketable securities	16,747	1,501
Maturities of marketable securities	116,126	285,699
Acquisition of property and equipment	(34,994)	(50,222)
Acquisition of purchased technology and other intangible assets	(3,139)	(1,640)
Business acquisitions, net of cash acquired	(182,164)	(10,438)
Restricted cash	(224,952)	(8,020)
Purchases of other investments	(38)
Net cash used in investing activities	(1,277,155)	(55,538)
Financing activities:
Taxes paid related to net share settlement of ZSUs	(23,500)
Repurchases of common stock		(261,270)
Exercise of stock options	533	1,205
Net proceeds from issuance of preferred stock		485,314
Net cash provided by (used in) financing activities	(22,967)	225,249
Effect of exchange rate changes on cash and cash equivalents	36	21
Net increase (decrease) in cash and cash equivalents	(1,221,269)	273,389
Cash and cash equivalents, beginning of period	1,582,343	187,831
Cash and cash equivalents, end of period	$ 361,074	$ 461,220