Consolidated Statements of Cash Flows (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Cash flows from operating activities:
Net income	$ 140,823	$ 118,710
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	124,228	104,113
Stock-based compensation expense	42,465	57,973
Provision for deferred income taxes, net	20,906	66,898
Amortization of deferred financing costs	0	457
Provision for doubtful accounts	1,236	2,107
Excess tax benefits from stock-based compensation	(11,460)	(22,379)
Loss on investments and disposal of property and equipment, net	(172)	(223)
Non-cash portion of loss on early extinguishment of debt	0	294
Changes in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable	(7,821)	(6,342)
Prepaid expenses and other current assets	(78)	(41,393)
Accounts payable, accrued expenses and other current liabilities	(5,268)	20,573
Deferred revenue	(1,386)	(7,126)
Accrued restructuring	(180)	(167)
Other non-current assets and liabilities	13,355	(1,399)
Net cash provided by operating activities	316,648	292,096
Cash flows from investing activities:
Cash paid for acquisition of business, net of cash acquired	(550)	(12,210)
Purchases of property and equipment	(105,769)	(119,591)
Capitalization of internal-use software costs	(30,523)	(23,754)
Purchases of short- and long-term marketable securities	(727,453)	(900,087)
Proceeds from sales of short- and long-term marketable securities	545,568	538,645
Proceeds from maturities of short- and long-term marketable securities	354,552	250,537
Increase in other investments	0	(500)
Proceeds from the sale of property and equipment	135	52
Decrease in restricted investments held for security deposits	221	8
Net cash provided by (used in) investing activities	36,181	(266,900)
Cash flows from financing activities:
Proceeds from the issuance of common stock under stock option and employee stock purchase plans	13,305	31,946
Excess tax benefits from stock-based compensation	11,460	22,379
Employee taxes paid related to net share settlement of equity awards	(5,680)	0
Repurchases of common stock	(247,738)	(65,126)
Net cash used in financing activities	(228,653)	(10,801)
Effects of exchange rate changes on cash and cash equivalents	(443)	1,867
Net increase in cash and cash equivalents	123,733	16,262
Cash and cash equivalents at beginning of period	231,866	181,305
Cash and cash equivalents at end of period	355,599	197,567
Supplemental disclosure of cash flow information:
Cash paid for income taxes	26,530	23,829
Cash paid for interest	0	967
Non-cash financing and investing activities:
Capitalization of stock-based compensation, net of impairments	5,406	5,597
Common stock issued upon conversion of 1% convertible senior notes	0	141,135
Common stock returned upon settlement of escrow claims related to prior business acquisitions	$ 0	$ (125)