Consolidated Statements of Cash Flows (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Cash flows from operating activities:
Net income	$ 98,538	$ 79,001
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	82,467	67,634
Stock-based compensation expense	27,324	39,384
Provision for deferred income taxes, net	0	44,611
Amortization of deferred financing costs	0	394
Provision for doubtful accounts	454	1,445
Excess tax benefits from stock-based compensation	(10,850)	(12,923)
Loss on investments and disposal of property and equipment, net	4	(245)
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	456	(16,406)
Prepaid expenses and other current assets	841	(40,284)
Accounts payable, accrued expenses and other current liabilities	(5,713)	11,878
Deferred revenue	(2,182)	(1,319)
Accrued restructuring	(32)	(93)
Other non-current assets and liabilities	9,052	762
Net cash provided by operating activities	200,359	174,133
Cash flows from investing activities:
Cash paid for acquisition of business, net of cash acquired	(550)	(12,010)
Purchases of property and equipment	(68,525)	(86,446)
Capitalization of internal-use software costs	(20,450)	(14,841)
Purchases of short- and long-term marketable securities	(578,135)	(614,679)
Proceeds from sales of short- and long-term marketable securities	272,709	274,620
Proceeds from maturities of short- and long-term marketable securities	238,428	230,102
Increase in other investments	0	(500)
Proceeds from the sale of property and equipment	88	38
Decrease in restricted investments held for security deposits	221	8
Net cash used in investing activities	(156,214)	(223,708)
Cash flows from financing activities:
Proceeds from the issuance of common stock under stock option and employee stock purchase plans	12,122	20,993
Excess tax benefits from stock-based compensation	10,850	12,923
Employee taxes paid related to net share settlement of equity awards	(3,507)	0
Repurchases of common stock	(92,613)	(42,621)
Net cash used in financing activities	(73,148)	(8,705)
Effects of exchange rate changes on cash and cash equivalents	2,766	(2,519)
Net decrease in cash and cash equivalents	(26,237)	(60,799)
Cash and cash equivalents at beginning of period	231,866	181,305
Cash and cash equivalents at end of period	205,629	120,506
Supplemental disclosure of cash flow information:
Cash paid for income taxes	17,898	22,130
Cash paid for interest	0	966
Non-cash financing and investing activities:
Capitalization of stock-based compensation, net of impairments	3,465	3,679
Common stock issued upon conversion of 1% convertible senior notes	0	136,193
Common stock returned upon settlement of escrow claims related to prior business acquisitions	$ 0	$ (125)