Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011
Operating Activities
Net income	$ 68,267		$ 73,347
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of intangible assets	27,002	[1]	16,208	[1]
Depreciation and amortization of property and equipment	22,545		19,641
Stock-based compensation expense	30,557		17,884
(Gain) Loss on investments	(3,366)		490
Provision for doubtful accounts	546		(901)
Provision for product returns	2,945		1,530
Provision for inventory reserves	411		517
Tax effect of stock-based compensation	13,856		15,492
Excess tax benefit from exercise of stock options	(14,597)		(15,502)
Effects of exchange rate changes on monetary assets and liabilities denominated in foreign currencies	(1,202)		(3,350)
Other non-cash items	791		964
Total adjustments to reconcile net income to net cash provided by operating activities	79,488		52,973
Changes in operating assets and liabilities, net of the effects of acquisitions:
Accounts receivable	88,114		85,622
Inventories	(1,334)		(1,050)
Prepaid expenses and other current assets	(18,682)		(6,009)
Other assets	2,536		(1,293)
Deferred tax assets, net	15,293		(14,196)
Accounts payable	(4,513)		(21,456)
Accrued expenses and other current liabilities	(872)		(41,759)
Deferred revenues	23,001		2,240
Other liabilities	(8,228)		30,809
Total changes in operating assets and liabilities, net of the effects of acquisitions	95,315		32,908
Net cash provided by operating activities	243,070		159,228
Investing Activities
Purchases of available for-sale investments	(314,387)		(182,919)
Proceeds from sales of available-for-sale investments	104,185		180,434
Proceeds from maturities of available-for-sale investments	138,488		169,008
Proceeds from the sale of cost method investments	5,559		0
Purchases of property and equipment	(23,147)		(26,845)
Purchases of cost method investments	(1,712)		(1,852)
Cash paid for acquisitions, net of cash acquired	(24,033)		(118,440)
Cash paid for licensing agreements and product related intangible assets	(61)		(1,522)
Net cash (used in) provided by investing activities	(115,108)		17,864
Financing Activities
Proceeds from issuance of common stock under stock-based compensation plans	30,260		42,337
Repayment of acquired debt	(2,456)		(10,926)
Excess tax benefit from exercise of stock options	14,597		15,502
Stock repurchases, net	(99,996)		(99,954)
Cash paid for tax withholding on vested stock awards	(14,102)		(8,797)
Net cash used in financing activities	(71,697)		(61,838)
Effect of exchange rate changes on cash and cash equivalents	1,320		3,924
Change in cash and cash equivalents	57,585		119,178
Cash and cash equivalents at beginning of period	333,296		396,162
Cash and cash equivalents at end of period	$ 390,881		$ 515,340

[1] Represents expenses presented to management on a consolidated basis only and not allocated to the operating segments.