Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Activities
Net income		$ 319,361	$ 251,723	$ 339,523
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization and impairment of intangible assets	[1]	239,915	192,325	139,541
Depreciation and amortization of property and equipment		152,964	137,945	127,959
Amortization of debt discount and transaction costs		36,013	23,293	0
Stock-based compensation expense		147,368	169,287	183,941
Deferred income tax benefit		(89,378)	(36,982)	(51,848)
Excess tax benefit from stock-based compensation		(5,873)	(6,132)	(12,552)
Effects of exchange rate changes on monetary assets and liabilities denominated in foreign currencies		13,416	5,233	5,888
Other non-cash items		8,740	12,419	5,417
Total adjustments to reconcile net income to net cash provided by operating activities		503,165	497,388	398,346
Changes in operating assets and liabilities, net of the effects of acquisitions:
Accounts receivable		(7,226)	(30,962)	(22,951)
Inventories		703	(1,167)	(5,591)
Prepaid expenses and other current assets		(8,057)	(8,133)	(7,928)
Other assets		(2,550)	1,498	5,076
Income taxes, net		51,994	(79,119)	(7,374)
Accounts payable		10,959	40	3,092
Accrued expenses and other current liabilities		49,586	62,195	23,028
Deferred revenues		107,150	146,123	201,455
Other liabilities		9,463	6,395	1,667
Total changes in operating assets and liabilities, net of the effects of acquisitions		212,022	96,870	190,474
Net cash provided by operating activities		1,034,548	845,981	928,343
Investing Activities
Purchases of available-for-sale investments		(2,182,831)	(2,390,950)	(1,703,976)
Proceeds from sales of available-for-sale investments		1,745,290	1,694,886	766,192
Proceeds from maturities of available-for-sale investments		637,052	406,334	504,314
Proceeds (purchases) from cost method investments, net		6,476	425	5,243
Cash paid for acquisitions, net of cash acquired		(256,907)	(101,059)	(334,881)
Purchases of property and equipment		(160,825)	(165,417)	(162,889)
Cash paid for licensing agreements and product related intangible assets		(11,403)	(13,676)	(12,153)
Other		(1,267)	0	0
Net cash used in investing activities		(224,415)	(569,457)	(938,150)
Financing Activities
Proceeds from issuance of common stock under stock-based compensation plans		112,285	46,618	73,655
Proceeds from issuance of convertible notes, net of issuance costs		0	1,415,717	0
Purchase of convertible note hedges		0	(184,288)	0
Proceeds from issuance of warrants		0	101,775	0
Proceeds from revolving credit facility		95,000	0	0
Repayments on credit facility		(95,000)	0	0
Repayment of acquired debt		(7,569)	(4,065)	(2,061)
Excess tax benefit from stock-based compensation		5,873	6,132	12,552
Stock repurchases, net		(755,704)	(1,640,885)	(406,326)
Cash paid for tax withholding on vested stock awards		(46,336)	(33,672)	(31,013)
Other		0	0	912
Net cash used in financing activities		(691,451)	(292,668)	(352,281)
Effect of exchange rate changes on cash and cash equivalents		(10,313)	(4,447)	(781)
Change in cash and cash equivalents		108,369	(20,591)	(362,869)
Cash and cash equivalents at beginning of period		260,149	280,740	643,609
Cash and cash equivalents at end of period		368,518	260,149	280,740
Supplemental Cash Flow Information
Cash paid for income taxes		45,827	130,502	92,672
Cash paid for interest		$ 8,215	$ 5,027	$ 127

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