Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Activities
Net income		$ 536,112	$ 319,361	$ 251,723
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization and impairment of intangible assets	[1]	89,592	239,915	192,325
Depreciation and amortization of property and equipment		159,446	152,964	137,945
Amortization of debt discount and transaction costs		37,085	36,013	23,293
Stock-based compensation expense		184,788	147,368	169,287
Deferred income tax benefit		(41,104)	(89,378)	(36,982)
Excess tax benefit from stock-based compensation		(16,049)	(5,873)	(6,132)
Effects of exchange rate changes on monetary assets and liabilities denominated in foreign currencies		5,189	13,416	5,233
Other non-cash items		11,628	8,740	12,419
Total adjustments to reconcile net income to net cash provided by operating activities		430,575	503,165	497,388
Changes in operating assets and liabilities, net of the effects of acquisitions:
Accounts receivable		(60,636)	(7,226)	(30,962)
Inventories		(4,133)	703	(1,167)
Prepaid expenses and other current assets		(12,472)	(8,057)	(8,133)
Other assets		(2,460)	(2,550)	1,498
Income taxes, net		49,834	51,994	(79,119)
Accounts payable		(20,905)	10,959	40
Accrued expenses and other current liabilities		33,150	49,586	62,195
Deferred revenues		144,439	107,150	146,123
Other liabilities		22,326	9,463	6,395
Total changes in operating assets and liabilities, net of the effects of acquisitions		149,143	212,022	96,870
Net cash provided by operating activities		1,115,830	1,034,548	845,981
Investing Activities
Purchases of available-for-sale investments		(2,238,784)	(2,182,831)	(2,390,950)
Proceeds from sales of available-for-sale investments		1,294,636	1,745,290	1,694,886
Proceeds from maturities of available-for-sale investments		632,517	637,052	406,334
Proceeds from cost method investments, net		920	6,476	425
Purchases of property and equipment		(134,170)	(160,825)	(165,417)
Cash paid for acquisitions, net of cash acquired		(13,242)	(256,907)	(101,059)
Cash paid for licensing agreements and product related intangible assets		(26,342)	(11,403)	(13,676)
Other		261	(1,267)	0
Net cash used in investing activities		(484,204)	(224,415)	(569,457)
Financing Activities
Proceeds from issuance of common stock under stock-based compensation plans		41,247	112,285	46,618
Proceeds from issuance of convertible notes, net of issuance costs		0	0	1,415,717
Purchase of convertible note hedges		0	0	(184,288)
Proceeds from issuance of warrants		0	0	101,775
Proceeds from revolving credit facility		0	95,000	0
Repayments on credit facility		0	(95,000)	0
Repayment of acquired debt		0	(7,569)	(4,065)
Excess tax benefit from stock-based compensation		16,049	5,873	6,132
Stock repurchases, net		(28,689)	(755,704)	(1,640,885)
Cash paid for tax withholding on vested stock awards		(66,638)	(46,336)	(33,672)
Net cash used in financing activities		(38,031)	(691,451)	(292,668)
Effect of exchange rate changes on cash and cash equivalents		(5,157)	(10,313)	(4,447)
Change in cash and cash equivalents		588,438	108,369	(20,591)
Cash and cash equivalents at beginning of period		368,518	260,149	280,740
Cash and cash equivalents at end of period		956,956	368,518	260,149
Supplemental Cash Flow Information
Cash paid for income taxes		64,361	45,827	130,502
Cash paid for interest		$ 7,847	$ 8,215	$ 5,027

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