Akamai (AKAM) 10-Q 12 May 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2014	6-May-14
Document and Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	31-Mar-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q1	'
Entity Registrant Name	'AKAMAI TECHNOLOGIES INC	'
Entity Central Index Key	'0001086222	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	178,001,071

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$248,726	$333,891
Marketable securities	449,404	340,005
Accounts receivable, net of reserves of $6,933 and $3,703 at March 31, 2014 and December 31, 2013, respectively	301,954	271,988
Prepaid expenses and other current assets	89,198	62,096
Deferred income tax assets	38,018	21,734
Total current assets	1,127,300	1,029,714
Property and equipment, net	503,601	450,287
Marketable securities	721,271	573,026
Goodwill	1,050,780	757,368
Acquired intangible assets, net	157,621	77,429
Deferred income tax assets	2,476	2,325
Other assets	88,443	67,536
Total assets	3,651,492	2,957,685
Current liabilities:	'	'
Accounts payable	61,707	73,710
Accrued expenses	130,447	150,385
Deferred revenue	48,359	36,952
Other current liabilities	3,673	2,119
Total current liabilities	244,186	263,166
Deferred revenue	4,181	3,199
Deferred income tax liabilities	28,445	4,737
Convertible senior notes	590,714	0
Other liabilities	71,821	57,152
Total liabilities	939,347	328,254
Commitments and contingencies	'	'
Stockholders’ equity:	'	'
Preferred stock, $0.01 par value; 5,000,000 shares authorized; 700,000 shares designated as Series A Junior Participating Preferred Stock; no shares issued or outstanding	0	0
Common stock, $0.01 par value; 700,000,000 shares authorized; 180,494,143 shares issued and 178,517,946 shares outstanding at March 31, 2014 and 178,580,696 shares issued and outstanding at December 31, 2013	1,832	1,808
Additional paid-in capital	4,687,512	4,561,929
Accumulated other comprehensive loss	-1,637	-2,091
Treasury stock, at cost, 1,976,197 shares at March 31, 2014 and no shares at December 31, 2013	-116,147	0
Accumulated deficit	-1,859,415	-1,932,215
Total stockholders’ equity	2,712,145	2,629,431
Total liabilities and stockholders’ equity	$3,651,492	$2,957,685

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Accounts receivable reserve (in dollars)	$6,933	$3,703
Preferred stock, par value (in dollars per share)	$0.01	$0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares designated as Series A Junior Participating Preferred Stock	700,000	700,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$0.01	$0.01
Common stock, shares authorized	700,000,000	700,000,000
Common stock, shares issued	180,494,143	178,580,696
Common stock, shares outstanding	178,517,946	178,580,696
Treasury stock, shares	1,976,197	0

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Income Statement [Abstract]	'	'
Revenue	$453,502	$368,046
Costs and operating expenses:	'	'
Cost of revenue	139,612	120,392
Research and development	28,234	21,905
Sales and marketing	81,065	62,690
General and administrative	76,161	55,380
Amortization of acquired intangible assets	6,848	6,060
Restructuring charges	735	431
Total costs and operating expenses	332,655	266,858
Income from operations	120,847	101,188
Interest income	1,639	1,608
Interest expense	-1,941	0
Other expense, net	-881	-132
Income before provision for income taxes	119,664	102,664
Provision for income taxes	46,864	31,177
Net income	$72,800	$71,487
Net income per share:	'	'
Basic (in dollars per share)	$0.41	$0.40
Diluted (in dollars per share)	$0.40	$0.39
Shares used in per share calculations:	'	'
Basic (in shares)	178,705	177,899
Diluted (in shares)	182,038	181,562

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Statement of Comprehensive Income [Abstract]	'	'
Net income	$72,800	$71,487
Other comprehensive income (loss):	'	'
Foreign currency translation adjustments	1,367	-4,014
Change in unrealized (loss) gain on investments, net of income tax benefit (provision) of $123 and $(10) for the three months ended March 31, 2014 and 2013, respectively	-913	71
Other comprehensive income (loss)	454	-3,943
Comprehensive income	$73,254	$67,544

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Statement of Comprehensive Income [Abstract]	'	'
Tax on change in unrealized gain on investments, net	$123	($10)

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities:	'	'
Net income	$72,800	$71,487
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation and amortization	53,516	42,375
Stock-based compensation	25,114	22,931
Provision for doubtful accounts	87	320
Excess tax benefits from stock-based compensation	-15,178	-4,119
Provision for deferred income taxes	1,660	0
Amortization of debt discount and issuance costs	1,941	0
Loss (gain) from disposal of property and equipment	215	-71
Gain from divestiture of a business	0	-1,188
Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:	'	'
Accounts receivable	-18,137	-28,355
Prepaid expenses and other current assets	-20,961	-11,447
Accounts payable and accrued expenses	-22,511	-4,528
Deferred revenue	5,159	8,225
Other current liabilities	1,287	-111
Other non-current assets and liabilities	4,031	-2,295
Net cash provided by operating activities	89,023	93,224
Cash flows from investing activities:	'	'
Cash paid for acquired businesses, net of cash acquired	-386,647	0
Purchases of property and equipment	-52,011	-43,831
Capitalization of internal-use software development costs	-31,995	-16,998
Purchases of short- and long-term marketable securities	-658,943	-145,350
Proceeds from sales of short- and long-term marketable securities	297,059	55,509
Proceeds from maturities of short- and long-term marketable securities	102,911	66,171
Proceeds from the sale of property and equipment	166	260
Other non-currents assets and liabilities	-998	0
Net cash used in investing activities	-730,458	-84,239
Cash flows from financing activities:	'	'
Proceeds from the issuance of convertible senior notes, net of issuance costs	679,603	0
Proceeds from the issuance of warrants related to convertible senior notes	77,970	0
Purchase of note hedge related to convertible senior notes	-101,292	0
Payment of acquired debt and capital leases	-17,862	0
Proceeds related to the issuance of common stock under stock plans	44,329	10,364
Excess tax benefits from stock-based compensation	15,178	4,119
Employee taxes paid related to net share settlement of stock-based awards	-26,271	-17,315
Repurchases of common stock	-116,147	-40,278
Net cash provided by (used in) financing activities	555,508	-43,110
Effects of exchange rate changes on cash and cash equivalents	762	-2,589
Net decrease in cash and cash equivalents	-85,165	-36,714
Cash and cash equivalents at beginning of period	333,891	201,989
Cash and cash equivalents at end of period	248,726	165,275
Supplemental disclosure of cash flow information:	'	'
Cash paid for income taxes	54,479	16,097
Non-cash financing and investing activities:	'	'
Purchases of property and equipment and capitalization of internal-use software development costs included in accrued expenses	20,093	18,136
Capitalization of stock-based compensation	3,784	2,938
Convertible note receivable received for divestiture of a business	$0	$18,882

Nature_of_Business_and_Basis_o

Nature of Business and Basis of Presentation	3 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Nature of Business and Basis of Presentation	'
	Nature of Business and Basis of Presentation
	Akamai Technologies, Inc. (the “Company”) provides cloud services for delivering, optimizing and securing online content and business applications. The Company's globally distributed platform comprises more than 145,000 servers in approximately 1,200 networks in over 90 countries. The Company was incorporated in Delaware in 1998 and is headquartered in Cambridge, Massachusetts. The Company currently operates in one industry segment: providing services for accelerating and improving the delivery of content and applications over the Internet.
	The accompanying interim consolidated financial statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information. These financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in the accompanying financial statements.
	Certain information and footnote disclosures normally included in the Company’s annual audited consolidated financial statements and accompanying notes have been condensed or omitted in these interim financial statements. Accordingly, the unaudited consolidated financial statements included herein should be read in conjunction with the audited consolidated financial statements and accompanying notes included in the Company’s annual report on Form 10-K for the year ended December 31, 2013, filed with the Securities and Exchange Commission on March 3, 2014.
	The results of operations presented in this quarterly report on Form 10-Q are not necessarily indicative of the results of operations that may be expected for any future periods. In the opinion of management, these unaudited consolidated financial statements include all adjustments, consisting only of normal recurring adjustments, that are necessary for a fair statement of the results of all interim periods reported herein.
	Revision of Prior Period Amounts
	During the third quarter of 2013, the Company identified immaterial classification errors in its historical consolidated statements of cash flows. The errors relate to the timing of cash payments for property and equipment, cash receipts from employees for common stock related to the Company's employee stock purchase plan and cash payments for lease deposits. The cash flows for these items were improperly reflected as changes in operating assets and liabilities rather than as investing or financing activities. There was no impact to the net change in cash and cash equivalents. The Company concluded these errors are immaterial to all annual and quarterly periods previously presented and has reflected the corrections as a revision to the consolidated statements of cash flows previously filed.
	The effect of the revisions to the consolidated statements of cash flows for the three months ended March 31, 2013, is as follows (in thousands):
		As Previously Reported		Adjustment		As Revised
	Cash flows from operating activities:
	Changes in operating assets and liabilities, net of effects from acquisitions:
	Prepaid expenses and other current assets	(14,035	)	2,588		(11,447	)
	Accounts payable and accrued expenses	7,838		(12,366	)	(4,528	)
	Other non-current assets and liabilities	(2,257	)	(38	)	(2,295	)
	Net cash provided by operating activities	103,040		(9,816	)	93,224
	Cash flows from investing activities:
	Purchases of property and equipment	(46,478	)	2,647		(43,831	)
	Net cash used in investing activities	(86,886	)	2,647		(84,239	)
	Cash flows from financing activities:
	Proceeds related to the issuance of common stock under stock plans	3,195		7,169		10,364
	Net cash used in financing activities	(50,279	)	7,169		(43,110	)
	Net decrease in cash and cash equivalents	(36,714	)	—		(36,714	)

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2014
Marketable Securities [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	The following is a summary of available-for-sale marketable securities held as of March 31, 2014 and December 31, 2013 (in thousands):
					Gross Unrealized									Classification Balance Sheet
		Amortized Cost			Gains			Losses			Aggregate			Short-Term		Long-Term
											Fair Value			Marketable		Marketable
														Securities		Securities
	As of March 31, 2014
	Certificates of deposit	$	225		$	—		$	—		$	225		$	172	$	53
	Commercial paper	24,986			—			(12		)	24,974			24,974		—
	Corporate bonds	874,265			1,087			(1,161		)	874,191			358,887		515,304
	U.S. government agency obligations	271,705			14			(434		)	271,285			65,371		205,914
		$	1,171,181		$	1,101		$	(1,607	)	$	1,170,675		$	449,404	$	721,271
	As of December 31, 2013
	Certificates of deposit	$	222		$	—		$	—		$	222		$	173	$	49
	Corporate bonds	736,945			1,197			(281		)	737,861			278,318		459,543
	U.S. government agency obligations	174,982			51			(85		)	174,948			61,514		113,434
		$	912,149		$	1,248		$	(366	)	$	913,031		$	340,005	$	573,026
	Unrealized gains and unrealized temporary losses on investments classified as available-for-sale are included within accumulated other comprehensive loss in the consolidated balance sheets. Upon realization, those amounts are reclassified from accumulated other comprehensive loss to interest income in the statements of operations. As of March 31, 2014, the Company did not hold any investment-related assets that had been in a continuous loss position for more than 12 months.
	The following table details the fair value measurements within the fair value hierarchy of the Company’s financial assets and liability at March 31, 2014 and December 31, 2013 (in thousands):
		Total Fair Value			Fair Value Measurements at Reporting Date Using
					Level 1			Level 2			Level 3
	As of March 31, 2014
	Cash Equivalents and Marketable Securities:
	Money market funds	$	21,401		$	21,401		$	—		$	—
	Certificates of deposit	225			225			—			—
	Commercial paper	48,471			—			48,471			—
	Corporate bonds	876,199			—			876,199			—
	U.S. government agency obligations	271,285			—			271,285			—
		$	1,217,581		$	21,626		$	1,195,955		$	—
	Other Assets:
	Note receivable	$	23,245		$	—		$	—		$	23,245
	Other Liabilities:
	Contingent consideration obligation related to Velocius acquisition	$	(2,600	)	$	—		$	—		$	(2,600	)
	As of December 31, 2013
	Cash Equivalents and Marketable Securities:
	Money market funds	$	40,482		$	40,482		$	—		$	—
	Certificates of deposit	3,418			3,418			—			—
	Commercial paper	29,999			—			29,999			—
	Corporate bonds	737,861			—			737,861			—
	U.S. government agency obligations	174,948			—			174,948			—
		$	986,708		$	43,900		$	942,808		$	—
	Other Assets:
	Note receivable	$	22,879		$	—		$	—		22,879
	Other Liabilities:
	Contingent consideration obligation related to Velocius acquisition	$	(2,600	)	$	—		$	—		$	(2,600	)
	As of March 31, 2014 and December 31, 2013, the Company grouped money market funds and certificates of deposit using a Level 1 valuation because market prices for such investments are readily available in active markets. As of March 31, 2014 and December 31, 2013, the Company grouped commercial paper, U.S. government agency obligations and corporate bonds using a Level 2 valuation because quoted prices for identical or similar assets are available in markets that are inactive.
	When developing fair value estimates, the Company maximizes the use of observable inputs and minimizes the use of unobservable inputs. When available, the Company uses quoted market prices to measure fair value. The valuation technique used to measure fair value for the Company's Level 1 and Level 2 assets is a market approach, using prices and other relevant information generated by market transactions involving identical or comparable assets. If market prices are not available, the fair value measurement is based on models that use primarily market-based parameters including yield curves, volatilities, credit ratings and currency rates. In certain cases where market rate assumptions are not available, the Company is required to make judgments about assumptions market participants would use to estimate the fair value of a financial instrument.
	The valuation technique used to measure fair value for the Company's Level 3 asset, which consists of a $25.0 million face value convertible note receivable that is due and payable on July 24, 2014, is primarily an income approach, where the expected weighted average future cash flows are discounted back to present value. The significant unobservable inputs used in the fair value measurement of the convertible note receivable are the probability of conversion to equity and the fair value of equity in which the note is convertible to.
	The valuation technique used to measure fair value of the Company's Level 3 liability, which consists of contingent consideration related to the acquisition of Velocius Networks, Inc. ("Velocius") (Note 5), is primarily an income approach. The significant unobservable input used in the fair value measurement of the Velocius contingent consideration is the likelihood of achieving development milestones to integrate the acquired technology into the Company's technology.
	Significant increases or decreases in the underlying assumptions used to value the Company's Level 3 asset and liability held at March 31, 2014 and December 31, 2013, could significantly increase or decrease the fair value estimates recorded in the consolidated balance sheets.
	Contractual maturities of the Company’s available-for-sale marketable securities held at March 31, 2014 and December 31, 2013 were as follows (in thousands):
		March 31,			December 31,
		2014			2013
	Due in 1 year or less	$	449,404		$	340,005
	Due after 1 year through 5 years	721,271			573,026
		$	1,170,675		$	913,031
	The following table reflects the activity for the Company’s major classes of assets and liabilities measured at fair value using Level 3 inputs for the three months ended March 31, 2014 (in thousands):
		Other Assets:			Other Liabilities:
		Note Receivable			Contingent Consideration Obligation
	Balance as of January 1, 2014	$	22,879		$	(2,600	)
	Unrealized gain on convertible note receivable included in other comprehensive income	366			—
	Balance as of March 31, 2014	$	23,245		$	(2,600	)

Accounts_Receivable

Accounts Receivable	3 Months Ended
	Mar. 31, 2014
Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]	'
Accounts Receivable	'
	Accounts Receivable
	Net accounts receivable consisted of the following as of March 31, 2014 and December 31, 2013 (in thousands):
		March 31,			December 31,
		2014			2013
	Trade accounts receivable	$	218,310		$	175,391
	Unbilled accounts receivable	90,577			100,300
	Gross accounts receivable	308,887			275,691
	Allowance for doubtful accounts	(754		)	(708		)
	Reserve for cash-basis customers	(6,179		)	(2,995		)
	Total accounts receivable reserves	(6,933		)	(3,703		)
	Accounts receivable, net	$	301,954		$	271,988

Goodwill_and_Acquired_Intangib

Goodwill and Acquired Intangible Assets	3 Months Ended
	Mar. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Acquired Intangible Assets	'
	Goodwill and Acquired Intangible Assets
	The change in the carrying amount of goodwill for the three months ended March 31, 2014 was as follows (in thousands):
	Balance as of January 1, 2014	$	757,368
	Acquisition of Prolexic Technologies, Inc.	293,412
	Balance as of March 31, 2014	$	1,050,780
	The Company tests goodwill for impairment at least annually. Through the date the consolidated financial statements were issued, no triggering events had occurred that would indicate a potential impairment exists.
	Acquired intangible assets that are subject to amortization consist of the following as of March 31, 2014 and December 31, 2013 (in thousands):
		March 31, 2014							December 31, 2013
		Gross		Accumulated Amortization			Net		Gross		Accumulated			Net
		Carrying					Carrying		Carrying		Amortization			Carrying
		Amount					Amount		Amount					Amount
	Completed technology	$	92,431	$	(38,631	)	$	53,800	$	65,631	$	(35,476	)	$	30,155
	Customer-related intangible assets	173,600		(78,708		)	94,892		115,100		(75,563		)	39,537
	Non-compete agreements	8,890		(3,060		)	5,830		7,950		(2,623		)	5,327
	Trademarks and trade names	4,200		(1,101		)	3,099		3,400		(990		)	2,410
	Acquired license rights	490		(490		)	—		490		(490		)	—
	Total	$	279,611	$	(121,990	)	$	157,621	$	192,571	$	(115,142	)	$	77,429
	Aggregate expense related to amortization of acquired intangible assets for the three months ended March 31, 2014 and 2013 was $6.8 million and $6.1 million, respectively. Based on the Company’s acquired intangible assets as of March 31, 2014, aggregate expense related to amortization of acquired intangible assets is expected to be $25.2 million for the remainder of 2014, and $26.8 million, $25.2 million, $23.1 million and $16.2 million for 2015, 2016, 2017 and 2018, respectively.

Business_Acquisitions

Business Acquisitions	3 Months Ended
	Mar. 31, 2014
Business Combinations [Abstract]	'
Business Acquisitions	'
	Business Acquisitions
	Prolexic Acquisition
	On February 18, 2014, the Company acquired all of the outstanding preferred and common stock of Prolexic Technologies, Inc. ("Prolexic") in exchange for $392.2 million in cash and the assumption of unvested stock options, subject to post-closing adjustments. The goal of acquiring Prolexic is to provide customers with a comprehensive portfolio of security solutions designed to defend an enterprise’s Web and IP infrastructure against application-layer, network-layer and data center attacks delivered via the Internet. The consolidated financial statements include the operating results of Prolexic from the date of acquisition. The revenue and earnings included in the Company's consolidated financial statements since the acquisition date are not material. Pro forma results of the operations have not been presented because the effects are not material to the consolidated financial statements. Acquisition-related costs were $3.9 million for the three months ended March 31, 2014.
	The Company is in the process of gathering the facts and circumstances existing as of the acquisition date in order to finalize the allocation of the purchase price to the fair value of assets acquired and liabilities assumed and establish the related tax basis. As a result, the purchase price allocation is preliminary.
	The following table presents the preliminary allocation of the purchase price for Prolexic (in thousands):
	Total purchase consideration		$	392,219
	Allocation of the purchase consideration:
	Cash		$	33,072
	Accounts receivable		11,306
	Property and equipment		12,169
	Identifiable intangible assets		87,040
	Goodwill		293,412
	Deferred tax assets		16,000
	Other current and long-term assets		5,883
	Total assets acquired		458,882
	Other current liabilities		(7,501		)
	Current deferred revenue		(5,812		)
	Deferred tax liabilities		(33,723		)
	Debt, capital leases and other long-term liabilities		(19,627		)
	Total liabilities assumed		(66,663		)
	Net assets acquired		$	392,219
	The value of the goodwill can be attributed to a number of business factors, including a trained technical and sales workforce; and the fair value of expected cost synergies to be realized. The total amount of goodwill related to the acquisition of Prolexic expected to be deducted for tax purposes is $62.4 million.
	The following were the identified intangible assets acquired and their respective weighted average useful lives, as determined based on preliminary valuations (in thousands, except for years):
		Gross Carrying Amount				Weighted Average Useful Life (in years)
	Completed technologies	$	26,800			6.9
	Customer-related intangible assets	58,500				10.4
	Non-compete agreements	940				3
	Trademark	800				4.9
	Total	$	87,040
	Velocius Acquisition
	On November 8, 2013, the Company acquired Velocius in exchange for $4.3 million in cash. In addition, the Company recorded a liability of $2.6 million for contingent consideration related to expected achievement of post-closing milestones. The Company acquired Velocius with a goal of complementing its hybrid cloud optimization strategy for optimizing IP application traffic across the Internet for remote and branch-end users. The Company allocated $5.4 million of the cost of the acquisition to goodwill and $2.5 million to acquired intangible assets. The allocation of the purchase price was finalized in the first quarter of 2014. The total weighted average useful life of the intangible assets acquired from Velocius is 7.9 years. The value of the goodwill from the acquisition can be attributed to a number of business factors including a trained technical workforce and cost synergies. The total amount of goodwill related to the acquisition of Velocius expected to be deducted for tax purposes is $0.5 million.
	Strategic Network Transaction
	On November 30, 2012, the Company entered into a strategic alliance with AT&T Services, Inc. ("AT&T"). Under the agreement, AT&T became a reseller of the Company's services and the Company acquired certain assets and contracted to purchase bandwidth, co-location and related services from AT&T. The total consideration is $55.0 million, of which $27.5 million was paid during the third quarter of 2013 and $27.5 million was paid during the first quarter of 2014.

Convertible_Senior_Notes

Convertible Senior Notes	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
Convertible Senior Notes	'
	Convertible Senior Notes
	In February 2014, the Company issued $690.0 million par value of convertible senior notes due 2019 (the "Notes"). The Notes are senior unsecured obligations of the Company, do not bear regular interest and mature on February 15, 2019, unless repurchased or converted prior to maturity.
	At their option, holders may convert their Notes prior to the close of business on the business day immediately preceding August 15, 2018 only under the following circumstances:
	•	during any calendar quarter commencing after the calendar quarter ending June 30, 2014 (and only during such calendar quarter), if the last reported sale price of the Company's common stock for at least 20 trading days (whether or not consecutive) during the period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day;
	•	during the five business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company's common stock and the conversion rate on each such trading day; or
	•	upon the occurrence of specified corporate events.
	On or after August 15, 2018, holders may convert all or any portion of their Notes at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date, regardless of the foregoing circumstances.
	Upon conversion, the Company, at its election, may pay or deliver to holders cash, shares of the Company's common stock or a combination of cash and shares of the Company's common stock. The initial conversion rate is 11.1651 shares of the Company's common stock per $1,000 principal amount, which is equivalent to an initial conversion price of approximately $89.56 per share, subject to adjustments in certain events, and represents a potential conversion into 7.7 million shares.
	In accounting for the issuance of the Notes, the Company separated the Notes into liability and equity components. The carrying cost of the liability component was calculated by measuring the fair value of a similar debt obligation that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was determined by deducting the fair value of the liability component from the par value of the Notes. The difference between the principal amount of the Notes and the proceeds allocated to the liability component (“debt discount”), is amortized to interest expense using the effective interest method over the term of the Notes. The equity component is recorded in additional paid-in capital in the consolidated balance sheet and will not be remeasured as long as it continues to meet the conditions for equity classification.
	In accounting for the transaction costs related to the issuance of the Notes, the Company allocated the total transaction costs incurred to the liability and equity components based on their relative values. Transaction costs attributable to the liability component are being amortized to interest expense over the term of the Notes, and transaction costs attributable to the equity component are netted with the equity component of the Notes in stockholders’ equity.
	The Notes consisted of the following components (in thousands):
		March 31, 2014
	Liability component:
	Principal	$	690,000
	Less: debt discount, net of amortization	(99,286		)
	Net carrying amount	$	590,714
	Equity component:	$	101,276
	The estimated fair value of the Company's Notes at March 31, 2014 was $683.7 million. The fair value was determined based on data points other than quoted prices that are observable, either directly or indirectly, and has been classified as Level 2 within the fair value hierarchy. Based on the closing price of the Company's common stock of $58.21 on March 31, 2014, the value of the Notes if converted to common stock was less than the principal amount of $690.0 million.
	The Company used $62.0 million of the proceeds from the offering to repurchase shares of its common stock, concurrent with the issuance of the Notes. The repurchase was made in accordance with the stock repurchase plan previously approved by the Board of Directors (Note 7). Additionally, $23.3 million of the proceeds was used for the net cost of the convertible note hedge and warrant transactions. The Company intends to use the remaining net proceeds for working capital and other general corporate purposes, as well as for potential acquisitions and strategic transactions.
	Note Hedge
	To minimize the impact of potential dilution upon conversion of the Notes, the Company entered into convertible note hedge transactions with respect to its common stock. The Company paid $101.3 million for the note hedge transactions. The note hedge transactions cover approximately 7.7 million shares of the Company’s common stock at a strike price that corresponds to the initial conversion price of the Notes, also subject to adjustment, and are exercisable upon conversion of the Notes.  The note hedge transactions are intended to reduce dilution upon potential conversion of the Notes.
	Warrants
	Separately, the Company entered into warrant transactions, whereby the Company sold warrants to acquire, subject to anti-dilution adjustments, up to 7.7 million shares of the Company’s common stock at a strike price of approximately $104.49 per share. The Company received aggregate proceeds of $78.0 million from the sale of the warrants.  The convertible note hedge and warrant transactions will generally have the effect of increasing the conversion price of the Notes to approximately $104.49 per share.
	Interest Expense
	The Notes do not bear regular interest, but have an effective interest rate of 3.2% attributable to the conversion feature. The following table sets forth total interest expense included in the statement of operations related to the Notes (in thousands):
		For the Three Months Ended March 31, 2014
	Amortization of debt discount	$	188
	Amortization of debt issuance costs	1,990
	Capitalization of interest expense	(237		)
	Total interest expense	$	1,941

Stockholders_Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2014
Stockholders' Equity Note [Abstract]	'
Stockholders' Equity	'
	Stockholders’ Equity
	Stock Repurchase Program
	In January 2013, the Board of Directors authorized a $150.0 million extension of its share repurchase program, effective for a twelve-month period beginning February 1, 2013. In October 2013, the Board of Directors authorized a new $750.0 million share repurchase program, effective from October 16, 2013 through December 31, 2016. During the three months ended March 31, 2014, the Company repurchased 2.0 million shares of its common stock for $116.1 million. During the three months ended March 31, 2013, the Company repurchased 1.1 million shares of its common stock for $40.3 million.
	Stock-Based Compensation
	The following table summarizes stock-based compensation included in the Company’s consolidated statements of operations for the three months ended March 31, 2014 and 2013 (in thousands):
		For the Three Months
		Ended March 31,
		2014			2013
	Cost of revenue	$	2,795		$	2,627
	Research and development	4,477			4,369
	Sales and marketing	10,532			9,431
	General and administrative	7,310			6,504
	Total stock-based compensation	25,114			22,931
	Provision for income taxes	(8,224		)	(6,964		)
	Total stock-based compensation, net of income taxes	$	16,890		$	15,967
	In addition to the amounts of stock-based compensation reported in the table above, the Company’s consolidated statements of operations for the three months ended March 31, 2014 and 2013 include stock-based compensation reflected as a component of amortization of capitalized internal-use software of $1.9 million, before income taxes.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Loss	3 Months Ended
	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'
Comprehensive Income	'
	Accumulated Other Comprehensive Loss
	The following table summarizes the changes in accumulated other comprehensive loss, which is reported as a component of stockholders' equity, for the three months ended March 31, 2014 (in thousands):
		Foreign Currency Translation Adjustments			Net Unrealized Gain (Loss) on Investments			Total
	Balance as of January 1, 2014	$	(6,715	)	$	4,624		$	(2,091	)
	Other comprehensive income (loss)	1,367			(913		)	454
	Balance as of March 31, 2014	$	(5,348	)	$	3,711		$	(1,637	)
	The tax effect on accumulated unrealized gain on investments was insignificant as of March 31, 2014 and December 31, 2013. Amounts reclassified from accumulated other comprehensive loss to net income were insignificant for the three months ended March 31, 2014.

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	The Company’s effective income tax rate, including discrete items, was 39.2% and 30.4% for the three months ended March 31, 2014 and 2013, respectively. The effective income tax rate is based upon estimated income for the year, the estimated composition of the income in different jurisdictions and discrete adjustments, if any, in the applicable quarterly periods, including retroactive changes in tax legislation, settlements of tax audits or assessments, the resolution or identification of tax position uncertainties and acquisitions of other companies. The discrete items in the first quarter of 2014 include a deferred tax charge, the tax effect of certain stock options and interest and penalties related to uncertain tax positions.
	For the three months ended March 31, 2014, the effective income tax rate was higher than the federal statutory tax rate mainly due to the effects of accounting for stock-based compensation in accordance with the authoritative guidance for share-based payments and state income tax. For the three months ended March 31, 2013, the effective income tax rate was lower than the federal statutory tax rate mainly due to the composition of income in foreign jurisdictions that is taxed at lower rates compared to the statutory tax rates in the United States, as well as the reinstatement of the federal research and development credit at the beginning of 2013 which was retroactive to 2012.

Net_Income_per_Share

Net Income per Share	3 Months Ended
	Mar. 31, 2014
Earnings Per Share Reconciliation [Abstract]	'
Net Income per Share	'
	Net Income per Share
	Basic net income per share is computed using the weighted average number of common shares outstanding during the applicable period. Diluted net income per share is computed using the weighted average number of common shares outstanding during the period, plus the dilutive effect of potential common stock. Potential common stock consists of shares issuable pursuant to stock options, restricted stock units (“RSUs”), deferred stock units, convertible senior notes and warrants issued by the Company. The dilutive effect of outstanding awards and convertible securities is reflected in diluted earnings per share by application of the treasury stock method.
	The following table sets forth the components used in the computation of basic and diluted net income per share for three months ended March 31, 2014 and 2013 (in thousands, except per share data):
		For the Three Months
		Ended March 31,
		2014			2013
	Numerator:
	Net income	$	72,800		$	71,487
	Denominator:
	Shares used for basic net income per share	178,705			177,899
	Effect of dilutive securities:
	Stock options	1,382			1,776
	RSUs and deferred stock units	1,951			1,887
	Convertible senior notes	—			—
	Warrants related to issuance of convertible senior notes	—			—
	Shares used for diluted net income per share	182,038			181,562
	Basic net income per share	$	0.41		$	0.4
	Diluted net income per share	$	0.4		$	0.39
	For the three months ended March 31, 2014 and 2013, certain potential outstanding shares from stock options, service-based RSUs, convertible notes and warrants were excluded from the computation of diluted net income per share because the effect of including these items would be anti-dilutive. Additionally, certain performance-based RSUs were excluded from the computation of diluted net income per share because the underlying performance conditions for such RSUs had not been met as of these dates. The number of potentially outstanding shares excluded from the computation of diluted net income per share for three months ended March 31, 2014 and 2013 are as follows (in thousands):
		For the Three Months
		Ended March 31,
		2014		2013
	Stock options	651		2,148
	Service-based RSUs	514		495
	Performance-based RSUs	575		1,148
	Convertible senior notes	7,704		—
	Warrants related to issuance of convertible senior notes	7,704		—
	The calculation of assumed proceeds used to determine the diluted weighted average shares outstanding under the treasury stock method in the periods presented was adjusted by tax windfalls and shortfalls associated with all of the Company’s outstanding stock awards. Such windfalls and shortfalls are computed by comparing the tax deductible amount of outstanding stock awards to their grant date fair values and multiplying the results by the applicable statutory tax rate. A positive result creates a windfall, which increases the assumed proceeds, and a negative result creates a shortfall, which reduces the assumed proceeds.

Nature_of_Business_and_Basis_o1

Nature of Business and Basis of Presentation (Tables)	3 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Schedule of Effect of the Revisions to the Consolidated Statements of Cash Flows	'
	The effect of the revisions to the consolidated statements of cash flows for the three months ended March 31, 2013, is as follows (in thousands):
		As Previously Reported		Adjustment		As Revised
	Cash flows from operating activities:
	Changes in operating assets and liabilities, net of effects from acquisitions:
	Prepaid expenses and other current assets	(14,035	)	2,588		(11,447	)
	Accounts payable and accrued expenses	7,838		(12,366	)	(4,528	)
	Other non-current assets and liabilities	(2,257	)	(38	)	(2,295	)
	Net cash provided by operating activities	103,040		(9,816	)	93,224
	Cash flows from investing activities:
	Purchases of property and equipment	(46,478	)	2,647		(43,831	)
	Net cash used in investing activities	(86,886	)	2,647		(84,239	)
	Cash flows from financing activities:
	Proceeds related to the issuance of common stock under stock plans	3,195		7,169		10,364
	Net cash used in financing activities	(50,279	)	7,169		(43,110	)
	Net decrease in cash and cash equivalents	(36,714	)	—		(36,714	)

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2014
Marketable Securities [Abstract]	'
Schedule of Marketable Securities	'
	The following is a summary of available-for-sale marketable securities held as of March 31, 2014 and December 31, 2013 (in thousands):
					Gross Unrealized									Classification Balance Sheet
		Amortized Cost			Gains			Losses			Aggregate			Short-Term		Long-Term
											Fair Value			Marketable		Marketable
														Securities		Securities
	As of March 31, 2014
	Certificates of deposit	$	225		$	—		$	—		$	225		$	172	$	53
	Commercial paper	24,986			—			(12		)	24,974			24,974		—
	Corporate bonds	874,265			1,087			(1,161		)	874,191			358,887		515,304
	U.S. government agency obligations	271,705			14			(434		)	271,285			65,371		205,914
		$	1,171,181		$	1,101		$	(1,607	)	$	1,170,675		$	449,404	$	721,271
	As of December 31, 2013
	Certificates of deposit	$	222		$	—		$	—		$	222		$	173	$	49
	Corporate bonds	736,945			1,197			(281		)	737,861			278,318		459,543
	U.S. government agency obligations	174,982			51			(85		)	174,948			61,514		113,434
		$	912,149		$	1,248		$	(366	)	$	913,031		$	340,005	$	573,026
Schedule of Fair Value Measurement	'
	The following table details the fair value measurements within the fair value hierarchy of the Company’s financial assets and liability at March 31, 2014 and December 31, 2013 (in thousands):
		Total Fair Value			Fair Value Measurements at Reporting Date Using
					Level 1			Level 2			Level 3
	As of March 31, 2014
	Cash Equivalents and Marketable Securities:
	Money market funds	$	21,401		$	21,401		$	—		$	—
	Certificates of deposit	225			225			—			—
	Commercial paper	48,471			—			48,471			—
	Corporate bonds	876,199			—			876,199			—
	U.S. government agency obligations	271,285			—			271,285			—
		$	1,217,581		$	21,626		$	1,195,955		$	—
	Other Assets:
	Note receivable	$	23,245		$	—		$	—		$	23,245
	Other Liabilities:
	Contingent consideration obligation related to Velocius acquisition	$	(2,600	)	$	—		$	—		$	(2,600	)
	As of December 31, 2013
	Cash Equivalents and Marketable Securities:
	Money market funds	$	40,482		$	40,482		$	—		$	—
	Certificates of deposit	3,418			3,418			—			—
	Commercial paper	29,999			—			29,999			—
	Corporate bonds	737,861			—			737,861			—
	U.S. government agency obligations	174,948			—			174,948			—
		$	986,708		$	43,900		$	942,808		$	—
	Other Assets:
	Note receivable	$	22,879		$	—		$	—		22,879
	Other Liabilities:
	Contingent consideration obligation related to Velocius acquisition	$	(2,600	)	$	—		$	—		$	(2,600	)
Schedule of Contractual Maturities of Marketable Securities and Other Investment Related Assets	'
	Contractual maturities of the Company’s available-for-sale marketable securities held at March 31, 2014 and December 31, 2013 were as follows (in thousands):
		March 31,			December 31,
		2014			2013
	Due in 1 year or less	$	449,404		$	340,005
	Due after 1 year through 5 years	721,271			573,026
		$	1,170,675		$	913,031
Schedule of Fair Value Assets and Liabilities Unobservable Input Reconciliation	'
	The following table reflects the activity for the Company’s major classes of assets and liabilities measured at fair value using Level 3 inputs for the three months ended March 31, 2014 (in thousands):
		Other Assets:			Other Liabilities:
		Note Receivable			Contingent Consideration Obligation
	Balance as of January 1, 2014	$	22,879		$	(2,600	)
	Unrealized gain on convertible note receivable included in other comprehensive income	366			—
	Balance as of March 31, 2014	$	23,245		$	(2,600	)

Accounts_Receivable_Tables

Accounts Receivable (Tables)	3 Months Ended
	Mar. 31, 2014
Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]	'
Schedule of Accounts Receivable	'
	Net accounts receivable consisted of the following as of March 31, 2014 and December 31, 2013 (in thousands):
		March 31,			December 31,
		2014			2013
	Trade accounts receivable	$	218,310		$	175,391
	Unbilled accounts receivable	90,577			100,300
	Gross accounts receivable	308,887			275,691
	Allowance for doubtful accounts	(754		)	(708		)
	Reserve for cash-basis customers	(6,179		)	(2,995		)
	Total accounts receivable reserves	(6,933		)	(3,703		)
	Accounts receivable, net	$	301,954		$	271,988

Goodwill_and_Acquired_Intangib1

Goodwill and Acquired Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Schedule of Goodwill	'
	The change in the carrying amount of goodwill for the three months ended March 31, 2014 was as follows (in thousands):
	Balance as of January 1, 2014	$	757,368
	Acquisition of Prolexic Technologies, Inc.	293,412
	Balance as of March 31, 2014	$	1,050,780
Schedule of Acquired Intangible Assets	'
	Acquired intangible assets that are subject to amortization consist of the following as of March 31, 2014 and December 31, 2013 (in thousands):
		March 31, 2014							December 31, 2013
		Gross		Accumulated Amortization			Net		Gross		Accumulated			Net
		Carrying					Carrying		Carrying		Amortization			Carrying
		Amount					Amount		Amount					Amount
	Completed technology	$	92,431	$	(38,631	)	$	53,800	$	65,631	$	(35,476	)	$	30,155
	Customer-related intangible assets	173,600		(78,708		)	94,892		115,100		(75,563		)	39,537
	Non-compete agreements	8,890		(3,060		)	5,830		7,950		(2,623		)	5,327
	Trademarks and trade names	4,200		(1,101		)	3,099		3,400		(990		)	2,410
	Acquired license rights	490		(490		)	—		490		(490		)	—
	Total	$	279,611	$	(121,990	)	$	157,621	$	192,571	$	(115,142	)	$	77,429

Business_Acquisitions_Tables

Business Acquisitions (Tables)	3 Months Ended
	Mar. 31, 2014
Business Acquisition [Line Items]	'
Schedule of Acquired Intangible Assets	'
	Acquired intangible assets that are subject to amortization consist of the following as of March 31, 2014 and December 31, 2013 (in thousands):
		March 31, 2014									December 31, 2013
		Gross				Accumulated Amortization			Net		Gross		Accumulated			Net
		Carrying							Carrying		Carrying		Amortization			Carrying
		Amount							Amount		Amount					Amount
	Completed technology	$	92,431			$	(38,631	)	$	53,800	$	65,631	$	(35,476	)	$	30,155
	Customer-related intangible assets	173,600				(78,708		)	94,892		115,100		(75,563		)	39,537
	Non-compete agreements	8,890				(3,060		)	5,830		7,950		(2,623		)	5,327
	Trademarks and trade names	4,200				(1,101		)	3,099		3,400		(990		)	2,410
	Acquired license rights	490				(490		)	—		490		(490		)	—
	Total	$	279,611			$	(121,990	)	$	157,621	$	192,571	$	(115,142	)	$	77,429
Prolexic Technologies, Inc.	'
Business Acquisition [Line Items]	'
Schedule of Preliminary Allocation of the Purchase Price	'
	The following table presents the preliminary allocation of the purchase price for Prolexic (in thousands):
	Total purchase consideration		$	392,219
	Allocation of the purchase consideration:
	Cash		$	33,072
	Accounts receivable		11,306
	Property and equipment		12,169
	Identifiable intangible assets		87,040
	Goodwill		293,412
	Deferred tax assets		16,000
	Other current and long-term assets		5,883
	Total assets acquired		458,882
	Other current liabilities		(7,501		)
	Current deferred revenue		(5,812		)
	Deferred tax liabilities		(33,723		)
	Debt, capital leases and other long-term liabilities		(19,627		)
	Total liabilities assumed		(66,663		)
	Net assets acquired		$	392,219
Schedule of Acquired Intangible Assets	'
	The following were the identified intangible assets acquired and their respective weighted average useful lives, as determined based on preliminary valuations (in thousands, except for years):
		Gross Carrying Amount				Weighted Average Useful Life (in years)
	Completed technologies	$	26,800			6.9
	Customer-related intangible assets	58,500				10.4
	Non-compete agreements	940				3
	Trademark	800				4.9
	Total	$	87,040

Convertible_Senior_Notes_Table

Convertible Senior Notes (Tables)	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
Schedule of Convertible Senior Notes	'
	The Notes consisted of the following components (in thousands):
		March 31, 2014
	Liability component:
	Principal	$	690,000
	Less: debt discount, net of amortization	(99,286		)
	Net carrying amount	$	590,714
	Equity component:	$	101,276
Schedule of Interest Expense	'
	The following table sets forth total interest expense included in the statement of operations related to the Notes (in thousands):
		For the Three Months Ended March 31, 2014
	Amortization of debt discount	$	188
	Amortization of debt issuance costs	1,990
	Capitalization of interest expense	(237		)
	Total interest expense	$	1,941

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2014
Stockholders' Equity Note [Abstract]	'
Schedule of Stock-Based Compensation Expense	'
	The following table summarizes stock-based compensation included in the Company’s consolidated statements of operations for the three months ended March 31, 2014 and 2013 (in thousands):
		For the Three Months
		Ended March 31,
		2014			2013
	Cost of revenue	$	2,795		$	2,627
	Research and development	4,477			4,369
	Sales and marketing	10,532			9,431
	General and administrative	7,310			6,504
	Total stock-based compensation	25,114			22,931
	Provision for income taxes	(8,224		)	(6,964		)
	Total stock-based compensation, net of income taxes	$	16,890		$	15,967

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Loss (Tables)	3 Months Ended
	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'
Schedule of Accumulated Other Comprehensive Income (Loss)	'
	The following table summarizes the changes in accumulated other comprehensive loss, which is reported as a component of stockholders' equity, for the three months ended March 31, 2014 (in thousands):
		Foreign Currency Translation Adjustments			Net Unrealized Gain (Loss) on Investments			Total
	Balance as of January 1, 2014	$	(6,715	)	$	4,624		$	(2,091	)
	Other comprehensive income (loss)	1,367			(913		)	454
	Balance as of March 31, 2014	$	(5,348	)	$	3,711		$	(1,637	)

Net_Income_per_Share_Tables

Net Income per Share (Tables)	3 Months Ended
	Mar. 31, 2014
Earnings Per Share Reconciliation [Abstract]	'
Schedule of Components Used in Diluted and Basic Income Per Common Share	'
	The following table sets forth the components used in the computation of basic and diluted net income per share for three months ended March 31, 2014 and 2013 (in thousands, except per share data):
		For the Three Months
		Ended March 31,
		2014			2013
	Numerator:
	Net income	$	72,800		$	71,487
	Denominator:
	Shares used for basic net income per share	178,705			177,899
	Effect of dilutive securities:
	Stock options	1,382			1,776
	RSUs and deferred stock units	1,951			1,887
	Convertible senior notes	—			—
	Warrants related to issuance of convertible senior notes	—			—
	Shares used for diluted net income per share	182,038			181,562
	Basic net income per share	$	0.41		$	0.4
	Diluted net income per share	$	0.4		$	0.39
Schedule of Shares Excluded from Computation of Diluted Earnings Per Share	'
	The number of potentially outstanding shares excluded from the computation of diluted net income per share for three months ended March 31, 2014 and 2013 are as follows (in thousands):
		For the Three Months
		Ended March 31,
		2014		2013
	Stock options	651		2,148
	Service-based RSUs	514		495
	Performance-based RSUs	575		1,148
	Convertible senior notes	7,704		—
	Warrants related to issuance of convertible senior notes	7,704		—

Nature_of_Business_and_Basis_o2

Nature of Business and Basis of Presentation - Narrative (Details)	3 Months Ended
	Mar. 31, 2014
	segment
	server
	countries
	network
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Number of servers	145,000
Number of networks	1,200
Number of countries servers are in	90
Number of industry segments	1

Nature_of_Business_and_Basis_o3

Nature of Business and Basis of Presentation - Revision of Prior Period Amounts (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Changes in operating assets and liabilities, net of effects from acquisitions:	'	'
Prepaid expenses and other current assets	($20,961)	($11,447)
Accounts payable and accrued expenses	-22,511	-4,528
Other non-current assets and liabilities	4,031	-2,295
Net cash provided by operating activities	89,023	93,224
Purchases of property and equipment	-52,011	-43,831
Net cash used in investing activities	-730,458	-84,239
Proceeds related to the issuance of common stock under stock plans	44,329	10,364
Net cash used in financing activities	555,508	-43,110
Net decrease in cash and cash equivalents	-85,165	-36,714
As previously reported [Member]	'	'
Changes in operating assets and liabilities, net of effects from acquisitions:	'	'
Prepaid expenses and other current assets	'	-14,035
Accounts payable and accrued expenses	'	7,838
Other non-current assets and liabilities	'	-2,257
Net cash provided by operating activities	'	103,040
Purchases of property and equipment	'	-46,478
Net cash used in investing activities	'	-86,886
Proceeds related to the issuance of common stock under stock plans	'	3,195
Net cash used in financing activities	'	-50,279
Net decrease in cash and cash equivalents	'	-36,714
Adjustment [Member]	'	'
Changes in operating assets and liabilities, net of effects from acquisitions:	'	'
Prepaid expenses and other current assets	'	2,588
Accounts payable and accrued expenses	'	-12,366
Other non-current assets and liabilities	'	-38
Net cash provided by operating activities	'	-9,816
Purchases of property and equipment	'	2,647
Net cash used in investing activities	'	2,647
Proceeds related to the issuance of common stock under stock plans	'	7,169
Net cash used in financing activities	'	7,169
Net decrease in cash and cash equivalents	'	$0

Fair_Value_Measurements_Narrat

Fair Value Measurements - Narrative (Details) (USD $)	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Face value of note receivable	$25,000,000

Fair_Value_Measurements_Market

Fair Value Measurements - Marketable Securities (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	$1,171,181	$912,149
Gross Unrealized Gains	1,101	1,248
Gross Unrealized Losses	-1,607	-366
Aggregate Fair Value	1,170,675	913,031
Short-Term Marketable Securities	449,404	340,005
Long-Term Marketable Securities	721,271	573,026
Certificates of deposit	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	225	222
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Aggregate Fair Value	225	222
Short-Term Marketable Securities	172	173
Long-Term Marketable Securities	53	49
Commercial paper	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	24,986	'
Gross Unrealized Gains	0	'
Gross Unrealized Losses	-12	'
Aggregate Fair Value	24,974	'
Short-Term Marketable Securities	24,974	'
Long-Term Marketable Securities	0	'
Corporate bonds	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	874,265	736,945
Gross Unrealized Gains	1,087	1,197
Gross Unrealized Losses	-1,161	-281
Aggregate Fair Value	874,191	737,861
Short-Term Marketable Securities	358,887	278,318
Long-Term Marketable Securities	515,304	459,543
U.S. government agency obligations	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	271,705	174,982
Gross Unrealized Gains	14	51
Gross Unrealized Losses	-434	-85
Aggregate Fair Value	271,285	174,948
Short-Term Marketable Securities	65,371	61,514
Long-Term Marketable Securities	$205,914	$113,434

Fair_Value_Measurements_Schedu

Fair Value Measurements - Schedule of Fair Value Measurement (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	$1,170,675	$913,031
Certificates of deposit	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	225	222
Commercial paper	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	24,974	'
Corporate bonds	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	874,191	737,861
U.S. government agency obligations	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	271,285	174,948
Total Fair Value	'	'
Cash Equivalents and Marketable Securities:	'	'
Cash equivalents and marketable securities	1,217,581	986,708
Other Assets:	'	'
Note receivable	23,245	22,879
Other Liabilities:	'	'
Contingent consideration obligation related to Velocius acquisition	-2,600	-2,600
Total Fair Value | Money market funds	'	'
Cash Equivalents and Marketable Securities:	'	'
Money market funds	21,401	40,482
Total Fair Value | Certificates of deposit	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	225	3,418
Total Fair Value | Commercial paper	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	48,471	29,999
Total Fair Value | Corporate bonds	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	876,199	737,861
Total Fair Value | U.S. government agency obligations	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	271,285	174,948
Level 1	'	'
Cash Equivalents and Marketable Securities:	'	'
Cash equivalents and marketable securities	21,626	43,900
Other Assets:	'	'
Note receivable	0	0
Other Liabilities:	'	'
Contingent consideration obligation related to Velocius acquisition	0	0
Level 1 | Money market funds	'	'
Cash Equivalents and Marketable Securities:	'	'
Money market funds	21,401	40,482
Level 1 | Certificates of deposit	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	225	3,418
Level 1 | Commercial paper	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	0	0
Level 1 | Corporate bonds	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	0	0
Level 1 | U.S. government agency obligations	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	0	0
Level 2	'	'
Cash Equivalents and Marketable Securities:	'	'
Cash equivalents and marketable securities	1,195,955	942,808
Other Assets:	'	'
Note receivable	0	0
Other Liabilities:	'	'
Contingent consideration obligation related to Velocius acquisition	0	0
Level 2 | Money market funds	'	'
Cash Equivalents and Marketable Securities:	'	'
Money market funds	0	0
Level 2 | Certificates of deposit	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	0	0
Level 2 | Commercial paper	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	48,471	29,999
Level 2 | Corporate bonds	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	876,199	737,861
Level 2 | U.S. government agency obligations	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	271,285	174,948
Level 3	'	'
Cash Equivalents and Marketable Securities:	'	'
Cash equivalents and marketable securities	0	0
Other Assets:	'	'
Note receivable	23,245	22,879
Other Liabilities:	'	'
Contingent consideration obligation related to Velocius acquisition	-2,600	-2,600
Level 3 | Money market funds	'	'
Cash Equivalents and Marketable Securities:	'	'
Money market funds	0	0
Level 3 | Certificates of deposit	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	0	0
Level 3 | Commercial paper	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	0	0
Level 3 | Corporate bonds	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	0	0
Level 3 | U.S. government agency obligations	'	'
Cash Equivalents and Marketable Securities:	'	'
Aggregate Fair Value	$0	$0

Fair_Value_Measurements_Contra

Fair Value Measurements - Contractual Maturities (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value Disclosures [Abstract]	'	'
Due in 1 year or less	$449,404	$340,005
Due after 1 year through 5 years	721,271	573,026
Aggregate fair value	$1,170,675	$913,031

Fair_Value_Measurements_Schedu1

Fair Value Measurements - Schedule of Activity of Major Classes of Assets Measured at Fair Value Using Level 3 Inputs (Details) (Level 3, USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014
Level 3	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'
Balance as of January 1, 2014, other assets	$22,879
Balance as of January 1, 2014, other liabilities	-2,600
Unrealized gain on convertible note receivable included in other comprehensive income	366
Balance as of March 31, 2014, other assets	23,245
Balance as of March 31, 2014, other liabilities	($2,600)

Accounts_Receivable_Schedule_o

Accounts Receivable - Schedule of Accounts Receivable (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Gross accounts receivable	$308,887	$275,691
Allowance for doubtful accounts	-754	-708
Reserve for cash-basis customers	-6,179	-2,995
Total accounts receivable reserves	-6,933	-3,703
Accounts receivable, net	301,954	271,988
Trade accounts receivable	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Gross accounts receivable	218,310	175,391
Unbilled accounts receivable	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Gross accounts receivable	$90,577	$100,300

Goodwill_and_Acquired_Intangib2

Goodwill and Acquired Intangible Assets - Schedule of Goodwill (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014
Schedule of Goodwill	'
Balance as of January 1, 2014	$757,368
Acquisition of Prolexic Technologies, Inc.	293,412
Balance as of March 31, 2014	$1,050,780

Goodwill_and_Acquired_Intangib3

Goodwill and Acquired Intangible Assets - Schedule of Acquired Intangible Assets (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Finite-Lived Intangible Assets [Line Items]	'	'
Gross Carrying Amount	$279,611	$192,571
Accumulated Amortization	-121,990	-115,142
Net Carrying Amount	157,621	77,429
Completed technology	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Gross Carrying Amount	92,431	65,631
Accumulated Amortization	-38,631	-35,476
Net Carrying Amount	53,800	30,155
Customer-related intangible assets	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Gross Carrying Amount	173,600	115,100
Accumulated Amortization	-78,708	-75,563
Net Carrying Amount	94,892	39,537
Non-compete agreements	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Gross Carrying Amount	8,890	7,950
Accumulated Amortization	-3,060	-2,623
Net Carrying Amount	5,830	5,327
Trademarks and trade names	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Gross Carrying Amount	4,200	3,400
Accumulated Amortization	-1,101	-990
Net Carrying Amount	3,099	2,410
Acquired license rights	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Gross Carrying Amount	490	490
Accumulated Amortization	-490	-490
Net Carrying Amount	$0	$0

Goodwill_and_Acquired_Intangib4

Goodwill and Acquired Intangible Assets - Narrative (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'	'
Amortization of acquired intangible assets	$6,848,000	$6,060,000
Future amortization expense to be recognized in remainder of 2014	25,200,000	'
Future amortization expense 2015	26,800,000	'
Future amortization expense 2016	25,200,000	'
Future amortization expense 2017	23,100,000	'
Future amortization expense 2018	$16,200,000	'

Business_Acquisitions_Narrativ

Business Acquisitions - Narrative (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Feb. 18, 2014	Nov. 08, 2013	Nov. 30, 2012	Mar. 31, 2014	Sep. 30, 2013
			Prolexic Technologies, Inc.	Velocius	Strategic Network Acquisition	Strategic Network Acquisition	Strategic Network Acquisition
Business Acquisition [Line Items]	'	'	'	'	'	'	'
Total purchase consideration	'	'	$392,219,000	$4,300,000	$55,000,000	'	'
Acquisition-related costs	'	'	3,900,000	'	'	'	'
Contingent consideration liability	'	'	'	2,600,000	'	'	'
Allocated to goodwill	1,050,780,000	757,368,000	293,412,000	5,400,000	'	'	'
Allocated to intangible assets	'	'	87,040,000	2,500,000	'	'	'
Weighted Average Useful Life (in years)	'	'	'	'7 years 10 months 24 days	'	'	'
Goodwill, expected tax deductible amount	'	'	62,400,000	500,000	'	'	'
Consideration paid	'	'	'	'	'	$27,500,000	$27,500,000

Business_Acquisitions_Schedule

Business Acquisitions - Schedule of Preliminary Allocation of the Purchase Price (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Feb. 18, 2014
			Prolexic Technologies, Inc.
Business Acquisition [Line Items]	'	'	'
Total purchase consideration	'	'	$392,219,000
Allocation of the purchase consideration:	'	'	'
Cash	'	'	33,072,000
Accounts receivable	'	'	11,306,000
Property and equipment	'	'	12,169,000
Identifiable intangible assets	'	'	87,040,000
Goodwill	1,050,780,000	757,368,000	293,412,000
Deferred tax assets	'	'	16,000,000
Other current and long-term assets	'	'	5,883,000
Total assets acquired	'	'	458,882,000
Other current liabilities	'	'	-7,501,000
Current deferred revenue	'	'	-5,812,000
Deferred tax liabilities	'	'	-33,723,000
Debt, capital leases and other long-term liabilities	'	'	-19,627,000
Total liabilities assumed	'	'	-66,663,000
Net assets acquired	'	'	$392,219,000

Business_Acquisitions_Schedule1

Business Acquisitions - Schedule of Acquired Intangible Assets (Details) (Prolexic Technologies, Inc., USD $)	0 Months Ended
In Thousands, unless otherwise specified	Feb. 18, 2014
Business Acquisition [Line Items]	'
Gross Carrying Amount	$87,040
Completed technology	'
Business Acquisition [Line Items]	'
Gross Carrying Amount	26,800
Weighted Average Useful Life (in years)	'6 years 10 months 24 days
Customer-related intangible assets	'
Business Acquisition [Line Items]	'
Gross Carrying Amount	58,500
Weighted Average Useful Life (in years)	'10 years 4 months 18 days
Non-compete agreements	'
Business Acquisition [Line Items]	'
Gross Carrying Amount	940
Weighted Average Useful Life (in years)	'3 years
Trademarks and trade names	'
Business Acquisition [Line Items]	'
Gross Carrying Amount	$800
Weighted Average Useful Life (in years)	'4 years 10 months 24 days

Convertible_Senior_Notes_Narra

Convertible Senior Notes - Narrative (Details) (USD $)	1 Months Ended	3 Months Ended
Share data in Millions, except Per Share data, unless otherwise specified	Feb. 28, 2014	Mar. 31, 2014	Mar. 31, 2013
	D
Debt Instrument [Line Items]	'	'	'
Debt issued	$690,000,000	$690,000,000	'
Conversion rate (in shares)	11.1651	'	'
Principal amount per conversion	1,000	'	'
Conversion price (in dollars per share)	$89.56	'	'
Potential shares to be converted (in shares)	7.7	'	'
Threshold trading days exceeding price	20	'	'
Threshold consecutive trading days exceeding price	'30 days	'	'
Threshold greater than percentage of stock price trigger	130.00%	'	'
Threshold trading days not exceeding price	5	'	'
Threshold consecutive trading days not exceeding price	'5 days	'	'
Threshold less than percentage of stock price trigger	98.00%	'	'
Fair value of note receivable	'	683,700,000	'
Closing price of common stock (in dollars per share)	'	$58.21	'
Repurchases of common stock	62,000,000	116,147,000	40,278,000
Payments for purchase of convertible note hedge and warrant transactions	23,300,000	'	'
Payments for note hedge transactions	101,300,000	101,292,000	0
Warrant strike price (in dollars per share)	104.49	'	'
Proceeds from sale of warrants	$78,000,000	$77,970,000	$0
Effective interest rate	3.20%	'	'

Convertible_Senior_Notes_Sched

Convertible Senior Notes - Schedule of Convertible Senior Notes (Details) (USD $)	Mar. 31, 2014	Feb. 28, 2014	Dec. 31, 2013
Liability component:	'	'	'
Principal	$690,000,000	$690,000,000	'
Less: debt discount, net of amortization	-99,286,000	'	'
Net carrying amount	590,714,000	'	0
Convertible senior notes	'	'	'
Liability component:	'	'	'
Equity component	$101,276,000	'	'

Convertible_Senior_Notes_Sched1

Convertible Senior Notes - Schedule of Interest Expense (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Debt Disclosure [Abstract]	'	'
Amortization of debt discount	$188	'
Amortization of debt issuance costs	1,990	'
Capitalization of interest expense	-237	'
Interest expense	$1,941	$0

Stockholders_Equity_Narrative_

Stockholders' Equity - Narrative (Details) (USD $)	1 Months Ended		3 Months Ended
Share data in Millions, unless otherwise specified	Oct. 31, 2013	Jan. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Stockholders' Equity Note [Abstract]	'	'	'	'
Stock repurchase program, authorized amount	$750,000,000	$150,000,000	'	'
Shares repurchased during period (in shares)	'	'	2	1.1
Value of shares repurchased during period	'	'	116,100,000	40,300,000
Amortization expense from capitalized stock-based compensation	'	'	$1,900,000	'

Stockholders_Equity_Schedule_o

Stockholders' Equity - Schedule of Stock Based Compensation Expense (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Total stock-based compensation	$25,114	$22,931
Provision for income taxes	-8,224	-6,964
Total stock-based compensation, net of income taxes	16,890	15,967
Cost of revenues	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Total stock-based compensation	2,795	2,627
Research and development	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Total stock-based compensation	4,477	4,369
Sales and marketing	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Total stock-based compensation	10,532	9,431
General and administrative	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Total stock-based compensation	$7,310	$6,504

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Income Loss (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Accumulated Other Comprehensive Loss [Roll Forward]	'	'
Balance as of January 1, 2014	($2,091)	'
Other comprehensive income (loss)	454	-3,943
Balance as of March 31, 2014	-1,637	'
Foreign Currency Translation Adjustments	'	'
Accumulated Other Comprehensive Loss [Roll Forward]	'	'
Balance as of January 1, 2014	-6,715	'
Other comprehensive income (loss)	1,367	'
Balance as of March 31, 2014	-5,348	'
Net Unrealized Gain (Loss) on Investments	'	'
Accumulated Other Comprehensive Loss [Roll Forward]	'	'
Balance as of January 1, 2014	4,624	'
Other comprehensive income (loss)	-913	'
Balance as of March 31, 2014	$3,711	'

Income_Taxes_Narrative_Details

Income Taxes - Narrative (Details)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Tax Disclosure [Abstract]	'	'
Effective income tax rate	39.20%	30.40%

Net_Income_per_Share_Schedule_

Net Income per Share - Schedule of Components Used in Diluted and Basic Income Per Common Share (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Numerator [Abstract]	'	'
Net income	$72,800	$71,487
Denominator [Abstract]	'	'
Shares used for basic net income per share (in shares)	178,705	177,899
Effect of dilutive securities:	'	'
Convertible senior notes	0	0
Warrants related to issuance of convertible senior notes	0	0
Shares used for diluted net income per share (in shares)	182,038	181,562
Basic net income per share (in dollars per share)	$0.41	$0.40
Diluted net income per share (in dollars per share)	$0.40	$0.39
Stock options	'	'
Effect of dilutive securities:	'	'
Dilutive securities	1,382	1,776
RSUs and deferred stock units	'	'
Effect of dilutive securities:	'	'
Dilutive securities	1,951	1,887

Net_Income_per_Share_Schedule_1

Net Income per Share - Schedule of Shares Excluded from Computation of Diluted EPS (Details)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Stock options	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Anti-dilutive securities	651	2,148
Service-based RSUs	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Anti-dilutive securities	514	495
Performance-based RSUs	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Anti-dilutive securities	575	1,148
Convertible senior notes	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Anti-dilutive securities	7,704	0
Warrants related to issuance of convertible senior notes	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Anti-dilutive securities	7,704	0