Twitter (TWTR) 10-Q 6 Nov 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 31, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'TWTR	'
Entity Registrant Name	'TWITTER, INC.	'
Entity Central Index Key	'0001418091	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Non-accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	634,511,461

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$2,252,795	$841,010
Short-term investments	1,394,887	1,393,044
Accounts receivable, net of allowance for doubtful accounts of $4,102 and $2,020 as of September 30, 2014 and December 31, 2013, respectively	324,731	247,328
Prepaid expenses and other current assets	201,472	93,297
Total current assets	4,173,885	2,574,679
Property and equipment, net	503,958	332,662
Intangible assets	115,346	77,627
Goodwill	622,638	363,477
Other assets	32,827	17,795
Total assets	5,448,654	3,366,240
Current liabilities:	'	'
Accounts payable	30,619	27,994
Accrued and other current liabilities	301,330	110,310
Capital leases, short-term	110,527	87,126
Total current liabilities	442,476	225,430
Convertible notes	1,293,604	'
Capital leases, long-term	121,621	110,520
Deferred and other long-term tax liabilities, net	29,420	59,500
Other long-term liabilities	36,495	20,784
Total liabilities	1,923,616	416,234
Commitments and contingencies (Note 12)	'	'
Stockholders' equity:	'	'
Common stock, $0.000005 par value-- 5,000,000 shares authorized; 632,158 and 569,922 shares issued and outstanding as of September 30, 2014 and December 31, 2013, respectively	3	3
Additional paid-in capital	4,973,349	3,944,952
Accumulated other comprehensive loss	-1,220	-323
Accumulated deficit	-1,447,094	-994,626
Total stockholders' equity	3,525,038	2,950,006
Total liabilities and stockholders' equity	$5,448,654	$3,366,240

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Statement Of Financial Position [Abstract]	'	'
Allowance for doubtful accounts receivable	$4,102	$2,020
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	5,000,000,000	5,000,000,000
Common stock, shares issued	632,158,000	569,922,000
Common stock, shares outstanding	632,158,000	569,922,000

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]	'	'	'	'
Revenue	$361,266	$168,580	$923,924	$422,215
Costs and expenses	'	'	'	'
Cost of revenue	124,166	62,239	309,696	154,067
Research and development	183,342	87,307	509,828	199,144
Sales and marketing	164,015	61,214	410,511	138,911
General and administrative	51,174	21,152	134,602	56,248
Total costs and expenses	522,697	231,912	1,364,637	548,370
Loss from operations	-161,431	-63,332	-440,713	-126,155
Interest income (expense), net	-5,795	-1,727	-10,472	-4,473
Other income (expense), net	-8,079	818	-5,501	-1,730
Loss before income taxes	-175,305	-64,241	-456,686	-132,358
Provision (benefit) for income taxes	159	360	-4,218	1,494
Net loss	($175,464)	($64,601)	($452,468)	($133,852)
Net loss per share attributable to common stockholders:	'	'	'	'
Basic	($0.29)	($0.48)	($0.76)	($1.02)
Diluted	($0.29)	($0.48)	($0.76)	($1.02)
Weighted-average shares used to compute net loss per share attributable to common stockholders:	'	'	'	'
Basic	614,395	133,699	596,722	131,196
Diluted	614,395	133,699	596,722	131,196

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement Of Income And Comprehensive Income [Abstract]	'	'	'	'
Net loss	($175,464)	($64,601)	($452,468)	($133,852)
Other comprehensive income (loss):	'	'	'	'
Unrealized gain (loss) on investments in available-for-sale securities, net of tax	-153	42	-231	10
Foreign currency translation adjustment	-1,266	268	-666	304
Net change in accumulated other comprehensive loss	-1,419	310	-897	314
Comprehensive loss	($176,883)	($64,291)	($453,365)	($133,538)

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities	'	'
Net loss	($452,468)	($133,852)
Adjustments to reconcile net loss to net cash provided by operating activities:	'	'
Depreciation and amortization	145,737	77,670
Stock-based compensation expense	454,382	79,170
Provision for bad debt	2,944	758
Deferred income tax benefit	-9,737	-492
Non-cash acquisition-related costs	320	566
Amortization of investment premium and other	9,420	2,124
Amortization of discount on convertible notes	2,411	'
Changes in assets and liabilities, net of assets acquired and liabilities assumed from acquisitions:	'	'
Accounts receivable	-77,833	-34,262
Prepaid expenses and other assets	-140,710	-2,410
Accounts payable	5,298	-8,292
Accrued and other liabilities	98,714	23,286
Net cash provided by operating activities	38,478	4,266
Cash flows from investing activities	'	'
Purchases of property and equipment	132,839	46,628
Purchases of marketable securities	-1,617,415	-281,574
Proceeds from maturities of marketable securities	1,522,582	300,167
Proceeds from sales of marketable securities	168,168	34,765
Restricted cash	-11,029	-7,541
Business combinations, net of cash acquired and purchases of intangible assets	-165,177	-8,072
Net cash used in investing activities	-235,710	-8,883
Cash flows from financing activities	'	'
Proceeds from issuance of convertible notes	1,800,000	'
Convertible notes initial issuance discount	-27,475	'
Purchases of convertible note hedges	-387,450	'
Proceeds from issuance of warrants	275,130	'
Taxes paid related to net share settlement of equity awards	-16,168	'
Repayments of capital lease obligations	-75,076	-49,242
Proceeds from exercise of stock options, net of repurchase	25,027	6,937
Proceeds from issuances of common stock under employee stock purchase plan	21,224	'
Other financing activities	-2,662	-1,125
Net cash provided by (used in) financing activities	1,612,550	-43,430
Net increase (decrease) in cash and cash equivalents	1,415,318	-48,047
Foreign exchange effect on cash and cash equivalents	-3,533	423
Cash and cash equivalents at beginning of period	841,010	203,328
Cash and cash equivalents at end of period	2,252,795	155,704
Supplemental disclosures of non-cash investing and financing activities	'	'
Common and convertible preferred stock issued in connection with acquisitions	147,958	112,945
Equipment purchases under capital leases	110,409	95,500
Changes in accrued equipment purchases	14,345	16,522
Unpaid deferred offering costs	'	$2,786

Description_of_Business_and_Su

Description of Business and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]	'
Description of Business and Summary of Significant Accounting Policies	'
	Note 1. Description of Business and Summary of Significant Accounting Policies
	Twitter, Inc. (“Twitter” or the “Company”) was incorporated in Delaware in April 2007, and is headquartered in San Francisco, California. Twitter is a public platform where any user can create a Tweet and any user can follow other users. Each Tweet is limited to 140 characters of text, but can also contain rich media, including photos, videos and applications.
	Convertible Notes Offering
	In September 2014, the Company issued $900.0 million principal amount of 0.25% convertible senior notes due 2019 (the “2019 Notes”) and $900.0 million principal amount of 1.00% convertible senior notes due 2021 (the “2021 Notes” and together with the 2019 Notes, the “Notes”) in a private placement to qualified institutional buyers pursuant to Rule144A under the Securities Act of 1933, as amended. The total net proceeds from this offering, after deducting initial purchasers’ discount and debt issuance costs, were approximately $1.77 billion.
	Concurrently with the issuance of the 2019 Notes and 2021 Notes, the Company entered into convertible note hedge transactions for which it paid $387.5 million. In addition, the Company sold warrants for which it received $275.1 million.
	Basis of Presentation
	The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation.
	The accompanying unaudited consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”). The unaudited interim consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and reflect, in management’s opinion, all adjustments of a normal, recurring nature that are necessary for the fair statement of the Company’s financial position, results of operations and cash flows for the interim periods, but are not necessarily indicative of the results expected for the full fiscal year or any other period.
	The accompanying interim consolidated financial statements and these related notes should be read in conjunction with the consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013.
	Use of Estimates
	The preparation of the Company’s consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses, as well as related disclosure of contingent assets and liabilities. The Company bases its estimates on past experience and other assumptions that the Company believes are reasonable under the circumstances, and the Company evaluates these estimates on an ongoing basis. Actual results could differ materially from the Company’s estimates. To the extent that there are material differences between these estimates and actual results, the Company’s financial condition or operating results will be affected.
	Recent Accounting Pronouncements
	In July 2013, the Financial Accounting Standards Board (“FASB”) issued a new accounting standard update on the financial statement presentation of unrecognized tax benefits. The new guidance provides that a liability related to an unrecognized tax benefit would be presented as a reduction of a deferred tax asset for a net operating loss carryforward, a similar tax loss or a tax credit carryforward, if such settlement is required or expected in the event the uncertain tax position is disallowed. The Company adopted this guidance prospectively for unrecognized tax benefits as of January 1, 2014. The application of this guidance resulted in a $15.8 million decrease in net deferred tax assets and the related liability for unrecognized tax benefits upon adoption.
	In May 2014, the FASB issued a new accounting standard update on revenue recognition from contracts with customers. The new guidance will replace all current U.S. GAAP guidance on this topic and eliminate all industry-specific guidance.  According to the new guidance, revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration for which the Company expects to be entitled in exchange for those goods or services. This guidance will be effective for the Company beginning January 1, 2017 and can be applied either retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. Early adoption is not permitted. The Company has not yet selected a transition method and is evaluating the impact of adopting this new accounting standard update on the financial statements and related disclosures.
	In June 2014, the FASB issued a new accounting standard update on stock-based compensation when the terms of an award provide that a performance target could be achieved after the requisite service period. The new guidance requires that a performance target that affects vesting, and that could be achieved after the requisite service period, be treated as a performance condition. As such, the performance target should not be reflected in estimating the grant date fair value of the award. This update further clarifies that compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the periods for which the requisite service has already been rendered. This guidance will be effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015 and can be applied either prospectively or retrospectively to all awards outstanding as of the beginning of the earliest annual period presented as an adjustment to opening retained earnings. Early adoption is permitted. Adoption of this new accounting standard update is expected to have no impact to the Company’s financial statements.

Cash_Cash_Equivalents_and_Shor

Cash, Cash Equivalents and Short-term Investments	9 Months Ended
	Sep. 30, 2014
Cash And Cash Equivalents [Abstract]	'
Cash, Cash Equivalents and Short-term Investments	'
	Note 2. Cash, Cash Equivalents and Short-term Investments
	Cash, cash equivalents and short-term investments consist of the following (in thousands):
		September 30,		December 31,
		2014		2013
	Cash and cash equivalents:
	Cash	$	1,626,946	$	164,135
	Money market funds		330,849		229,529
	U.S. government and agency securities including treasury bills		141,549		251,593
	Corporate notes and commercial paper		153,451		195,753
	Total cash and cash equivalents	$	2,252,795	$	841,010
	Short-term investments:
	U.S. government and agency securities including treasury bills	$	652,936	$	785,536
	Corporate notes, certificates of deposit and commercial paper		741,951		607,508
	Total short-term investments	$	1,394,887	$	1,393,044
	The following tables summarize unrealized gains and losses related to available-for-sale securities classified as short-term investments on the Company’s consolidated balance sheets (in thousands):
		30-Sep-14
		Gross		Gross			Gross			Aggregated
		Amortized		Unrealized			Unrealized			Estimated
		Costs		Gains			Losses			Fair Value
	U.S. Government and agency securities including	$	652,908	$	50		$	(22	)	$	652,936
	treasury bills
	Corporate notes, certificates of deposit and		742,290		27			(366	)		741,951
	commercial paper
	Total available-for-sale securities classified as	$	1,395,198	$	77		$	(388	)	$	1,394,887
	short-term investments
		31-Dec-13
		Gross		Gross			Gross			Aggregated
		Amortized		Unrealized			Unrealized			Estimated
		Costs		Gains			Losses			Fair Value
	U.S. Government and agency securities including	$	785,535	$	22		$	(21	)	$	785,536
	treasury bills
	Corporate notes, certificates of deposit and		607,590		11			(93	)		607,508
	commercial paper
	Total available-for-sale securities classified as	$	1,393,125	$	33		$	(114	)	$	1,393,044
	short-term investments
	The securities classified as cash and cash equivalents on the consolidated balance sheets are not included in the tables above as the gross unrealized gains and losses were immaterial for each period and the carrying value approximates fair value because of the short maturity period of these instruments.
	The following tables show all short-term investments in an unrealized loss position for which other-than-temporary impairment has not been recognized and the related gross unrealized losses and fair value, aggregated by investment category and the length of time that individual securities have been in a continuous unrealized loss position (in thousands):
		30-Sep-14
		Less than 12 Months					12 Months or Greater					Total
				Unrealized						Unrealized				Unrealized
		Fair Value		Loss			Fair Value			Loss		Fair Value		Loss
	U.S. Government and agency securities	$	219,392	$	(22	)	$	—		$	—	$	219,392	$	(22	)
	including treasury bills
	Corporate notes, certificates of deposit		445,403		(366	)		—			—		445,403		(366	)
	and commercial paper
	Total short-term investments in an	$	664,795	$	(388	)	$	—		$	—	$	664,795	$	(388	)
	unrealized loss position
		31-Dec-13
		Less than 12 Months					12 Months or Greater					Total
				Unrealized						Unrealized				Unrealized
		Fair Value		Loss			Fair Value			Loss		Fair Value		Loss
	U.S. Government and agency securities	$	230,478	$	(21	)	$	—		$	—	$	230,478	$	(21	)
	including treasury bills
	Corporate notes, certificates of deposit		171,894		(93	)		—			—		171,894		(93	)
	and commercial paper
	Total short-term investments in an	$	402,372	$	(114	)	$	—		$	—	$	402,372	$	(114	)
	unrealized loss position
	Investments are reviewed periodically to identify possible other-than-temporary impairments. No impairment loss has been recorded on the securities included in the tables above as the Company believes that the decrease in fair value of these securities is temporary and expects to recover up to (or beyond) the initial cost of investment for these securities.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Note 3. Fair Value Measurements
	The following tables set forth the fair value of the Company’s financial assets and liabilities measured at fair value on a recurring basis as of September 30, 2014 and December 31, 2013 based on the three-tier fair value hierarchy (in thousands):
		30-Sep-14
		Level 1		Level 2		Level 3		Total
	Assets
	Cash equivalents:
	Money market funds	$	330,849	$	—	$	—	$	330,849
	Treasury bills		141,549		—		—		141,549
	Commercial paper		—		153,451		—		153,451
	Short-term investments:
	Treasury bills		68,474		—		—		68,474
	Commercial paper		—		164,033		—		164,033
	Corporate notes		—		532,332		—		532,332
	U.S. government securities		—		584,462		—		584,462
	Certificates of deposit		—		45,586		—		45,586
	Total	$	540,872	$	1,479,864	$	—	$	2,020,736
		31-Dec-13
		Level 1		Level 2		Level 3		Total
	Assets
	Cash equivalents:
	Money market funds	$	229,529	$	—	$	—	$	229,529
	Treasury bills		244,048		—		—		244,048
	Commercial paper		—		194,742		—		194,742
	U.S. government securities		—		7,545		—		7,545
	Corporate notes		—		1,011		—		1,011
	Short-term investments:
	Treasury bills		265,878		—		—		265,878
	Agency securities		—		18,286		—		18,286
	Commercial paper		—		272,617		—		272,617
	Corporate notes		—		255,546		—		255,546
	U.S. government securities		—		501,372		—		501,372
	Certificates of deposit		—		79,345		—		79,345
	Total	$	739,455	$	1,330,464	$	—	$	2,069,919
	The fair value of the Company’s Level 1 financial assets is based on quoted market prices of the identical underlying security. The fair value of the Company’s Level 2 financial assets is based on inputs that are directly or indirectly observable in the market, including the readily-available pricing sources for the identical underlying security that may not be actively traded.
	The estimated fair value of our 2019 Notes and 2021 Notes based on a market approach was approximately $879.9 million and $882.3 million respectively, which represents a Level 2 valuation.  The estimated fair value was determined based on the quoted closing price of the Notes in an over-the-counter market on September 30, 2014.

Property_and_Equipment_Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2014
Property Plant And Equipment [Abstract]	'
Property and Equipment, Net	'
	Note 4. Property and Equipment, Net
	The following table presents the detail of property and equipment, net for the periods presented (in thousands):
		September 30,			December 31,
		2014			2013
	Property and equipment, net
	Equipment	$	535,092		$	367,949
	Furniture and leasehold improvements		113,069			54,965
	Capitalized software		78,436			47,290
	Construction in progress		61,743			29,523
	Total		788,340			499,727
	Less: Accumulated depreciation and amortization		(284,382	)		(167,065	)
	Property and equipment, net	$	503,958		$	332,662

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2014
Goodwill And Intangible Assets Disclosure [Abstract]	'
Goodwill and Other Intangible Assets	'
	Note 5. Goodwill and Other Intangible Assets
	The following table presents the goodwill activities for the periods presented (in thousands):
	Goodwill
	Balance as of December 31, 2013	$	363,477
	Gnip acquisition		104,747
	Other acquisitions		155,054
	Foreign currency translation adjustment		(640	)
	Balance as of September 30, 2014	$	622,638
	For each of the period presented, gross goodwill balance equaled the net balance since no impairment charges have been recorded.
	The following table presents the detail of other intangible assets for the periods presented (in thousands):
		Gross Carrying			Accumulated			Net Carrying
		Value			Amortization			Value
	September 30, 2014:
	Patents and developed technologies	$	153,497		$	(64,170	)	$	89,327
	Publisher and advertiser relationships		32,000			(7,439	)		24,561
	Assembled workforce		1,960			(1,092	)		868
	Other intangible assets		1,100			(510	)		590
	Total	$	188,557		$	(73,211	)	$	115,346
	December 31, 2013:
	Patents and developed technologies	$	100,553		$	(45,440	)	$	55,113
	Publisher and advertiser relationships		21,100			(1,248	)		19,852
	Assembled workforce		1,960			(300	)		1,660
	Other intangible assets		1,100			(98	)		1,002
	Total	$	124,713		$	(47,086	)	$	77,627
	Amortization expense associated with other intangible assets for the three months ended September 30, 2014 and 2013 was $11.8 million and $3.8 million, respectively, and for the nine months ended September 30, 2014 and 2013 was $26.1 million and $11.0 million, respectively.
	Estimated future amortization expense as of September 30, 2014 is as follows (in thousands):
	Remainder of 2014	$	10,095
	2015		35,555
	2016		26,391
	2017		11,624
	2018		9,832
	Thereafter		21,849
	Total	$	115,346

Other_Balance_Sheet_Components

Other Balance Sheet Components	9 Months Ended
	Sep. 30, 2014
Statement Of Financial Position [Abstract]	'
Other Balance Sheet Components	'
	Note 6. Other Balance Sheet Components
	Prepaid and other current assets
	The following table presents the detail of prepaid and other current assets for the periods presented (in thousands):
		September 30,		December 31,
		2014		2013
	Deferred income taxes, net	$	31,107	$	62,122
	Prepaid and other		170,365		31,175
	Total	$	201,472	$	93,297
	Accrued and other current liabilities
	The following table presents the detail of accrued and other current liabilities for the periods presented (in thousands):
		September 30,		December 31,
		2014		2013
	Accrued compensation	$	82,970	$	29,882
	Unsettled purchases of marketable securities		76,670		—
	Accrued fixed assets and maintenance		30,166		5,697
	Deferred revenue		21,881		14,479
	Accrued publisher payments		20,819		15,370
	Accrued professional services		10,301		7,089
	Accrued tax liabilities		17,341		9,515
	Accrued other		41,182		28,278
	Total	$	301,330	$	110,310

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2014
Business Combinations [Abstract]	'
Acquisitions	'
	Note 7. Acquisitions
	In May 2014, the Company completed its acquisition of privately held Gnip, Inc. (“Gnip”), a leading provider of social data and analytics headquartered in Boulder, Colorado. The acquisition is expected to allow the Company to further enhance its data analytics capabilities. Under the terms of the acquisition, the Company agreed to pay $107.3 million in cash and issue a total of 0.6 million shares of its common stock, including shares of restricted stock subject to continued employment, in consideration for all of the issued and outstanding shares of capital stock of Gnip.  In addition, the Company agreed to issue up to 0.4 million shares of the Company’s common stock as a result of assumed Gnip equity awards held by individuals, who will continue to provide services to the Company. The fair value of the total consideration of $134.1 million, including the earned portion of assumed stock options and other equity awards, was preliminarily allocated to the acquired tangible and intangible assets and assumed liabilities based on their estimated fair values at closing as follows: $23.2 million to developed technology, $9.3 million to customer relationships, $9.1 million to tangible assets acquired, $5.8 million to liabilities assumed, $6.4 million to deferred tax liability recorded, and the excess $104.7 million of the purchase price over the fair value of net assets acquired was recorded as goodwill. This goodwill is primarily attributable to the potential expansion and future development of the Company’s data products, expected synergies arising from the acquisition and the value of acquired talent. Goodwill is not expected to be deductible for U.S. income tax purposes. Both developed technology and customer relationships will be amortized on a straight-line basis over their estimated useful life of 60 months. The discounted cash flow method, which calculates the fair value of an asset based on the value of cash flows that the asset is expected to generate in the future, was used to estimate the fair value of these intangible assets acquired.
	During the nine months ended September 30, 2014, the Company acquired eight other companies, which were accounted for as business combinations. The total purchase price of $188.1 million (paid in shares of the Company’s common stock having a total fair value of $121.2 million and cash of $66.9 million) for these acquisitions was preliminarily allocated as follows: $28.1 million to developed technologies, $1.6 million to customer relationships, $6.5 million to net tangible assets acquired based on their estimated fair value on the acquisition date, $3.2 million to deferred tax liability, and the excess $155.1 million of the purchase price over the fair value of net assets acquired to goodwill. Goodwill resulting from these acquisitions is not expected to be deductible for U.S. income tax purposes. Developed technologies and customer relationships will be amortized on a straight-line basis over their estimated useful lives of 12 to 48 months.
	In connection with all of the acquisitions completed during the nine months ended September 30, 2014, the Company also agreed to pay cash and shares of the Company’s common stock with a total fair value up to $97.7 million, which is to be paid to certain employees of the acquired entities contingent upon their continued employment with the Company. The Company recognizes compensation expense related to the cash and equity consideration over the requisite services periods of up to 48 months from the respective acquisition dates on a straight-line basis. In addition, the Company will recognize approximately $16.9 million of stock-based compensation expense in relation to these assumed stock options over the remaining requisite service periods of up to 48 months from the respective acquisition dates on a straight-line basis, excluding the fair value of the assumed stock options that was allocated and recorded as part of the purchase price for the portion of the service period completed prior to the closing of the applicable acquisition.
	The results of operations for each of these acquisitions have been included in the Company’s consolidated statements of operations since the date of acquisition. Pro forma revenue and results of operations for these acquisitions have not been presented because they do not have a material impact to the consolidated revenue and results of operations, either individually or in aggregate.

Net_Loss_Per_Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Net Loss Per Share	'
	Note 8. Net Loss per Share
	The Company computes net loss per share of common stock in conformity with the two-class method required for participating securities. The Company considers the shares issued upon the early exercise of stock options subject to repurchase to be participating securities, because holders of such shares have non-forfeitable dividend rights in the event a dividend is paid on common stock. Prior to their conversion to common stock, the Company also considered all series of the Company’s redeemable convertible preferred stock and convertible preferred stock to be participating securities as the holders of the preferred stock were entitled to receive a noncumulative dividend on a pari passu basis in the event that a dividend was paid on common stock. The holders of all series of convertible preferred stock and the holders of early exercised shares subject to repurchase do not have a contractual obligation to share in the losses of the Company. As such, the Company’s net losses for the three and nine months ended September 30, 2014 and 2013 were not allocated to these participating securities.
	Basic net loss per share is computed by dividing total net loss attributable to common stockholders by the weighted-average common shares outstanding. The weighted-average common shares outstanding is adjusted for shares subject to repurchase such as unvested restricted stock granted to employees in connection with acquisitions, contingently returnable shares and escrowed shares supporting indemnification obligations that are issued in connection with acquisitions and unvested stock options exercised. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding including potential dilutive common stock instruments. In the three and nine months ended September 30, 2014 and 2013, the Company’s potential common stock instruments such as stock options, RSUs, shares to be issued under the Employee Stock Purchase Plan (“ESPP”), shares subject to repurchases, conversion feature of the Notes and the warrants were not included in the computation of diluted loss per share as the effect of including these shares in the calculation would have been anti-dilutive.
	The following table presents the calculation of basic and diluted net loss per share for periods presented (in thousands, except per share data).
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
	Net loss	$	(175,464	)	$	(64,601	)	$	(452,468	)	$	(133,852	)
	Basic shares:
	Weighted-average common shares outstanding		624,205			140,438			605,756			137,486
	Weighted-average restricted stock		(9,810	)		(6,739	)		(9,034	)		(6,290	)
	subject to repurchase
	Weighted-average shares used to compute basic net loss per share		614,395			133,699			596,722			131,196
	Diluted shares:
	Weighted-average shares used to compute diluted net loss per share		614,395			133,699			596,722			131,196
	Net loss per share attributable to common stockholders:
	Basic	$	(0.29	)	$	(0.48	)	$	(0.76	)	$	(1.02	)
	Diluted	$	(0.29	)	$	(0.48	)	$	(0.76	)	$	(1.02	)
	The following number of potential common shares at the end of each period were excluded from the calculation of diluted net loss per share attributable to common stockholders because their effect would have been anti-dilutive for the periods presented (in thousands):
		Three and Nine Months Ended September 30,
		2014			2013
	Stock options		22,327			42,709
	RSUs		74,114			41,733
	Employee stock purchase plan		1,147			—
	Shares subject to repurchase		10,070			7,520
	Warrants		23,183			117
	Since the Company expects to settle the principal amount of the outstanding Notes in cash, the Company uses the treasury stock method for calculating any potential dilutive effect of the conversion spread on diluted net income per share, if applicable.  The conversion spread will have a dilutive impact on diluted net income per share of common stock when the average market price of our common stock for a given period exceeds the conversion price of $77.64 per share for the Notes.
	If the average market price of the common stock exceeds the exercise price of the warrants, $105.28, the warrants will have a dilutive effect on the earnings per share assuming that the Company is profitable.  Since the average market price of the common stock is below $105.28, the warrants are anti-dilutive.

Common_Stock_and_Stockholders_

Common Stock and Stockholders' Equity	9 Months Ended
	Sep. 30, 2014
Stockholders Equity Note [Abstract]	'
Common Stock and Stockholders' Equity	'
	Note 9. Common Stock and Stockholders’ Equity
	Common Stock
	Each share of common stock is entitled to one vote. The holders of common stock are also entitled to receive dividends whenever funds are legally available and when and if declared by the Board of Directors. As of September 30, 2014, no dividends have been declared.
	Restricted Common Stock
	The Company has granted restricted common stock to certain key continuing employees in connection with the acquisitions. Vesting of this stock is dependent on the respective employee’s continued employment at the Company during the requisite service period, which is generally two to four years from the issuance date, and the Company has the option to repurchase the unvested shares upon termination of employment. The fair value of the restricted common stock issued to employees is recorded as compensation expense on a straight-line basis over the requisite service period.
	The activities for the restricted common stock issued to employees for the nine months ended September 30, 2014 are summarized as follows (in thousands, except per share data):
						Weighted-Average
			Number of			Grant-Date Fair
			Shares			Value Per Share
	Unvested restricted common stock at December 31, 2013			6,866		$	17.6
	Granted			2,467		$	33.8
	Vested			(2,256	)	$	17.18
	Canceled			(98	)	$	13.46
	Unvested restricted common stock at September 30, 2014			6,979		$	23.52
	During the three months ended September 30, 2014 and 2013, the Company recorded $14.2 million and $7.8 million, respectively, and recorded $38.2 million and $20.3 million during the nine months ended September 30, 2014 and 2013, respectively, of compensation expense related to restricted common stock issued to employees. As of September 30, 2014, there was $114.7 million of unamortized stock-based compensation expense related to restricted common stock issued which is expected to be recognized over a weighted-average period of 2.50 years. To the extent the actual forfeiture rate is different from the Company’s estimate, stock-based compensation expense related to these stock awards will be different.
	Equity Incentive Plans
	As of September 30, 2014, the total number of RSUs and options outstanding under the 2013 Equity Incentive Plan was 26.2 million shares, and 79.3 million shares were available for future issuance. There were 68.2 million shares underlying options and RSUs outstanding under the 2007 Equity Incentive Plan as of September 30, 2014. No additional equity awards will be issued under the 2007 Equity Incentive Plan.
	Under the 2007 Equity Incentive Plan, RSUs granted to domestic and international employees prior to February 2013 (“Pre-2013 RSUs”) vest upon the satisfaction of both a service condition and a performance condition. The service condition for these awards is generally satisfied over four years. The performance condition was satisfied in February 2014 pursuant to the terms of the 2007 Equity Incentive Plan. An aggregate of 17.1 million shares of common stock were issued as a result of vesting and settlement of the Pre-2013 RSUs in the first quarter of 2014.  During the same period, the Company's employees who are not executive officers were allowed to sell a portion of vested and settled Pre-2013 RSUs in the public market to satisfy the income tax obligations related to the vesting and settlement of such awards.  The proceeds from selling the shares required to satisfy the employees' minimum statutory tax obligation were withheld and remitted to the appropriate tax authorities. RSUs granted to domestic employees starting in February 2013 (“Post-2013 RSUs”) are not subject to a performance condition in order to vest. The majority of Post-2013 RSUs vest over a service period of four years. Under the terms of the 2007 Equity Incentive Plan and the 2013 Equity Incentive Plan, the shares underlying Post-2013 RSUs that satisfy the service condition are to be delivered to holders no later than the fifteenth day of the third month following the end of the calendar year the service condition is satisfied, or if later, the end of the Company’s tax year.
	In addition, the Company undertook a net settlement of vested Pre-2013 RSUs held by the executive officers upon satisfaction of the performance condition in 2014 and withheld shares and remitted income tax of $16.2 million in cash on behalf of the applicable executive officers at the applicable minimum statutory rates in the nine months ended September 30, 2014.  These shares withheld by the Company as a result of the net settlement of Pre-2013 RSUs are no longer considered issued and outstanding.
	Employee Stock Purchase Plan
	On May 15, 2014, the first purchase under the ESPP was made and employees purchased an aggregate of 1.0 million shares at a price of $22.10 per share. As of September 30, 2014, 16.7 million shares were available for future issuance under the ESPP. During the three and nine months ended September 30, 2014, the Company recorded $9.1 million and $25.8 million, respectively, of stock-based compensation expense related to the ESPP.
	Stock Option Activity
	A summary of stock option activity for the nine months ended September 30, 2014 is as follows (in thousands, except years and per share data):
			Options Outstanding
										Weighted-
						Weighted-				Average
						Average				Remaining
			Number of			Exercise				Contractual Life				Aggregate
			Shares			Price Per Share				(in years)				Intrinsic Value
	Outstanding at December 31, 2013			42,246		$	1.89				6.47			$	2,609,295
	Options granted			500		$	42.05
	Options assumed in connection with acquisitions			819		$	1.6
	Options exercised			(20,652	)	$	1.22
	Options canceled			(586	)	$	8.24
	Outstanding at September 30, 2014			22,327		$	3.23				6.1			$	1,079,592
	Vested and expected to vest at			21,885		$	3.1				6.07			$	1,061,031
	September 30, 2014 (1)
	Exercisable at September 30, 2014			17,638		$	1.54				5.68			$	882,557
	-1	The expected to vest options are the result of applying pre-vesting forfeiture rate assumptions to unvested options outstanding.
	The aggregate intrinsic value in the table above represents the difference between the fair value of common stock and the exercise price of outstanding, in-the-money stock options.
	The total intrinsic value of stock options exercised during the three months ended September 30, 2014 and 2013 were $265.2 million and $24.0 million, respectively and $802.3 million and $95.3 million in the nine months ended September 30, 2014 and 2013, respectively. The total grant date fair value of stock options vested during the three months ended September 30, 2014 and 2013 were $4.8 million and $4.4 million, respectively, and $10.7 million and $8.7 million in the nine months ended September 30, 2014 and 2013, respectively.
	RSU Activity
	The following table summarizes the activity related to the Company’s Pre- and Post-2013 RSUs for the nine months ended September 30, 2014. For purposes of this table, vested RSUs represent the shares for which the service condition had been fulfilled as of each respective date (in thousands, except per share data):
			RSUs Outstanding
						Weighted-
						Average Grant-
						Date Fair Value
			Shares			Per Share
	Unvested and outstanding at December 31, 2013			79,876		$	19.54
	Granted			22,718		$	49.12
	Vested			(19,403	)	$	19.38
	Canceled			(9,077	)	$	17.07
	Unvested and outstanding at September 30, 2014			74,114		$	28.56
	The fair value as of the respective vesting dates of RSUs that vested during the three and nine months ended September 30, 2014 was $469.8 million and $940.4 million, respectively and $65.2 million and $155.4 million, respectively during the three and nine months ended September 30, 2013.
	Stock-Based Compensation Expense
	Total stock-based compensation expense recorded for employee and non-employee stock options, RSUs, shares issued under the ESPP, restricted common stock and Class A junior preferred stock in the three and nine months ended September 30, 2014 and 2013 is summarized as follows (in thousands):
			Three Months Ended September 30,							Nine Months Ended September 30,
			2014			2013				2014				2013
	Employee		$	167,249		$	43,320			$	447,698			$	77,735
	Non-employee			2,353			282				6,684				1,435
	Total		$	169,602		$	43,602			$	454,382			$	79,170
	Stock-based compensation expense is allocated based on the cost center to which the award holder belongs. Total stock-based compensation expense by function is as follows (in thousands):
			Three Months Ended September 30,							Nine Months Ended September 30,
		2014			2013				2014				2013
Cost of revenue		$	13,596		$	3,060			$	37,296			$	5,015
Research and development			93,973			29,180				264,784				53,377
Sales and marketing			42,884			5,742				108,232				10,356
General and administrative			19,149			5,620				44,070				10,422
Total		$	169,602		$	43,602			$	454,382			$	79,170
.
The Company capitalized $10.9 million and $3.4 million of stock-based compensation expense associated with the cost for developing software for internal use in the three months ended September 30, 2014 and 2013, respectively, and $26.4 million and $6.7 million in the nine months ended September 30, 2014 and 2013, respectively.
The weighted-average grant-date fair value of stock options granted to employees, including stock assumed in connection with acquisitions, in the three months ended September 30, 2014 was $26.10 per share, and in the nine months ended September 30, 2014 and 2013 were $30.12 and $11.13 per share, respectively. The Company did not grant additional options to employees during the three months ended September 30, 2013. The fair value of stock options granted to employees and options assumed in connection with acquisitions was determined using the Black-Scholes option pricing model with the following weighted-average assumptions:
		Three Months Ended September 30,					Nine Months Ended September 30,
		2014			2013		2014				2013
Expected dividend yield			—		N/A			—				—
Risk-free interest rate			1.86	%	N/A			1.47	%			1.07	%
Expected volatility			43.7	%	N/A			42.54	%			53.77	%
Expected term (in years)			5.85		N/A			4.73				5.63
As of September 30, 2014, there was $39.7 million of unamortized stock-based compensation expense related to unvested stock options granted to employees and non-employee service providers which is expected to be recognized over a weighted-average period of 2.29 years. As of September 30, 2014, the unamortized stock-based compensation expense related to Pre- and Post-2013 RSUs of $69.0 million and $1.42 billion, respectively, is expected to be recognized over a weighted-average period of 1.99 years and 3.12 years, respectively. $5.8 million of unamortized stock-based compensation expense related to the ESPP is expected to be recognized over a period of 0.23 years. To the extent the actual forfeiture rate is different from the Company’s estimate, stock-based compensation expense related to these stock awards will be different.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Note 10. Income Taxes
	The Company is subject to taxation in the United States and various state and foreign jurisdictions. Earnings from non-US activities are subject to local country income tax. The material jurisdictions in which the Company is subject to potential examination by taxing authorities include the United States, California and Ireland. The Company is currently under an income tax examination by the Internal Revenue Service (IRS) for tax year 2012 and in California for tax years 2010 and 2011. The Company believes that adequate amounts have been reserved in these jurisdictions. The Company does not provide for federal income taxes on the undistributed earnings of its foreign subsidiaries as such earnings are to be reinvested indefinitely outside the U.S. The Company computes its quarterly income tax provision by using a forecasted annual effective tax rate and adjusts for any discrete items arising during the quarter.
	The Company recorded an income tax provision of $0.2 million and $0.4 million for the three months ended September 30, 2014 and 2013, respectively, and an income tax benefit of $4.2 million and an income tax provision of $1.5 million for the nine months ended September 30, 2014 and 2013, respectively. The income tax provision decreased in the three and nine months ended September 30, 2014 compared to the same periods last year, primarily due to the deferred income tax benefits related to acquisitions concluded during the second and third quarters, partially offset by increased foreign and state income tax expenses. As of September 30, 2014, based on the available objective evidence, management believes it is more likely than not that the tax benefits of the U.S. losses incurred during the nine months ended September 30, 2014 will not be realized by the end of the 2014 fiscal year. Accordingly, the Company did not record the tax benefits of the U.S. losses incurred during the nine months ended September 30, 2014. The primary difference between the effective tax rate and the federal statutory tax rate relates to the valuation allowances on the Company’s net operating losses and foreign tax rate differences.
	During the three and nine months ended September 30, 2014, the amount of gross unrecognized tax benefits increased by $26.2 million and $62.6 million, respectively. As of September 30, 2014, the Company has $105.7 million of unrecognized tax benefits which are subject to full valuation allowance and, if recognized, will not affect the annual effective tax rate.
	As a result of employee RSUs that vested in the three and nine months ended September 30, 2014, the Company’s federal net operating losses increased by approximately $435.4 million and $1.59 billion, respectively, and the state net operating losses increased by approximately $114.7 million and $418.7 million, respectively.  The portion of the increased net operating loss carryforwards related to excess tax benefits from the RSUs for the three and nine months ended September 30, 2014 was approximately $235.0 million and $1.02 billion, respectively for federal tax purposes and $61.9 million and $269.2 million, respectively for state tax purposes, the benefit of which will be credited to additional paid-in capital when realized.

Convertible_Notes

Convertible Notes	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Convertible Notes	'
	Note 11. Convertible Notes
	In September 2014, the Company issued $900.0 million principal amount of 2019 Notes and $900.0 million principal amount of 2021 Notes in a private placement to qualified institutional buyers pursuant to Rule144A under the Securities Act of 1933, as amended. The total net proceeds from this offering, after deducting transaction costs, were approximately $1.77 billion. The Company incurred a total of $27.0 million of initial purchasers’ discount and $0.5 million debt issuance costs in connection with the 2019 Notes and the 2021 Notes.
	The interest rates are fixed at 0.25% and 1.00% per annum and are payable semi-annually in arrears on March 15 and September 15 of each year, commencing on March 15, 2015.  During the three and nine months ended September 30, 2014, the Company recognized $0.2 million of interest expense related to the amortization of initial purchasers’ discount and debt issuance costs, and $0.4 million of accrued coupon interest expense.
	Each $1,000 of principal of these notes will initially be convertible into 12.8793 shares of the Company’s common stock, which is equivalent to an initial conversion price of approximately $77.64 per share, subject to adjustment upon the occurrence of specified events.  Holders of these notes may convert their notes at their option at any time until close of business on the second scheduled trading day immediately preceding the relevant maturity date which is March 15, 2019 for the 2019 Notes and March 15, 2021 for the 2021 Notes.  Further, holders of each of these notes may convert their notes at their option prior to the respective dates above, only under the following circumstances:
	1)	during any calendar quarter commencing after the calendar quarter ending on December 31, 2014 (and only during such calendar quarter), if the last reported sale price of Twitter’s common stock for at least 20 trading days (whether or not consecutive) during a 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 for the relevant series of notes on each applicable trading day;
	2)	during the five business day period after any five consecutive trading day period (the “measurement period”) in which the trading price (as defined in the related Indenture) per $1,000 principal amount of 2019 notes or 2021 notes, as applicable, for each trading day of the measurement period was less than 98% of the product of the last reported sale price of Twitter’s common stock and the conversion rate for the notes of the relevant series on each such trading day; or
	3)	upon the occurrence of certain specified corporate events.
	Upon conversion of the 2019 Notes and 2021 Notes, the Company will pay or deliver, as the case may be, cash, shares of its common stock or a combination of cash and shares of its common stock, at the Company’s election. If the Company satisfies its conversion obligation solely in cash or through payment and delivery, as the case may be, of a combination of cash and shares of its common stock, the amount of cash and shares of common stock, if any, due upon conversion will be based on a daily conversion value (as described herein) calculated on a proportionate basis for each trading day in a 30 trading day observation period.
	If a fundamental change (as defined in the relevant indenture governing the applicable series of Notes) occurs prior to the maturity date, holders of the 2019 Notes and 2021 Notes may require the Company to repurchase all or a portion of their notes for cash at a repurchase price equal to 100% of the principal amount of the notes, plus any accrued and unpaid interest to, but excluding, the repurchase date. In addition, if specific corporate events occur prior to the applicable maturity date, the Company will be required to increase the conversion rate for holders who elect to convert their notes in certain circumstances.
	In accordance with accounting guidance on embedded conversion features, the Company valued and bifurcated the conversion option associated with the 2019 Notes and 2021 Notes from the respective host debt instrument, which is referred to as debt discount, and initially recorded the conversion option of $214.6 million for the 2019 Notes and $267.4 million for the 2021 Notes in stockholders’ equity. The resulting debt discounts on the 2019 Notes and 2021 Notes are being amortized to interest expense at an effective interest rate of 5.75% and 6.25%, respectively, over the contractual terms of the notes.   The Company allocated $0.1 million of debt issuance costs to the equity component, and the remaining debt issuance costs of $0.4 million are being amortized to interest expense.
	During the three and nine months ended September 30, 2014, the Company recognized $2.4 million of interest expense related to the amortization of the debt discount. As of September 30, 2014, the net carrying value, net of the initial purchasers’ discount and debt discount, of 2021 Notes and 2019 Notes was $673.3 million and $620.3 million, respectively.
	The Notes consisted of the following (in thousands):
			30-Sep-14
			2019 Notes			2021 Notes
	Principal amounts:
	Principal		$	900,000		$	900,000
	Unamortized initial purchasers' discount and debt discount (1)			(226,672	)		(279,724	)
	Net carrying amount		$	673,328		$	620,276
	Carrying amount of the equity component (2)		$	214,591		$	267,381
	-1	Included in the consolidated balance sheets within convertible notes and amortized over the remaining lives of the Notes.
	-2	Included in the consolidated balance sheets within additional paid-in capital.
	As of September 30, 2014, the remaining life of the 2019 Notes and 2021 Notes is approximately 59 months and 83 months, respectively.
	Concurrently with the offering of these notes in September 2014, the Company entered into convertible note hedge transactions with certain bank counterparties whereby the Company has the option to purchase initially (subject to adjustment for certain specified events) a total of approximately 23.2 million shares of its common stock at a price of approximately $77.64 per share. The total cost of the convertible note hedge transactions was $387.5 million. In addition, the Company sold warrants to certain bank counterparties whereby the holders of the warrants have the option to purchase initially (subject to adjustment for certain specified events) a total of approximately 23.2 million shares of the Company’s common stock at a price of $105.28. The Company received $275.1 million in cash proceeds from the sale of these warrants.
	Taken together, the purchase of the convertible note hedges and the sale of warrants are intended to offset any actual dilution from the conversion of these notes and to effectively increase the overall conversion price from $77.64 to $105.28 per share. As these transactions meet certain accounting criteria, the convertible note hedges and warrants are recorded in stockholders’ equity and are not accounted for as derivatives. The net cost incurred in connection with the convertible note hedge and warrant transactions was recorded as a reduction to additional paid-in capital in the consolidated balance sheet as of September 30, 2014.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2014
Commitments And Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Note 12. Commitments and Contingencies
	Credit Facility
	The Company entered into a revolving credit agreement with certain lenders in 2013, which provided for a $1.0 billion revolving unsecured credit facility maturing on October 22, 2018. Loans under the credit facility bear interest, at the Company’s option, at (i) a base rate based on the highest of the prime rate, the federal funds rate plus 0.50% and an adjusted LIBOR rate for a one-month interest period plus 1.00%, in each case plus a margin ranging from 0.00% to 0.75% or (ii) an adjusted LIBOR rate plus a margin ranging from 1.00% to 1.75%. This margin is determined based on the total leverage ratio for the preceding four fiscal quarter period. The Company is obligated to pay other customary fees for a credit facility of this size and type, including an upfront fee and an unused commitment fee. Obligations under the credit facility are guaranteed by one of the Company’s wholly-owned subsidiaries. In addition, the credit facility contains restrictions on payments including cash payment of dividends.
	The revolving credit agreement was amended in September 2014 to increase the amount of indebtedness that the Company may incur and increase the amount of restricted payments that the Company may make. This amendment to the revolving credit agreement also provides that if the Company’s total leverage ratio exceeds 2.5:1.0 and if the amount outstanding under the credit facility exceeds $500.0 million, or 50% of the amount that may be borrowed under the credit facility, the credit facility will become secured by substantially all of the Company’s and certain of its subsidiaries’ assets, subject to limited exceptions. As of September 30, 2014, no amounts were drawn under the credit facility.
	Operating and Capital Leases
	The Company has entered into various non-cancelable operating lease agreements for certain offices and data center facilities with contractual lease periods expiring between 2014 and 2026.
	A summary of gross and net lease commitments as of September 30, 2014 is as follows (in thousands):
		Operating		Capital
		Leases		Leases
	Remainder of 2014	$	22,075	$	31,863
	2015		107,583		109,579
	2016		133,760		71,702
	2017		136,985		30,421
	2018		133,060		2,709
	Thereafter		394,802		—
		$	928,265		246,274
	Less: Amounts representing interest				14,126
	Total capital lease obligation				232,148
	Less: Short-term portion				110,527
	Long-term portion			$	121,621
	Legal Proceedings
	The Company is currently involved in, and will likely in the future be involved in, legal proceedings, claims and governmental investigations in the normal course of business. Legal fees and other costs associated with such actions are expensed as incurred. The Company assesses, in conjunction with its legal counsel, the need to record a liability for litigation and contingencies. Litigation accruals are recorded when and if it is determined that a loss related matter is both probable and reasonably estimable. Material loss contingencies that are reasonably possible of occurrence, if any, are subject to disclosure. As of September 30, 2014 and December 31, 2013, there was no litigation or contingency with at least a reasonable possibility of a material loss. No losses have been recorded during three and nine months ended September 30, 2014 and 2013 with respect to litigation or loss contingencies.
	Indemnification
	In the ordinary course of business, the Company often includes standard indemnification provisions in its arrangements with its customers, partners, suppliers and vendors. Pursuant to these provisions, the Company may be obligated to indemnify such parties for losses or claims suffered or incurred in connection with its service, breach of representations or covenants, intellectual property infringement or other claims made against such parties. These provisions may limit the time within which an indemnification claim can be made. It is not possible to determine the maximum potential amount under these indemnification obligations due to the limited history of prior indemnification claims and the unique facts and circumstances involved in each particular agreement. The Company has never incurred significant expense defending its licensees against third-party claims, nor has it ever incurred significant expense under its standard service warranties or arrangements with its customers, partners, suppliers and vendors. Accordingly, the Company had no liabilities recorded for these provisions as of September 30, 2014 and December 31, 2013.

Operations_by_Geographic_Area

Operations by Geographic Area	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Operations by Geographic Area	'
	Note 13. Operations by Geographic Area
	Revenue
	Revenue by geography is based on the billing addresses of the customers. The following table sets forth revenue by geographic area (in thousands):
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
	Revenue:
	United States	$	240,169	$	124,687	$	630,673	$	315,486
	International		121,097		43,893		293,251		106,729
	Total revenue	$	361,266	$	168,580	$	923,924	$	422,215
	The United Kingdom accounted for $37.5 million, or 10%, $17.2 million, or 10%, $94.8 million, or 10%, and $43.0 million, or 10% of the total revenue for the three months ended September 30, 2014 and 2013, and for the nine months ended September 30, 2014 and 2013, respectively.
	Long-Lived Assets
	The following table sets forth long-lived assets by geographic area (in thousands):
		September 30,		December 31,
		2014		2013
	Long-lived assets:
	United States	$	479,020	$	327,250
	International		24,938		5,412
	Total long-lived assets	$	503,958	$	332,662

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	Note 14. Subsequent Events
	In October 2014, the Company issued an additional $35 million aggregate principal amount of 2019 Notes and $54 million aggregate principal amount of 2021 Notes, pursuant to the exercise of the overallotment options of the initial purchasers. In connection with such issuance, the Company also entered into additional convertible note hedge transactions covering approximately 1.1 million shares of its common stock. The total cost of the additional convertible note hedge transactions was $19.7 million. In addition, the Company sold additional warrants to purchase initially (subject to adjustment for certain specified events) a total of approximately 1.1 million shares of its common stock. The Company received $14.1 million in cash proceeds from the sale of these additional warrants.

Description_of_Business_and_Su1

Description of Business and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation.
	The accompanying unaudited consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”). The unaudited interim consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and reflect, in management’s opinion, all adjustments of a normal, recurring nature that are necessary for the fair statement of the Company’s financial position, results of operations and cash flows for the interim periods, but are not necessarily indicative of the results expected for the full fiscal year or any other period.
	The accompanying interim consolidated financial statements and these related notes should be read in conjunction with the consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013.
Use of Estimates	'
	Use of Estimates
	The preparation of the Company’s consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses, as well as related disclosure of contingent assets and liabilities. The Company bases its estimates on past experience and other assumptions that the Company believes are reasonable under the circumstances, and the Company evaluates these estimates on an ongoing basis. Actual results could differ materially from the Company’s estimates. To the extent that there are material differences between these estimates and actual results, the Company’s financial condition or operating results will be affected.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In July 2013, the Financial Accounting Standards Board (“FASB”) issued a new accounting standard update on the financial statement presentation of unrecognized tax benefits. The new guidance provides that a liability related to an unrecognized tax benefit would be presented as a reduction of a deferred tax asset for a net operating loss carryforward, a similar tax loss or a tax credit carryforward, if such settlement is required or expected in the event the uncertain tax position is disallowed. The Company adopted this guidance prospectively for unrecognized tax benefits as of January 1, 2014. The application of this guidance resulted in a $15.8 million decrease in net deferred tax assets and the related liability for unrecognized tax benefits upon adoption.
	In May 2014, the FASB issued a new accounting standard update on revenue recognition from contracts with customers. The new guidance will replace all current U.S. GAAP guidance on this topic and eliminate all industry-specific guidance.  According to the new guidance, revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration for which the Company expects to be entitled in exchange for those goods or services. This guidance will be effective for the Company beginning January 1, 2017 and can be applied either retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. Early adoption is not permitted. The Company has not yet selected a transition method and is evaluating the impact of adopting this new accounting standard update on the financial statements and related disclosures.
	In June 2014, the FASB issued a new accounting standard update on stock-based compensation when the terms of an award provide that a performance target could be achieved after the requisite service period. The new guidance requires that a performance target that affects vesting, and that could be achieved after the requisite service period, be treated as a performance condition. As such, the performance target should not be reflected in estimating the grant date fair value of the award. This update further clarifies that compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the periods for which the requisite service has already been rendered. This guidance will be effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015 and can be applied either prospectively or retrospectively to all awards outstanding as of the beginning of the earliest annual period presented as an adjustment to opening retained earnings. Early adoption is permitted. Adoption of this new accounting standard update is expected to have no impact to the Company’s financial statements.

Cash_Cash_Equivalents_and_Shor1

Cash, Cash Equivalents and Short-term Investments (Tables)	9 Months Ended
	Sep. 30, 2014
Cash And Cash Equivalents [Abstract]	'
Cash, Cash and Equivalents and Short-term Investments	'
	Cash, cash equivalents and short-term investments consist of the following (in thousands):
		September 30,		December 31,
		2014		2013
	Cash and cash equivalents:
	Cash	$	1,626,946	$	164,135
	Money market funds		330,849		229,529
	U.S. government and agency securities including treasury bills		141,549		251,593
	Corporate notes and commercial paper		153,451		195,753
	Total cash and cash equivalents	$	2,252,795	$	841,010
	Short-term investments:
	U.S. government and agency securities including treasury bills	$	652,936	$	785,536
	Corporate notes, certificates of deposit and commercial paper		741,951		607,508
	Total short-term investments	$	1,394,887	$	1,393,044
Summary of Unrealized Gains and Losses Related to Available-for-Sale Securities Classified as Short-term Investments	'
	The following tables summarize unrealized gains and losses related to available-for-sale securities classified as short-term investments on the Company’s consolidated balance sheets (in thousands):
		30-Sep-14
		Gross		Gross			Gross			Aggregated
		Amortized		Unrealized			Unrealized			Estimated
		Costs		Gains			Losses			Fair Value
	U.S. Government and agency securities including	$	652,908	$	50		$	(22	)	$	652,936
	treasury bills
	Corporate notes, certificates of deposit and		742,290		27			(366	)		741,951
	commercial paper
	Total available-for-sale securities classified as	$	1,395,198	$	77		$	(388	)	$	1,394,887
	short-term investments
		31-Dec-13
		Gross		Gross			Gross			Aggregated
		Amortized		Unrealized			Unrealized			Estimated
		Costs		Gains			Losses			Fair Value
	U.S. Government and agency securities including	$	785,535	$	22		$	(21	)	$	785,536
	treasury bills
	Corporate notes, certificates of deposit and		607,590		11			(93	)		607,508
	commercial paper
	Total available-for-sale securities classified as	$	1,393,125	$	33		$	(114	)	$	1,393,044
	short-term investments
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Table Text Block]	'
	The following tables show all short-term investments in an unrealized loss position for which other-than-temporary impairment has not been recognized and the related gross unrealized losses and fair value, aggregated by investment category and the length of time that individual securities have been in a continuous unrealized loss position (in thousands):
		30-Sep-14
		Less than 12 Months					12 Months or Greater					Total
				Unrealized						Unrealized				Unrealized
		Fair Value		Loss			Fair Value			Loss		Fair Value		Loss
	U.S. Government and agency securities	$	219,392	$	(22	)	$	—		$	—	$	219,392	$	(22	)
	including treasury bills
	Corporate notes, certificates of deposit		445,403		(366	)		—			—		445,403		(366	)
	and commercial paper
	Total short-term investments in an	$	664,795	$	(388	)	$	—		$	—	$	664,795	$	(388	)
	unrealized loss position
		31-Dec-13
		Less than 12 Months					12 Months or Greater					Total
				Unrealized						Unrealized				Unrealized
		Fair Value		Loss			Fair Value			Loss		Fair Value		Loss
	U.S. Government and agency securities	$	230,478	$	(21	)	$	—		$	—	$	230,478	$	(21	)
	including treasury bills
	Corporate notes, certificates of deposit		171,894		(93	)		—			—		171,894		(93	)
	and commercial paper
	Total short-term investments in an	$	402,372	$	(114	)	$	—		$	—	$	402,372	$	(114	)
	unrealized loss position

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	'
	The following tables set forth the fair value of the Company’s financial assets and liabilities measured at fair value on a recurring basis as of September 30, 2014 and December 31, 2013 based on the three-tier fair value hierarchy (in thousands):
		30-Sep-14
		Level 1		Level 2		Level 3		Total
	Assets
	Cash equivalents:
	Money market funds	$	330,849	$	—	$	—	$	330,849
	Treasury bills		141,549		—		—		141,549
	Commercial paper		—		153,451		—		153,451
	Short-term investments:
	Treasury bills		68,474		—		—		68,474
	Commercial paper		—		164,033		—		164,033
	Corporate notes		—		532,332		—		532,332
	U.S. government securities		—		584,462		—		584,462
	Certificates of deposit		—		45,586		—		45,586
	Total	$	540,872	$	1,479,864	$	—	$	2,020,736
		31-Dec-13
		Level 1		Level 2		Level 3		Total
	Assets
	Cash equivalents:
	Money market funds	$	229,529	$	—	$	—	$	229,529
	Treasury bills		244,048		—		—		244,048
	Commercial paper		—		194,742		—		194,742
	U.S. government securities		—		7,545		—		7,545
	Corporate notes		—		1,011		—		1,011
	Short-term investments:
	Treasury bills		265,878		—		—		265,878
	Agency securities		—		18,286		—		18,286
	Commercial paper		—		272,617		—		272,617
	Corporate notes		—		255,546		—		255,546
	U.S. government securities		—		501,372		—		501,372
	Certificates of deposit		—		79,345		—		79,345
	Total	$	739,455	$	1,330,464	$	—	$	2,069,919

Property_and_Equipment_Net_Tab

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2014
Property Plant And Equipment [Abstract]	'
Schedule of Property and Equipment, Net	'
	The following table presents the detail of property and equipment, net for the periods presented (in thousands):
		September 30,			December 31,
		2014			2013
	Property and equipment, net
	Equipment	$	535,092		$	367,949
	Furniture and leasehold improvements		113,069			54,965
	Capitalized software		78,436			47,290
	Construction in progress		61,743			29,523
	Total		788,340			499,727
	Less: Accumulated depreciation and amortization		(284,382	)		(167,065	)
	Property and equipment, net	$	503,958		$	332,662

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2014
Goodwill And Intangible Assets Disclosure [Abstract]	'
Schedule of Goodwill Activities	'
	The following table presents the goodwill activities for the periods presented (in thousands):
	Goodwill
	Balance as of December 31, 2013	$	363,477
	Gnip acquisition		104,747
	Other acquisitions		155,054
	Foreign currency translation adjustment		(640	)
	Balance as of September 30, 2014	$	622,638
Schedule of Other Intangible Assets	'
	The following table presents the detail of other intangible assets for the periods presented (in thousands):
		Gross Carrying			Accumulated			Net Carrying
		Value			Amortization			Value
	September 30, 2014:
	Patents and developed technologies	$	153,497		$	(64,170	)	$	89,327
	Publisher and advertiser relationships		32,000			(7,439	)		24,561
	Assembled workforce		1,960			(1,092	)		868
	Other intangible assets		1,100			(510	)		590
	Total	$	188,557		$	(73,211	)	$	115,346
	December 31, 2013:
	Patents and developed technologies	$	100,553		$	(45,440	)	$	55,113
	Publisher and advertiser relationships		21,100			(1,248	)		19,852
	Assembled workforce		1,960			(300	)		1,660
	Other intangible assets		1,100			(98	)		1,002
	Total	$	124,713		$	(47,086	)	$	77,627
Schedule of Estimated Future Amortization Expenses	'
	Estimated future amortization expense as of September 30, 2014 is as follows (in thousands):
	Remainder of 2014	$	10,095
	2015		35,555
	2016		26,391
	2017		11,624
	2018		9,832
	Thereafter		21,849
	Total	$	115,346

Other_Balance_Sheet_Components1

Other Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2014
Statement Of Financial Position [Abstract]	'
Prepaid and Other Current Assets	'
	The following table presents the detail of prepaid and other current assets for the periods presented (in thousands):
		September 30,		December 31,
		2014		2013
	Deferred income taxes, net	$	31,107	$	62,122
	Prepaid and other		170,365		31,175
	Total	$	201,472	$	93,297
Accrued and Other Current Liabilities	'
	The following table presents the detail of accrued and other current liabilities for the periods presented (in thousands):
		September 30,		December 31,
		2014		2013
	Accrued compensation	$	82,970	$	29,882
	Unsettled purchases of marketable securities		76,670		—
	Accrued fixed assets and maintenance		30,166		5,697
	Deferred revenue		21,881		14,479
	Accrued publisher payments		20,819		15,370
	Accrued professional services		10,301		7,089
	Accrued tax liabilities		17,341		9,515
	Accrued other		41,182		28,278
	Total	$	301,330	$	110,310

Net_Loss_Per_Share_Tables

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Basic and Diluted Net Loss Per Share	'
	The following table presents the calculation of basic and diluted net loss per share for periods presented (in thousands, except per share data).
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
	Net loss	$	(175,464	)	$	(64,601	)	$	(452,468	)	$	(133,852	)
	Basic shares:
	Weighted-average common shares outstanding		624,205			140,438			605,756			137,486
	Weighted-average restricted stock		(9,810	)		(6,739	)		(9,034	)		(6,290	)
	subject to repurchase
	Weighted-average shares used to compute basic net loss per share		614,395			133,699			596,722			131,196
	Diluted shares:
	Weighted-average shares used to compute diluted net loss per share		614,395			133,699			596,722			131,196
	Net loss per share attributable to common stockholders:
	Basic	$	(0.29	)	$	(0.48	)	$	(0.76	)	$	(1.02	)
	Diluted	$	(0.29	)	$	(0.48	)	$	(0.76	)	$	(1.02	)
Summary of Potential Common Shares Excluded from Calculation of Diluted Net Loss Per Share Attributable to Common Stockholders	'
	The following number of potential common shares at the end of each period were excluded from the calculation of diluted net loss per share attributable to common stockholders because their effect would have been anti-dilutive for the periods presented (in thousands):
		Three and Nine Months Ended September 30,
		2014			2013
	Stock options		22,327			42,709
	RSUs		74,114			41,733
	Employee stock purchase plan		1,147			—
	Shares subject to repurchase		10,070			7,520
	Warrants		23,183			117
	Since the Company expects to settle the principal amount of the outstanding Notes in cash, the Company uses the treasury stock method for calculating any potential dilutive effect of the conversion spread on diluted net income per share, if applicable.  The conversion spread will have a dilutive impact on diluted net income per share of common stock when the average market price of our common stock for a given period exceeds the conversion price of $77.64 per share for the Notes.
	If the average market price of the common stock exceeds the exercise price of the warrants, $105.28, the warrants will have a dilutive effect on the earnings per share assuming that the Company is profitable.  Since the average market price of the common stock is below $105.28, the warrants are anti-dilutive.

Common_Stock_and_Stockholders_1

Common Stock and Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2014
Stockholders Equity Note [Abstract]	'
Summary of Restricted Stock Activity	'
	The activities for the restricted common stock issued to employees for the nine months ended September 30, 2014 are summarized as follows (in thousands, except per share data):
						Weighted-Average
			Number of			Grant-Date Fair
			Shares			Value Per Share
	Unvested restricted common stock at December 31, 2013			6,866		$	17.6
	Granted			2,467		$	33.8
	Vested			(2,256	)	$	17.18
	Canceled			(98	)	$	13.46
	Unvested restricted common stock at September 30, 2014			6,979		$	23.52
Summary of Stock Option Activity	'
	A summary of stock option activity for the nine months ended September 30, 2014 is as follows (in thousands, except years and per share data):
			Options Outstanding
										Weighted-
						Weighted-				Average
						Average				Remaining
			Number of			Exercise				Contractual Life				Aggregate
			Shares			Price Per Share				(in years)				Intrinsic Value
	Outstanding at December 31, 2013			42,246		$	1.89				6.47			$	2,609,295
	Options granted			500		$	42.05
	Options assumed in connection with acquisitions			819		$	1.6
	Options exercised			(20,652	)	$	1.22
	Options canceled			(586	)	$	8.24
	Outstanding at September 30, 2014			22,327		$	3.23				6.1			$	1,079,592
	Vested and expected to vest at			21,885		$	3.1				6.07			$	1,061,031
	September 30, 2014 (1)
	Exercisable at September 30, 2014			17,638		$	1.54				5.68			$	882,557
	-1	The expected to vest options are the result of applying pre-vesting forfeiture rate assumptions to unvested options outstanding.
Summary of RSU Activity	'
	The following table summarizes the activity related to the Company’s Pre- and Post-2013 RSUs for the nine months ended September 30, 2014. For purposes of this table, vested RSUs represent the shares for which the service condition had been fulfilled as of each respective date (in thousands, except per share data):
			RSUs Outstanding
						Weighted-
						Average Grant-
						Date Fair Value
			Shares			Per Share
	Unvested and outstanding at December 31, 2013			79,876		$	19.54
	Granted			22,718		$	49.12
	Vested			(19,403	)	$	19.38
	Canceled			(9,077	)	$	17.07
	Unvested and outstanding at September 30, 2014			74,114		$	28.56
Stock-Based Compensation Expense Recorded for Employee and Non-Employee Stock Options	'
	Total stock-based compensation expense recorded for employee and non-employee stock options, RSUs, shares issued under the ESPP, restricted common stock and Class A junior preferred stock in the three and nine months ended September 30, 2014 and 2013 is summarized as follows (in thousands):
			Three Months Ended September 30,							Nine Months Ended September 30,
			2014			2013				2014				2013
	Employee		$	167,249		$	43,320			$	447,698			$	77,735
	Non-employee			2,353			282				6,684				1,435
	Total		$	169,602		$	43,602			$	454,382			$	79,170
Compensation Expense Allocated	'
	Stock-based compensation expense is allocated based on the cost center to which the award holder belongs. Total stock-based compensation expense by function is as follows (in thousands):
			Three Months Ended September 30,							Nine Months Ended September 30,
			2014			2013				2014				2013
	Cost of revenue		$	13,596		$	3,060			$	37,296			$	5,015
	Research and development			93,973			29,180				264,784				53,377
	Sales and marketing			42,884			5,742				108,232				10,356
	General and administrative			19,149			5,620				44,070				10,422
	Total		$	169,602		$	43,602			$	454,382			$	79,170
Schedule of Share-based Payment Award, Valuation Assumptions	'
	The weighted-average grant-date fair value of stock options granted to employees, including stock assumed in connection with acquisitions, in the three months ended September 30, 2014 was $26.10 per share, and in the nine months ended September 30, 2014 and 2013 were $30.12 and $11.13 per share, respectively. The Company did not grant additional options to employees during the three months ended September 30, 2013. The fair value of stock options granted to employees and options assumed in connection with acquisitions was determined using the Black-Scholes option pricing model with the following weighted-average assumptions:
			Three Months Ended September 30,					Nine Months Ended September 30,
			2014			2013		2014				2013
	Expected dividend yield			—		N/A			—				—
	Risk-free interest rate			1.86	%	N/A			1.47	%			1.07	%
	Expected volatility			43.7	%	N/A			42.54	%			53.77	%
	Expected term (in years)			5.85		N/A			4.73				5.63

Convertible_Notes_Tables

Convertible Notes (Tables)	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Components of Notes	'
	The Notes consisted of the following (in thousands):
		30-Sep-14
		2019 Notes			2021 Notes
	Principal amounts:
	Principal	$	900,000		$	900,000
	Unamortized initial purchasers' discount and debt discount (1)		(226,672	)		(279,724	)
	Net carrying amount	$	673,328		$	620,276
	Carrying amount of the equity component (2)	$	214,591		$	267,381

Commitment_and_Contingencies_T

Commitment and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2014
Commitments And Contingencies Disclosure [Abstract]	'
Minimum Commitments Under Non-Cancelable Capital and Operating Lease Agreements	'
	A summary of gross and net lease commitments as of September 30, 2014 is as follows (in thousands):
		Operating		Capital
		Leases		Leases
	Remainder of 2014	$	22,075	$	31,863
	2015		107,583		109,579
	2016		133,760		71,702
	2017		136,985		30,421
	2018		133,060		2,709
	Thereafter		394,802		—
		$	928,265		246,274
	Less: Amounts representing interest				14,126
	Total capital lease obligation				232,148
	Less: Short-term portion				110,527
	Long-term portion			$	121,621

Operations_by_Geographic_Area_

Operations by Geographic Area (Tables)	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Revenue by Geography	'
	Revenue by geography is based on the billing addresses of the customers. The following table sets forth revenue by geographic area (in thousands):
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
	Revenue:
	United States	$	240,169	$	124,687	$	630,673	$	315,486
	International		121,097		43,893		293,251		106,729
	Total revenue	$	361,266	$	168,580	$	923,924	$	422,215
Long-lived Assets by Geographic Area	'
	The following table sets forth long-lived assets by geographic area (in thousands):
		September 30,		December 31,
		2014		2013
	Long-lived assets:
	United States	$	479,020	$	327,250
	International		24,938		5,412
	Total long-lived assets	$	503,958	$	332,662

Description_of_Business_and_Su2

Description of Business and Summary of Significant Accounting Policies - Additional Information (Details) (USD $)	1 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014	Jan. 01, 2014
Description Of Business And Summary Of Significant Accounting Policies [Line Items]	'	'	'
Proceeds from offerings, net of transaction costs	$1,770,000,000	$1,770,000,000	'
Purchases of convertible note hedges	'	387,450,000	'
Proceeds from issuance of warrants	'	275,130,000	'
Decrease in net deferred tax assets and liability	'	'	15,800,000
0.25% convertible senior notes due 2019	'	'	'
Description Of Business And Summary Of Significant Accounting Policies [Line Items]	'	'	'
Debt instrument, principal amount	900,000,000	900,000,000	'
Debt Instrument, Interest Rate, Stated Percentage	0.25%	0.25%	'
Debt Instrument, Maturity Date, Description	'	'2019	'
1.00% convertible senior notes due 2021	'	'	'
Description Of Business And Summary Of Significant Accounting Policies [Line Items]	'	'	'
Debt instrument, principal amount	$900,000,000	$900,000,000	'
Debt Instrument, Interest Rate, Stated Percentage	1.00%	1.00%	'
Debt Instrument, Maturity Date, Description	'	'2021	'

Cash_Cash_Equivalents_and_Shor2

Cash, Cash Equivalents and Short-term Investments - Cash, Cash and Equivalents and Short-term Investments (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Cash and cash equivalents:	'	'	'	'
Cash and cash equivalents	$2,252,795	$841,010	$155,704	$203,328
Short-term investments:	'	'	'	'
Short-term investments	1,394,887	1,393,044	'	'
Cash	'	'	'	'
Cash and cash equivalents:	'	'	'	'
Cash and cash equivalents	1,626,946	164,135	'	'
Money Market Funds	'	'	'	'
Cash and cash equivalents:	'	'	'	'
Cash and cash equivalents	330,849	229,529	'	'
U.S. Government and Agency Securities Including Treasury Bills	'	'	'	'
Cash and cash equivalents:	'	'	'	'
Cash and cash equivalents	141,549	251,593	'	'
Short-term investments:	'	'	'	'
Short-term investments	652,936	785,536	'	'
Corporate Notes And Commercial Paper	'	'	'	'
Cash and cash equivalents:	'	'	'	'
Cash and cash equivalents	153,451	195,753	'	'
Corporate Notes, Certificates of Deposit and Commercial Paper	'	'	'	'
Short-term investments:	'	'	'	'
Short-term investments	$741,951	$607,508	'	'

Cash_Cash_Equivalents_and_Shor3

Cash, Cash Equivalents and Short-term Investments - Summary of Unrealized Gains and Losses Related to Available-for-Sale Securities Classified as Short-term Investments (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule Of Available For Sale Securities [Line Items]	'	'
Gross Amortized Costs	$1,395,198	$1,393,125
Gross Unrealized Gains	77	33
Gross Unrealized Losses	-388	-114
Short-term investments	1,394,887	1,393,044
U.S. Government and Agency Securities Including Treasury Bills	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Gross Amortized Costs	652,908	785,535
Gross Unrealized Gains	50	22
Gross Unrealized Losses	-22	-21
Short-term investments	652,936	785,536
Corporate Notes, Certificates of Deposit and Commercial Paper	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Gross Amortized Costs	742,290	607,590
Gross Unrealized Gains	27	11
Gross Unrealized Losses	-366	-93
Short-term investments	$741,951	$607,508

Cash_Cash_Equivalents_and_Shor4

Cash, Cash Equivalents and Short-term Investments - Summary of Short-term Investments in Unrealized Loss Position and Related Gross Unrealized Losses and Fair Value, Aggregated by Investment Category and Length of Time (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule Of Available For Sale Securities [Line Items]	'	'
Less than 12 Months, Fair Value	$664,795	$402,372
Less than 12 Months, Unrealized Loss	-388	-114
12 Months or Greater, Fair Value	0	0
12 Months or Greater, Unrealized Loss	0	0
Total Fair Value	664,795	402,372
Total Unrealized Loss	-388	-114
U.S. Government and Agency Securities Including Treasury Bills	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Less than 12 Months, Fair Value	219,392	230,478
Less than 12 Months, Unrealized Loss	-22	-21
12 Months or Greater, Fair Value	0	0
12 Months or Greater, Unrealized Loss	0	0
Total Fair Value	219,392	230,478
Total Unrealized Loss	-22	-21
Corporate Notes, Certificates of Deposit and Commercial Paper	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Less than 12 Months, Fair Value	445,403	171,894
Less than 12 Months, Unrealized Loss	-366	-93
12 Months or Greater, Fair Value	0	0
12 Months or Greater, Unrealized Loss	0	0
Total Fair Value	445,403	171,894
Total Unrealized Loss	($366)	($93)

Cash_Cash_Equivalents_and_Shor5

Cash, Cash Equivalents and Short-term Investments - Additional Information (Details) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Investments Debt And Equity Securities [Abstract]	'	'
Impairment loss on securities	$0	$0

Fair_Value_Measurements_Schedu

Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) (Fair Value, Measurements, Recurring, USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets	'	'
Total	$2,020,736	$2,069,919
Agency Securities	'	'
Assets	'	'
Short-term investments	'	18,286
Money Market Funds	'	'
Assets	'	'
Cash equivalents	330,849	229,529
Treasury Bills	'	'
Assets	'	'
Cash equivalents	141,549	244,048
Short-term investments	68,474	265,878
Commercial Paper	'	'
Assets	'	'
Cash equivalents	153,451	194,742
Short-term investments	164,033	272,617
Corporate Notes	'	'
Assets	'	'
Cash equivalents	'	1,011
Short-term investments	532,332	255,546
US Government Securities	'	'
Assets	'	'
Cash equivalents	'	7,545
Short-term investments	584,462	501,372
Certificates of Deposit	'	'
Assets	'	'
Short-term investments	45,586	79,345
Level 1	'	'
Assets	'	'
Total	540,872	739,455
Level 1 | Money Market Funds	'	'
Assets	'	'
Cash equivalents	330,849	229,529
Level 1 | Treasury Bills	'	'
Assets	'	'
Cash equivalents	141,549	244,048
Short-term investments	68,474	265,878
Level 2	'	'
Assets	'	'
Total	1,479,864	1,330,464
Level 2 | Agency Securities	'	'
Assets	'	'
Short-term investments	'	18,286
Level 2 | Commercial Paper	'	'
Assets	'	'
Cash equivalents	153,451	194,742
Short-term investments	164,033	272,617
Level 2 | Corporate Notes	'	'
Assets	'	'
Cash equivalents	'	1,011
Short-term investments	532,332	255,546
Level 2 | US Government Securities	'	'
Assets	'	'
Cash equivalents	'	7,545
Short-term investments	584,462	501,372
Level 2 | Certificates of Deposit	'	'
Assets	'	'
Short-term investments	$45,586	$79,345

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Details) (Level 2, USD $)	Sep. 30, 2014
In Millions, unless otherwise specified
Convertible Senior Notes 2019	'
Fair Value Disclosure [Line Items]	'
Estimated fair value of notes based on a market approach	$879.90
Convertible Senior Notes 2021	'
Fair Value Disclosure [Line Items]	'
Estimated fair value of notes based on a market approach	$882.30

Property_and_Equipment_Net_Sch

Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property and equipment, net	'	'
Property and equipment, gross	$788,340	$499,727
Less: Accumulated depreciation and amortization	-284,382	-167,065
Property and equipment, net	503,958	332,662
Equipment	'	'
Property and equipment, net	'	'
Property and equipment, gross	535,092	367,949
Furniture and Leasehold Improvements	'	'
Property and equipment, net	'	'
Property and equipment, gross	113,069	54,965
Capitalized Software	'	'
Property and equipment, net	'	'
Property and equipment, gross	78,436	47,290
Construction in Progress	'	'
Property and equipment, net	'	'
Property and equipment, gross	$61,743	$29,523

Goodwill_and_Other_Intangible_2

Goodwill and Other Intangible Assets - Schedule of Goodwill Activities (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014
Goodwill [Line Items]	'
Beginning balance	$363,477
Foreign currency translation adjustment	-640
Ending balance	622,638
Gnip acquisition	'
Goodwill [Line Items]	'
Acquisition	104,747
Other acquisitions	'
Goodwill [Line Items]	'
Acquisition	155,054
Ending balance	$155,100

Goodwill_and_Other_Intangible_3

Goodwill and Other Intangible Assets - Schedule of Other Intangible Assets (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Finite Lived Intangible Assets [Line Items]	'	'
Gross Carrying Value	$188,557	$124,713
Accumulated Amortization	-73,211	-47,086
Net Carrying Value	115,346	77,627
Patents and Developed Technologies	'	'
Finite Lived Intangible Assets [Line Items]	'	'
Gross Carrying Value	153,497	100,553
Accumulated Amortization	-64,170	-45,440
Net Carrying Value	89,327	55,113
Publisher and Advertiser Relationships	'	'
Finite Lived Intangible Assets [Line Items]	'	'
Gross Carrying Value	32,000	21,100
Accumulated Amortization	-7,439	-1,248
Net Carrying Value	24,561	19,852
Assembled Workforce	'	'
Finite Lived Intangible Assets [Line Items]	'	'
Gross Carrying Value	1,960	1,960
Accumulated Amortization	-1,092	-300
Net Carrying Value	868	1,660
Other Intangible Assets	'	'
Finite Lived Intangible Assets [Line Items]	'	'
Gross Carrying Value	1,100	1,100
Accumulated Amortization	-510	-98
Net Carrying Value	$590	$1,002

Goodwill_and_Other_Intangible_4

Goodwill and Other Intangible Assets - Additional Information (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Goodwill And Intangible Assets Disclosure [Abstract]	'	'	'	'
Amortization of intangible assets	$11.80	$3.80	$26.10	$11

Goodwill_and_Other_Intangible_5

Goodwill and Other Intangible Assets - Schedule of Estimated Future Amortization Expenses (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Goodwill And Intangible Assets Disclosure [Abstract]	'	'
Remainder of 2014	$10,095	'
2015	35,555	'
2016	26,391	'
2017	11,624	'
2018	9,832	'
Thereafter	21,849	'
Net Carrying Value	$115,346	$77,627

Other_Balance_Sheet_Components2

Other Balance Sheet Components - Prepaid and Other Current Assets (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]	'	'
Deferred income taxes, net	$31,107	$62,122
Prepaid and other	170,365	31,175
Total	$201,472	$93,297

Other_Balance_Sheet_Components3

Other Balance Sheet Components - Accrued and Other Current Liabilities (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Payables And Accruals [Abstract]	'	'
Accrued compensation	$82,970	$29,882
Unsettled purchases of marketable securities	76,670	'
Accrued fixed assets and maintenance	30,166	5,697
Deferred revenue	21,881	14,479
Accrued publisher payments	20,819	15,370
Accrued professional services	10,301	7,089
Accrued tax liabilities	17,341	9,515
Accrued other	41,182	28,278
Total	$301,330	$110,310

Acquisitions_Additional_Inform

Acquisitions - Additional Information (Detail) (USD $)

9 Months Ended

1 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

Share data in Millions, unless otherwise specified

Sep. 30, 2014

Dec. 31, 2013

31-May-14

Sep. 30, 2014

31-May-14

Sep. 30, 2014

31-May-14

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Gnip Inc

Gnip Inc

Gnip Inc

Gnip Inc

Gnip Inc

Series of Individually Immaterial Business Acquisitions

Series of Individually Immaterial Business Acquisitions

Series of Individually Immaterial Business Acquisitions

Series of Individually Immaterial Business Acquisitions

Series of Individually Immaterial Business Acquisitions

All Acquisitions

Developed Technology Rights

Developed Technology Rights

Customer Relationships

Customer Relationships

Acquisition

Developed Technology Rights

Developed Technology Rights

Developed Technology Rights

Customer Relationships

Employee Stock Option

Minimum

Maximum

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Business acquisition, purchase price cash consideration

'

'

$107,300,000

'

'

'

'

$66,900,000

'

'

'

'

'

Business acquisition, common stock issued including shares of restricted stock

'

'

0.6

'

'

'

'

'

'

'

'

'

'

Business acquisition, common shares issuable in respect of assumed equity awards held by individuals

'

'

0.4

'

'

'

'

'

'

'

'

'

'

Business Combination, Consideration Transferred

'

'

134,100,000

'

'

'

'

188,100,000

'

'

'

'

'

Acquisition purchase price allocated to finite lived intangible assets

'

'

'

'

23,200,000

'

9,300,000

'

28,100,000

'

'

1,600,000

'

Acquisition purchase price allocated to liability

'

'

5,800,000

'

'

'

'

'

'

'

'

'

'

Acquisition purchase price allocated to deferred tax liability

'

'

6,400,000

'

'

'

'

3,200,000

'

'

'

'

'

Goodwill

622,638,000

363,477,000

104,700,000

'

'

'

'

155,100,000

'

'

'

'

'

Acquisition purchase price allocated to assets

'

'

9,100,000

'

'

'

'

6,500,000

'

'

'

'

'

Estimated useful life of intangible assets

'

'

'

'60 months

'

'60 months

'

'

'

'12 months

'48 months

'

'

Number of businesses acquired

'

'

'

'

'

'

'

8

'

'

'

'

'

Business acquisition, common stock issued

'

'

'

'

'

'

'

121,200,000

'

'

'

'

'

Fair value of contingent payment

97,700,000

'

'

'

'

'

'

'

'

'

'

'

'

Equity compensation service period

'4 years

'

'

'

'

'

'

'

'

'

'

'

'48 months

Unrecognized share-based compensation expense

'

'

'

'

'

'

'

'

'

'

'

'

$16,900,000

Net_Loss_Per_Share_Basic_and_D

Net Loss Per Share - Basic and Diluted Net Loss Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Net loss	($175,464)	($64,601)	($452,468)	($133,852)
Basic shares:	'	'	'	'
Weighted-average common shares outstanding	624,205	140,438	605,756	137,486
Weighted-average restricted stock subject to repurchase	-9,810	-6,739	-9,034	-6,290
Weighted-average shares used to compute basic net loss per share	614,395	133,699	596,722	131,196
Diluted shares:	'	'	'	'
Weighted-average shares used to compute diluted net loss per share	614,395	133,699	596,722	131,196
Net loss per share attributable to common stockholders:	'	'	'	'
Basic	($0.29)	($0.48)	($0.76)	($1.02)
Diluted	($0.29)	($0.48)	($0.76)	($1.02)

Net_Loss_Per_Share_Summary_of_

Net Loss Per Share - Summary of Potential Common Shares Excluded from Calculation of Diluted Net Loss Per Share Attributable to Common Stockholders (Details)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Stock Options	'	'	'	'
Earnings Per Share Basic [Line Items]	'	'	'	'
Anti-dilutive securities excluded from the computation of diluted net income per share	22,327	42,709	22,327	42,709
RSUs	'	'	'	'
Earnings Per Share Basic [Line Items]	'	'	'	'
Anti-dilutive securities excluded from the computation of diluted net income per share	74,114	41,733	74,114	41,733
Employee Stock Purchase Plans	'	'	'	'
Earnings Per Share Basic [Line Items]	'	'	'	'
Anti-dilutive securities excluded from the computation of diluted net income per share	1,145	'	1,147	'
Shares Subject to Repurchase	'	'	'	'
Earnings Per Share Basic [Line Items]	'	'	'	'
Anti-dilutive securities excluded from the computation of diluted net income per share	10,070	7,520	10,070	7,520
Warrant	'	'	'	'
Earnings Per Share Basic [Line Items]	'	'	'	'
Anti-dilutive securities excluded from the computation of diluted net income per share	23,183	117	23,183	117

Net_Loss_Per_Share_Additional_

Net Loss Per Share - Additional Information (Details) (USD $)	Sep. 30, 2014
Earnings Per Share Basic [Line Items]	'
Exercise price of the warrants	$105.28
Convertible Senior Notes Due 2019 and 2021	'
Earnings Per Share Basic [Line Items]	'
Conversion Price	$77.64

Common_Stock_and_Stockholders_2

Common Stock and Stockholders' Equity - Additional Information (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

0 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

15-May-14

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

RSUs

RSUs

RSUs

RSUs

Employee Stock Purchase Plans

Employee Stock Purchase Plans

Employee Stock Purchase Plans

2013 Equity Incentive Plan

2007 Equity Incentive Plan

Restricted Common Stock

Pre-2013 RSUs

Pre-2013 RSUs

Post-2013 RSUs

Employee Stock Option

Employee Stock Option

Employee Stock Option

Employee Stock Option

Employee Stock Option

Minimum

Maximum

2007 Equity Incentive Plan

All Acquisitions

Restricted Common Stock

Restricted Common Stock

All Acquisitions

All Acquisitions

Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Equity compensation service period

'

'

'4 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'48 months

'2 years

'4 years

Compensation expense related to restricted stock

$14,200,000

$7,800,000

$38,200,000

$20,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unamortized stock-based compensation expense related to restricted stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

114,700,000

69,000,000

'

1,420,000,000

'

'

'

'

'

'

'

Unamortized stock-based compensation expense, weighted average recognition period

'

'

'

'

'

'

'

'

'

'

'

'2 months 23 days

'

'

'2 years 6 months

'1 year 11 months 27 days

'

'3 years 1 month 13 days

'

'

'2 years 3 months 15 days

'

'

'

'

Stock options outstanding

22,327,000

'

22,327,000

'

42,246,000

'

'

'

'

'

'

'

26,200,000

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, capital shares reserved for future issuance

'

'

'

'

'

'

'

'

'

'

16,700,000

16,700,000

79,300,000

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, shares issued

632,158,000

'

632,158,000

'

569,922,000

'

'

'

'

'

'

'

'

'

'

17,100,000

'

'

'

'

'

'

'

'

'

Income taxes paid

'

'

16,168,000

'

'

'

'

'

'

'

'

'

'

'

'

'

16,200,000

'

'

'

'

'

'

'

'

Stock options restricted stock units outstanding

'

'

'

'

'

'

'

'

'

'

'

'

'

68,200,000

'

'

'

'

'

'

'

'

'

'

'

Number of shares purchased

'

'

'

'

'

'

'

'

'

1,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares purchased price, per share

'

'

'

'

'

'

'

'

'

$22.10

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based compensation expense

'

'

'

'

'

'

'

'

'

'

9,100,000

25,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock options exercised, intrinsic value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

265,200,000

24,000,000

802,300,000

95,300,000

'

'

'

Stock options vested, fair value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,800,000

4,400,000

10,700,000

8,700,000

'

'

'

Fair Value as of vesting dates of RSUs that are vested during the period

'

'

'

'

'

469,800,000

65,200,000

940,400,000

155,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based compensation, capitalized amount

10,900,000

3,400,000

26,400,000

6,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based compensation, weighted average grant date fair value

$26.10

'

$30.12

$11.13

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unamortized share-based compensation expense related to unvested stock options

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

39,700,000

'

39,700,000

'

'

'

'

Unrecognized share-based compensation expense

'

'

'

'

'

'

'

'

'

'

$5,800,000

$5,800,000

'

'

'

'

'

'

'

'

'

'

$16,900,000

'

'

Common_Stock_and_Stockholders_3

Common Stock and Stockholders' Equity - Summary of Restricted Stock Activity (Details) (Restricted Common Stock, USD $)	9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014
Restricted Common Stock	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Number of Unvested Shares, beginning of period	6,866
Number of shares, granted	2,467
Number of Shares, vested	-2,256
Number of Shares, Canceled	-98
Number of Unvested Shares, end of period	6,979
Weighted Average Grant Date Fair Value Per Share, beginning of period	$17.60
Weighted Average Grant Date Fair Value Per Share, Granted	$33.80
Weighted Average Grant Date Fair Value Per Share, Vested	$17.18
Weighted Average Grant Date Fair Value Per Share, Canceled	$13.46
Weighted Average Grant Date Fair Value Per Share, end of period	$23.52

Common_Stock_and_Stockholders_4

Common Stock and Stockholders' Equity - Summary of Stock Option Activity (Details) (USD $)	9 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Options Outstanding - Number of Shares	'	'
Outstanding at beginning of period	42,246	'
Options granted	500	'
Options assumed in connection with acquisitions	819	'
Options exercised	-20,652	'
Options canceled	-586	'
Outstanding at end of period	22,327	42,246
Vested and expected to vest at end of period	21,885	'
Exercisable at end of period	17,638	'
Options Outstanding - Weighted-Average Exercise Price Per Share	'	'
Outstanding at beginning of period	$1.89	'
Options granted	$42.05	'
Options assumed in connection with acquisitions	$1.60	'
Options exercised	$1.22	'
Options canceled	$8.24	'
Outstanding at end of period	$3.23	$1.89
Vested and expected to vest at end of period	$3.10	'
Exercisable at end of period	$1.54	'
Options Outstanding - Weighted-Average Remaining Contractual Life	'	'
Outstanding	'6 years 1 month 6 days	'6 years 5 months 19 days
Vested and expected to vest at end of period	'6 years 26 days	'
Exercisable at end of period	'5 years 8 months 5 days	'
Options Outstanding - Aggregate Intrinsic Value	'	'
Outstanding at beginning of period	$2,609,295	'
Outstanding at end of period	1,079,592	2,609,295
Vested and expected to vest at end of period	1,061,031	'
Exercisable at end of period	$882,557	'

Common_Stock_and_Stockholders_5

Common Stock and Stockholders' Equity - Summary of RSU Activity (Details) (RSUs, USD $)	9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014
RSUs	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Number of Unvested Shares, beginning of period	79,876
Number of shares, granted	22,718
Number of Shares, vested	-19,403
Number of Shares, Canceled	-9,077
Number of Unvested Shares, end of period	74,114
Weighted Average Grant Date Fair Value Per Share, beginning of period	$19.54
Weighted Average Grant Date Fair Value Per Share, Granted	$49.12
Weighted Average Grant Date Fair Value Per Share, Vested	$19.38
Weighted Average Grant Date Fair Value Per Share, Canceled	$17.07
Weighted Average Grant Date Fair Value Per Share, end of period	$28.56

Common_Stock_and_Stockholders_6

Common Stock and Stockholders' Equity - Stock Based Compensation Expense Recorded for Employee and Non Employee Stock Options (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	$169,602	$43,602	$454,382	$79,170
Employee	'	'	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	167,249	43,320	447,698	77,735
Non-Employee	'	'	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	$2,353	$282	$6,684	$1,435

Common_Stock_and_Stockholders_7

Common Stock and Stockholders' Equity - Compensation Expense Allocated (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	$169,602	$43,602	$454,382	$79,170
Cost of Revenue	'	'	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	13,596	3,060	37,296	5,015
Research and Development	'	'	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	93,973	29,180	264,784	53,377
Sales and Marketing	'	'	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	42,884	5,742	108,232	10,356
General and Administrative	'	'	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	$19,149	$5,620	$44,070	$10,422

Common_Stock_and_Stockholders_8

Common Stock and Stockholders' Equity - Schedule of Share-based Payment Award, Valuation Assumptions (Details) (Employee Stock Option)	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2013
Employee Stock Option	'	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'	'
Expected dividend yield	0.00%	0.00%	0.00%
Risk-free interest rate	1.86%	1.47%	1.07%
Expected volatility	43.70%	42.54%	53.77%
Expected term (in years)	'5 years 10 months 6 days	'4 years 8 months 23 days	'5 years 7 months 17 days

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Tax Contingency [Line Items]	'	'	'	'
Provision (benefit) for income taxes	$159,000	$360,000	($4,218,000)	$1,494,000
Unrecognized tax benefits, period change	26,200,000	'	62,600,000	'
Unrecognized tax benefits, gross	105,700,000	'	105,700,000	'
RSUs | Federal	'	'	'	'
Income Tax Contingency [Line Items]	'	'	'	'
Increase of Operating Loss Carryforwards	435,400,000	'	1,590,000,000	'
Excess tax benefits from restricted stock	235,000,000	'	1,020,000,000	'
RSUs | State	'	'	'	'
Income Tax Contingency [Line Items]	'	'	'	'
Increase of Operating Loss Carryforwards	114,700,000	'	418,700,000	'
Excess tax benefits from restricted stock	$61,900,000	'	$269,200,000	'

Convertible_Notes_Additional_I

Convertible Notes - Additional Information (Details) (USD $)	1 Months Ended		3 Months Ended		9 Months Ended
Share data in Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2014		Sep. 30, 2014
Debt Instrument [Line Items]	'		'		'
Initial purchasers' discount	$27,000,000		$27,000,000		$27,000,000
Debt issuance costs	'		'		500,000
Proceeds from offerings, net of transaction costs	1,770,000,000		'		1,770,000,000
Debt Instrument, frequency of periodic payment	'		'		'semi-annually
Debt Instrument, date of first required payment	'		'		15-Mar-15
Debt Instrument, payment terms	'		'		'The interest rates are fixed at 0.25% and 1.00% per annum and are payable semi-annually in arrears on March 15 and September 15 of each year, commencing on March 15, 2015.
Amortization of debt discount allocated to interest expense	'		200,000		200,000
Accrued coupon interest expense	'		400,000		400,000
Price percentage for repurchase of notes if repurchase option is elected	'		'		100.00%
Debt issuance costs allocated to the carrying component	'		'		100,000
Amortization of discount on convertible notes	'		2,411,000		2,411,000
Convertible notes	1,293,604,000		1,293,604,000		1,293,604,000
Number of shares authorized for repurchase under hedge agreement	23.2		23.2		23.2
Exercise price of the option to repurchase stock	'		'		$77.64
Purchases of convertible note hedges	'		'		387,450,000
Number of warrants issued	23.2		23.2		23.2
Exercise price of the warrants	$105.28		$105.28		$105.28
Proceeds from issuance of warrants	'		'		275,130,000
Interest Expense	'		'		'
Debt Instrument [Line Items]	'		'		'
Amortization of discount on convertible notes	'		'		400,000
Scenario One	'		'		'
Debt Instrument [Line Items]	'		'		'
Convertible debt instrument, consecutive trading days threshold	'		'		'30 days
Convertible debt instrument, percentage of conversion price to trigger conversion to common stock	'		'		130.00%
Scenario One | Minimum	'		'		'
Debt Instrument [Line Items]	'		'		'
Convertible debt instrument, trading days threshold	'		'		20
Scenario Two	'		'		'
Debt Instrument [Line Items]	'		'		'
Convertible debt instrument, trading days threshold	'		'		5
Convertible debt instrument, consecutive trading days threshold	'		'		'5 days
Convertible debt instrument, percentage of conversion price to trigger conversion to common stock	'		'		98.00%
Common Stock	'		'		'
Debt Instrument [Line Items]	'		'		'
Debt instrument, conversion principal amount	'		'		1,000
Debt Instrument, conversion ratio	'		'		12.8793
Conversion Price	$77.64		$77.64		$77.64
Debt Instrument, terms of conversion	'		'		'Each $1,000 of principal of these notes will initially be convertible into 12.8793 shares of the Companybs common stock, which is equivalent to an initial conversion price of approximately $77.64 per share, subject to adjustment upon the occurrence of specified events.
Convertible Senior Notes 2019	'		'		'
Debt Instrument [Line Items]	'		'		'
Debt instrument, principal amount	900,000,000		900,000,000		900,000,000
Initial purchasers' discount	226,672,000	[1]	226,672,000	[1]	226,672,000	[1]
Debt Instrument, conversion earliest date	'		'		15-Mar-19
Effective interest rate for amortization to interest expense	5.75%		5.75%		5.75%
Carrying amount of the equity component	214,591,000	[2]	214,591,000	[2]	214,591,000	[2]
Convertible notes	673,328,000		673,328,000		673,328,000
Remaining period for convertible debt	'		'		'59 months
Convertible Senior Notes 2021	'		'		'
Debt Instrument [Line Items]	'		'		'
Debt instrument, principal amount	900,000,000		900,000,000		900,000,000
Initial purchasers' discount	279,724,000	[1]	279,724,000	[1]	279,724,000	[1]
Debt Instrument, conversion earliest date	'		'		15-Mar-21
Effective interest rate for amortization to interest expense	6.25%		6.25%		6.25%
Carrying amount of the equity component	267,381,000	[2]	267,381,000	[2]	267,381,000	[2]
Convertible notes	$620,276,000		$620,276,000		$620,276,000
Remaining period for convertible debt	'		'		'83 months
[1]	Included in the consolidated balance sheets within convertible notes and amortized over the remaining lives of the Notes.
[2]	Included in the consolidated balance sheets within additional paid-in capital.

Convertible_Notes_Components_o

Convertible Notes - Components of Notes (Details) (USD $)	Sep. 30, 2014
Principal amounts:	'
Unamortized initial purchasers' discount and debt discount	($27,000,000)
Net carrying amount	1,293,604,000
Convertible Senior Notes 2019	'
Principal amounts:	'
Debt instrument, principal amount	900,000,000
Unamortized initial purchasers' discount and debt discount	-226,672,000	[1]
Net carrying amount	673,328,000
Carrying amount of the equity component	214,591,000	[2]
Convertible Senior Notes 2021	'
Principal amounts:	'
Debt instrument, principal amount	900,000,000
Unamortized initial purchasers' discount and debt discount	-279,724,000	[1]
Net carrying amount	620,276,000
Carrying amount of the equity component	$267,381,000	[2]
[1]	Included in the consolidated balance sheets within convertible notes and amortized over the remaining lives of the Notes.
[2]	Included in the consolidated balance sheets within additional paid-in capital.

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Details) (USD $)	9 Months Ended
	Sep. 30, 2014
Other Commitments [Line Items]	'
Unsecured revolving credit facility	$1,000,000,000
Line of credit facility, expiration date	22-Oct-18
Line of credit facility, interest rate description	'Loans under the credit facility bear interest, at the Companybs option, at (i) a base rate based on the highest of the prime rate, the federal funds rate plus 0.50% and an adjusted LIBOR rate for a one-month interest period plus 1.00%, in each case plus a margin ranging from 0.00% to 0.75% or (ii) an adjusted LIBOR rate plus a margin ranging from 1.00% to 1.75%.
Expiration year of operating lease, earliest	'2014
Expiration year of operating lease, last	'2026
Amended revolving credit agreement, leverage ratio above which security will be requited	2.50%
Amended revolving credit agreement, outstanding amount above which security will be requited	$500,000,000
Amended revolving credit agreement, percentage of borrowed amount to borrowing capacity above which security will be requited	50.00%
Base Rate | Minimum	'
Other Commitments [Line Items]	'
Line of credit facility, interest rate	0.00%
Base Rate | Maximum	'
Other Commitments [Line Items]	'
Line of credit facility, interest rate	0.75%
London Interbank Offered Rate (LIBOR) | Minimum	'
Other Commitments [Line Items]	'
Line of credit facility, interest rate	1.00%
London Interbank Offered Rate (LIBOR) | Maximum	'
Other Commitments [Line Items]	'
Line of credit facility, interest rate	1.75%
Federal Funds Rate Plus 0.50%	'
Other Commitments [Line Items]	'
Line of credit facility, interest rate	0.50%
Libor Rate One Month Interest Period Plus 1.00%	'
Other Commitments [Line Items]	'
Line of credit facility, interest rate	1.00%

Commitments_and_Contingencies_1

Commitments and Contingencies - Minimum Commitments Under Non-Cancelable Capital and Operating Lease Agreements (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Commitments And Contingencies Disclosure [Abstract]	'	'
Remainder of 2014	$22,075	'
2015	107,583	'
2016	133,760	'
2017	136,985	'
2018	133,060	'
Thereafter	394,802	'
Total	928,265	'
Remainder of 2014	31,863	'
2015	109,579	'
2016	71,702	'
2017	30,421	'
2018	2,709	'
Thereafter	0	'
Total	246,274	'
Less: Amounts representing interest	14,126	'
Total capital lease obligation	232,148	'
Less: Short-term portion	110,527	87,126
Long-term portion	$121,621	$110,520

Operations_by_Geographic_Area_1

Operations by Geographic Area - Revenue by Geographic Area (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenue:	'	'	'	'
Revenue	$361,266	$168,580	$923,924	$422,215
United States	'	'	'	'
Revenue:	'	'	'	'
Revenue	240,169	124,687	630,673	315,486
International	'	'	'	'
Revenue:	'	'	'	'
Revenue	$121,097	$43,893	$293,251	$106,729

Operations_by_Geographic_Area_2

Operations by Geographic Area - Additional Information (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenues From External Customers And Long Lived Assets [Line Items]	'	'	'	'
Revenue	$361,266	$168,580	$923,924	$422,215
Sales | United Kingdom	'	'	'	'
Revenues From External Customers And Long Lived Assets [Line Items]	'	'	'	'
Revenue	$37,500	$17,200	$94,800	$43,000
Geographic Concentration Risk | Sales Revenue Net | United Kingdom	'	'	'	'
Revenues From External Customers And Long Lived Assets [Line Items]	'	'	'	'
Revenue percentage	10.00%	10.00%	10.00%	10.00%

Operations_by_Geographic_Area_3

Operations by Geographic Area - Long-Lived Assets by Geographic Area (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Long-lived assets:	'	'
Property and equipment, net	$503,958	$332,662
United States	'	'
Long-lived assets:	'	'
Property and equipment, net	479,020	327,250
International	'	'
Long-lived assets:	'	'
Property and equipment, net	$24,938	$5,412

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Details) (USD $)	9 Months Ended	1 Months Ended
Share data in Millions, unless otherwise specified	Sep. 30, 2014	Oct. 31, 2014	Oct. 31, 2014	Oct. 31, 2014
		Subsequent Event	Subsequent Event	Subsequent Event
			Two Thousand Nineteen Notes	Two Thousand Twenty One Notes
Subsequent Event [Line Items]	'	'	'	'
Debt instrument, principal amount	'	'	$35,000,000	$54,000,000
Number of shares issued for repurchase under hedge agreement	23.2	1.1	'	'
Purchases of convertible note hedges	387,450,000	19,700,000	'	'
Number of warrants issued	23.2	1.1	'	'
Proceeds from issuance of warrants	$275,130,000	$14,100,000	'	'