Twitter (TWTR) 10-Q 6 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 26, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Trading Symbol	TWTR
Entity Registrant Name	TWITTER, INC.
Entity Central Index Key	1,418,091
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		682,946,653

CONSOLIDATED BALANCE SHEETS (Un

CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 876,432	$ 1,510,724
Short-term investments	2,612,762	2,111,154
Accounts receivable, net of allowance for doubtful accounts of $4,575 and $5,507 as of September 30, 2015 and December 31, 2014, respectively	536,788	418,454
Prepaid expenses and other current assets	237,577	215,521
Total current assets	4,263,559	4,255,853
Property and equipment, net	699,502	557,019
Intangible assets	147,286	105,011
Goodwill	1,123,121	622,570
Other assets	55,596	42,629
Total assets	6,289,064	5,583,082
Current liabilities:
Accounts payable	40,100	53,241
Accrued and other current liabilities	294,057	228,233
Capital leases, short-term	93,621	112,320
Total current liabilities	427,778	393,794
Convertible notes	1,434,968	1,376,020
Capital leases, long-term	73,525	118,950
Deferred and other long-term tax liabilities, net	32,958	24,706
Other long-term liabilities	45,672	43,209
Total liabilities	$ 2,014,901	$ 1,956,679
Commitments and contingencies (Note 12)
Stockholders' equity:
Preferred stock, $0.000005 par value-- 200,000 shares authorized; none issued and outstanding
Common stock, $0.000005 par value-- 5,000,000 shares authorized; 681,409 and 642,385 shares issued and outstanding as of September 30, 2015 and December 31, 2014, respectively	$ 3	$ 3
Additional paid-in capital	6,311,697	5,208,870
Accumulated other comprehensive loss	(34,296)	(10,024)
Accumulated deficit	(2,003,241)	(1,572,446)
Total stockholders' equity	4,274,163	3,626,403
Total liabilities and stockholders' equity	$ 6,289,064	$ 5,583,082

CONSOLIDATED BALANCE SHEETS (U3

CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 4,575	$ 5,507
Preferred stock, par value	$ 0.000005	$ 0.000005
Preferred stock, shares authorized	200,000,000	200,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.000005	$ 0.000005
Common stock, shares authorized	5,000,000,000	5,000,000,000
Common stock, shares issued	681,409,000	642,385,000
Common stock, shares outstanding	681,409,000	642,385,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Revenue	$ 569,237	$ 361,266	$ 1,507,559	$ 923,924
Costs and expenses
Cost of revenue	200,195	124,166	511,293	309,696
Research and development	207,937	183,342	596,590	509,828
Sales and marketing	208,797	164,015	594,302	410,511
General and administrative	57,545	51,174	188,231	134,602
Total costs and expenses	674,474	522,697	1,890,416	1,364,637
Loss from operations	(105,237)	(161,431)	(382,857)	(440,713)
Interest expense	(25,239)	(6,079)	(73,995)	(11,835)
Other income (expense), net	1,948	(7,795)	10,378	(4,138)
Loss before income taxes	(128,528)	(175,305)	(446,474)	(456,686)
Provision (benefit) for income taxes	3,162	159	(15,679)	(4,218)
Net loss	$ (131,690)	$ (175,464)	$ (430,795)	$ (452,468)
Net loss per share attributable to common stockholders:
Basic	$ (0.20)	$ (0.29)	$ (0.66)	$ (0.76)
Diluted	$ (0.20)	$ (0.29)	$ (0.66)	$ (0.76)
Weighted-average shares used to compute net loss per share attributable to common stockholders:
Basic	670,604	614,395	655,721	596,722
Diluted	670,604	614,395	655,721	596,722

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (131,690)	$ (175,464)	$ (430,795)	$ (452,468)
Other comprehensive income (loss):
Unrealized gain (loss) on investments in available-for-sale securities, net of tax	866	(153)	921	(231)
Foreign currency translation adjustment	(2,328)	(1,266)	(25,193)	(666)
Net change in accumulated other comprehensive loss	(1,462)	(1,419)	(24,272)	(897)
Comprehensive loss	$ (133,152)	$ (176,883)	$ (455,067)	$ (453,365)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities
Net loss	$ (430,795)	$ (452,468)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	225,377	145,737
Stock-based compensation expense	523,869	454,382
Amortization of discount on convertible notes	51,139	2,411
Provision for bad debt	360	2,944
Deferred income tax benefit	(24,220)	(9,737)
Other adjustments	5,327	9,740
Changes in assets and liabilities, net of assets acquired and liabilities assumed from acquisitions:
Accounts receivable	(105,486)	(77,833)
Prepaid expenses and other assets	(12,684)	(140,710)
Accounts payable	(9,511)	5,298
Accrued and other liabilities	60,452	98,714
Net cash provided by operating activities	283,828	38,478
Cash flows from investing activities
Purchases of property and equipment	(266,816)	(132,839)
Purchases of marketable securities	(3,086,004)	(1,617,415)
Proceeds from maturities of marketable securities	2,225,255	1,522,582
Proceeds from sales of marketable securities	359,817	168,168
Changes in restricted cash	(2,840)	(11,029)
Business combinations, net of cash acquired	(51,644)	(163,477)
Purchases of cost method investments and other	(12,430)	(1,700)
Net cash used in investing activities	(834,662)	(235,710)
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	(8,878)	(16,168)
Repayments of capital lease obligations	(91,365)	(75,076)
Proceeds from exercise of stock options	8,450	25,027
Proceeds from issuances of common stock under employee stock purchase plan	21,600	21,224
Other financing activities	1,983	(2,662)
Net cash provided by (used in) financing activities	(68,210)	1,612,550
Net increase (decrease) in cash and cash equivalents	(619,044)	1,415,318
Foreign exchange effect on cash and cash equivalents	(15,248)	(3,533)
Cash and cash equivalents at beginning of period	1,510,724	841,010
Cash and cash equivalents at end of period	876,432
Supplemental disclosures of non-cash investing and financing activities
Common stock issued in connection with acquisitions	516,538	147,958
Equipment purchases under capital leases	24,236	110,409
Changes in accrued equipment purchases	$ (4,380)	$ 14,345

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block]	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 offers products and services for users, advertisers, developers and platform and data partners. 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. Certain prior period amounts have been reclassified to conform to the current period presentation. 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, 2014. 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 May 2014, the Financial Accounting Standards Board (“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 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. In July 2015, the FASB decided to delay the effective date of the guidance by one year and permit early adoption for annual and interim periods beginning after December 15, 2016. As a result of the revision, the guidance will be effective for fiscal years, and interim periods with those fiscal years, beginning after December 15, 2017 and can be applied either retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. 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. In February 2015, the FASB issued a new accounting standard update on consolidation analysis. The new guidance amends the current consolidation guidance with respect to the analysis that a reporting entity must perform to determine whether it should consolidate certain types of legal entities. This guidance will be effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted, but the guidance must be applied as of the beginning of the fiscal year containing the adoption date. Adoption of this new accounting standard update is not expected to have a material impact on the Company’s financial statements. In April 2015, the FASB issued a new accounting standard update on the presentation of debt issuance costs. The new guidance requires the debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. This guidance will be effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted. Adoption of this new accounting standard update is not expected to have a material impact on the Company’s financial statements. In September 2015, the FASB issued a new accounting standard update on simplifying the accounting for measurement-period adjustments in business combinations. The new guidance requires that the adjustments to provisional amounts that are identified during the measurement period be recognized in the reporting period when the adjustments are determined. In addition, the effect on earnings of changes as a result of the change to the provisional amounts is required to be recorded in the same period’s financial statements. This guidance will be effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted. Adoption of this new accounting standard update is not expected to have a material impact on the Company’s financial statements.

Cash, Cash Equivalents and Shor

Cash, Cash Equivalents and Short-term Investments	9 Months Ended
	Sep. 30, 2015
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, 2015 2014 Cash and cash equivalents: Cash $ 210,399 $ 147,848 Money market funds 337,045 882,443 U.S. government and agency securities including treasury bills — 271,418 Corporate notes, certificates of deposit and commercial paper 328,988 209,015 Total cash and cash equivalents $ 876,432 $ 1,510,724 Short-term investments: U.S. government and agency securities including treasury bills $ 1,160,104 $ 1,009,541 Corporate notes, certificates of deposit and commercial paper 1,452,658 1,101,613 Total short-term investments $ 2,612,762 $ 2,111,154 Marketable securities are classified as available-for-sale for use in current operations and are presented as short-term investments in the consolidated balance sheets. The contractual maturities of securities classified as available-for-sale as of September 30, 2015 were as follows (in thousands): September 30, 2015 Due within one year $ 1,946,341 Due after one year through two years 666,421 Total $ 2,612,762 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): September 30, 2015 Gross Gross Gross Aggregated Amortized Unrealized Unrealized Estimated Costs Gains Losses Fair Value U.S. government and agency securities including treasury bills $ 1,159,601 $ 535 $ (32 ) $ 1,160,104 Corporate notes, certificates of deposit and commercial paper 1,453,198 175 (715 ) 1,452,658 Total available-for-sale securities classified as short-term investments $ 2,612,799 $ 710 $ (747 ) $ 2,612,762 December 31, 2014 Gross Gross Gross Aggregated Amortized Unrealized Unrealized Estimated Costs Gains Losses Fair Value U.S. government and agency securities including treasury bills $ 1,009,827 $ 8 $ (294 ) $ 1,009,541 Corporate notes, certificates of deposit and commercial paper 1,102,275 4 (666 ) 1,101,613 Total available-for-sale securities classified as short-term investments $ 2,112,102 $ 12 $ (960 ) $ 2,111,154 There were no securities in a continuous loss position for 12 months or longer as of September 30, 2015 and December 31, 2014. 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, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 3. Fair Value Measurements The Company measures its cash equivalents, short-term investments and derivative financial instruments at fair value. The Company classifies its cash equivalents, short-term investments and derivative financial instruments within Level 1 or Level 2 because the Company values these investments using quoted market prices or alternative pricing sources and models utilizing market observable inputs. 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 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, 2015 and December 31, 2014 based on the three-tier fair value hierarchy (in thousands): September 30, 2015 Level 1 Level 2 Level 3 Total Assets Cash equivalents: Money market funds $ 337,045 $ — $ — $ 337,045 Commercial paper — 328,988 — 328,988 Short-term investments: Treasury bills 38,074 — — 38,074 U.S. government securities — 531,520 — 531,520 Agency securities — 590,510 — 590,510 Corporate notes — 647,449 — 647,449 Commercial paper — 301,465 — 301,465 Certificates of deposit — 503,744 — 503,744 Other current assets: Foreign currency forward contracts — 413 — 413 Liabilities Other current liabilities: Foreign currency forward contracts — (533 ) — (533 ) Total $ 375,119 $ 2,903,556 $ — $ 3,278,675 December 31, 2014 Level 1 Level 2 Level 3 Total Assets Cash equivalents: Money market funds $ 882,443 $ — $ — $ 882,443 Treasury bills 73,525 — — 73,525 U.S. government securities — 157,895 — 157,895 Agency securities — 39,998 — 39,998 Corporate notes — 13,684 — 13,684 Commercial paper — 185,321 — 185,321 Certificates of deposit — 10,010 — 10,010 Short-term investments: Treasury bills 167,575 — — 167,575 U.S. government securities — 746,128 — 746,128 Agency securities — 95,838 — 95,838 Corporate notes — 551,604 — 551,604 Commercial paper — 300,589 — 300,589 Certificates of deposit — 249,420 — 249,420 Total $ 1,123,543 $ 2,350,487 $ — $ 3,474,030 In 2014, the Company issued $935.0 million principal amount of 0.25% convertible senior notes due in 2019 (the “2019 Notes”) and $954.0 million principal amount of 1.00% convertible senior notes due in 2021 (the “2021 Notes” and together with the 2019 Notes, the “Notes”) in a private placement to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended. Refer to Note 8 – Convertible Senior Notes for further details on the Notes. The estimated fair value of the 2019 Notes and 2021 Notes based on a market approach as of September 30, 2015 was approximately $822.5 million and $815.2 million respectively, which represents a Level 2 valuation. The estimated fair value was determined based on the estimated or actual bids and offers of the Notes in an over-the-counter market on September 30, 2015. Derivative Financial Instruments The Company enters into foreign currency forward contracts with financial institutions to reduce the risk that its earnings may be adversely affected by the impact of exchange rate fluctuations on monetary assets or liabilities denominated in currencies other than the functional currency of a subsidiary. These contracts do not subject the Company to material balance sheet risk due to exchange rate movements because gains and losses on these derivatives are intended to offset gains and losses on the hedged foreign currency denominated assets and liabilities. These foreign currency forward contracts are not designated as hedging instruments. The Company recognizes these derivative instruments as either assets or liabilities in the consolidated balance sheets at fair value based on a Level 2 valuation. The Company records changes in the fair value (i.e., gains or losses) of the derivatives as other income (expense), net in the consolidated statements of operations. The notional principal of foreign currency forward contracts outstanding was equivalent to $299.3 million at September 30, 2015. There were no outstanding foreign currency forward contracts as of December 31, 2014. The fair values of outstanding derivative instruments for the periods presented on a gross basis are as follows (in thousands): September 30, Balance Sheet Location 2015 Assets Foreign currency forward contracts not designated as hedging instruments Other current assets $ 413 Liabilities Foreign currency forward contracts not designated as hedging instruments Other current liabilities 533 Total $ (120 ) The Company recognized $3.7 million gains on the foreign currency contracts in both the three and nine months ended September 30, 2015. The Company did not have any derivative financial instruments in the three and nine months ended September 30, 2014.

Property and Equipment, Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2015
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, 2015 2014 Property and equipment, net Equipment $ 675,559 $ 584,561 Furniture and leasehold improvements 241,981 131,851 Capitalized software 196,783 82,052 Construction in progress 95,509 89,806 Total 1,209,832 888,270 Less: Accumulated depreciation and amortization (510,330 ) (331,251 ) Property and equipment, net $ 699,502 $ 557,019

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Note 5. Goodwill and Intangible Assets The following table presents the goodwill activities for the periods presented (in thousands): Goodwill Balance as of December 31, 2014 $ 622,570 TellApart acquisition 394,989 Other acquisitions 106,198 Foreign currency translation adjustment (636 ) Balance as of September 30, 2015 $ 1,123,121 For the periods presented, the gross goodwill balance equaled the net balance since no impairment charges have been recorded. The following table presents the detail of intangible assets for the periods presented (in thousands): Gross Carrying Accumulated Net Carrying Value Amortization Value September 30, 2015: Patents and developed technologies $ 141,169 $ (51,270 ) $ 89,899 Publisher and advertiser relationships 75,300 (19,606 ) 55,694 Assembled workforce 1,960 (1,650 ) 310 Other intangible assets 3,200 (1,817 ) 1,383 Total $ 221,629 $ (74,343 ) $ 147,286 December 31, 2014: Patents and developed technologies $ 105,052 $ (23,165 ) $ 81,887 Publisher and advertiser relationships 32,000 (9,831 ) 22,169 Assembled workforce 1,960 (1,457 ) 503 Other intangible assets 1,100 (648 ) 452 Total $ 140,112 $ (35,101 ) $ 105,011 Amortization expense associated with intangible assets for the three months ended September 30, 2015 and 2014 was $14.5 million and $11.8 million, respectively, and for the nine months ended September 30, 2015 and 2014 was $39.2 million and $26.1 million, respectively. Estimated future amortization expense as of September 30, 2015 is as follows (in thousands): Remainder of 2015 $ 13,541 2016 43,877 2017 27,872 2018 21,239 2019 13,644 Thereafter 27,113 Total $ 147,286

Accrued and Other Current Liabi

Accrued and Other Current Liabilities	9 Months Ended
	Sep. 30, 2015
Statement Of Financial Position [Abstract]
Accrued and Other Current Liabilities	Note 6. 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, 2015 2014 Accrued compensation $ 89,053 $ 68,000 Accrued publisher payments 33,598 27,996 Deferred revenue 28,813 18,679 Accrued tax liabilities 22,536 18,380 Accrued sales and marketing expenses 12,312 25,264 Accrued other 107,745 69,914 Total $ 294,057 $ 228,233

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2015
Business Combinations [Abstract]
Acquisitions	Note 7. Acquisitions In May 2015, the Company completed its acquisition of TellApart, Inc. (“TellApart”), a privately held marketing technology company with unique retargeting capabilities headquartered in Burlingame, California. The acquisition is expected to bring the power of retargeting to the Company to help advertisers reach their users. The acquisition of TellApart has been accounted for as a business combination. The fair value of assets acquired and liabilities assumed at the acquisition date was based on a preliminary valuation and estimates and assumptions that are subject to change within the measurement period. The fair value of the total consideration of $479.1 million (paid in shares of the Company’s common stock having a total fair value of $456.5 million and cash of $22.6 million) for the acquisition of TellApart was allocated to the acquired tangible and intangible assets and assumed liabilities based on their estimated fair values at closing as follows: $21.4 million to developed technology, $43.3 million to advertiser relationships, $2.1 million to trade name, $29.6 million to cash acquired, $19.7 million to account receivables acquired, which are expected to be substantially collected, $2.2 million to other tangible assets acquired, $11.8 million to liabilities assumed, $22.4 million to deferred tax liability recorded, and the excess $395.0 million of the purchase price over the fair value of net assets acquired was recorded as goodwill. This goodwill is primarily attributable to the expected synergies from potential monetization opportunities and from integrating the retargeting technologies into the Company’s mobile platforms, During the nine months ended September 30, 2015, the Company acquired four other companies, which were accounted for as business combinations. The total purchase price of $118.9 million (paid in shares of the Company’s common stock having a total fair value of $60.1 million and cash of $58.8 million) for these acquisitions was allocated as follows: $12.9 million to developed technologies, $3.2 million to net tangible assets acquired based on their estimated fair value on the acquisition date, $3.4 million to deferred tax liability, and the excess $106.2 million of the purchase price over the fair value of net assets acquired to goodwill. Tax deductible goodwill resulting from certain of these acquisitions was $4.1 million. The remaining goodwill is not tax deductible for U.S. income tax purposes. Developed technologies will be amortized on a straight-line basis over their estimated useful lives of 12 to 60 months. In connection with all of the acquisitions completed during the nine months ended September 30, 2015, the Company also agreed to pay cash and issue shares of its common stock with a total fair value up to $102.9 million, which is to be paid to certain employees of the acquired entities contingent upon their continued employment with the Company. The Company will recognize compensation expense related to the equity consideration over the requisite service periods of up to 48 months from the respective acquisition dates on a straight-line basis. In addition, the Company will recognize approximately $37.2 million of stock-based compensation expense in relation to assumed stock options over the remaining requisite service periods of up to 45 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. Actual and 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.

Convertible Senior Notes

Convertible Senior Notes	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Convertible Senior Notes	Note 8. Convertible Senior 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. In October 2014, pursuant to the exercise of the overallotment option by the initial purchasers, the Company issued an additional $35.0 million principal amount of 2019 Notes and $54.0 million principal amount of 2021 Notes. The total net proceeds from this offering were approximately $1.86 billion, after deducting $28.3 million of initial purchasers’ discount and $0.5 million debt issuance costs in connection with the 2019 Notes and the 2021 Notes. The 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. For the three and nine months ended September 30, 2015, the Company recognized $18.8 million and $55.3 million, respectively, of interest expense related to the amortization of the debt discount. As of September 30, 2015, the net carrying value, net of the initial purchasers’ discount and debt discount, of 2019 Notes and 2021 Notes was $742.0 million and $692.9 million, respectively. The Notes consisted of the following (in thousands): September 30, 2015 December 31, 2014 2019 Notes 2021 Notes 2019 Notes 2021 Notes Principal amounts: Principal $ 935,000 $ 954,000 $ 935,000 $ 954,000 Unamortized initial purchasers' discount and debt discount (1) (192,957 ) (261,075 ) (225,104 ) (287,876 ) Net carrying amount $ 742,043 $ 692,925 $ 709,896 $ 666,124 Carrying amount of the equity component (2) $ 222,826 $ 283,283 $ 222,826 $ 283,283 (1) (2) As of September 30, 2015, the remaining life of the 2019 Notes and 2021 Notes is approximately 47 months and 71 months, respectively. Concurrently with the offering of these Notes in September and October 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 24.3 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 $407.2 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 24.3 million shares of the Company’s common stock at a price of $105.28. The Company received $289.3 million in cash proceeds from the sale of these warrants.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Net Loss Per Share	Note 9. Net Loss per Share 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, 2015 and 2014, the Company’s potential common stock instruments such as stock options, Restricted Stock Units (“RSUs”), shares to be purchased under the 2013 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, 2015 2014 2015 2014 Net loss $ (131,690 ) $ (175,464 ) $ (430,795 ) $ (452,468 ) Basic shares: Weighted-average common shares outstanding 678,817 624,205 663,897 605,756 Weighted-average restricted stock subject to repurchase (8,213 ) (9,810 ) (8,176 ) (9,034 ) Weighted-average shares used to compute basic net loss per share 670,604 614,395 655,721 596,722 Diluted shares: Weighted-average shares used to compute diluted net loss per share 670,604 614,395 655,721 596,722 Net loss per share attributable to common stockholders: Basic $ (0.20 ) $ (0.29 ) $ (0.66 ) $ (0.76 ) Diluted $ (0.20 ) $ (0.29 ) $ (0.66 ) $ (0.76 ) The following number of potential shares of the Company’s common stock 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, 2015 2014 RSUs 46,582 74,114 Warrants 24,329 23,183 Stock options 17,384 22,327 Shares subject to repurchase 7,959 10,070 Employee stock purchase plan 1,760 1,147 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 of 24.3 million shares will have a dilutive impact on diluted net income per share of common stock when the average market price of the Company’s 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 Company’s 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 Company’s common stock is below $105.28, the warrants are anti-dilutive.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2015
Stockholders Equity Note [Abstract]
Stockholders' Equity	Note 10. Stockholders’ Equity Restricted Common Stock The Company has granted restricted common stock to certain 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 right 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, 2015 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, 2014 4,955 $ 25.62 Granted 2,466 $ 40.00 Vested (1,849 ) $ 24.27 Canceled (239 ) $ 32.34 Unvested restricted common stock at September 30, 2015 5,333 $ 32.28 As of September 30, 2015, the total compensation cost related to unvested restricted common stock not yet recognized was $132.5 million. This amount is expected to be recognized over a weighted-average period of 2.4 years. Equity Incentive Plans The Company’s 2013 Equity Incentive Plan became effective upon the completion of the Company’s initial public offering and serves as the successor to the 2007 Equity Incentive Plan. Initially, 68.3 million shares were reserved under the 2013 Equity Plan and any shares subject to options or other similar awards granted under the 2007 Equity Incentive Plan that expire, are forfeited, are repurchased by the Company or otherwise terminate unexercised will become available under the 2013 Equity Incentive Plan. The number of shares of the Company’s common stock available for issuance under the 2013 Equity Incentive Plan were and will be increased on the first day of each fiscal year beginning with the 2014 fiscal year, in an amount equal to the least of (i) 60,000,000 shares, (ii) 5% of the outstanding shares on the last day of the immediately preceding fiscal year or (iii) such number of shares determined by the Company’s Board of Directors. No additional shares will be issued under the 2007 Equity Incentive Plan. Employee Stock Purchase Plan The number of shares available for sale under the ESPP were and will be increased on the first day of each fiscal year beginning with the 2014 fiscal year, in an amount equal to the least of (i) 11.3 million shares; (ii) 1% of the outstanding shares of the Company’s common stock as of the last day of the immediately preceding fiscal year; or (iii) such other amount as determined by the Company’s Board of Directors. During the nine months ended September 30, 2015, employees purchased an aggregate of 0.7 million shares under the ESPP at a price of $31.07 per share. During the three months ended September 30, 2015 and 2014, the Company recorded $5.0 million and $9.1 million, respectively, and recorded $13.1 million and $25.8 million during the nine months ended September 30, 2015 and 2014, respectively, of stock-based compensation expense related to the ESPP. As of September 30, 2015, the total compensation costs related to the current ESPP plans not yet recognized were $11.4 million. This amount is expected to be recognized over a weighted-average period of 0.4 years. Stock Option Activity The number of stock options outstanding was 17.4 million and 20.4 million as of September 30, 2015 and December 31, 2014, respectively. The total intrinsic value of stock options exercised during the three months ended September 30, 2015 and 2014 was $18.2 million and $265.2 million, respectively and $158.8 million and $802.3 million in the nine months ended September 30, 2015 and 2014, respectively. As of September 30, 2015, the total compensation costs related to stock options not yet recognized was $44.4 million. This amount is expected to be recognized over a weighted-average period of 2.3 years. RSU Activity The following table summarizes the activity related to the Company’s RSUs for the nine months ended September 30, 2015. 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, 2014 64,135 $ 29.08 Granted 11,918 $ 40.99 Vested (18,570 ) $ 27.52 Canceled (10,901 ) $ 28.57 Unvested and outstanding at September 30, 2015 46,582 $ 32.88 The total fair value of RSUs vested during the three months ended September 30, 2015 and 2014 was $198.3 million and $470.0 million, respectively and $702.7 million and $1.69 billion during the nine months ended September 30, 2015 and 2014, respectively. As of September 30, 2015, the total compensation cost related to unvested RSUs not yet recognized was $1.17 billion. This amount is expected to be recognized over a weighted-average period of 2.7 years. Stock-Based Compensation Expense 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, 2015 2014 2015 2014 Cost of revenue $ 8,973 $ 13,596 $ 32,345 $ 37,296 Research and development 100,673 93,973 306,830 264,784 Sales and marketing 37,889 42,884 120,154 108,232 General and administrative 18,386 19,149 64,540 44,070 Total $ 165,921 $ 169,602 $ 523,869 $ 454,382 The Company capitalized $8.6 million and $10.9 million of stock-based compensation expense associated with the cost for developing software for internal use in the three months ended September 30, 2015 and 2014, respectively, and $38.4 million and $26.4 million in the nine months ended September 30, 2015 and 2014, respectively.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Note 11. 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 a Federal income tax examination by the Internal Revenue Service (IRS) for tax years 2011, 2012 and 2013. In the third quarter of 2015, the Company concluded its California income tax examination for tax years 2010 and 2011 with adjustments that immaterially impacted the deferred tax balances with an offset to the valuation allowance, resulting in no additional net tax expense or benefit. However, the Company’s California R&D tax credit carryfoward attributes remain open and subject to examination in future years until used. 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 $3.2 million and $0.2 million for the three months ended September 30, 2015 and 2014, respectively, and an income tax benefit of $15.7 million and $4.2 million for the nine months ended September 30, 2015 and 2014, respectively. The increase in the income tax provision in the three months ended September 30, 2015 compared to the same period last year was primarily due to a decrease in deferred tax benefits arising from acquisitions and an increase in foreign income tax expenses. The increase in the income tax benefit in the nine months ended September 30, 2015 compared to the same period last year was primarily due to deferred tax benefits arising from acquisitions in the first two quarters of 2015, partially offset by an increase in foreign income tax expenses. As of September 30, 2015, 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, 2015 will not be realized by the end of the 2015 fiscal year. Accordingly, the Company did not record the tax benefits of the U.S. losses incurred during the nine months ended September 30, 2015. 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. On July 27, 2015, the United States Tax Court issued an opinion (Altera Corp. et al. v. Commissioner), which invalidated the 2003 final Treasury rule that requires participants in qualified cost-sharing arrangements to share stock-based compensation costs. While the opinion is subject to being issued as a final decision and is also subject to appeal by the Internal Revenue Service, the Company filed its 2014 federal tax return based upon the opinion rendered in this case, which the Company believes will more likely than not be sustained, and which resulted in an increase in the 2014 net operating loss in the U.S jurisdiction with a commensurate decrease in the overall pre-tax loss in foreign jurisdictions. As the Company maintains a full valuation allowance on its US deferred tax assets, no benefit was realized in the financial statements as a result of this filing position. On an ongoing basis, stock-based compensation will be excluded from intercompany charges. During the three and nine months ended September 30, 2015, the amount of gross unrecognized tax benefits decreased by $13.6 million and increased by $24.2 million, respectively. As of September 30, 2015, the Company has $206.7 million of unrecognized tax benefits which, if recognized, will not affect the annual effective tax rate as these unrecognized tax benefits would increase deferred tax assets which would be subject to a full valuation allowance.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 12. Commitments and Contingencies Credit Facility The Company has a revolving credit agreement with certain lenders, which provided for a $1.0 billion revolving unsecured credit facility maturing on October 22, 2018. The Company is obligated to pay interest on loans under the credit facility and 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 payments of dividends. As of September 30, 2015, no amounts had been drawn under the credit facility. 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 2015 and 2028. In 2015, the Company entered into various new office space leases for an aggregate future minimum lease payments of approximately $95.7 million. Under the terms of certain leases, the Company is committed to pay for certain taxes, insurance, maintenance and management expenses. Certain of these arrangements have free rent periods or escalating rent payment provisions, and the Company recognizes rent expense under such arrangements on a straight-line basis. Legal Proceedings The Company is currently involved in, and will likely in the future be involved in, legal proceedings, claims and 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, 2015 and December 31, 2014, there was no litigation or contingency with at least a reasonable possibility of a material loss. No material losses have been recorded during the three and nine months ended September 30, 2015 and 2014 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, 2015 and December 31, 2014.

Operations by Geographic Area

Operations by Geographic Area	9 Months Ended
	Sep. 30, 2015
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 services and revenue by geographic area (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Revenue by services: Advertising services $ 512,867 $ 320,196 $ 1,353,356 $ 823,687 Data licensing and other 56,370 41,070 154,203 100,237 Total revenue $ 569,237 $ 361,266 $ 1,507,559 $ 923,924 Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Revenue by geographic area: United States $ 369,856 $ 240,169 $ 979,975 $ 630,673 International 199,381 121,097 527,584 293,251 Total revenue $ 569,237 $ 361,266 $ 1,507,559 $ 923,924 No individual country from the international markets contributed in excess of 10% of the total revenue for the three and nine months ended September 30, 2015. The United Kingdom accounted for $37.5 million, or 10%, and $94.8 million, or 10%, of total revenue for the three and nine months ended September 30, 2014, respectively. Long-Lived Assets The following table sets forth long-lived assets by geographic area (in thousands): September 30, December 31, 2015 2014 Property and equipment, net: United States $ 649,635 $ 523,810 International 49,867 33,209 Total property and equipment, net $ 699,502 $ 557,019

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2015
Related Party Transactions [Abstract]
Related Party Transactions	Note 14. Related Party Transactions In September 2015, the Company entered into a partnership agreement for no consideration with Square, Inc., for which Jack Dorsey (the Company’s Chief Executive Officer) serves as Chief Executive Officer, to enable U.S. political donations through Tweets. Neither Square, Inc. nor the Company will pay each other any amounts in connection with the agreement.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2015
Subsequent Events [Abstract]
Subsequent Events	Note 15. Subsequent Events On October 12, 2015, the Board of Directors of the Company approved a restructuring and reduction in force plan of up to 336 employees, constituting approximately 8% of the Company’s global workforce. The Company estimates it will incur approximately $10 million to $20 million of cash expenditures, substantially all of which will be severance costs. Total restructuring expenses are estimated at $5M to $15M, which is lower than cash restructuring costs due to a credit related to non-cash stock-based compensation expense reversals for unvested stock awards. The Company expects to recognize most of these pre-tax restructuring charges in the quarter ended December 31, 2015. On October 22, 2015, the Company and the Jack Dorsey Revocable Trust dated December 8, 2010 (the “Jack Dorsey Trust”), for which Jack Dorsey (the Company’s Chief Executive Officer) serves as trustee, entered into a Contribution Agreement that the Jack Dorsey Trust will give back and contribute to Twitter, without any cost or charge, an aggregate of 6,814,085 shares of Twitter’s common stock. Upon the Company’s stockholders approval of an equity incentive plan at the annual meeting of stockholders to be held in 2016, the same number of shares will be granted over time to employees and other service providers. In connection with this agreement, the Board has approved Twitter’s 2016 Equity Incentive Plan (the “2016 Plan”) to provide for the granting of stock options, restricted stock, restricted stock units and other equity awards to eligible employees, directors and consultants from time to time, and has approved an aggregate of 6,814,085 shares of Twitter’s common stock to be reserved for issuance under the 2016 Plan.

Description of Business and S22

Description of Business and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2015
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. Certain prior period amounts have been reclassified to conform to the current period presentation. 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, 2014.
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 May 2014, the Financial Accounting Standards Board (“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 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. In July 2015, the FASB decided to delay the effective date of the guidance by one year and permit early adoption for annual and interim periods beginning after December 15, 2016. As a result of the revision, the guidance will be effective for fiscal years, and interim periods with those fiscal years, beginning after December 15, 2017 and can be applied either retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. 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. In February 2015, the FASB issued a new accounting standard update on consolidation analysis. The new guidance amends the current consolidation guidance with respect to the analysis that a reporting entity must perform to determine whether it should consolidate certain types of legal entities. This guidance will be effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted, but the guidance must be applied as of the beginning of the fiscal year containing the adoption date. Adoption of this new accounting standard update is not expected to have a material impact on the Company’s financial statements. In April 2015, the FASB issued a new accounting standard update on the presentation of debt issuance costs. The new guidance requires the debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. This guidance will be effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted. Adoption of this new accounting standard update is not expected to have a material impact on the Company’s financial statements. In September 2015, the FASB issued a new accounting standard update on simplifying the accounting for measurement-period adjustments in business combinations. The new guidance requires that the adjustments to provisional amounts that are identified during the measurement period be recognized in the reporting period when the adjustments are determined. In addition, the effect on earnings of changes as a result of the change to the provisional amounts is required to be recorded in the same period’s financial statements. This guidance will be effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted. Adoption of this new accounting standard update is not expected to have a material impact on the Company’s financial statements.

Cash, Cash Equivalents and Sh23

Cash, Cash Equivalents and Short-term Investments (Tables)	9 Months Ended
	Sep. 30, 2015
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, 2015 2014 Cash and cash equivalents: Cash $ 210,399 $ 147,848 Money market funds 337,045 882,443 U.S. government and agency securities including treasury bills — 271,418 Corporate notes, certificates of deposit and commercial paper 328,988 209,015 Total cash and cash equivalents $ 876,432 $ 1,510,724 Short-term investments: U.S. government and agency securities including treasury bills $ 1,160,104 $ 1,009,541 Corporate notes, certificates of deposit and commercial paper 1,452,658 1,101,613 Total short-term investments $ 2,612,762 $ 2,111,154
Contractual Maturities of Securities Classified as Available-for-Sale	The contractual maturities of securities classified as available-for-sale as of September 30, 2015 were as follows (in thousands): September 30, 2015 Due within one year $ 1,946,341 Due after one year through two years 666,421 Total $ 2,612,762
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): September 30, 2015 Gross Gross Gross Aggregated Amortized Unrealized Unrealized Estimated Costs Gains Losses Fair Value U.S. government and agency securities including treasury bills $ 1,159,601 $ 535 $ (32 ) $ 1,160,104 Corporate notes, certificates of deposit and commercial paper 1,453,198 175 (715 ) 1,452,658 Total available-for-sale securities classified as short-term investments $ 2,612,799 $ 710 $ (747 ) $ 2,612,762 December 31, 2014 Gross Gross Gross Aggregated Amortized Unrealized Unrealized Estimated Costs Gains Losses Fair Value U.S. government and agency securities including treasury bills $ 1,009,827 $ 8 $ (294 ) $ 1,009,541 Corporate notes, certificates of deposit and commercial paper 1,102,275 4 (666 ) 1,101,613 Total available-for-sale securities classified as short-term investments $ 2,112,102 $ 12 $ (960 ) $ 2,111,154

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2015
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, 2015 and December 31, 2014 based on the three-tier fair value hierarchy (in thousands): September 30, 2015 Level 1 Level 2 Level 3 Total Assets Cash equivalents: Money market funds $ 337,045 $ — $ — $ 337,045 Commercial paper — 328,988 — 328,988 Short-term investments: Treasury bills 38,074 — — 38,074 U.S. government securities — 531,520 — 531,520 Agency securities — 590,510 — 590,510 Corporate notes — 647,449 — 647,449 Commercial paper — 301,465 — 301,465 Certificates of deposit — 503,744 — 503,744 Other current assets: Foreign currency forward contracts — 413 — 413 Liabilities Other current liabilities: Foreign currency forward contracts — (533 ) — (533 ) Total $ 375,119 $ 2,903,556 $ — $ 3,278,675 December 31, 2014 Level 1 Level 2 Level 3 Total Assets Cash equivalents: Money market funds $ 882,443 $ — $ — $ 882,443 Treasury bills 73,525 — — 73,525 U.S. government securities — 157,895 — 157,895 Agency securities — 39,998 — 39,998 Corporate notes — 13,684 — 13,684 Commercial paper — 185,321 — 185,321 Certificates of deposit — 10,010 — 10,010 Short-term investments: Treasury bills 167,575 — — 167,575 U.S. government securities — 746,128 — 746,128 Agency securities — 95,838 — 95,838 Corporate notes — 551,604 — 551,604 Commercial paper — 300,589 — 300,589 Certificates of deposit — 249,420 — 249,420 Total $ 1,123,543 $ 2,350,487 $ — $ 3,474,030
Schedule of Fair Values of Outstanding Derivative Instruments	The fair values of outstanding derivative instruments for the periods presented on a gross basis are as follows (in thousands): September 30, Balance Sheet Location 2015 Assets Foreign currency forward contracts not designated as hedging instruments Other current assets $ 413 Liabilities Foreign currency forward contracts not designated as hedging instruments Other current liabilities 533 Total $ (120 )

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2015
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, 2015 2014 Property and equipment, net Equipment $ 675,559 $ 584,561 Furniture and leasehold improvements 241,981 131,851 Capitalized software 196,783 82,052 Construction in progress 95,509 89,806 Total 1,209,832 888,270 Less: Accumulated depreciation and amortization (510,330 ) (331,251 ) Property and equipment, net $ 699,502 $ 557,019

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2015
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, 2014 $ 622,570 TellApart acquisition 394,989 Other acquisitions 106,198 Foreign currency translation adjustment (636 ) Balance as of September 30, 2015 $ 1,123,121
Schedule of Intangible Assets	The following table presents the detail of intangible assets for the periods presented (in thousands): Gross Carrying Accumulated Net Carrying Value Amortization Value September 30, 2015: Patents and developed technologies $ 141,169 $ (51,270 ) $ 89,899 Publisher and advertiser relationships 75,300 (19,606 ) 55,694 Assembled workforce 1,960 (1,650 ) 310 Other intangible assets 3,200 (1,817 ) 1,383 Total $ 221,629 $ (74,343 ) $ 147,286 December 31, 2014: Patents and developed technologies $ 105,052 $ (23,165 ) $ 81,887 Publisher and advertiser relationships 32,000 (9,831 ) 22,169 Assembled workforce 1,960 (1,457 ) 503 Other intangible assets 1,100 (648 ) 452 Total $ 140,112 $ (35,101 ) $ 105,011
Schedule of Estimated Future Amortization Expenses	Estimated future amortization expense as of September 30, 2015 is as follows (in thousands): Remainder of 2015 $ 13,541 2016 43,877 2017 27,872 2018 21,239 2019 13,644 Thereafter 27,113 Total $ 147,286

Components of Accrued and Other

Components of Accrued and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2015
Statement Of Financial Position [Abstract]
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, 2015 2014 Accrued compensation $ 89,053 $ 68,000 Accrued publisher payments 33,598 27,996 Deferred revenue 28,813 18,679 Accrued tax liabilities 22,536 18,380 Accrued sales and marketing expenses 12,312 25,264 Accrued other 107,745 69,914 Total $ 294,057 $ 228,233

Convertible Senior Notes (Table

Convertible Senior Notes (Tables)	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Components of Notes	The Notes consisted of the following (in thousands): September 30, 2015 December 31, 2014 2019 Notes 2021 Notes 2019 Notes 2021 Notes Principal amounts: Principal $ 935,000 $ 954,000 $ 935,000 $ 954,000 Unamortized initial purchasers' discount and debt discount (1) (192,957 ) (261,075 ) (225,104 ) (287,876 ) Net carrying amount $ 742,043 $ 692,925 $ 709,896 $ 666,124 Carrying amount of the equity component (2) $ 222,826 $ 283,283 $ 222,826 $ 283,283 (1) (2)

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2015
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, 2015 2014 2015 2014 Net loss $ (131,690 ) $ (175,464 ) $ (430,795 ) $ (452,468 ) Basic shares: Weighted-average common shares outstanding 678,817 624,205 663,897 605,756 Weighted-average restricted stock subject to repurchase (8,213 ) (9,810 ) (8,176 ) (9,034 ) Weighted-average shares used to compute basic net loss per share 670,604 614,395 655,721 596,722 Diluted shares: Weighted-average shares used to compute diluted net loss per share 670,604 614,395 655,721 596,722 Net loss per share attributable to common stockholders: Basic $ (0.20 ) $ (0.29 ) $ (0.66 ) $ (0.76 ) Diluted $ (0.20 ) $ (0.29 ) $ (0.66 ) $ (0.76 )
Summary of Potential Common Shares Excluded from Calculation of Diluted Net Loss Per Share Attributable to Common Stockholders	The following number of potential shares of the Company’s common stock 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, 2015 2014 RSUs 46,582 74,114 Warrants 24,329 23,183 Stock options 17,384 22,327 Shares subject to repurchase 7,959 10,070 Employee stock purchase plan 1,760 1,147

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2015
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, 2015 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, 2014 4,955 $ 25.62 Granted 2,466 $ 40.00 Vested (1,849 ) $ 24.27 Canceled (239 ) $ 32.34 Unvested restricted common stock at September 30, 2015 5,333 $ 32.28
Summary of RSU Activity	The following table summarizes the activity related to the Company’s RSUs for the nine months ended September 30, 2015. 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, 2014 64,135 $ 29.08 Granted 11,918 $ 40.99 Vested (18,570 ) $ 27.52 Canceled (10,901 ) $ 28.57 Unvested and outstanding at September 30, 2015 46,582 $ 32.88
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, 2015 2014 2015 2014 Cost of revenue $ 8,973 $ 13,596 $ 32,345 $ 37,296 Research and development 100,673 93,973 306,830 264,784 Sales and marketing 37,889 42,884 120,154 108,232 General and administrative 18,386 19,149 64,540 44,070 Total $ 165,921 $ 169,602 $ 523,869 $ 454,382

Operations by Geographic Area (

Operations by Geographic Area (Tables)	9 Months Ended
	Sep. 30, 2015
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 services and revenue by geographic area (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Revenue by services: Advertising services $ 512,867 $ 320,196 $ 1,353,356 $ 823,687 Data licensing and other 56,370 41,070 154,203 100,237 Total revenue $ 569,237 $ 361,266 $ 1,507,559 $ 923,924 Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Revenue by geographic area: United States $ 369,856 $ 240,169 $ 979,975 $ 630,673 International 199,381 121,097 527,584 293,251 Total revenue $ 569,237 $ 361,266 $ 1,507,559 $ 923,924
Long-lived Assets by Geographic Area	The following table sets forth long-lived assets by geographic area (in thousands): September 30, December 31, 2015 2014 Property and equipment, net: United States $ 649,635 $ 523,810 International 49,867 33,209 Total property and equipment, net $ 699,502 $ 557,019

Cash, Cash Equivalents and Sh32

Cash, Cash Equivalents and Short-term Investments - Cash, Cash and Equivalents and Short-term Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Cash and cash equivalents:
Cash	$ 210,399	$ 147,848
Cash and cash equivalents	876,432	1,510,724	$ 2,252,795	$ 841,010
Short-term investments:
Short-term investments	2,612,762	2,111,154
Money Market Funds
Cash and cash equivalents:
Cash and cash equivalents	337,045	882,443
U.S. Government and Agency Securities Including Treasury Bills
Cash and cash equivalents:
Cash and cash equivalents		271,418
Short-term investments:
Short-term investments	1,160,104	1,009,541
Corporate Notes Certificates Of Deposit And Commercial Paper
Cash and cash equivalents:
Cash and cash equivalents	328,988	209,015
Short-term investments:
Short-term investments	$ 1,452,658	$ 1,101,613

Cash, Cash Equivalents and Sh33

Cash, Cash Equivalents and Short-term Investments - Contractual Maturities of Securities Classified as Available-for-Sale (Details) $ in Thousands	Sep. 30, 2015USD ($)
Cash And Cash Equivalents And Marketable Securities [Abstract]
Due within one year	$ 1,946,341
Due after one year through two years	666,421
Total	$ 2,612,762

Cash, Cash Equivalents and Sh34

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 ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule Of Available For Sale Securities [Line Items]
Gross Amortized Costs	$ 2,612,799	$ 2,112,102
Gross Unrealized Gains	710	12
Gross Unrealized Losses	(747)	(960)
Short-term investments	2,612,762	2,111,154
U.S. Government and Agency Securities Including Treasury Bills
Schedule Of Available For Sale Securities [Line Items]
Gross Amortized Costs	1,159,601	1,009,827
Gross Unrealized Gains	535	8
Gross Unrealized Losses	(32)	(294)
Short-term investments	1,160,104	1,009,541
Corporate Notes Certificates Of Deposit And Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Gross Amortized Costs	1,453,198	1,102,275
Gross Unrealized Gains	175	4
Gross Unrealized Losses	(715)	(666)
Short-term investments	$ 1,452,658	$ 1,101,613

Cash, Cash Equivalents and Sh35

Cash, Cash Equivalents and Short-term Investments - Additional Information (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Investments Debt And Equity Securities [Abstract]
Securities continuous loss position for 12 months or longer	$ 0	$ 0
Impairment loss on securities	$ 0	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Net Asset (Liability) [Abstract]
Short-term investments	$ 2,612,762	$ 2,111,154
Other current assets	413
Other current liabilities	(533)
Fair Value, Measurements, Recurring
Fair Value, Net Asset (Liability) [Abstract]
Total	3,278,675	3,474,030
Fair Value, Measurements, Recurring | Agency Securities
Fair Value, Net Asset (Liability) [Abstract]
Cash equivalents		39,998
Short-term investments	590,510	95,838
Fair Value, Measurements, Recurring | Money Market Funds
Fair Value, Net Asset (Liability) [Abstract]
Cash equivalents	337,045	882,443
Fair Value, Measurements, Recurring | Treasury Bills
Fair Value, Net Asset (Liability) [Abstract]
Cash equivalents		73,525
Short-term investments	38,074	167,575
Fair Value, Measurements, Recurring | US Government Securities
Fair Value, Net Asset (Liability) [Abstract]
Cash equivalents		157,895
Short-term investments	531,520	746,128
Fair Value, Measurements, Recurring | Corporate Notes
Fair Value, Net Asset (Liability) [Abstract]
Cash equivalents		13,684
Short-term investments	647,449	551,604
Fair Value, Measurements, Recurring | Commercial Paper
Fair Value, Net Asset (Liability) [Abstract]
Cash equivalents	328,988	185,321
Short-term investments	301,465	300,589
Fair Value, Measurements, Recurring | Certificates of Deposit
Fair Value, Net Asset (Liability) [Abstract]
Cash equivalents		10,010
Short-term investments	503,744	249,420
Fair Value, Measurements, Recurring | Foreign currency forward contracts
Fair Value, Net Asset (Liability) [Abstract]
Other current assets	413
Other current liabilities	(533)
Level 1 | Fair Value, Measurements, Recurring
Fair Value, Net Asset (Liability) [Abstract]
Total	375,119	1,123,543
Level 1 | Fair Value, Measurements, Recurring | Money Market Funds
Fair Value, Net Asset (Liability) [Abstract]
Cash equivalents	337,045	882,443
Level 1 | Fair Value, Measurements, Recurring | Treasury Bills
Fair Value, Net Asset (Liability) [Abstract]
Cash equivalents		73,525
Short-term investments	38,074	167,575
Level 2 | Fair Value, Measurements, Recurring
Fair Value, Net Asset (Liability) [Abstract]
Total	2,903,556	2,350,487
Level 2 | Fair Value, Measurements, Recurring | Agency Securities
Fair Value, Net Asset (Liability) [Abstract]
Cash equivalents		39,998
Short-term investments	590,510	95,838
Level 2 | Fair Value, Measurements, Recurring | US Government Securities
Fair Value, Net Asset (Liability) [Abstract]
Cash equivalents		157,895
Short-term investments	531,520	746,128
Level 2 | Fair Value, Measurements, Recurring | Corporate Notes
Fair Value, Net Asset (Liability) [Abstract]
Cash equivalents		13,684
Short-term investments	647,449	551,604
Level 2 | Fair Value, Measurements, Recurring | Commercial Paper
Fair Value, Net Asset (Liability) [Abstract]
Cash equivalents	328,988	185,321
Short-term investments	301,465	300,589
Level 2 | Fair Value, Measurements, Recurring | Certificates of Deposit
Fair Value, Net Asset (Liability) [Abstract]
Cash equivalents		10,010
Short-term investments	503,744	$ 249,420
Level 2 | Fair Value, Measurements, Recurring | Foreign currency forward contracts
Fair Value, Net Asset (Liability) [Abstract]
Other current assets	413
Other current liabilities	$ (533)

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Notional principal of foreign currency forward contracts outstanding	$ 299,300,000	$ 299,300,000	$ 0
Gains on the foreign currency contracts	3,700,000	3,700,000
Convertible Notes | Senior Notes Due 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt instrument, principal amount	$ 935,000,000	$ 935,000,000	$ 935,000,000	$ 900,000,000
Debt Instrument, percentage	0.25%	0.25%	0.25%
Debt Instrument, due date		2,019
Convertible Notes | Senior Notes Due 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt instrument, principal amount	$ 954,000,000	$ 954,000,000	$ 954,000,000	$ 900,000,000
Debt Instrument, percentage	1.00%	1.00%	1.00%
Debt Instrument, due date		2,021
Level 2 | Convertible Notes | Senior Notes Due 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Estimated fair value of notes based on a market approach	$ 822,500,000	$ 822,500,000
Level 2 | Convertible Notes | Senior Notes Due 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Estimated fair value of notes based on a market approach	$ 815,200,000	$ 815,200,000

Fair Value Measurements - Sch38

Fair Value Measurements - Schedule of Fair Values of Outstanding Derivative Instruments (Details) $ in Thousands	Sep. 30, 2015USD ($)
Assets
Foreign currency forward contracts not designated as hedging instruments	$ 413
Liabilities
Foreign currency forward contracts not designated as hedging instruments	533
Total	$ (120)

Property and Equipment, Net - S

Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Property and equipment, net
Property and equipment, gross	$ 1,209,832	$ 888,270
Less: Accumulated depreciation and amortization	(510,330)	(331,251)
Property and equipment, net	699,502	557,019
Equipment
Property and equipment, net
Property and equipment, gross	675,559	584,561
Furniture and Leasehold Improvements
Property and equipment, net
Property and equipment, gross	241,981	131,851
Computer Software
Property and equipment, net
Property and equipment, gross	196,783	82,052
Construction in Progress
Property and equipment, net
Property and equipment, gross	$ 95,509	$ 89,806

Goodwill and Intangible Asset40

Goodwill and Intangible Assets - Schedule of Goodwill Activities (Details) - USD ($) $ in Thousands	1 Months Ended	9 Months Ended
	May. 31, 2015	Sep. 30, 2015
Goodwill
Beginning balance		$ 622,570
Foreign currency translation adjustment		(636)
Ending balance		1,123,121
TellApart Inc
Goodwill
Acquisition	$ 395,000	394,989
Other acquisitions
Goodwill
Acquisition		$ 106,198

Goodwill and Intangible Asset41

Goodwill and Intangible Assets - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 221,629	$ 140,112
Accumulated Amortization	(74,343)	(35,101)
Net Carrying Value	147,286	105,011
Patents and Developed Technologies
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	141,169	105,052
Accumulated Amortization	(51,270)	(23,165)
Net Carrying Value	89,899	81,887
Publisher and Advertiser Relationships
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	75,300	32,000
Accumulated Amortization	(19,606)	(9,831)
Net Carrying Value	55,694	22,169
Assembled Workforce
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	1,960	1,960
Accumulated Amortization	(1,650)	(1,457)
Net Carrying Value	310	503
Other Intangible Assets
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	3,200	1,100
Accumulated Amortization	(1,817)	(648)
Net Carrying Value	$ 1,383	$ 452

Goodwill and Intangible Asset42

Goodwill and Intangible Assets - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 14.5	$ 11.8	$ 39.2	$ 26.1

Goodwill and Intangible Asset43

Goodwill and Intangible Assets - Schedule of Estimated Future Amortization Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Goodwill And Intangible Assets Disclosure [Abstract]
Remainder of 2015	$ 13,541
2,016	43,877
2,017	27,872
2,018	21,239
2,019	13,644
Thereafter	27,113
Net Carrying Value	$ 147,286	$ 105,011

Accrued and Other Current Lia44

Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Payables And Accruals [Abstract]
Accrued compensation	$ 89,053	$ 68,000
Accrued publisher payments	33,598	27,996
Deferred revenue	28,813	18,679
Accrued tax liabilities	22,536	18,380
Accrued sales and marketing expenses	12,312	25,264
Accrued other	107,745	69,914
Total	$ 294,057	$ 228,233

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) $ in Thousands, shares in Millions	1 Months Ended	9 Months Ended
	May. 31, 2015USD ($)shares	Sep. 30, 2015USD ($)Acquisition
Business Acquisition [Line Items]
Fair value of contingent payment		$ 102,900
Equity compensation service period		48 months
Employee Stock Options
Business Acquisition [Line Items]
Unrecognized share-based compensation expense		$ 44,400
TellApart Inc
Business Acquisition [Line Items]
Business acquisition, purchase price cash consideration	$ 22,600
Business acquisition, common stock issued | shares	12.2
Business acquisition, assumed common shares / stock options | shares	1.2
Business Combination, Consideration Transferred	$ 479,100
Business acquisition, common stock issued	456,500
Acquisition purchase price allocated to cash	29,600
Account receivables	19,700
Other tangible assets	2,200
Acquisition purchase price allocated to liability	11,800
Acquisition purchase price allocated to deferred tax liability	22,400
Goodwill acquired	395,000	$ 394,989
TellApart Inc | Developed Technology Rights
Business Acquisition [Line Items]
Acquisition purchase price allocated to finite lived intangible assets	21,400
TellApart Inc | Developed Technology Rights | Minimum
Business Acquisition [Line Items]
Intangible assets, estimated useful lives		12 months
TellApart Inc | Developed Technology Rights | Maximum
Business Acquisition [Line Items]
Intangible assets, estimated useful lives		72 months
TellApart Inc | Advertiser Relationships
Business Acquisition [Line Items]
Acquisition purchase price allocated to finite lived intangible assets	43,300
TellApart Inc | Advertiser Relationships | Minimum
Business Acquisition [Line Items]
Intangible assets, estimated useful lives		12 months
TellApart Inc | Advertiser Relationships | Maximum
Business Acquisition [Line Items]
Intangible assets, estimated useful lives		72 months
TellApart Inc | Trade Name
Business Acquisition [Line Items]
Acquisition purchase price allocated to finite lived intangible assets	$ 2,100
TellApart Inc | Trade Name | Minimum
Business Acquisition [Line Items]
Intangible assets, estimated useful lives		12 months
TellApart Inc | Trade Name | Maximum
Business Acquisition [Line Items]
Intangible assets, estimated useful lives		72 months
TellApart Inc | Stock Options
Business Acquisition [Line Items]
Business acquisition, assumed common shares / stock options | shares	1.3
Other acquisitions
Business Acquisition [Line Items]
Business acquisition, purchase price cash consideration		$ 58,800
Business Combination, Consideration Transferred		118,900
Business acquisition, common stock issued		60,100
Acquisition purchase price allocated to deferred tax liability		3,400
Goodwill acquired		$ 106,198
Number of businesses acquired | Acquisition		4
Acquisition purchase price allocated to assets		$ 3,200
Business acquisition, goodwill expected tax deductible amount		4,100
Other acquisitions | Developed Technology Rights
Business Acquisition [Line Items]
Acquisition purchase price allocated to finite lived intangible assets		$ 12,900
Other acquisitions | Developed Technology Rights | Minimum
Business Acquisition [Line Items]
Intangible assets, estimated useful lives		12 months
Other acquisitions | Developed Technology Rights | Maximum
Business Acquisition [Line Items]
Intangible assets, estimated useful lives		60 months
All Acquisitions | Employee Stock Options
Business Acquisition [Line Items]
Equity compensation service period		45 months
Unrecognized share-based compensation expense		$ 37,200

Convertible Senior Notes - Addi

Convertible Senior Notes - Additional Information (Details) $ / shares in Units, shares in Millions		1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
		Oct. 31, 2014USD ($)	Sep. 30, 2015USD ($)$ / shares	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)$ / shares	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)$ / sharesshares
Debt Instrument [Line Items]
Amortization of discount on convertible notes					$ 51,139,000	$ 2,411,000
Convertible notes			$ 1,434,968,000		$ 1,434,968,000		$ 1,376,020,000
Exercise price of the warrants | $ / shares			$ 105.28		$ 105.28
Purchases of convertible note hedges						387,450,000
Proceeds from issuance of warrants						275,130,000
Convertible Notes
Debt Instrument [Line Items]
Initial purchasers' discount							28,300,000
Debt issuance costs						500,000
Proceeds from offerings, net of transaction costs							$ 1,860,000,000
Debt Instrument, frequency of periodic payment					semi-annually
Debt Instrument, date of first required payment					Mar. 15, 2015
Debt Instrument Payment Terms					The interest rates are fixed at 0.25% and 1.00% per annum, respectively, 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			$ 1,300,000	$ 200,000	$ 3,900,000	200,000
Accrued coupon interest expense			3,000,000	400,000	9,000,000	400,000
Exercise price of the warrants | $ / shares							$ 105.28
Number of shares authorized for repurchase under hedge agreement | shares							24.3
Exercise price of the option to repurchase stock | $ / shares							$ 77.64
Purchases of convertible note hedges							$ 407,200,000
Number of warrants issued | shares							24.3
Proceeds from issuance of warrants							$ 289,300,000
Convertible Notes | Interest Expense
Debt Instrument [Line Items]
Amortization of discount on convertible notes			$ 18,800,000		55,300,000
Convertible Notes | Common Stock
Debt Instrument [Line Items]
Debt instrument, conversion principal amount					$ 1,000
Debt Instrument, conversion ratio					12.8793
Conversion Price | $ / shares			$ 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 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.
Convertible Notes | Senior Notes Due 2019
Debt Instrument [Line Items]
Debt instrument, principal amount			$ 935,000,000	900,000,000	$ 935,000,000	900,000,000	935,000,000
Proceeds from Issuance of Debt		$ 35,000,000
Initial purchasers' discount	[1]		$ 192,957,000		$ 192,957,000		$ 225,104,000
Debt Instrument, percentage			0.25%		0.25%		0.25%
Convertible notes			$ 742,043,000		$ 742,043,000		$ 709,896,000
Remaining period for convertible debt					47 months
Convertible Notes | Senior Notes Due 2021
Debt Instrument [Line Items]
Debt instrument, principal amount			954,000,000	$ 900,000,000	$ 954,000,000	$ 900,000,000	954,000,000
Proceeds from Issuance of Debt		$ 54,000,000
Initial purchasers' discount	[1]		$ 261,075,000		$ 261,075,000		$ 287,876,000
Debt Instrument, percentage			1.00%		1.00%		1.00%
Convertible notes			$ 692,925,000		$ 692,925,000		$ 666,124,000
Remaining period for convertible debt					71 months
[1]	Included in the consolidated balance sheets within convertible notes and amortized over the remaining lives of the Notes.

Convertible Senior Notes - Comp

Convertible Senior Notes - Components of Notes (Details) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Principal amounts:
Net carrying amount		$ 1,434,968	$ 1,376,020
Convertible Notes
Principal amounts:
Unamortized initial purchasers' discount and debt discount			(28,300)
Convertible Notes | Senior Notes Due 2019
Principal amounts:
Debt instrument, principal amount		935,000	935,000	$ 900,000
Unamortized initial purchasers' discount and debt discount	[1]	(192,957)	(225,104)
Net carrying amount		742,043	709,896
Carrying amount of the equity component	[2]	222,826	222,826
Convertible Notes | Senior Notes Due 2021
Principal amounts:
Debt instrument, principal amount		954,000	954,000	$ 900,000
Unamortized initial purchasers' discount and debt discount	[1]	(261,075)	(287,876)
Net carrying amount		692,925	666,124
Carrying amount of the equity component	[2]	$ 283,283	$ 283,283
[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.

Net Loss Per Share - Basic and

Net Loss Per Share - Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Abstract]
Net loss	$ (131,690)	$ (175,464)	$ (430,795)	$ (452,468)
Basic shares:
Weighted-average common shares outstanding	678,817	624,205	663,897	605,756
Weighted-average restricted stock subject to repurchase	(8,213)	(9,810)	(8,176)	(9,034)
Weighted-average shares used to compute basic net loss per share	670,604	614,395	655,721	596,722
Diluted shares:
Weighted-average shares used to compute diluted net loss per share	670,604	614,395	655,721	596,722
Net loss per share attributable to common stockholders:
Basic	$ (0.20)	$ (0.29)	$ (0.66)	$ (0.76)
Diluted	$ (0.20)	$ (0.29)	$ (0.66)	$ (0.76)

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) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
RSUs
Earnings Per Share Basic [Line Items]
Anti-dilutive securities excluded from the computation of diluted net income per share	46,582	74,114	46,582	74,114
Warrants
Earnings Per Share Basic [Line Items]
Anti-dilutive securities excluded from the computation of diluted net income per share	24,329	23,183	24,329	23,183
Stock Options
Earnings Per Share Basic [Line Items]
Anti-dilutive securities excluded from the computation of diluted net income per share	17,384	22,327	17,384	22,327
Restricted Common Stock
Earnings Per Share Basic [Line Items]
Anti-dilutive securities excluded from the computation of diluted net income per share	7,959	10,070	7,959	10,070
Employee Stock Purchase Plans
Earnings Per Share Basic [Line Items]
Anti-dilutive securities excluded from the computation of diluted net income per share	1,760	1,147	1,760	1,147

Net Loss Per Share - Additional

Net Loss Per Share - Additional Information (Details)	9 Months Ended
	Sep. 30, 2015$ / sharesshares
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
Conversion spread will have a dilutive impact on diluted net income per share of common stock | shares	24,300,000

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity compensation service period			48 months
Issuance of common stock upon purchases under employee stock purchase plan, shares			700,000
Employee stock purchase plan (ESOP), weighted average purchase price of shares purchased			$ 31.07
Internal Use Software and Website Development Costs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation, capitalized amount	$ 8.6	$ 10.9	$ 38.4	$ 26.4
2013 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares initially reserved	68,300,000		68,300,000
Number of shares available for issuance	60,000,000		60,000,000
Outstanding shares of common stock percentage			5.00%
2013 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized share-based compensation expense	$ 11.4		$ 11.4
Unrecognized share-based compensation expense, weighted average recognition period			4 months 24 days
Number of shares available for issuance	11,300,000		11,300,000
Outstanding shares of common stock percentage			1.00%
Share-based compensation expense	$ 5	9.1	$ 13.1	25.8
Restricted Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized share-based compensation expense	$ 132.5		$ 132.5
Unrecognized share-based compensation expense, weighted average recognition period			2 years 4 months 24 days
Restricted Common Stock | All Acquisitions | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity compensation service period			2 years
Restricted Common Stock | All Acquisitions | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity compensation service period			4 years
Employee Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized share-based compensation expense, weighted average recognition period			2 years 3 months 18 days
Stock option outstanding	17,400,000		17,400,000		20,400,000
Stock options exercised, intrinsic value	$ 18.2	265.2	$ 158.8	802.3
Unrecognized share-based compensation expense	44.4		$ 44.4
Employee Stock Options | All Acquisitions
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity compensation service period			45 months
Unrecognized share-based compensation expense	37.2		$ 37.2
RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized share-based compensation expense	1,170		$ 1,170
Unrecognized share-based compensation expense, weighted average recognition period			2 years 8 months 12 days
Fair Value as of vesting dates of RSUs that are vested during the period	$ 198.3	$ 470	$ 702.7	$ 1,690

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Restricted Stock Activity (Details) - Restricted Common Stock shares in Thousands	9 Months Ended
	Sep. 30, 2015$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Unvested Shares, beginning of period | shares	4,955
Number of Shares, granted | shares	2,466
Number of Shares, vested | shares	(1,849)
Number of Shares, Canceled | shares	(239)
Number of Unvested Shares, end of period | shares	5,333
Weighted Average Grant Date Fair Value Per Share, beginning of period	$ 25.62
Weighted Average Grant Date Fair Value Per Share, Granted	40
Weighted Average Grant Date Fair Value Per Share, Vested	24.27
Weighted Average Grant Date Fair Value Per Share, Canceled	32.34
Weighted Average Grant Date Fair Value Per Share, end of period	$ 32.28

Stockholders' Equity - Summar53

Stockholders' Equity - Summary of RSU Activity (Details) - RSUs shares in Thousands	9 Months Ended
	Sep. 30, 2015$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Unvested Shares, beginning of period | shares	64,135
Number of Shares, granted | shares	11,918
Number of Shares, vested | shares	(18,570)
Number of Shares, Canceled | shares	(10,901)
Number of Unvested Shares, end of period | shares	46,582
Weighted Average Grant Date Fair Value Per Share, beginning of period	$ 29.08
Weighted Average Grant Date Fair Value Per Share, Granted	40.99
Weighted Average Grant Date Fair Value Per Share, Vested	27.52
Weighted Average Grant Date Fair Value Per Share, Canceled	28.57
Weighted Average Grant Date Fair Value Per Share, end of period	$ 32.88

Stockholders' Equity - Compensa

Stockholders' Equity - Compensation Expense Allocated (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 165,921	$ 169,602	$ 523,869	$ 454,382
Cost of Revenue
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	8,973	13,596	32,345	37,296
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	100,673	93,973	306,830	264,784
Sales and Marketing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	37,889	42,884	120,154	108,232
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 18,386	$ 19,149	$ 64,540	$ 44,070

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Provision (benefit) for income taxes	$ 3,162	$ 159	$ (15,679)	$ (4,218)
Unrecognized tax benefits, period change	13,600		24,200
Unrecognized tax benefits	$ 206,700		$ 206,700

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	9 Months Ended
	Sep. 30, 2015USD ($)
Other Commitments [Line Items]
Expiration year of operating lease, earliest	2,015
Expiration year of operating lease, last	2,028
Future minimum lease payments	$ 95,700,000
Revolving Credit Facility
Other Commitments [Line Items]
Unsecured revolving credit facility	$ 1,000,000,000
Line of credit facility, expiration date	Oct. 22, 2018
Line of credit facility amount	$ 0

Operations by Geographic Area -

Operations by Geographic Area - Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenue:
Revenue	$ 569,237	$ 361,266	$ 1,507,559	$ 923,924
United States
Revenue:
Revenue	369,856	240,169	979,975	630,673
International
Revenue:
Revenue	199,381	121,097	527,584	293,251
Advertising Services
Revenue:
Revenue	512,867	320,196	1,353,356	823,687
Data Licensing And Other
Revenue:
Revenue	$ 56,370	$ 41,070	$ 154,203	$ 100,237

Operations by Geographic Area58

Operations by Geographic Area - Additional Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)Country	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)Country	Sep. 30, 2014USD ($)
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 569,237	$ 361,266	$ 1,507,559	$ 923,924
International
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 199,381	121,097	$ 527,584	293,251
Revenue | International
Revenues From External Customers And Long Lived Assets [Line Items]
Number of individual country that contributed in excess of ten percent to revenue | Country	0		0
Revenue | United Kingdom
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue		$ 37,500		$ 94,800
Revenue | Geographic Concentration Risk | United Kingdom
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue percentage		10.00%		10.00%

Operations by Geographic Area59

Operations by Geographic Area - Long-Lived Assets by Geographic Area (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Property and equipment, net:
Property and equipment, net	$ 699,502	$ 557,019
United States
Property and equipment, net:
Property and equipment, net	649,635	523,810
International
Property and equipment, net:
Property and equipment, net	$ 49,867	$ 33,209

Related Party Transactions - Ad

Related Party Transactions - Additional Infomation (Details)	1 Months Ended
	Sep. 30, 2015USD ($)
Square Inc
Related Party Transaction [Line Items]
Agreement consideration amount	$ 0

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - Subsequent Event $ in Millions	Oct. 12, 2015USD ($)Employee	Oct. 22, 2015shares
Subsequent Event [Line Items]
Restructuring and reduction of employees | Employee	336
Percentage on employees restructuring and reduction plan	8.00%
Number of shares given back and contributed by Chief Executive Officer | shares		6,814,085
2016 Equity Incentive Plan
Subsequent Event [Line Items]
Common stock approved to be reserved for issuance | shares		6,814,085
Minimum
Subsequent Event [Line Items]
Cash expenditures on severance costs	$ 10
Restructuring expenses	5
Maximum
Subsequent Event [Line Items]
Cash expenditures on severance costs	20
Restructuring expenses	$ 15