Pandora Media (P) 10-K 16 Feb 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Feb. 13, 2017	Jun. 30, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	Pandora Media, Inc.
Entity Central Index Key	1,230,276
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		235,287,441
Entity Voluntary Filers	No
Entity Well Known Seasoned Issuer	Yes
Entity Public Float			$ 2,088

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 199,944	$ 334,667
Short-term investments	37,109	35,844
Accounts receivable, net of allowance of $2,165 at December 31, 2015 and $3,633 at December 31, 2016	309,267	277,075
Prepaid content acquisition costs	46,310	2,099
Prepaid expenses and other current assets	33,191	33,821
Total current assets	625,821	683,506
Long-term investments	6,252	46,369
Property and equipment, net	124,088	66,370
Goodwill	306,691	303,875
Intangible assets, net	90,425	110,745
Other long-term assets	31,533	29,792
Total assets	1,184,810	1,240,657
Current liabilities
Accounts payable	15,224	17,897
Accrued liabilities	35,465	37,185
Accrued content acquisition costs	93,723	97,390
Accrued compensation	60,353	43,788
Deferred revenue	28,359	19,939
Other current liabilities	20,993	15,632
Total current liabilities	254,117	231,831
Long-term debt, net	342,247	234,577
Other long-term liabilities	34,187	30,862
Total liabilities	630,551	497,270
Stockholders’ equity
Common stock, $0.0001 par value, 1,000,000,000 shares authorized: 224,970,412 shares issued and outstanding at December 31, 2015 and 235,162,757 at December 31, 2016	24	23
Additional paid-in capital	1,264,693	1,110,539
Accumulated deficit	(709,636)	(366,658)
Accumulated other comprehensive loss	(822)	(517)
Total stockholders’ equity	554,259	743,387
Total liabilities and stockholders’ equity	$ 1,184,810	$ 1,240,657

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Accounts receivable, allowance	$ 3,633	$ 2,165
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	235,162,757	224,970,412
Common stock, shares outstanding	235,162,757	224,970,412

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenue
Advertising	$ 1,072,490	$ 933,305	$ 732,338
Subscription and other	225,786	220,571	188,464
Ticketing service	86,550	10,167	0
Total revenue	1,384,826	1,164,043	920,802
Cost of revenue
Cost of revenue—Content acquisition costs	734,353	610,362	446,377
Cost of revenue—Other	101,289	79,858	61,627
Cost of revenue—Ticketing service	59,280	7,121	0
Total cost of revenue	894,922	697,341	508,004
Gross profit	489,904	466,702	412,798
Operating expenses
Product development	141,636	84,581	53,153
Sales and marketing	491,455	398,169	277,330
General and administrative	175,572	153,943	112,443
Total operating expenses	808,663	636,693	442,926
Loss from operations	(318,759)	(169,991)	(30,128)
Interest expense	(26,144)	(1,976)	(528)
Other income, net	1,697	756	834
Total other income (expense), net	(24,447)	(1,220)	306
Loss before benefit from (provision for) income taxes	(343,206)	(171,211)	(29,822)
Benefit from (provision for) income taxes	228	1,550	(584)
Net loss	$ (342,978)	$ (169,661)	$ (30,406)
Weighted-average common shares outstanding used in computing basic and diluted net loss per share (in shares)	230,693	213,790	205,273
Net loss per share, basic and diluted (in dollars per share)	$ (1.49)	$ (0.79)	$ (0.15)

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net loss	$ (342,978)	$ (169,661)	$ (30,406)
Change in foreign currency translation adjustment	(594)	53	(184)
Change in net unrealized losses on marketable securities	289	106	(191)
Other comprehensive income (loss)	(305)	159	(375)
Total comprehensive loss	$ (343,283)	$ (169,502)	$ (30,781)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning balance at Dec. 31, 2013	$ 508,231	$ 20	$ 675,103	$ (301)	$ (166,591)
Beginning balance (in shares) at Dec. 31, 2013		195,395,940
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon exercise of stock options	17,116	$ 1	17,115
Issuance of common stock upon exercise of stock options (in shares)		10,437,509
Stock-based compensation	87,055		87,055
Vesting of restricted stock units	0
Vesting of restricted stock units (in shares)		3,169,456
Share cancellations to satisfy tax withholding on vesting of restricted stock units	(2,019)		(2,019)
Share cancellations to satisfy tax withholding on vesting of restricted stock units (in shares)		(73,682)
Stock issued under employee stock purchase plan	3,407		3,407
Stock issued under employee stock purchase plan (in shares)		142,265
Excess tax benefit from stock-based awards	348		348
Components of comprehensive loss:
Net loss	(30,406)				(30,406)
Other comprehensive income (loss)	(375)			(375)
Ending balance at Dec. 31, 2014	583,357	$ 21	781,009	(676)	(196,997)
Ending balance (in shares) at Dec. 31, 2014		209,071,488
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon exercise of stock options	5,156		5,156
Issuance of common stock upon exercise of stock options (in shares)		1,077,797
Issuance of common stock related to acquisitions	148,490	$ 2	148,488
Issuance of common stock related to acquisitions (in shares)		10,246,616
Stock-based compensation	111,645		111,645
Vesting of restricted stock units	0
Vesting of restricted stock units (in shares)		4,184,415
Share cancellations to satisfy tax withholding on vesting of restricted stock units	(2,540)		(2,540)
Share cancellations to satisfy tax withholding on vesting of restricted stock units (in shares)		(148,302)
Stock issued under employee stock purchase plan	6,973		6,973
Stock issued under employee stock purchase plan (in shares)		538,398
Equity component of convertible note issuance, net of issuance costs	102,968		102,968
Purchase of capped call	(43,160)		(43,160)
Components of comprehensive loss:
Net loss	(169,661)				(169,661)
Other comprehensive income (loss)	159			159
Ending balance at Dec. 31, 2015	743,387	$ 23	1,110,539	(517)	(366,658)
Ending balance (in shares) at Dec. 31, 2015		224,970,412
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon exercise of stock options	3,464		3,464
Issuance of common stock upon exercise of stock options (in shares)		1,588,781
Stock-based compensation	145,968		145,968
Vesting of restricted stock units	0	$ 1	(1)
Vesting of restricted stock units (in shares)		7,666,647
Vesting of market stock units	0
Vesting of market stock units (in shares)		56,903
Share cancellations to satisfy tax withholding on vesting of restricted stock units	(3,368)		(3,368)
Share cancellations to satisfy tax withholding on vesting of restricted stock units (in shares)		(354,638)
Stock issued under employee stock purchase plan	$ 8,484		8,484
Stock issued under employee stock purchase plan (in shares)	1,254,910	1,254,910
Fair value of escrow settlement	$ (393)		(393)
Fair value of escrow settlement (in shares)		(20,258)
Components of comprehensive loss:
Net loss	(342,978)				(342,978)
Other comprehensive income (loss)	(305)			(305)
Ending balance at Dec. 31, 2016	$ 554,259	$ 24	$ 1,264,693	$ (822)	$ (709,636)
Ending balance (in shares) at Dec. 31, 2016		235,162,757

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating activities
Net loss	$ (342,978)	$ (169,661)	$ (30,406)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities
Depreciation and amortization	60,757	24,458	15,431
Stock-based compensation	138,458	111,645	87,055
Amortization of premium on investments, net	405	1,911	2,833
Other operating activities	4,403	2,134	1,366
Amortization of debt discount	18,315	1,084	0
Excess tax benefit from stock-based awards	0	0	(348)
Changes in assets and liabilities
Accounts receivable	(35,710)	(55,904)	(55,478)
Prepaid content acquisition costs	(44,211)	(1,399)	(700)
Prepaid expenses and other assets	(12,321)	(17,519)	(8,519)
Accounts payable, accrued and other current liabilities	5,294	18,080	4,830
Accrued content acquisition costs	(3,668)	23,736	7,608
Accrued compensation	15,364	7,378	13,736
Other long-term liabilities	1,384	6,005	7,690
Deferred revenue	8,420	4,946	(28,238)
Reimbursement of cost of leasehold improvements	4,397	1,024	4,169
Net cash provided by (used in) operating activities	(181,691)	(42,082)	21,029
Investing activities
Purchases of property and equipment	(59,769)	(23,512)	(25,465)
Internal-use software costs	(30,210)	(8,562)	(4,574)
Changes in restricted cash	(250)	0	0
Purchases of investments	(12,413)	(140,980)	(340,679)
Proceeds from maturities of investments	47,656	228,998	258,518
Proceeds from sales of investments	3,507	111,356	0
Payments related to acquisitions, net of cash acquired	(676)	(269,566)	0
Net cash used in investing activities	(52,155)	(102,266)	(112,200)
Financing activities
Proceeds from issuance of convertible notes	0	345,000	0
Payments for purchase of capped call	0	(43,160)	0
Payment of debt issuance costs	(32)	(8,909)	0
Borrowings under debt arrangements	90,000	0	0
Proceeds from employee stock purchase plan	9,701	7,552	6,438
Proceeds from exercise of stock options	3,457	5,192	16,894
Tax payments from net share settlements of restricted stock units	(3,369)	(2,540)	(2,019)
Excess tax benefit from stock-based awards	0	0	348
Net cash provided by financing activities	99,757	303,135	21,661
Effect of exchange rate changes on cash and cash equivalents	(634)	(77)	(288)
Net increase (decrease) in cash and cash equivalents	(134,723)	158,710	(69,798)
Cash and cash equivalents at beginning of period	334,667	175,957	245,755
Cash and cash equivalents at end of period	199,944	334,667	175,957
Supplemental disclosures of cash flow information
Cash paid during the period for income taxes	297	389	164
Cash paid during the period for interest	7,222	351	314
Purchases of property and equipment recorded in accounts payable and accrued liabilities	1,129	5,890	751
Fair value of shares issued related to the acquisition of a business	$ 0	$ 146,855	$ 0

Description of Business and Bas

Description of Business and Basis of Presentation	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation	Description of Business and Basis of Presentation Pandora — Internet Radio Service Pandora is the world’s most powerful music discovery platform, offering a personalized experience for each of our listeners wherever and whenever they want to listen to music—whether through earbuds, car speakers or live on stage. Pandora is available as an ad-supported service or as a subscription service, which we call Pandora Plus. The majority of our listener hours occur on mobile devices, with the majority of our revenue generated from advertising on our ad-supported service on these devices. We offer both local and national advertisers the opportunity to deliver targeted messages to our listeners using a combination of audio, display and video advertisements. We also generate revenue from subscriptions to Pandora Plus. We were incorporated as a California corporation in January 2000 and reincorporated as a Delaware corporation in December 2010. Our principal operations are located in the United States, and we also operate in Australia, New Zealand, Canada and the United Kingdom. Ticketing Service We operate our ticketing service through our subsidiary Ticketfly, a leading live events technology company that provides ticketing and marketing software and services for our clients, which are venues and event promoters, across North America. Ticketfly's ticketing, digital marketing and analytics software helps promoters book talent, sell tickets and drive in-venue revenue, while Ticketfly's consumer tools help fans find and purchase tickets to events. Ticketfly’s revenue primarily consists of service and merchant processing fees from ticketing operations. We completed the acquisition of Ticketfly on October 31, 2015. As used herein, "Pandora," "we," "our," "the Company" and similar terms include Pandora Media, Inc. and its subsidiaries, unless the context indicates otherwise. Basis of Presentation The consolidated financial statements and accompanying notes have been prepared in accordance with United States generally accepted accounting principles ("U.S. GAAP") and include the accounts of Pandora and our wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Certain changes in presentation have been made to conform the prior period presentation to current period reporting. We have reclassified internal-use software costs from the purchases of property and equipment line item to the internal-use software costs line item of our consolidated statements of cash flows. We have also reclassified prepaid content acquisition costs from the prepaid expenses and other assets line item to the prepaid content acquisition costs line item of our consolidated balance sheets and our consolidated statements of cash flows. Lastly, we have reclassified interest expense from the other income (expense), net line item to the interest expense line item of our consolidated statements of operations. Use of Estimates

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Revenue Recognition We recognize revenue when four basic criteria are met: (1) persuasive evidence exists of an arrangement with the customer reflecting the terms and conditions under which the products or services will be provided; (2) delivery has occurred or services have been provided; (3) the fee is fixed or determinable; and (4) collection is reasonably assured. We consider a signed agreement, a binding insertion order or other similar documentation to be persuasive evidence of an arrangement. Collectability is assessed based on a number of factors, including transaction history and the creditworthiness of a customer. If it is determined that collection is not reasonably assured, revenue is not recognized until collection becomes reasonably assured, which is generally upon receipt of cash. We record cash received in advance of revenue recognition as deferred revenue. Gross versus net revenue recognition. We report revenue on a gross or net basis based on management’s assessment of whether we act as a principal or agent in the transaction. To the extent we act as the principal, revenue is reported on a gross basis. The determination of whether we act as a principal or an agent in a transaction is based on an evaluation of whether we have the substantial risks and rewards of ownership under the terms of an arrangement. Advertising revenue. We generate advertising revenue primarily from audio, display and video advertising. We generate the majority of our advertising revenue through the delivery of advertising impressions sold on a cost per thousand, or CPM, basis. In determining whether an arrangement exists, we ensure that a binding arrangement, such as an insertion order or a fully executed customer-specific agreement, is in place. We generally recognize revenue based on delivery information from our campaign trafficking systems. We also generate advertising revenue pursuant to arrangements with advertising agencies and brokers. Under these arrangements, we provide the agencies and brokers the ability to sell advertising inventory on our service directly to advertisers. We report this revenue net of amounts due to agencies and brokers because we are not the primary obligor under these arrangements, we do not set the pricing nor do we establish or maintain the relationships with the advertisers. Subscription and other revenue. Our new subscription service, Pandora Plus, launched on September 15, 2016. Prior to the launch of Pandora Plus, our subscription service was Pandora One. Pandora Plus and Pandora One are premium monthly or annual paid versions of the Pandora service, which include advertisement-free access, higher quality audio on supported devices and longer timeout-free listening. Pandora Plus also includes additional features such as replays, additional skipping and offline listening. Subscription revenue derived from direct sales to listeners is recognized on a straight-line basis over the duration of the subscription period and is recognized net of sales tax amounts collected from subscribers. Subscription revenue derived from sales through some mobile device app stores may be subject to refund or cancellation terms which may affect the timing or amount of the subscription revenue recognition. When refund rights exist, we recognize revenue when services have been provided and the rights lapse or when we have developed sufficient transaction history to estimate a reserve. We were required to defer revenue for certain subscriptions purchased through mobile device app stores that contained refund rights until the refund rights lapsed or until we developed sufficient operating history to estimate a return reserve. As of December 31, 2013, we had deferred all revenue related to these mobile subscriptions subject to refund rights totaling approximately $14.2 million , as we did not have sufficient history to estimate a return reserve. Beginning in January 2014, we had sufficient historic transactional information which enabled us to estimate future returns. Accordingly, in January 2014, we began recording revenue related to these mobile subscriptions net of estimated returns. This change resulted in a one-time increase in subscription revenue in the quarter ended March 31, 2014 of approximately $14.2 million , as the previously deferred revenue was recognized. As of December 31, 2015 and 2016 , the deferred revenue related to the return reserve was not significant. Multiple-element arrangements. We enter into arrangements with customers to sell advertising packages that include different media placements or ad services that are delivered at the same time, or within close proximity of one another. We recognize the relative fair value of the media placements or ad services as they are delivered assuming all other revenue recognition criteria are met. We allocate arrangement consideration in multiple-deliverable revenue arrangements at the inception of an arrangement to all deliverables or those packages in which all components of the package are delivered at the same time, based on the relative selling price method in accordance with the selling price hierarchy, which includes: (1) vendor-specific objective evidence ("VSOE") if available; (2) third-party evidence ("TPE") if VSOE is not available; and (3) best estimate of selling price ("BESP") if neither VSOE nor TPE is available. We determine VSOE based on our historical pricing and discounting practices for the specific product or service when sold separately. In determining VSOE, we require that a substantial majority of the selling prices for these services fall within a reasonably narrow pricing range. We have not historically priced our advertising products within a narrow range. As a result, we have not been able to establish VSOE for any of our advertising products. When VSOE cannot be established for deliverables in multiple element arrangements, we apply judgment with respect to whether it can establish a selling price based on TPE. TPE is determined based on competitor prices for similar deliverables when sold separately. Generally, our go-to-market strategy differs from that of our peers and our offerings contain a significant level of differentiation such that the comparable pricing of services cannot be obtained. Furthermore, we are unable to reliably determine what similar competitor services' selling prices are on a stand-alone basis. As a result, we have not been able to establish selling price based on TPE. When we are unable to establish selling price using VSOE or TPE, we use BESP in our allocation of arrangement consideration. The objective of BESP is to determine the price at which we would transact a sale if the service were sold on a stand-alone basis. BESP is generally used to allocate the selling price to deliverables in our multiple element arrangements. We determine BESP for deliverables by considering multiple factors including, but not limited to, prices we charge for similar offerings, market conditions, competitive landscape and pricing practices. We limit the amount of allocable arrangement consideration to amounts that are fixed or determinable and that are not contingent on future performance or future deliverables. We regularly review BESP. Changes in assumptions or judgments or changes to the elements in the arrangement may cause an increase or decrease in the amount of revenue that we report in a particular period. Ticketing service revenue. Ticketing service revenue is generated primarily from service and merchant processing fees generated on ticket sales through the Ticketfly platform. Ticketfly sells tickets to fans for events on behalf of clients and charges a fee per ticket, which generally increases as the face value of the ticket increases, or a percentage of the total convenience charge and order processing fee, for its services at the time the ticket for an event is sold. Ticketing service revenue is recorded net of the face value of the ticket at the time of the sale, as Ticketfly generally acts as an agent with respect to the ticket price in these transactions. Concentration of Credit Risk Financial instruments that potentially subject us to concentrations of credit risk consist principally of cash and cash equivalents, investments and trade accounts receivable. We maintain cash and cash equivalents with domestic financial institutions of high credit quality. We perform periodic evaluations of the relative credit standing of such institutions. We perform ongoing credit evaluations of customers to assess the probability of accounts receivable collection based on a number of factors, including past transaction experience with the customer, evaluation of their credit history, and review of the invoicing terms of the contract. We generally do not require collateral. We maintain reserves for potential credit losses on customer accounts when deemed necessary. Actual credit losses during the years ended December 31, 2014 , 2015 and 2016 were $1.1 million , $1.1 million and $2.0 million , respectively. For the years ended December 31, 2014 , 2015 and 2016 , we had no individual customers that accounted for 10% or more of total revenue. As of December 31, 2015 and 2016 , there were no individual customers that accounted for 10% or more of our total accounts receivable. Cash, Cash Equivalents and Investments We classify our highly liquid investments with maturities of three months or less at the date of purchase as cash equivalents. Our investments consist of corporate debt securities. These investments are classified as available-for-sale securities and are carried at fair value with the unrealized gains and losses reported as a component of stockholders' equity. Management determines the appropriate classification of our investments at the time of purchase and reevaluates the available-for-sale designations as of each balance sheet date. We classify our investments as either short-term or long-term based on each instrument's underlying contractual maturity date. Investments with maturities of twelve months or less are classified as short-term and those with maturities greater than twelve months are classified as long-term. The cost basis for investments sold is based upon the specific identification method. Accounts Receivable and Allowance for Doubtful Accounts Accounts receivable are recorded net of an allowance for doubtful accounts. Our allowance for doubtful accounts is based upon historical loss patterns, the number of days that billings are past due and an evaluation of the potential risk of los s associated with delinquent accounts. We also consider any changes to the financial condition of our customers and any other external market factors that could impact the collectability of our receivables in the determination of our allowance for doubtful accounts. Accounts receivable amounts that are deemed uncollectable are charged against the allowance for doubtful accounts when identified. Property and Equipment, net Property and equipment is recorded at cost, less accumulated depreciation and amortization. Depreciation is computed using the straight-line method based on the estimated useful lives of the assets, which typically range from three to five years. Leasehold improvements are amortized over the shorter of the lease term or expected useful lives of the improvements. Property and equipment is reviewed for impairment whenever events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. Recoverability of these assets is measured by a comparison of the carrying amounts to the future undiscounted cash flows the assets are expected to generate. If property and equipment are considered to be impaired, the impairment to be recognized equals the amount by which the carrying value of the asset exceeds its fair market value. If we reduce the estimated useful life assumption for any asset, the remaining unamortized balance would be amortized or depreciated over the revised estimated useful life. Capitalized Internal-Use Software We capitalize certain costs incurred to develop software for internal use. Costs incurred in the preliminary stages of development are expensed as incurred. Once software has reached the development stage, internal and external costs, if direct and incremental, are capitalized until the software is substantially complete and ready for its intended use. Capitalization ceases upon completion of all substantial testing. We also capitalize costs related to specific upgrades and enhancements when it is probable the expenditures will result in additional functionality. Capitalized costs are recorded as part of property and equipment. Maintenance and training costs are expensed as incurred. Capitalized internal-use software costs are amortized on a straight-line basis over their three to five -year estimated useful lives. As of December 31, 2015 and 2016 , we had approximately $6.3 million and $25.7 million of capitalized internal use software and website development costs, net of accumulated amortization. We evaluate the useful lives of these assets and test for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets. There were no material impairments to internal-use software during the years ended December 31, 2014, 2015 and 2016. Ticketing Contract Advances Ticketing contract advances, which are either recoupable or non-recoupable, represent amounts paid in advance to clients pursuant to ticketing agreements. These amounts are reflected in prepaid expenses and other current assets if the amount is expected to be recouped or recognized over a period of twelve months or less or in other long-term assets if the amount is expected to be recouped or recognized over a period of more than twelve months. Recoupable ticketing contract advances are generally recoupable against future royalties earned by clients, based on the contract terms, over the lives of their contracts which typically range between three and five years. Non-recoupable ticketing contract advances are fixed incentives paid by Ticketfly to secure exclusive rights with certain clients and are amortized to sales and marketing expense over the life of the contract on a straight-line basis. Amortization expense for the years ended December 31, 2015 and 2016 was $0.7 million and $5.7 million . We maintain an allowance for doubtful accounts to reserve for recoupable ticketing contract advances that we potentially do not expect to recoup. Our allowance is based on historical loss patterns, the aging of balances and known factors about customers’ current financial conditions. Business Combinations, Goodwill and Intangible Assets, net We allocate the fair value of purchase consideration to the tangible assets acquired, liabilities assumed and intangible assets acquired based on their estimated fair values. The excess of the fair value of purchase consideration over the fair values of these identifiable assets and liabilities is recorded as goodwill. Such valuations require management to make significant estimates and assumptions, especially with respect to intangible assets. Significant estimates in valuing certain intangible assets include, but are not limited to, future expected cash flows from acquired users, acquired technology, and trade names from a market participant perspective, useful lives and discount rates. Management’s estimates of fair value are based upon assumptions believed to be reasonable, but which are inherently uncertain and unpredictable and, as a result, actual results may differ from estimates. During the measurement period, which is one year from the acquisition date, we may record adjustment s to the assets acquired and liabilities assumed, with the corresponding offset to goodwill. Upon the conclusion of the measurement period, any subsequent adjustments are recorded to earnings. We do not amortize goodwill and intangible assets with indefinite useful lives, rather such assets are required to be tested for impairment at least annually or sooner whenever events or changes in circumstances indicate that the assets may be impaired. We perform our goodwill and intangible asset impairment tests in the fourth quarter of each year. As of December 31, 2016 , no impairment of goodwill or indefinite-lived intangible assets has been identified. For purposes of testing goodwill for impairment, we established reporting units based on our current reporting structure. As of December 31, 2016 , our goodwill was allocated to our Pandora and Ticketfly reporting units. Acquired finite-lived intangible assets are amortized over the estimated useful lives of the assets, which range from two to eleven years. Acquired finite-lived intangible assets consist primarily of patents, customer relationships, developed technology and trade names resulting from business combinations. We evaluate the recoverability of our intangible assets for potential impairment whenever events or circumstances indicate that the carrying amount of such assets may not be recoverable. Recoverability of these assets is measured by a comparison of the carrying amounts to the future undiscounted cash flows the assets are expected to generate. If such review indicates that the carrying amount of intangible assets is not recoverable, the carrying amount of such assets is reduced to the fair value. In addition to the recoverability assessment, we routinely review the remaining estimated useful lives of finite-lived intangible assets. If we reduce the estimated useful life assumption for any asset, the remaining unamortized balance would be amortized over the revised estimated useful life. We record the amortization of intangible assets to the financial statement line item in our consolidated statement of operations that the asset directly relates to. To the extent that purchased intangibles are used in revenue generating activities, we record the amortization of these intangible assets to cost of revenue. Stock-Based Compensation—Restricted Stock Units and Stock Options Stock-based awards granted to employees, including grants of restricted stock units ("RSUs") and stock options, are recognized as expense in our statements of operations based on their grant date fair value. We recognize stock-based compensation expense on a straight-line basis over the service period of the award, which is generally four years. We estimate the fair value of RSUs at our stock price on the grant date. We generally estimate the grant date fair value of stock options using the Black-Scholes option-pricing model. The Black-Scholes option-pricing model is affected by our stock price on the date of grant, the expected stock price volatility over the expected term of the award, which is based on projected employee stock option exercise behaviors, the risk-free interest rate for the expected term of the award and expected dividends. Stock-based compensation expense is recorded net of estimated forfeitures in the statement of operations for only those stock-based awards that we expect to vest. We estimate the forfeiture rate based on historical forfeitures of equity awards and adjust the rate to reflect changes in facts and circumstances, if any. We revise our estimated forfeiture rate if actual forfeitures differ from our initial estimates. We have elected to use the "with and without" approach as described in Accounting Standards Codification 740 - Income Taxes in determining the order in which tax attributes are utilized. As a result, we will only recognize a tax benefit from stock-based awards in additional paid-in capital if an incremental tax benefit is realized after all other tax attributes currently available to us have been utilized. In addition, we have elected to account for the indirect effects of stock-based awards on other tax attributes, such as the research tax credit, through the statement of operations. Stock-Based Compensation—Employee Stock Purchase Plan In December 2013, our board of directors approved the Employee Stock Purchase Plan ("ESPP"), which was approved by our stockholders at the annual meeting in June 2014. We estimate the fair value of shares to be issued under the ESPP on the first day of the offering period using the Black-Scholes valuation model. The determination of the fair value is affected by our stock price on the first date of the offering period, as well as other assumptions including the risk-free interest rate, the estimated volatility of our stock price over the term of the offering period, the expected term of the offering period and the expected dividend rate. Stock-based compensation expense related to the ESPP is recognized on a straight-line basis over the offering period, net of estimated forfeitures. Stock-Based Compensation—MSUs In March 2015, the compensation committee of the board of directors granted performance awards consisting of market stock units to certain key executives under our 2011 Plan. Specifically, MSUs measure Pandora’s total stockholder return ("TSR") performance against that of the Russell 2000 Index across three performance periods. We have determined the grant-date fair value of the MSUs using a Monte Carlo simulation performed by a third-party valuation specialist. The Monte Carlo simulation model utilizes multiple input variables to estimate the probability that market conditions will be achieved. The variables used in these models are reviewed on an annual basis and adjusted, as needed. We recognize stock-based compensation for the MSUs over the requisite service period using the accelerated attribution method. Stock-Based Compensation—PSUs We implemented a performance stock unit program in April 2016 for stock-settled performance-based RSUs to certain key executives. We have determined the grant-date fair value of the PSUs granted in 2016 using a Monte Carlo simulation performed by a third-party valuation firm. The Monte Carlo simulation model utilizes multiple input variables to estimate the probability that market conditions will be achieved. The variables used in these models are reviewed on an annual basis and adjusted, as needed. We recognize stock-based compensation for the PSUs over the requisite service period, which is approximately four years, using the accelerated attribution method. Cost of Revenue — Content Acquisition Costs Cost of revenue—content acquisition costs principally consist of licensing fees paid for streaming music or other content to our listeners. Content acquisition costs are currently calculated using negotiated rates documented in direct license agreements with major and independent record labels, music publishers and PROs. Prior to September 15, 2016, the majority of our content acquisition costs for sound recordings were based on a fee per public performance of a sound recording. Subsequent to September 15, 2016, depending on the applicable service, these license agreements generally require us to pay either a per-performance fee based on the number of sound recordings we transmit, a percentage of revenue associated with the service, or a per-subscriber minimum amount, all generally subject to certain discounts. Prior to January 1, 2016, the majority of our content acquisition costs for the underlying musical works contained in sound recording were based on a percentage of our revenue. From January 1, 2016 until September 15, 2016, the majority of our content acquisition costs for the underlying musical works were based on a percentage of content acquisition costs paid for sound recordings. Subsequent to September 15, 2016, the majority of our content acquisition costs for the underlying musical works contained in sound recordings are determined in the same manner they were prior to September 15, 2016, but this calculation only applies to the performance rights on our ad-supported service and content acquisition costs for the reproduction rights on our subscription services are determined in accordance with the statutory license set forth in 17 U.S.C. §115. Certain of our direct license agreements are also subject to minimum guarantee payments, some of which are paid in advance and amortized over the minimum guarantee period. For certain content acquisition arrangements, we accrue for estimated content acquisition costs based on the available facts and circumstances and adjust these estimates as more information becomes available. Several of our direct license agreements also include so-called "most favored nations" provisions, which, if triggered, could cause our payments under those agreements to escalate. We recognize an accrual when it is probable that we will make additional payments under these provisions. The expense related to these accruals is recognized in cost of revenue—content acquisition costs. Prepaid Content Acquisition Costs Prepaid content acquisition costs are primarily comprised of minimum guarantees under content acquisition agreements. In 2015 and 2016, we signed direct license agreements with major and independent labels, distributors and publishers. Certain of these license agreements include minimum guarantee payments, some of which are paid in advance. These minimum guarantees may take the form of either a contractually obligated minimum over a specified period of time that requires a true-up payment at the end of the specified period if the cumulative payments have not met or exceeded the specified minimum, or cash advance payments made at the beginning of, or at intervals during, the specified period, which cash payments are then recoupable against content acquisition costs over the specified period. On a quarterly basis, we record the greater of the cumulative actual content acquisition costs incurred or the cumulative minimum guarantee based on forecasted usage for the minimum guarantee period. The minimum guarantee period is the period of time that the minimum guarantee relates to, as specified in each agreement, which may be annual or a longer period. The cumulative minimum guarantee, based on forecasted usage considers factors such as listening hours, revenue, subscribers and other terms of each agreement that impact our expected attainment or recoupment of the minimum guarantees on a non-straight line basis. Cost of Revenue — Ticketing Service Cost of revenue—ticketing service consists primarily of ticketing revenue share costs, credit card fees and intangible amortization expense. The majority of the cost is related to revenue share costs which consist of royalties paid to clients for their share of convenience and order processing fees. Payments to clients are recorded as an expense to the extent that the fair value of the identifiable benefit received in the exchange exceeds the amount of the payment to the client. Intangible amortization expense is related to amortization of developed technology. Cost of Revenue — Other Cost of revenue—other consists primarily of ad and music serving costs, employee-related and facilities and equipment costs and other costs of ad sales. Ad and music serving costs consist of content streaming, maintaining our internet radio service and creating and serving advertisements through third-party ad servers. We make payments to third-party ad servers for the period the advertising impressions are delivered or click-through actions occur, and accordingly, we record this as a cost of revenue in the related period. Employee-related costs include salaries and benefits associated with supporting music and ad-serving functions. Other costs of ad sales include costs related to music events that are sold as part of certain of our advertising arrangements. Product Development Product development consists primarily of employee-related, facilities and equipment costs, including salaries and benefits related to employees in software engineering, music analysis and product management departments, information technology and costs associated with supporting consumer connected-device manufacturers in implementing our service in their products. We incur product development expenses primarily for improvements to our website and the Pandora app, development of new advertising products and development and enhancement of our personalized station generating system. We have generally expensed product development as incurred. Certain website development and internal use software development costs are capitalized when specific criteria are met. In such cases, the capitalized amounts are amortized over the useful life of the related application once the application is placed in service. Sales and Marketing Sales and marketing consists primarily of employee-related and facilities and equipment costs, including salaries, commissions and benefits related to employees in sales, sales support, marketing, advertising and music maker group departments. In addition, sales and marketing expenses include transaction processing commissions on subscription purchases through mobile app stores, external sales and marketing expenses such as brand marketing, advertising, direct response and search engine marketing costs, public relations expenses, costs related to music events, agency platform and media measurement expenses, infrastructure costs and amortization expense related to acquired intangible assets. We expense the costs of producing advertisements as they are incurred and expense the cost of communicating advertisements at the time the advertisement airs or the event occurs, in each case as sales and marketing expense within the accompanying consolidated statements of operations. During the years ended December 31, 2014 , 2015 and 2016 , we recorded advertising expenses of $10.4 million , $35.1 million and $45.7 million , respectively. General and Administrative General and administrative consists primarily of employee-related and facilities and equipment costs, including salaries, benefits and severance expense for finance, accounting, legal, internal information technology and other administrative personnel. In addition, general and administrative expenses include professional services costs for outside legal and accounting services, infrastructure costs, credit card fees and sales and other tax expense. Provision for (Benefit from) Income Taxes Our provision for (benefit from) income taxes is computed using the asset and liability method, under which deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted statutory income tax rates in effect for the year in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce net deferred tax assets to the amount expected to b e realized. We recognize a tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such positions are then measured based on the largest benefit that has a greater than 50% likelihood of being realized upon settlement. We will recognize interest and penalties related to unrecognized tax benefits in the provision for (benefit from) income taxes in the accompanying statement of operations. We calculate the current and deferred income tax provision based on estimates and assumptions that could differ from the actual results reflected in income tax returns filed in subsequent years. Adjustments based on filed income tax returns are recorded when identified. The amount of income taxes paid is subject to examination by U.S. federal, state and international tax authorities. The estimate of the potential outcome of any uncertain tax issue is subject to management's assessment of relevant risks, facts and circumstances existing at that time. To the extent that the assessment of such tax positions change, the change in estimate is recorded in the period in which the determination is made. Net Loss Per Share Basic net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by giving effect to all potential shares of common stock, including stock options, restricted stock units, market stock units and performance-based RSUs, to the extent dilutive. Basic and diluted net loss per share were the same for each period presented as the inclusion of all potential common shares outstanding wou

Composition of Certain Financia

Composition of Certain Financial Statement Captions	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Composition of Certain Financial Statement Captions	Composition of Certain Financial Statement Captions Cash, Cash Equivalents and Investments Cash, cash equivalents and investments consisted of the following: As of December 31, 2015 2016 (in thousands) Cash and cash equivalents Cash $ 104,361 $ 144,192 Money market funds 180,021 55,752 Commercial paper 31,089 — Corporate debt securities 2,000 — U.S. government and government agency debt securities 17,196 — Total cash and cash equivalents $ 334,667 $ 199,944 Short-term investments Commercial paper $ 4,792 $ — Corporate debt securities 31,052 37,109 Total short-term investments $ 35,844 $ 37,109 Long-term investments Corporate debt securities $ 46,369 $ 6,252 Total long-term investments $ 46,369 $ 6,252 Total cash, cash equivalents and investments $ 416,880 $ 243,305 Our short-term investments have maturities of twelve months or less and are classified as available-for-sale. Our long-term investments have maturities of greater than twelve months and are classified as available-for-sale. The following tables summarize our available-for-sale securities’ adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category as of December 31, 2015 and 2016 . As of December 31, 2015 Adjusted Cost Unrealized Gains Unrealized Losses Fair Value (in thousands) Cash equivalents and marketable securities Money market funds $ 180,021 $ — $ — $ 180,021 Commercial paper 35,881 — — 35,881 Corporate debt securities 79,760 8 (347 ) 79,421 U.S. government and government agency debt securities 17,198 — (2 ) 17,196 Total cash equivalents and marketable securities $ 312,860 $ 8 $ (349 ) $ 312,519 As of December 31, 2016 Adjusted Cost Unrealized Gains Unrealized Losses Fair Value (in thousands) Cash equivalents and marketable securities Money market funds $ 55,752 $ — $ — $ 55,752 Corporate debt securities 43,413 3 (55 ) 43,361 Total cash equivalents and marketable securities $ 99,165 $ 3 $ (55 ) $ 99,113 The following tables present available-for-sale investments by contractual maturity date as of December 31, 2015 and 2016 : As of December 31, 2015 Adjusted Cost Fair Value (in thousands) Due in one year or less $ 266,205 $ 266,150 Due after one year through three years 46,655 46,369 Total $ 312,860 $ 312,519 As of December 31, 2016 Adjusted Cost Fair Value (in thousands) Due in one year or less $ 92,914 $ 92,861 Due after one year through three years 6,251 6,252 Total $ 99,165 $ 99,113 The following tables summarize our available-for-sale securities’ fair value and gross unrealized losses aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position as of December 31, 2015 and 2016 : As of December 31, 2015 Twelve Months or Less More than Twelve Months Total Fair Gross Unrealized Losses Fair Gross Unrealized Losses Fair Gross Unrealized Losses (in thousands) Corporate debt securities $ 64,804 $ (293 ) $ 8,531 $ (54 ) $ 73,335 $ (347 ) U.S. government and government agency debt securities 16,241 (2 ) — — 16,241 (2 ) Total $ 81,045 $ (295 ) $ 8,531 $ (54 ) $ 89,576 $ (349 ) As of December 31, 2016 Twelve Months or Less More than Twelve Months Total Fair Gross Unrealized Losses Fair Gross Unrealized Losses Fair Gross Unrealized Losses (in thousands) Corporate debt securities $ 34,257 $ (52 ) $ 4,099 $ (3 ) $ 38,356 $ (55 ) Total $ 34,257 $ (52 ) $ 4,099 $ (3 ) $ 38,356 $ (55 ) Our investment policy requires investments to be investment grade, primarily rated "A1" by Standard & Poor’s or "P1" by Moody’s or better for short-term investments and rated "A" by Standard & Poor’s or "A2" by Moody’s or better for long-term investments, with the objective of minimizing the potential risk of principal loss. In addition, the investment policy limits the amount of credit exposure to any one issuer. The unrealized losses on our available-for-sale securities as of December 31, 2016 were primarily a result of unfavorable changes in interest rates subsequent to the initial purchase of these securities. As of December 31, 2016 , we owned 30 securities that were in an unrealized loss position. Based on our cash flow needs, we may be required to sell a portion of these securities prior to maturity. However, we expect to recover the full carrying value of these securities. As a result, no portion of the unrealized losses at December 31, 2016 is deemed to be other-than-temporary and the unrealized losses are not deemed to be credit losses. When evaluating the investments for other-than-temporary impairment, we review factors such as the length of time and extent to which fair value has been below cost basis, the financial condition of the issuer and any changes thereto, and our intent to sell, or whether it is more likely than not we will be required to sell, the investment before recovery of the investment’s amortized cost basis. During the year ended December 31, 2016 , we did no t recognize any impairment charges. During the year ended December 31, 2016 , proceeds from the sale of available-for-sale securities were $3.5 million . We did no t recognize a realized gain or loss in connection with these sales. Accounts Receivable, net Accounts receivable, net consisted of the following as of December 31, 2015 and 2016 : As of December 31, 2015 2016 (in thousands) Accounts receivable, net Accounts receivable $ 279,240 $ 312,900 Allowance for doubtful accounts (2,165 ) (3,633 ) Total accounts receivable, net $ 277,075 $ 309,267 The following table summarizes our beginning allowance for doubtful accounts balance for each period, additions, write-offs net of recoveries and the balance at the end of each period for the years December 31, 2014 , 2015 and 2016 : Allowance for Doubtful Accounts Balance at Beginning of Period Additions Write-offs, Net of Recoveries Balance at End of Period (in thousands) For the year ended December 31, 2014 $ 1,272 1,064 (1,118 ) $ 1,218 For the year ended December 31, 2015 $ 1,218 2,085 (1,138 ) $ 2,165 For the year ended December 31, 2016 $ 2,165 3,508 (2,040 ) $ 3,633 Prepaid Content Acquisition Costs Prepaid content acquisition costs consist primarily of minimum guarantees under content acquisition agreements. These minimum guarantees may take the form of either a contractually obligated minimum over a specified period of time that requires a true-up payment at the end of the specified period if the cumulative payments have not met or exceeded the specified minimum, or cash advance payments made at the beginning of, or at intervals during, the specified period, which cash payments are then recoupable against content acquisition costs over the specified period. On a quarterly basis, we record the greater of the cumulative actual content acquisition costs incurred or the cumulative minimum guarantee based on forecasted usage for the minimum guarantee period. The minimum guarantee period is the period of time that the minimum guarantee relates to, as specified in each agreement, which may be annual or a longer period. The cumulative minimum guarantee, based on forecasted usage considers factors such as listening hours, revenue, subscribers and other terms of each agreement that impact our expected attainment or recoupment of the minimum guarantees on a non-straight line basis. As of December 31, 2015 and 2016 , we had prepaid content acquisition costs of $2.1 million and $46.3 million . Prepaid and Other Current Assets Prepaid and other current assets consisted of the following as of December 31, 2015 and 2016 : As of December 31, 2015 2016 (in thousands) Prepaid and other current assets Other current assets $ 15,821 $ 13,858 Prepaid expenses 13,908 13,533 Ticketing contract advances—short term, net 4,092 5,800 Total prepaid and other current assets $ 33,821 $ 33,191 As of December 31, 2015 and 2016 , other current assets consisted primarily of $12.9 million and $9.1 million in receivables for the reimbursement of costs of leasehold improvements in connection with our operating leases. Other Long-Term Assets Other long-term assets consisted of the following as of December 31, 2015 and 2016 : As of December 31, 2015 2016 (in thousands) Other long-term assets Ticketing contract advances—long-term $ 9,824 $ 15,395 Long-term security deposits 9,039 9,090 Other 10,929 7,048 Total other long-term assets $ 29,792 $ 31,533 Property and Equipment, net Property and equipment, net consisted of the following as of December 31, 2015 and 2016 : As of December 31, 2015 2016 (in thousands) Property and equipment, net Servers, computers and other related equipment $ 57,309 $ 85,541 Leasehold improvements 35,947 63,519 Office furniture and equipment 5,470 9,037 Construction in progress 12,550 20,393 Software developed for internal use 10,239 34,983 Total property and equipment $ 121,515 $ 213,473 Less accumulated depreciation and amortization (55,145 ) (89,385 ) Total property and equipment, net $ 66,370 $ 124,088 Depreciation expenses totaled $14.7 million , $20.4 million and $34.2 million for the years ended December 31, 2014 , 2015 and 2016 , respectively. There were no material write-offs during the years ended December 31, 2014 , 2015 and 2016 . Software developed for internal use generally has an expected useful life of three to five years from the date placed in service. As of December 31, 2015 and 2016 the net carrying amount was $6.3 million and $25.7 million , including accumulated amortization of $4.0 million and $9.3 million . Amortization expense for the years ended December 31, 2014 , 2015 and 2016 was $1.1 million , $2.2 million and $5.3 million , respectively. Other Current Liabilities Other current liabilities consisted of the following as of December 31, 2015 and 2016 : As of December 31, 2015 2016 (in thousands) Other current liabilities Ticketing amounts due to clients $ 13,104 $ 20,666 Other 2,528 327 Total other current liabilities $ 15,632 $ 20,993 Ticketing amounts due to clients consists of the face value of tickets sold and the revenue share costs related to tickets sold on the Ticketfly ticketing platform that are owed to clients. The face value of tickets sold on the Ticketfly ticketing platform is collected by Ticketfly and remitted to clients. Revenue share costs owed to clients related to tickets sold on the Ticketfly ticketing platform consist of fees paid to clients for their share of convenience and order processing fees. Other Long-Term Liabilities Other long-term liabilities consisted of the following as of December 31, 2015 and 2016 : As of December 31, 2015 2016 (in thousands) Other long-term liabilities Long-term deferred rent $ 23,662 $ 24,245 Other 7,200 9,942 Total other long-term liabilities $ 30,862 $ 34,187

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value	Fair Value We record cash equivalents and short-term investments at fair value. Fair value is an exit price, representing the amount that would be received from the sale of an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. Fair value measurements are required to be disclosed by level within the following fair value hierarchy: Level 1 — Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date. Level 2 — Inputs (other than quoted prices included in Level 1) are either directly or indirectly observable for the asset or liability through correlation with market data at the measurement date and for the duration of the instrument’s anticipated life. Level 3 — Inputs lack observable market data to corroborate management’s estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model. When determining fair value, whenever possible we use observable market data and rely on unobservable inputs only when observable market data is not available. The fair value of these financial assets and liabilities was determined using the following inputs at December 31, 2015 and 2016 : As of December 31, 2015 Fair Value Measurement Using Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Total (in thousands) Assets Commercial paper $ — $ 35,881 $ 35,881 Corporate debt securities — 79,421 79,421 U.S. government and government agency debt securities — 17,196 17,196 Total assets measured at fair value $ — $ 132,498 $ 132,498 As of December 31, 2016 Fair Value Measurement Using Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Total (in thousands) Assets Corporate debt securities $ — $ 43,361 $ 43,361 Total assets measured at fair value $ — $ 43,361 $ 43,361 Our other cash equivalents and short-term investments are classified as Level 2 within the fair value hierarchy because they are valued using professional pricing sources for identical or comparable instruments, rather than direct observations of quoted prices in active markets. As of December 31, 2015 and 2016 , we held no Level 3 assets or liabilities. Our money market funds are no longer classified within the fair value hierarchy, as the fair values are measured at net asset value using the practical expedient. As of December 31, 2015 and 2016 , the fair value of our money market funds were $180.0 million and $55.8 million .

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
Business Combinations	Business Combinations Year Ended December 31, 2016 During the year ended December 31, 2016, we completed a business combination that was not material to our consolidated financial statements. We had no material business combinations during the period. We have included the financial results of the acquired business in our consolidated financial statements from the respective date of acquisition. Pro forma results of operations related to this acquisition during the year ended December 31, 2016 have not been presented because they are not material to our consolidated statements of operations. The fair value of assets acquired and liabilities assumed from our acquisition was based on a preliminary valuation and our estimates and assumptions are subject to change within the measurement period. Measurement period adjustments that we determine to be material will be applied to the period in which the amounts are determined in our consolidated financial statements. Year Ended December 31, 2015 Ticketfly On October 31, 2015, we completed the acquisition of Ticketfly, a leading live events technology company that provides ticketing and marketing software and services for venues and event promoters across North America, for an aggregate purchase price of $335.3 million of common stock and cash, including 11,193,847 shares of the Company’s common stock and approximately $191.5 million in cash paid by the Company. In addition to the purchase price, unvested options and unvested RSUs of Ticketfly held by Ticketfly employees were converted into unvested options to acquire our common stock and our unvested RSUs. Upon acquisition, Ticketfly became a wholly owned subsidiary of Pandora. The acquisition was accounted for as a business combination, and the financial results of Ticketfly are included in our consolidated financial statements from the date of acquisition. The following table summarizes the components of the purchase consideration transferred based on the closing price of $12.18 per share of our common stock as of the acquisition date: (in thousands) Cash paid by Pandora $ 191,479 Cash paid by Ticketfly to option holders 7,238 Common stock (11,193,847 shares at $12.18 per share) issued by Pandora to selling shareholders 136,342 Fair value of stock options and restricted stock units assumed 10,514 Less: purchase price adjustments (6,995 ) Less: post-combination compensation expense (3,235 ) Purchase consideration $ 335,343 The $3.2 million of post-combination compensation expense (approximately 0.2 million shares of common stock and $1.9 million in cash) is subject to continuous employment and is being recognized over the required service period of up to three years. The following table summarizes the estimated fair values of assets acquired and liabilities assumed as of the date of acquisition: (in thousands) Current assets $ 39,809 Long-term assets 15,982 Current liabilities (21,853 ) Long-term liabilities (6,298 ) Deferred tax liability (1,738 ) Intangible assets 76,800 Goodwill 232,641 Total $ 335,343 The fair value of assets acquired and liabilities assumed from our acquisition of Ticketfly was based on a preliminary valuation and our estimates and assumptions are subject to change. We will recognize any subsequent adjustments to the purchase price prospectively in the period in which the adjustments are determined. A portion of the purchase price related to estimated liabilities for taxes totaling $5.1 million is held in escrow and may be recovered from this escrow amount. We have recorded a receivable in the amount of $5.1 million related to these liabilities, as we expect to recover any amounts required to be paid by us from the escrow amount. The following unaudited pro forma information presents the combined results of operations as if the acquisition had been completed on January 1, 2014, the beginning of the comparable prior annual reporting period. The unaudited pro forma results include: (i) amortization associated with preliminary estimates for the acquired intangible assets; (ii) recognition of the post-combination compensation expense; and (iii) share-based compensation expense related to the RSUs and options granted to Ticketfly employees. The unaudited pro forma results do not reflect any cost saving synergies from operating efficiencies or the effect of the incremental costs incurred in integrating the two companies. Accordingly, these unaudited pro forma results are presented for informational purpose only and are not necessarily indicative of what the actual results of operations of the combined company would have been if the acquisition had occurred at the beginning of the period presented, nor are they indicative of future results of operations: Year ended 2014 2015 (in thousands) Revenue $ 975,712 $ 1,222,452 Net loss $ (58,195 ) $ (210,111 ) Rdio, Inc. ("Rdio") On December 23, 2015, we completed the acquisition of technology and intellectual property from Rdio for $77.5 million , which includes $2.5 million in additional purchase consideration transferred prior to the closing of the acquisition. Goodwill generated from the assets acquired is primarily attributable to expected synergies that will allow us to broaden our subscription business and roll out our new subscription services, Pandora Plus and Pandora Premium. Pandora Plus launched on September 15, 2016 and Pandora Premium will launch in 2017. We have accounted for this acquisition as a business combination, and the financial results of Rdio are included in our consolidated financial statements from the date of acquisition. As a result of the sale of assets, Rdio discontinued its service as of December 22, 2015. Other acquisitions During the year ended December 31, 2015 , we completed the acquisitions of Next Big Sound ("NBS") and KXMZ-FM ("KXMZ"). These acquisitions were not material to our consolidated financial statements, either individually or in the aggregate. We have included the financial results of Ticketfly, Rdio, NBS and KXMZ in our consolidated financial statements from their respective dates of acquisition. Pro forma results of operations related to our acquisitions, other than Ticketfly, during the year ended December 31, 2015 have not been presented because they are not material to our consolidated statements of operations, either individually or in the aggregate. The following table summarizes the allocation of estimated fair values of the net assets acquired during the year ended December 31, 2015 , including the related estimated useful lives, where applicable: Ticketfly Rdio Other Estimated fair value Estimated useful life in years Estimated fair value Estimated useful life in years Estimated fair value Estimated useful life in years (in thousands, except for estimated useful life) Intangible assets: Customer relationships—clients $ 37,300 8 $ — $ — Developed technology 28,100 5 26,400 2-5 1,550 4 Tradename 10,400 8 1,000 3 320 2 Customer relationships—users 1,000 2 — 940 2 FCC license—broadcast radio — — 193 Tangible assets acquired, net 27,640 1,969 (490 ) Deferred tax liabilities (1,738 ) — (49 ) Net assets acquired $ 102,702 $ 29,369 $ 2,464 Goodwill 232,641 48,131 23,103 Total fair value consideration $ 335,343 $ 77,500 $ 25,567 Goodwill generated from the Ticketfly acquisition is primarily attributable to expected synergies from future growth and strategic advantages in the ticketing industry. Goodwill generated from Rdio is primarily attributable to expected synergies from future growth and strategic advantages in the online streaming music industry. Goodwill generated from all other business acquisitions during the year ended December 31, 2015

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets During the year ended December 31, 2016 we completed a business combination that was not material to our consolidated financial statements. During the year ended December 31, 2016 , we made an adjustment to goodwill and deferred tax liabilities as a result of the impact of final pre-acquisition Ticketfly income tax returns filed. The changes in the carrying amount of goodwill for the years ended December 31, 2015 and 2016 , are as follows: Goodwill (in thousands) Balance as of December 31, 2014 $ — Goodwill resulting from business combinations 303,875 Balance as of December 31, 2015 $ 303,875 Goodwill resulting from business combination and purchase price adjustments 2,816 Balance as of December 31, 2016 $ 306,691 The following summarizes information regarding the gross carrying amounts and accumulated amortization of intangibles: As of December 31, 2015 As of December 31, 2016 Gross Carrying Amount Accumulated Amortization Net Carrying Value Gross Carrying Amount Accumulated Amortization Net Carrying Value (in thousands) Finite-lived intangible assets Patents $ 8,030 $ (1,824 ) $ 6,206 $ 8,030 $ (2,556 ) $ 5,474 Developed technology 56,050 (1,265 ) 54,785 56,162 (13,599 ) 42,563 Customer relationships — clients 37,300 (777 ) 36,523 37,399 (5,487 ) 31,912 Customer relationships — users 1,940 (318 ) 1,622 1,940 (1,288 ) 652 Trade names 11,720 (304 ) 11,416 11,735 (2,104 ) 9,631 Total finite-lived intangible assets $ 115,040 $ (4,488 ) $ 110,552 $ 115,266 $ (25,034 ) $ 90,232 Indefinite-lived intangible assets FCC license—broadcast radio $ 193 $ — $ 193 $ 193 $ — $ 193 Total intangible assets $ 115,233 $ (4,488 ) $ 110,745 $ 115,459 $ (25,034 ) $ 90,425 Amortization expense of intangible assets was $0.7 million , $3.4 million and $20.5 million for the years ended December 31, 2014 , 2015 and 2016 , respectively. The following is a schedule of future amortization expense related to finite-lived intangible assets as of December 31, 2016 . As of (in thousands) 2017 $ 20,116 2018 17,654 2019 17,129 2020 15,896 2021 6,690 Thereafter 12,747 Total future amortization expense $ 90,232

Debt Instruments

Debt Instruments	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Debt Instruments	Debt Instruments Long-term debt, net consisted of the following: As of December 31, 2015 2016 (in thousands) 1.75% convertible senior notes due 2020 $ 345,000 $ 345,000 Credit facility — 90,000 Unamortized discount and deferred issuance costs (110,423 ) (92,753 ) Long-term debt, net $ 234,577 $ 342,247 Convertible Debt Offering On December 9, 2015, we completed an unregistered Rule 144A offering for the issuance of $345.0 million aggregate principal amount of our 1.75% Convertible Senior Notes due 2020 (the "Notes"). In connection with the issuance of the Notes, we entered into capped call transactions with the initial purchaser of the Notes and an additional financial institution (the "capped call transactions"). The net proceeds from the sale of the Notes were approximately $336.5 million , after deducting the initial purchasers' fees and other estimated expenses. We used approximately $43.2 million of the net proceeds to pay the cost of the capped call transactions. The Notes are unsecured, senior obligations of Pandora, and interest is payable semi-annually at a rate of 1.75% per annum. The Notes will mature on December 1, 2020, unless earlier repurchased or redeemed by Pandora or converted in accordance with their terms prior to such date. Prior to July 1, 2020, the Notes are convertible at the option of holders only upon the occurrence of specified events or during certain periods as further described below; thereafter, until the second scheduled trading day prior to maturity, the Notes will be convertible at the option of holders at any time. The conversion rate for the Notes is initially 60.9050 shares of common stock per $1,000 principal amount of the Notes, which is equivalent to an initial conversion price of approximately $16.42 per share of our common stock, and is subject to adjustment in certain circumstances. We will not have the right to redeem the Notes prior to December 5, 2018. We may redeem all or any portion of the Notes for cash at our option on or after December 5, 2018 if the last reported sale price of our common stock is at least 130% of the conversion price then in effect for at least 20 trading days, whether or not consecutive, during any 30 consecutive trading day period, including the last trading day of such period, ending on, and including, any of the five trading days immediately preceding the date on which we provide notice of redemption. Any optional redemption of the Notes will be at a redemption price equal to 100% of the principal amount of the Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. The maximum number of shares of common stock the Notes are convertible into is approximately 27.3 million , and is subject to adjustment under certain circumstances. The Notes will be convertible at the option of holders only under the following circumstances: • Prior to the close of business on the business day immediately preceding July 1, 2020, during any calendar quarter commencing after the calendar quarter ending on March 31, 2016 (and only during such calendar quarter), if the last reported sale price of our common stock for at least 20 trading days (whether or not consecutive), during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; • Prior to the close of business on the business day immediately preceding July 1, 2020, during the five business day period after any ten consecutive trading day period (the "measurement period") in which the trading price per $1,000 principal amount of Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of our common stock and the conversion rate on each such trading day; • Prior to the business day immediately preceding July 1, 2020, upon the occurrence of specified corporate events; or • At any time on or after July 1, 2020 until the close of business on the second scheduled trading day immediately preceding the December 1, 2020 maturity date. Upon the occurrence of a make-whole fundamental change or if we call all or any portion of the Notes for redemption prior to July 1, 2020, we will, in certain circumstances, increase the conversion rate by a number of additional shares for a holder that elects to convert its Notes in connection with such make-whole fundamental change or during the related redemption period. The Notes were separated into debt and equity components and assigned a fair value. The value assigned to the debt component is the estimated fair value as of the issuance date of similar debt without the conversion feature. The difference between the cash proceeds and this estimated fair value represents the value which has been assigned to the equity component and recorded as a debt discount. The debt discount is being accreted using the effective interest method over the period from the date of issuance through the December 1, 2020 maturity date. The initial debt component of the Notes was valued at $233.5 million , based on the contractual cash flows discounted at an appropriate market rate for non-convertible debt at the date of issuance. The carrying value of the permanent equity component reported in additional paid-in-capital was initially valued at $103.0 million , which is net of $2.6 million of fees and expenses allocated to the equity component. The following table outlines the effective interest rate, contractually stated interest expense and costs related to the amortization of the discount for the Notes: Year ended December 31, 2015 2016 (in thousands except for effective interest rate) Effective interest rate 10.18 % 10.18 % Contractually stated interest expense $ 369 $ 6,046 Amortization of discount $ 1,084 $ 18,315 The capped call transactions are expected to reduce the potential dilution to our common stock and/or offset the cash payments we would be required to make in excess of the principal amount of the converted Notes in the event that the market price of our common stock, as measured under the terms of the capped call transaction, is greater than the strike price of the capped call transaction, with such reduction and/or offset subject to a cap based on the cap price of the capped call transactions. The strike price of the capped call transactions corresponds to the initial conversion price of the Notes and is subject to certain adjustments under the terms of the capped call transactions. The capped call transactions have an initial cap price of $25.26 per share and are subject to certain adjustments under the terms of the capped call transactions. The capped call transactions have been included as a net reduction to additional paid-in capital within stockholders’ equity. The total estimated fair value of the Notes as of December 31, 2016 was $357.2 million . The fair value was determined using a methodology that combines direct market observations with quantitative pricing models to generate evaluated prices. We consider the fair value of the Notes to be a Level 2 measurement due to the limited trading activity of the Notes. The closing price of our common stock was $13.04 on December 31, 2016 , which was less than the initial conversion price for the Notes of approximately $16.42 per share. As such, the if-converted value of the Notes was less than the principal amount of $345.0 million . Credit Facility In May 2011, we entered into a credit facility and in December 2015, we amended this credit facility to increase the aggregate commitment amount to $120.0 million , with a maturity date of September 12, 2018. The amendment further increased the minimum liquidity financial covenant requirement from $5.0 million to $10.0 million at any time. The credit facility interest rate on US borrowings is based on an alternate base rate plus 1.00% - 1.25% and Eurocurrency borrowings are based on the LIBO rate plus 2.00% - 2.25% , both of which are per annum rates based on outstanding borrowings. The non-usage fee is 0.375% per annum. The available letters of credit under the amended credit facility is $15.0 million , and the annual charge for outstanding letters of credit is 2.00% - 2.25% per annum based on outstanding borrowings. The amount of borrowings available under the credit facility at any time is based on our monthly accounts receivable balance at such time and the amounts borrowed are collateralized by our personal property, including such accounts receivable but excluding intellectual property. The credit facility contains customary events of default, conditions to borrowing and covenants, including restrictions on our ability to dispose of assets, make acquisitions, incur debt, incur liens and make distributions to stockholders. During the continuance of an event of a default, the lenders may accelerate amounts outstanding, terminate the credit facility and foreclose on all collateral. In September 2016, we borrowed $90.0 million from the credit facility to enhance our working capital position. The amount borrowed is included in long-term debt on our balance sheet. Interest is payable quarterly at the applicable annual interest rate of 3.81% through September 2017. The applicable interest rate will be adjusted in September 2017. As of December 31, 2015 we had no outstanding borrowings, $1.1 million in letters of credit outstanding and $118.9 million of available borrowing capacity under the credit facility. As of December 31, 2016 , we had $90.0 million outstanding borrowings, $1.2 million in letters of credit outstanding and $28.8 million of available borrowing capacity under the credit facility. Total debt issuance costs associated with the 2015 credit facility amendment were $0.4 million , which are recorded as a debt discount that will be accreted as interest expense over the approximate two -year remaining term of credit facility agreement. For the years ended December 31, 2014 , 2015 and 2016 , $0.2 million , $0.2 million and $0.4 million

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases The following is a schedule of future minimum lease payments and future minimum sublease income under noncancelable operating leases as of December 31, 2016 : As of December 31, 2016 Future Minimum Lease Payments Future Minimum Sublease Income (in thousands) 2017 $ 26,035 $ 1,848 2018 25,023 907 2019 24,521 487 2020 21,996 501 2021 13,778 430 Thereafter 43,860 — Total $ 155,213 $ 4,173 We conduct our operations using leased office facilities in various locations. We lease office space under arrangements expiring through 2027. Rent expense for the years ended December 31, 2014 , 2015 and 2016 was $8.6 million , $12.2 million and $20.5 million , respectively. For operating leases that include escalation clauses over the term of the lease, tenant improvement reimbursements and rent abatement periods, we recognize rent expense on a straight-line basis over the lease term including expected renewal periods. The difference between rent expense and rent payments is recorded as deferred rent in current and long-term liabilities. As of December 31, 2015 and 2016 deferred rent was $23.9 million and $27.6 million . Minimum Guarantees and Other Provisions — Content Acquisition Costs Certain of our content acquisition agreements contain minimum guarantees and require that we make upfront minimum guarantee payments. Refer to our discussion of these matters in Item 1A—"Risk Factors". During the year ended December 31, 2016, we prepaid $163.8 million in content acquisition costs related to minimum guarantees, which were offset by amortization of prepaid content acquisition costs of $117.5 million . As of December 31, 2016 , we have future minimum guarantee commitments of $763.0 million , of which $355.6 million will be paid in 2017 and the remainder will be paid thereafter. On a quarterly basis, we record the greater of the cumulative actual content acquisition costs incurred or the cumulative minimum guarantee based on forecasted usage for the minimum guarantee period. The minimum guarantee period is the period of time that the minimum guarantee relates to, as specified in each agreement, which may be annual or a longer period. The cumulative minimum guarantee, based on forecasted usage considers factors such as listening hours, revenue, subscribers and other terms of each agreement that impact our expected attainment or recoupment of the minimum guarantees on a non-straight line basis. Several of our content acquisition agreements also include so-called "most favored nations" provisions, which, if triggered, could cause our payments under those agreements to escalate. In addition, record labels, publishers and PROs with whom we have entered into direct license agreements have the right to audit our content acquisition payments, and any such audit could result in disputes over whether we have paid the proper content acquisition costs. However, as of December 31, 2016, we do not believe it is probable that these provisions of our agreements discussed above will, individually or in the aggregate, have a material adverse effect on our business, financial position, results of operations or cash flows. Legal Proceedings We have been in the past, and continue to be, a party to various legal proceedings, which have consumed, and may continue to consume, financial and managerial resources. We record a liability when we believe that it is both probable that a loss has been incurred and the amount can be reasonably estimated. Our management periodically evaluates developments that could affect the amount, if any, of liability that we have previously accrued and make adjustments as appropriate. Determining both the likelihood and the estimated amount of a loss requires significant judgment, and management’s judgment may be incorrect. We do not believe the ultimate resolution of any pending legal matters is likely to have a material adverse effect on our business, financial position, results of operations or cash flows. Pre-1972 copyright litigation On April 17, 2014, UMG Recordings, Inc., Sony Music Entertainment, Capitol Records, LLC, Warner Music Group Corp. and ABKCO Music and Records, Inc. filed suit against Pandora Media Inc. in the Supreme Court of the State of New York. The complaint claims common law copyright infringement and unfair competition arising from allegations that Pandora owes royalties for the public performance of sound recordings recorded prior to February 15, 1972. In October 2015, the parties reached an agreement ("pre-1972 settlement") whereby we agreed to pay the plaintiffs a total of $90 million . The settlement resolves all past claims as to our use of pre-1972 recordings owned or controlled by the plaintiffs and enables us, without any additional payment, to reproduce, perform and broadcast such recordings in the United States through December 31, 2016. This agreement was approved by our board of directors and executed on October 21, 2015. As a result of this settlement, cost of revenue—content acquisition costs increased by $65.4 million in the year ended December 31, 2015, of which $57.9 million was related to a one-time cumulative charge to cost of revenue - content acquisition costs related to pre-1972 spins played through September 30, 2015. The remaining charge of $24.6 million was recorded in cost of revenue—content acquisition costs in 2016 based on the allocation of pre-1972 listening throughout the settlement period. On October 2, 2014, Flo & Eddie Inc. filed a class action suit against Pandora Media Inc. in the federal district court for the Central District of California. The complaint alleges misappropriation and conversion in connection with the public performance of sound recordings recorded prior to February 15, 1972. On December 19, 2014, Pandora filed a motion to strike the complaint pursuant to California’s Anti-Strategic Lawsuit Against Public Participation ("Anti-SLAPP") statute, which was appealed to the Ninth Circuit Court of Appeals. The district court litigation is currently stayed pending the Ninth Circuit’s decision. On December 8, 2016, the Ninth Circuit heard oral argument on the Anti-SLAPP motion and a decision by the Ninth Circuit on the motion is pending. Between September 14, 2015 and October 19, 2015, Arthur and Barbara Sheridan filed four separate class action suits against the Company in the federal district courts for the Northern District of California, Southern District of New York, District of New Jersey and Northern District of Illinois. The complaints allege a variety of violations of common law and state copyright statutes, common law misappropriation, unfair competition, conversion, unjust enrichment and violation of rights of publicity arising from allegations that we owe royalties for the public performance of sound recordings recorded prior to February 15, 1972. Currently, the action in California is stayed pending the Ninth Circuit’s decision in Flo & Eddie, Inc. v. Pandora Media, Inc. , and the actions in New York, New Jersey and Illinois are all stayed or otherwise suspended pending the Second Circuit’s decision in Flo & Eddie et al. v. Sirius XM . On September 7, 2016, Ponderosa Twins Plus One et al. filed a class action suit against the Company alleging claims similar to that of Flo & Eddie, Inc. v. Pandora Media Inc . The action is currently stayed in the Northern District of California pending the Ninth Circuit’s decision in Flo & Eddie, Inc. v. Pandora Media, Inc . The outcome of any litigation is inherently uncertain. Except as noted above, we do not believe it is probable that the final outcome of the matters discussed above will, individually or in the aggregate, have a material adverse effect on our business, financial position, results of operations or cash flows; however, in light of the uncertainties involved in such matters, there can be no assurance that the outcome of each case or the costs of litigation, regardless of outcome, will not have a material adverse effect on our business. Indemnification Agreements, Guarantees and Contingencies In the ordinary course of business, we are party to certain contractual agreements under which we may provide indemnifications of varying scope, terms and duration to customers, vendors, lessors, business partners and other parties with respect to certain matters, including, but not limited to, losses arising out of breach of such agreements, services to be provided by us or from intellectual property infringement claims made by third parties. In addition, we have entered into indemnification agreements with directors and certain officers and employees that will require us, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors, officers or employees. Such indemnification provisions are accounted for in accordance with guarantor’s accounting and disclosure requirements for guarantees, including indirect guarantees of indebtedness of others. To date, we have not incurred, do not anticipate incurring and therefore have not accrued for, any costs related to such indemnification provisions.

Provision for Income Taxes

Provision for Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Provision for Income Taxes	Provision for Income Taxes Loss before provision for income taxes by jurisdiction consists of the following: Year ended December 31, 2014 2015 2016 (in thousands) Jurisdiction Domestic $ (24,230 ) $ (163,460 ) $ (328,414 ) Foreign (5,592 ) (7,751 ) (14,792 ) Loss before provision for income taxes $ (29,822 ) $ (171,211 ) $ (343,206 ) The provision for income taxes consists of the following: Year ended December 31, 2014 2015 2016 (in thousands) Current Federal $ — $ — $ — State and local 353 9 26 International 231 214 443 Total current income tax expense $ 584 $ 223 $ 469 Deferred Federal (9,996 ) (17,943 ) (96,852 ) State and local (6,238 ) (2,174 ) (10,750 ) International — — (1,032 ) Valuation allowance 16,234 18,344 107,937 Total deferred income tax expense (benefit) $ — $ (1,773 ) $ (697 ) Total provision for (benefit from) income taxes $ 584 $ (1,550 ) $ (228 ) The benefit from income taxes decreased by $1.3 million during the year ended December 31, 2016 as a result of the tax amortization of indefinite lived assets acquired during the previous period. The following table presents a reconciliation of the statutory federal rate and our effective tax rate: Year ended December 31, 2014 2015 2016 U.S. federal taxes at statutory rate 34 % 34 % 34 % State taxes, net of federal benefit (1 ) — — Permanent differences 4 3 2 Foreign rate differential (7 ) (1 ) (2 ) Federal and state credits, net of reserve 11 2 2 Impact of acquired DTAs and DTLs — 1 1 Change in valuation allowance (55 ) (33 ) (32 ) Change in rate 6 (1 ) — Deferred adjustments 6 (4 ) (5 ) Effective tax rate (2 )% 1 % — % The major components of deferred tax assets and liabilities consist of the following: As of December 31, 2015 2016 (in thousands) Deferred tax assets Net operating loss carryforwards $ 91,658 $ 167,961 Tax credit carryforwards 14,204 21,111 Allowances and other 21,802 27,729 Stock options 29,927 32,986 Depreciation and amortization — 3,704 Total deferred tax assets $ 157,591 $ 253,491 Valuation allowance (92,772 ) (200,797 ) Total deferred tax assets, net of valuation allowance $ 64,819 $ 52,694 Deferred tax liabilities Convertible debt (37,580 ) (31,592 ) Depreciation and amortization (27,252 ) (22,360 ) Total deferred tax liabilities $ (64,832 ) $ (53,952 ) Net deferred tax assets (liabilities) $ (13 ) $ (1,258 ) During the years ended December 31, 2015 and 2016, we released $1.8 million and $1.9 million of our valuation allowance as a result of acquisitions. Deferred tax liabilities were established for the book-tax basis difference related to acquired intangible assets. The net deferred tax liabilities provided an additional source of income to support the realizability of pre-existing deferred tax assets. At December 31, 2016 , we had federal net operating loss carryforwards of approximately $818.5 million and tax credit carryforwards of approximately $14.8 million . If realized, approximately $377.3 million of the net operating loss carryforwards will be recognized as a benefit through additional paid in capital. The federal net operating losses and tax credits expire in years beginning in 2021 . At December 31, 2016 , we had state net operating loss carryforwards of approximately $552.2 million which expire in years beginning in 2017. In addition, we had state tax credit carryforwards of approximately $15.8 million that do not expire and approximately $5.7 million of credits that will expire beginning in 2024 . At December 31, 2016 , we had foreign net operating loss carryforwards of approximately $8.2 million which expire in years beginning in 2033 . Included in the net operating loss carryforward amounts above are approximately $62.4 million of federal, $41.3 million of state and $3.8 million of foreign net operating loss carryforwards related to acquisitions. Under Section 382 and 383 of the Internal Revenue Code of 1986, as amended, or the Code, if a corporation undergoes an "ownership change," the corporation's ability to use its pre-change net operating loss carryforwards and other pre-change attributes, such as research tax credits, to offset its post-change income may be limited. In general, an "ownership change" will occur if there is a cumulative change in our ownership by "5-percent shareholders" that exceeds 50 percentage points over a rolling three-year period. Similar rules may apply under state tax laws. Utilization of our net operating loss and tax credit carryforwards may be subject to annual limitations due to ownership changes. Such annual limitations could result in the expiration of our net operating loss and tax credit carryforwards before utilized. During the year ended December 31, 2016 , our valuation allowance increased by $108.0 million . At December 31, 2015 and 2016 , we maintained a full valuation allowance on our net deferred tax assets. The valuation allowance was determined in accordance with the provisions of Accounting Standards Codification 740 - Accounting for Income Taxes, which requires an assessment of both positive and negative evidence when determining whether it is more likely than not that deferred tax assets are recoverable. Such assessment is required on a jurisdiction by jurisdiction basis. Our history of cumulative losses, along with expected future U.S. losses required that a full valuation allowance be recorded against all net deferred tax assets. We intend to maintain a full valuation allowance on net deferred tax assets until sufficient positive evidence exists to support reversal of the valuation allowance. At December 31, 2015 and 2016 we have unrecognized tax benefits of approximately $6.9 million and $9.4 million . The increase in our unrecognized tax benefits was primarily attributable to current year activities. A reconciliation of the beginning and ending amounts of unrecognized tax benefits (excluding interest and penalties) is as follows: Year ended 2015 2016 (in thousands) Beginning balance $ 5,793 $ 6,864 Increases related to tax positions taken during a prior year — — Decreases related to tax positions taken during a prior year (74 ) (13 ) Increases related to tax positions taken during the current year 1,145 2,561 Ending balance $ 6,864 $ 9,412 The total unrecognized tax benefits, if recognized, would not affect the Company’s effective tax rate as the tax benefit would increase a deferred tax asset, which is currently offset with a full valuation allowance. We do not anticipate that the amount of existing unrecognized tax benefits will significantly increase or decrease within the next twelve months. Accrued interest and penalties related to unrecognized tax benefits are recorded in the provision for income taxes. We did no t have such interest, penalties or tax benefits during the years ended December 31, 2014 , 2015 and 2016 .

Stock-based Compensation Plans

Stock-based Compensation Plans and Awards	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation Plans and Awards	Stock-based Compensation Plans and Awards Stock Compensation Plans In 2000, our board of directors adopted the 2000 Stock Incentive Plan, as amended (the "2000 Plan"). In 2004, our board of directors adopted the 2004 Stock Option Plan (the "2004 Plan"), which replaced the 2000 Plan and provided for the issuance of incentive and non-statutory stock options to employees and other service providers of Pandora. In 2011, our board of directors adopted the Pandora Media, Inc. 2011 Equity Incentive Plan (the "2011 Plan" and, together with the 2000 Plan and the 2004 Plan, the "Plans"), which replaced the 2004 Plan. The Plans are administered by the compensation committee of our board of directors (the "Plan Administrator"). The 2011 Plan provides for the issuance of stock options, restricted stock units and other stock-based awards. Shares of common stock reserved for issuance under the 2011 Plan include 12,000,000 shares of common stock reserved for issuance under the 2011 Plan and 1,506,424 shares of common stock previously reserved but unissued under the 2004 Plan as of June 14, 2011. To the extent awards outstanding as of June 14, 2011 under the 2004 Plan expire or terminate for any reason prior to exercise or would otherwise return to the share reserve under the 2004 Plan, the shares of common stock subject to such awards will instead be available for future issuance under the 2011 Plan. Each year, the number of shares in the reserve under the Plan may be increased by the lesser of 10,000,000 shares, 4.0% of the outstanding shares of common stock on the last day of the prior fiscal year or another amount determined by our board of directors. The 2011 Plan is scheduled to terminate in 2021, unless our board of directors determines otherwise. Under the 2011 Plan, the Plan Administrator determines various terms and conditions of awards including option expiration dates (no more than ten years from the date of grant), vesting terms (generally over a four -year period) and payment terms. For stock option grants the exercise price is determined by the Plan Administrator, but generally may not be less than the fair market value of the common stock on the date of grant. In December 2013, our board of directors approved the ESPP, which was approved by our stockholders at the annual meeting in June 2014. The ESPP allows eligible employees to purchase shares of our common stock through payroll deductions of up to 15% of their eligible compensation, subject to a maximum of their eligible compensation, subject to a maximum of $25,000 per calendar year. Shares reserved for issuance under the ESPP include 4,000,000 shares of common stock. The ESPP provides for six -month offering periods, commencing in February and August of each year. At the end of each offering period employees are able to purchase shares at 85% of the lower of the fair market value of our common stock on the first trading day of the offering period or on the last day of the offering period. Shares available for grant as of December 31, 2016 and the activity during the year ended December 31, 2016 are as follows: Shares Available for Grant Equity Awards ESPP Total Balance as of December 31, 2015 11,723,327 3,319,337 15,042,664 Additional shares authorized 8,998,816 — 8,998,816 Restricted stock units granted (15,522,398 ) — (15,522,398 ) Performance stock units granted (1,835,250 ) — (1,835,250 ) ESPP shares issued — (1,254,910 ) (1,254,910 ) Options forfeited 1,592,289 — 1,592,289 Restricted stock units forfeited 2,587,203 — 2,587,203 Market stock units forfeited 185,714 — 185,714 Share adjustment 614,967 — 614,967 Balance as of December 31, 2016 8,344,668 2,064,427 10,409,095 Employee Stock Purchase Plan ("ESPP") We estimate the fair value of shares to be issued under the ESPP on the first day of the offering period using the Black-Scholes valuation model. The determination of the fair value is affected by our stock price on the first date of the offering period, as well as other assumptions including the risk-free interest rate, the estimated volatility of our stock price over the term of the offering period, the expected term of the offering period and the expected dividend rate. Stock-based compensation expense related to the ESPP is recognized on a straight-line basis over the offering period, net of estimated forfeitures. The per-share fair value of shares to be granted under the ESPP is determined on the first day of the offering period using the Black-Scholes option pricing model using the following assumptions: Year Ended December 31, 2014 2015 2016 Expected life (in years) 0.5 0.5 0.5 Risk-free interest rate 0.06 % 0.12 % 0.36 % Expected volatility 42 % 52 % 44 % Expected dividend yield 0 % 0 % 0 % During the years ended December 31, 2014 , 2015 and 2016 , we withheld $6.4 million , $7.6 million and $9.7 million in contributions from employees and recognized $2.1 million , $3.3 million and $3.4 million of stock-based compensation expense related to the ESPP, respectively. In the years ended December 31, 2014 , 2015 and 2016 , 149,378 , 538,398 and 1,254,910 shares of common stock were issued under the ESPP at a weighted average purchase price of $23.95 , $17.80 and $6.76 , respectively. Stock Options Stock option activity during the year ended December 31, 2016 was as follows: Options Outstanding Outstanding Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (1) (in thousands, except share and per share data) Balance as of December 31, 2015 12,815,891 $ 7.15 1.09 $ 101,151 Granted — — Exercised (1,588,781 ) 2.18 Forfeited (1,790,730 ) 19.02 Balance as of December 31, 2016 9,436,380 5.74 0.47 77,752 Vested and exercisable as of December 31, 2016 8,108,519 5.40 0.31 68,656 Expected to vest as of December 31, 2016 (2) 1,241,887 $ 7.94 1.50 $ 8,403 (1)Amounts represent the difference between the exercise price and the fair value of common stock at each period end for all in the money options outstanding based on the fair value per share of common stock of $13.41 and $13.04 as of December 31, 2015 and 2016. (2)Options expected to vest reflect an estimated forfeiture rate. The per-share fair value of stock options granted during the years ended December 31, 2014 and 2015 was determined on the grant date using the Black-Scholes option pricing model with the following assumptions. No stock option grants were made during the year ended December 31, 2016 . Year Ended December 31, 2014 2015 2016 Expected life (in years) 6.08 6.08 N/A Risk-free interest rate 1.71% - 1.93% 1.75% - 1.92% N/A Expected volatility 58% - 59% 49% - 50% N/A Expected dividend yield 0 % 0 % N/A The expected term of stock options granted represents the weighted average period that the stock options are expected to remain outstanding. We determined the expected term assumption based on our historical exercise behavior combined with estimates of the post-vesting holding period. Expected volatility is based on historical volatility of peer companies in our industry that have similar vesting and contractual terms. The risk-free interest rate is based on the implied yield currently available on U.S. Treasury issues with terms approximately equal to the expected life of the option. We currently have no history or expectation of paying cash dividends on our common stock. During the years ended December 31, 2014 , 2015 and 2016 , we recorded stock-based compensation expense related to stock options of approximately $14.7 million , $10.7 million and $13.8 million , respectively. As of December 31, 2016 , there was $11.2 million of unrecognized compensation cost related to outstanding employee stock options. This amount is expected to be recognized over a weighted-average period of 1.55 years. To the extent the actual forfeiture rate differs from our estimates, stock-based compensation related to these awards could differ from our expectations. The weighted-average fair value of stock option grants made during the years ended December 31, 2014 and 2015 was $19.74 and $9.08 . The aggregate intrinsic value of stock options exercised during the years ended December 31, 2014 , 2015 and 2016 was $169.2 million , $9.5 million and $17.3 million , respectively. The total fair value of options vested during the years ended December 31, 2014 , 2015 and 2016 was $16.5 million , $17.6 million and $10.2 million , respectively. Restricted Stock Units The fair value of the restricted stock units is expensed ratably over the vesting period. RSUs vest annually on a cliff basis over the service period, which is generally four years . During the years ended December 31, 2014 , 2015 and 2016 , we recorded stock-based compensation expense related to restricted stock units of approximately $69.9 million , $96.1 million and $124.3 million , respectively. As of December 31, 2016 , total compensation cost not yet recognized of approximately $251.0 million related to non-vested restricted stock units, is expected to be recognized over a weighted average period of 2.73 years. The following table summarizes the activities for our RSUs for the year ended December 31, 2016 : Number of RSUs Weighted-Average Grant Date Fair Value Unvested as of December 31, 2015 17,272,085 $ 17.91 Granted 15,522,398 10.21 Vested (7,666,647 ) 16.94 Forfeited (2,723,419 ) 14.84 Unvested as of December 31, 2016 22,404,417 13.26 Expected to vest as of December 31, 2016 (1) 20,325,998 $ 13.33 (1) RSUs expected to vest reflect an estimated forfeiture rate. MSUs In March 2015, the compensation committee of the board of directors granted performance awards consisting of market stock units to certain key executives under our 2011 Plan. MSUs granted in March 2015 are earned as a function of Pandora’s TSR performance measured against that of the Russell 2000 Index across three performance periods: • One-third of the target MSUs are eligible to be earned for a performance period that is the first calendar year of the MSU grant (the "One-Year Performance Period"); • One-third of the target MSUs are eligible to be earned for a performance period that is the first two calendar years of the MSU grant (the "Two-Year Performance Period"); and • Any remaining portion of the total potential MSUs are eligible to be earned for a performance period that is the entire three calendar years of the MSU grant (the "Three-Year Performance Period"). For each performance period, a "performance multiplier" is calculated by comparing Pandora’s TSR for the period to the Russell 2000 Index TSR for the same period, using the average adjusted closing stock price of Pandora stock, and the Russell 2000 Index, for ninety calendar days prior to the beginning of the performance period and the last ninety calendar days of the performance period. In each period, the target number of shares will vest if the Pandora TSR is equal to the Russell 2000 Index TSR. For each percentage point that the Pandora TSR falls below the Russell 2000 Index TSR for the period, the performance multiplier is decreased by three percentage points. The performance multiplier is capped at 100% for the One-Year and Two-Year Performance Periods. However, the full award is eligible for a payout up to 200% of target, less any shares earned in prior periods, in the Three-Year Performance Period. Specifically, for each percentage point that the Pandora TSR exceeds the Russell 2000 Index TSR for the Three-Year Performance Period, the performance multiplier is increased by 2% . As such, the ability to exceed the target number of shares is determined exclusively with respect to Pandora's three-year TSR during the term of the award. We have determined the grant-date fair value of the MSUs using a Monte Carlo simulation performed by a third-party valuation firm. We recognize stock-based compensation for the MSUs over the requisite service period, which is approximately three years, using the accelerated attribution method. During the year ended December 31, 2015 , we granted 776,000 MSUs at a total grant-date fair value of $4.3 million . There were no MSUs granted in the year ended December 31, 2016 . During the years ended December 31, 2015 and 2016 , we recorded stock-based compensation expense from MSUs of approximately $1.5 million and $0.7 million . As of December 31, 2016 , total compensation cost not yet recognized of approximately $0.8 million related to non-vested MSUs is expected to be recognized over a weighted average period of 1.13 years. There was no stock-based compensation expense related to MSUs or shares of common stock issued under the MSU plan in the year ended December 31, 2014 . In February 2016 and January 2017, the compensation committee of the board of directors certified the results of the One-Year Performance Period and Two-Year Performance Period of the 2015 MSU grant, which concluded December 31, 2015 and 2016. During the One-Year Performance Period, our relative TSR declined 26 percentage points relative to the Russell 2000 Index TSR for the period, which resulted in the vesting of the One-Year Performance Period at 22% of the one-third vesting opportunity for the period. During the Two-Year Performance Period, our relative TSR declined 48 percentage points relative to the Russell 2000 Index TSR for the period, which resulted in vesting of the Two-Year Performance Period at 0% of the one-third vesting opportunity for the period. The following table summarizes the activities for our MSUs for the year ended December 31, 2016 : Number of MSUs Weighted-Average Grant Date Fair Value Unvested as of December 31, 2015 776,000 $ 5.60 Granted — — Vested (56,903 ) 2.57 Forfeited (185,714 ) 5.91 Unvested as of December 31, 2016 533,383 5.49 Expected to vest as of December 31, 2016 (1) 398,831 $ 5.52 (1) MSUs expected to vest reflect an estimated forfeiture rate. PSUs In April 2016 and October 2016, the compensation committee of the board of directors granted 2016 Performance Awards consisting of stock-settled performance-based RSUs to certain key executives under our 2011 Plan. PSUs granted in April 2016 and October 2016 have a vesting period that includes a four-year service period, during which one fourth of the awards will vest after one year and the remainder will vest quarterly thereafter. The PSUs are earned when our trailing average ninety-day stock price is equal to or greater than $20.00 . If the trailing average ninety-day stock price does not equal or exceed $20.00 on the applicable vesting date, then the portion of the award that was scheduled to vest on such vesting date shall not vest but shall vest on the next vesting date on which the trailing average ninety-day stock price equals or exceeds $20.00 . Any portion of the award that remains unvested as of the final vesting date shall be canceled and forfeited. We have determined the grant-date fair value of the PSUs granted in April 2016 and October 2016 using a Monte Carlo simulation performed by a third-party valuation firm. We recognize stock-based compensation for the PSUs over the requisite service period, which is approximately four years, using the accelerated attribution method. During the year ended December 31, 2016 , we granted 1,835,250 PSUs at a total grant-date fair value of $9.8 million . During the year ended December 31, 2016 , we recorded stock-based compensation expense from PSUs of approximately $3.8 million . As of December 31, 2016 , total compensation cost not yet recognized of approximately $5.8 million related to non-vested PSUs is expected to be recognized over a weighted average period of 3.16 years. There was no stock-based compensation expense related to PSUs or shares of common stock issued as a result of vesting of PSUs in the years ended December 31, 2014 and 2015. The following table summarizes the activities for our PSUs for the year ended December 31, 2016 : Number of PSUs Weighted-Average Grant Date Fair Value Unvested as of December 31, 2015 — $ — Granted 1,835,250 5.33 Vested — — Forfeited — — Unvested as of December 31, 2016 1,835,250 5.33 Expected to vest as of December 31, 2016 (1) 1,658,031 $ 5.32 (1) PSUs expected to vest reflect an estimated forfeiture rate. Stock-based Compensation Expense Stock-based compensation expense related to all employee and non-employee stock-based awards was as follows: Year ended December 31, 2014 2015 2016 (in thousands) Stock-based compensation expense Cost of revenue—Other $ 4,414 $ 5,531 $ 6,108 Cost of revenue—Ticketing service — 40 188 Product development 17,546 23,671 30,975 Sales and marketing 42,165 52,747 58,118 General and administrative 22,930 29,656 43,069 Total stock-based compensation expense $ 87,055 $ 111,645 $ 138,458 During the year ended December 31, 2016 , we capitalized $7.5 million of stock-based compensation as internal use software and website development costs. During the year ended December 31, 2016 , we recorded $8.7 million

Common Stock and Net Loss Per S

Common Stock and Net Loss Per Share	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Common Stock and Net Loss Per Share	Common Stock and Net Loss per Share Each share of common stock has the right to one vote per share. The holders of common stock are also entitled to receive dividends as and when declared by our board of directors, whenever funds are legally available. Net Loss per Share Basic net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by giving effect to all potential shares of common stock, including stock options, restricted stock units, market stock units and performance-based RSUs, to the extent dilutive. Basic and diluted net loss per share were the same for the years ended December 31, 2014 , 2015 and 2016 , as the inclusion of all potential common shares outstanding would have been anti-dilutive. The following table sets forth the computation of historical basic and diluted net loss per share: Year Ended December 31, 2014 2015 2016 (in thousands except per share amounts) Numerator Net loss $ (30,406 ) $ (169,661 ) $ (342,978 ) Denominator Weighted-average common shares outstanding used in computing basic and diluted net loss per share 205,273 213,790 230,693 Net loss per share, basic and diluted $ (0.15 ) $ (0.79 ) $ (1.49 ) The following potential common shares outstanding were excluded from the computation of diluted net loss per share because including them would have been anti-dilutive: As of December 31, 2014 As of December 31, 2015 As of December 31, 2016 (in thousands) Options to purchase common stock 10,980 12,816 9,436 Restricted stock units 11,024 17,272 22,404 Performance awards* — 776 2,369 Total common stock equivalents 22,004 30,864 34,209 *Includes potential common shares outstanding for MSUs and PSUs On December 9, 2015, we completed an offering of our 1.75% convertible senior notes due 2020. Under the treasury stock method, the Notes will generally have a dilutive impact on earnings per share if our average stock price for the period exceeds approximately $16.42 per share of our common stock, the conversion price of the Notes. For the period from the issuance of the offering of the Notes through December 31, 2016, the conversion feature of the Notes was anti-dilutive.

Segment Data and Revenue by Geo

Segment Data and Revenue by Geographic Area	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Segment Data and Revenue by Geographic Area	Segment Data and Revenue by Geographic Area Segment Data We report segment information based on the “management” approach. The management approach designates the internal reporting used by management for making decisions and assessing performance as the source of our reportable operating segments. Our chief operating decision maker (the "CODM"), our Chief Executive Officer, manages our operations on a consolidated basis for purposes of allocating resources. When evaluating our financial performance, the CODM reviews revenue and gross profit on a disaggregated basis for our internet radio and ticketing services, while all other financial information is reviewed on a consolidated basis. Such evaluation excludes operating expenses and general corporate-level costs that are not specific to either of the reportable segments and are managed separately at the corporate level. The general corporate-level expenses relate to executive management, finance and accounting, human resources, legal, training and development, various nonrecurring charges and other separately managed general and administrative costs. Our two operating segments, which are the same as our two reportable segments, are as follows: Pandora — Internet Radio Service Pandora is the world’s most powerful music discovery platform, offering a personalized experience for each of our listeners wherever and whenever they want to listen to music—whether through earbuds, car speakers or live on stage. Pandora is available as an ad-supported service or as a subscription service, which we call Pandora Plus. The majority of our listener hours occur on mobile devices, with the majority of our revenue generated from advertising on our ad-supported service on these devices. We offer both local and national advertisers the opportunity to deliver targeted messages to our listeners using a combination of audio, display and video advertisements. We also generate revenue from subscriptions to Pandora Plus. Ticketing Service We operate our ticketing service through our subsidiary Ticketfly, a leading live events technology company that provides ticketing and marketing software and services for clients, which are venues and event promoters, across North America. Ticketfly's ticketing, digital marketing and analytics software helps promoters book talent, sell tickets and drive in-venue revenue, while Ticketfly's consumer tools help fans find and purchase tickets to events. Tickets are primarily sold through the Ticketfly platform but are also sold through other channels such as box offices. The measurement basis of segment profit or loss is gross profit, as operating expenses and working capital are all managed on an aggregate basis. Total segment assets have not been presented as segment assets are not reported to, or used by management to allocate resources to or assess performance of the segments. The following table provides the financial performance of our reportable segments, including a reconciliation of gross profit from segment operations to gross profit from total operations: Year ended December 31, 2015 2016 Pandora Ticketfly (1) Total Pandora Ticketfly Total (in thousands) (in thousands) Revenues $ 1,153,876 $ 10,167 $ 1,164,043 $ 1,298,276 $ 86,550 $ 1,384,826 Cost of revenues 690,220 7,121 697,341 835,642 59,280 894,922 Gross profit $ 463,656 $ 3,046 $ 466,702 $ 462,634 $ 27,270 $ 489,904 Operating and other expenses (636,363 ) (832,882 ) Net loss $ (169,661 ) $ (342,978 ) (1) Includes two months of revenue and expense for Ticketfly from the acquisition date of October 31, 2015 to December 31, 2015. The following table provides depreciation and amortization costs included in costs of revenues by segment included in the consolidated statements of operations: Year ended December 31, 2015 2016 Pandora Ticketfly (1) Total Pandora Ticketfly Total (in thousands) (in thousands) Depreciation and amortization $ 7,231 $ 949 $ 8,180 $ 8,667 $ 5,729 $ 14,396 (1) Includes two months of depreciation and amortization expense for Ticketfly from the acquisition date of October 31, 2015 to December 31, 2015. Revenue by Geographic Area The following table sets forth revenue by geographic area: Year ended December 31, 2014 2015 2016 (in thousands) Revenue by geographic area United States $ 917,008 $ 1,155,210 $ 1,366,330 International 3,794 8,833 18,496 Total revenue $ 920,802 $ 1,164,043 $ 1,384,826

Selected Quarterly Financial Da

Selected Quarterly Financial Data (unaudited)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (unaudited)	Selected Quarterly Financial Data (unaudited) Quarter ended March 31, June 30, September 30, December 31, March 31, June 30, September 30, December 31, 2015 2015 2015 2015 2016 2016 2016 2016 (in thousands, except per share data) Total revenue (1) $ 230,764 $ 285,560 $ 311,562 $ 336,157 $ 297,305 $ 343,022 $ 351,901 $ 392,598 Cost of revenue Cost of revenue—Content acquisition costs 126,023 130,134 211,272 142,933 171,264 176,633 174,334 212,122 Cost of revenue—Other 16,233 20,043 21,414 22,168 20,999 24,833 25,556 29,901 Cost of revenue—Ticketing service (1) — — — 7,121 14,646 15,259 15,318 14,057 Total cost of revenue 142,256 150,177 232,686 172,222 206,909 216,725 215,208 256,080 Gross profit 88,508 135,383 78,876 163,935 90,396 126,297 136,693 136,518 Operating expenses Product development (1) 15,875 18,742 21,849 28,115 35,846 33,808 33,657 38,325 Sales and marketing (1) 84,274 94,035 107,286 112,574 117,622 123,812 116,475 133,546 General and administrative (1) 36,754 38,812 35,603 42,774 46,296 40,562 41,768 46,946 Total operating expenses 136,903 151,589 164,738 183,463 199,764 198,182 191,900 218,817 Loss from operations (48,395 ) (16,206 ) (85,862 ) (19,528 ) (109,368 ) (71,885 ) (55,207 ) (82,299 ) Net loss (48,257 ) (16,065 ) (85,930 ) (19,409 ) (115,102 ) (76,333 ) (61,534 ) (90,009 ) Net loss per share, basic (0.23 ) (0.08 ) (0.40 ) (0.09 ) (0.51 ) (0.33 ) (0.27 ) (0.38 ) Net loss per share, diluted $ (0.23 ) $ (0.08 ) $ (0.40 ) $ (0.09 ) $ (0.51 ) $ (0.33 ) $ (0.27 ) $ (0.38 ) (1) Includes two months of revenue and expense for Ticketfly from the acquisition date of October 31, 2015 to December 31, 2015.

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2016
Subsequent Events [Abstract]
Subsequent Event	Subsequent Event On January 12, 2017, we announced a reduction in force plan affecting approximately 7% of our U.S. employee base, excluding Ticketfly. Our Board of Directors approved the plan on December 15, 2016 and the affected employees were informed of the plan on January 12, 2017. The reduction in force will allow us to focus and realign existing resources on execution and make further investments in product innovation to drive advertising revenue and subscription growth. We expect the reduction in force plan to be completed by the end of the first quarter of 2017. In connection with the reduction in force plan, we estimate we will incur approximately $5.0 million to $7.0 million of cash expenditures, substantially all of which are related to employee severance and benefits costs. Total reduction in force costs are estimated at $4.0 million to $6.0 million , which is lower than cash reduction in force costs due to a credit related to non-cash stock-based compensation expense reversals for unvested equity awards. We expect to recognize these pre-tax reduction in force charges in the first quarter of 2017.

Summary of Significant Accoun22

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Basis of Presentation	The consolidated financial statements and accompanying notes have been prepared in accordance with United States generally accepted accounting principles ("U.S. GAAP") and include the accounts of Pandora and our wholly owned subsidiaries.
Consolidation	All intercompany balances and transactions have been eliminated in consolidation.
Change in Presentation	Certain changes in presentation have been made to conform the prior period presentation to current period reporting. We have reclassified internal-use software costs from the purchases of property and equipment line item to the internal-use software costs line item of our consolidated statements of cash flows. We have also reclassified prepaid content acquisition costs from the prepaid expenses and other assets line item to the prepaid content acquisition costs line item of our consolidated balance sheets and our consolidated statements of cash flows. Lastly, we have reclassified interest expense from the other income (expense), net line item to the interest expense line item of our consolidated statements of operations.
Use of Estimates	The preparation of financial statements in conformity with U.S. GAAP requires management to make certain estimates, judgments and assumptions that affect the reported amounts of assets and liabilities and the related disclosures at the date of the financial statements, as well as the reported amounts of revenue and expenses during the periods presented. Estimates are used in several areas including, but not limited to determining accrued content acquisition costs, amortization of minimum guarantees under content acquisition agreements, selling prices for elements sold in multiple-element arrangements, the allowance for doubtful accounts, the fair value of stock options, market stock units ("MSUs"), stock-settled performance-based RSUs ("PSUs") and the Employee Stock Purchase Plan ("ESPP"), the impact of forfeitures on stock-based compensation, the provision for (benefit from) income taxes, the subscription return reserve, the fair value of convertible debt, the fair value of acquired property and equipment, capitalized internal-use software, intangible assets and goodwill and the useful lives of acquired intangible assets. To the extent there are material differences between these estimates, judgments or assumptions and actual results, our financial statements could be affected. In many cases, the accounting treatment of a particular transaction is specifically dictated by U.S. GAAP and does not require management’s judgment in its application. There are also areas in which management’s judgment in selecting among available alternatives would not produce a materially different result.
Revenue Recognition	We recognize revenue when four basic criteria are met: (1) persuasive evidence exists of an arrangement with the customer reflecting the terms and conditions under which the products or services will be provided; (2) delivery has occurred or services have been provided; (3) the fee is fixed or determinable; and (4) collection is reasonably assured. We consider a signed agreement, a binding insertion order or other similar documentation to be persuasive evidence of an arrangement. Collectability is assessed based on a number of factors, including transaction history and the creditworthiness of a customer. If it is determined that collection is not reasonably assured, revenue is not recognized until collection becomes reasonably assured, which is generally upon receipt of cash. We record cash received in advance of revenue recognition as deferred revenue. Gross versus net revenue recognition. We report revenue on a gross or net basis based on management’s assessment of whether we act as a principal or agent in the transaction. To the extent we act as the principal, revenue is reported on a gross basis. The determination of whether we act as a principal or an agent in a transaction is based on an evaluation of whether we have the substantial risks and rewards of ownership under the terms of an arrangement. Advertising revenue. We generate advertising revenue primarily from audio, display and video advertising. We generate the majority of our advertising revenue through the delivery of advertising impressions sold on a cost per thousand, or CPM, basis. In determining whether an arrangement exists, we ensure that a binding arrangement, such as an insertion order or a fully executed customer-specific agreement, is in place. We generally recognize revenue based on delivery information from our campaign trafficking systems. We also generate advertising revenue pursuant to arrangements with advertising agencies and brokers. Under these arrangements, we provide the agencies and brokers the ability to sell advertising inventory on our service directly to advertisers. We report this revenue net of amounts due to agencies and brokers because we are not the primary obligor under these arrangements, we do not set the pricing nor do we establish or maintain the relationships with the advertisers. Subscription and other revenue. Our new subscription service, Pandora Plus, launched on September 15, 2016. Prior to the launch of Pandora Plus, our subscription service was Pandora One. Pandora Plus and Pandora One are premium monthly or annual paid versions of the Pandora service, which include advertisement-free access, higher quality audio on supported devices and longer timeout-free listening. Pandora Plus also includes additional features such as replays, additional skipping and offline listening. Subscription revenue derived from direct sales to listeners is recognized on a straight-line basis over the duration of the subscription period and is recognized net of sales tax amounts collected from subscribers. Subscription revenue derived from sales through some mobile device app stores may be subject to refund or cancellation terms which may affect the timing or amount of the subscription revenue recognition. When refund rights exist, we recognize revenue when services have been provided and the rights lapse or when we have developed sufficient transaction history to estimate a reserve. We were required to defer revenue for certain subscriptions purchased through mobile device app stores that contained refund rights until the refund rights lapsed or until we developed sufficient operating history to estimate a return reserve. As of December 31, 2013, we had deferred all revenue related to these mobile subscriptions subject to refund rights totaling approximately $14.2 million , as we did not have sufficient history to estimate a return reserve. Beginning in January 2014, we had sufficient historic transactional information which enabled us to estimate future returns. Accordingly, in January 2014, we began recording revenue related to these mobile subscriptions net of estimated returns. This change resulted in a one-time increase in subscription revenue in the quarter ended March 31, 2014 of approximately $14.2 million , as the previously deferred revenue was recognized. As of December 31, 2015 and 2016 , the deferred revenue related to the return reserve was not significant. Multiple-element arrangements. We enter into arrangements with customers to sell advertising packages that include different media placements or ad services that are delivered at the same time, or within close proximity of one another. We recognize the relative fair value of the media placements or ad services as they are delivered assuming all other revenue recognition criteria are met. We allocate arrangement consideration in multiple-deliverable revenue arrangements at the inception of an arrangement to all deliverables or those packages in which all components of the package are delivered at the same time, based on the relative selling price method in accordance with the selling price hierarchy, which includes: (1) vendor-specific objective evidence ("VSOE") if available; (2) third-party evidence ("TPE") if VSOE is not available; and (3) best estimate of selling price ("BESP") if neither VSOE nor TPE is available. We determine VSOE based on our historical pricing and discounting practices for the specific product or service when sold separately. In determining VSOE, we require that a substantial majority of the selling prices for these services fall within a reasonably narrow pricing range. We have not historically priced our advertising products within a narrow range. As a result, we have not been able to establish VSOE for any of our advertising products. When VSOE cannot be established for deliverables in multiple element arrangements, we apply judgment with respect to whether it can establish a selling price based on TPE. TPE is determined based on competitor prices for similar deliverables when sold separately. Generally, our go-to-market strategy differs from that of our peers and our offerings contain a significant level of differentiation such that the comparable pricing of services cannot be obtained. Furthermore, we are unable to reliably determine what similar competitor services' selling prices are on a stand-alone basis. As a result, we have not been able to establish selling price based on TPE. When we are unable to establish selling price using VSOE or TPE, we use BESP in our allocation of arrangement consideration. The objective of BESP is to determine the price at which we would transact a sale if the service were sold on a stand-alone basis. BESP is generally used to allocate the selling price to deliverables in our multiple element arrangements. We determine BESP for deliverables by considering multiple factors including, but not limited to, prices we charge for similar offerings, market conditions, competitive landscape and pricing practices. We limit the amount of allocable arrangement consideration to amounts that are fixed or determinable and that are not contingent on future performance or future deliverables. We regularly review BESP. Changes in assumptions or judgments or changes to the elements in the arrangement may cause an increase or decrease in the amount of revenue that we report in a particular period. Ticketing service revenue. Ticketing service revenue is generated primarily from service and merchant processing fees generated on ticket sales through the Ticketfly platform. Ticketfly sells tickets to fans for events on behalf of clients and charges a fee per ticket, which generally increases as the face value of the ticket increases, or a percentage of the total convenience charge and order processing fee, for its services at the time the ticket for an event is sold. Ticketing service revenue is recorded net of the face value of the ticket at the time of the sale, as Ticketfly generally acts as an agent with respect to the ticket price in these transactions.
Concentration of Credit Risk	Financial instruments that potentially subject us to concentrations of credit risk consist principally of cash and cash equivalents, investments and trade accounts receivable. We maintain cash and cash equivalents with domestic financial institutions of high credit quality. We perform periodic evaluations of the relative credit standing of such institutions.
Cash, Cash Equivalents	We classify our highly liquid investments with maturities of three months or less at the date of purchase as cash equivalents.
Investments	Our investments consist of corporate debt securities. These investments are classified as available-for-sale securities and are carried at fair value with the unrealized gains and losses reported as a component of stockholders' equity. Management determines the appropriate classification of our investments at the time of purchase and reevaluates the available-for-sale designations as of each balance sheet date. We classify our investments as either short-term or long-term based on each instrument's underlying contractual maturity date. Investments with maturities of twelve months or less are classified as short-term and those with maturities greater than twelve months are classified as long-term. The cost basis for investments sold is based upon the specific identification method.
Accounts Receivable and Allowance for Doubtful Accounts	Accounts receivable are recorded net of an allowance for doubtful accounts. Our allowance for doubtful accounts is based upon historical loss patterns, the number of days that billings are past due and an evaluation of the potential risk of los s associated with delinquent accounts. We also consider any changes to the financial condition of our customers and any other external market factors that could impact the collectability of our receivables in the determination of our allowance for doubtful accounts. Accounts receivable amounts that are deemed uncollectable are charged against the allowance for doubtful accounts when identified.
Property and Equipment, net	Property and equipment is recorded at cost, less accumulated depreciation and amortization. Depreciation is computed using the straight-line method based on the estimated useful lives of the assets, which typically range from three to five years. Leasehold improvements are amortized over the shorter of the lease term or expected useful lives of the improvements. Property and equipment is reviewed for impairment whenever events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. Recoverability of these assets is measured by a comparison of the carrying amounts to the future undiscounted cash flows the assets are expected to generate. If property and equipment are considered to be impaired, the impairment to be recognized equals the amount by which the carrying value of the asset exceeds its fair market value. If we reduce the estimated useful life assumption for any asset, the remaining unamortized balance would be amortized or depreciated over the revised estimated useful life. Capitalized Internal-Use Software We capitalize certain costs incurred to develop software for internal use. Costs incurred in the preliminary stages of development are expensed as incurred. Once software has reached the development stage, internal and external costs, if direct and incremental, are capitalized until the software is substantially complete and ready for its intended use. Capitalization ceases upon completion of all substantial testing. We also capitalize costs related to specific upgrades and enhancements when it is probable the expenditures will result in additional functionality. Capitalized costs are recorded as part of property and equipment. Maintenance and training costs are expensed as incurred. Capitalized internal-use software costs are amortized on a straight-line basis over their three to five -year estimated useful lives. As of December 31, 2015 and 2016 , we had approximately $6.3 million and $25.7 million
Ticketing Contract Advances	Ticketing contract advances, which are either recoupable or non-recoupable, represent amounts paid in advance to clients pursuant to ticketing agreements. These amounts are reflected in prepaid expenses and other current assets if the amount is expected to be recouped or recognized over a period of twelve months or less or in other long-term assets if the amount is expected to be recouped or recognized over a period of more than twelve months. Recoupable ticketing contract advances are generally recoupable against future royalties earned by clients, based on the contract terms, over the lives of their contracts which typically range between three and five years. Non-recoupable ticketing contract advances are fixed incentives paid by Ticketfly to secure exclusive rights with certain clients and are amortized to sales and marketing expense over the life of the contract on a straight-line basis. Amortization expense for the years ended December 31, 2015 and 2016 was $0.7 million and $5.7 million .
Business Combinations	We allocate the fair value of purchase consideration to the tangible assets acquired, liabilities assumed and intangible assets acquired based on their estimated fair values. The excess of the fair value of purchase consideration over the fair values of these identifiable assets and liabilities is recorded as goodwill. Such valuations require management to make significant estimates and assumptions, especially with respect to intangible assets. Significant estimates in valuing certain intangible assets include, but are not limited to, future expected cash flows from acquired users, acquired technology, and trade names from a market participant perspective, useful lives and discount rates. Management’s estimates of fair value are based upon assumptions believed to be reasonable, but which are inherently uncertain and unpredictable and, as a result, actual results may differ from estimates. During the measurement period, which is one year from the acquisition date, we may record adjustments to the assets acquired and liabilities assumed, with the corresponding offset to goodwill. Upon the conclusion of the measurement period, any subsequent adjustments are recorded to earnings.
Goodwill and Intangible Assets, net	We do not amortize goodwill and intangible assets with indefinite useful lives, rather such assets are required to be tested for impairment at least annually or sooner whenever events or changes in circumstances indicate that the assets may be impaired. We perform our goodwill and intangible asset impairment tests in the fourth quarter of each year. As of December 31, 2016 , no impairment of goodwill or indefinite-lived intangible assets has been identified. For purposes of testing goodwill for impairment, we established reporting units based on our current reporting structure. As of December 31, 2016 , our goodwill was allocated to our Pandora and Ticketfly reporting units. Acquired finite-lived intangible assets are amortized over the estimated useful lives of the assets, which range from two to eleven years. Acquired finite-lived intangible assets consist primarily of patents, customer relationships, developed technology and trade names resulting from business combinations. We evaluate the recoverability of our intangible assets for potential impairment whenever events or circumstances indicate that the carrying amount of such assets may not be recoverable. Recoverability of these assets is measured by a comparison of the carrying amounts to the future undiscounted cash flows the assets are expected to generate. If such review indicates that the carrying amount of intangible assets is not recoverable, the carrying amount of such assets is reduced to the fair value. In addition to the recoverability assessment, we routinely review the remaining estimated useful lives of finite-lived intangible assets. If we reduce the estimated useful life assumption for any asset, the remaining unamortized balance would be amortized over the revised estimated useful life. We record the amortization of intangible assets to the financial statement line item in our consolidated statement of operations that the asset directly relates to. To the extent that purchased intangibles are used in revenue generating activities, we record the amortization of these intangible assets to cost of revenue.
Stock-Based Compensation	Stock-based awards granted to employees, including grants of restricted stock units ("RSUs") and stock options, are recognized as expense in our statements of operations based on their grant date fair value. We recognize stock-based compensation expense on a straight-line basis over the service period of the award, which is generally four years. We estimate the fair value of RSUs at our stock price on the grant date. We generally estimate the grant date fair value of stock options using the Black-Scholes option-pricing model. The Black-Scholes option-pricing model is affected by our stock price on the date of grant, the expected stock price volatility over the expected term of the award, which is based on projected employee stock option exercise behaviors, the risk-free interest rate for the expected term of the award and expected dividends. Stock-based compensation expense is recorded net of estimated forfeitures in the statement of operations for only those stock-based awards that we expect to vest. We estimate the forfeiture rate based on historical forfeitures of equity awards and adjust the rate to reflect changes in facts and circumstances, if any. We revise our estimated forfeiture rate if actual forfeitures differ from our initial estimates. We have elected to use the "with and without" approach as described in Accounting Standards Codification 740 - Income Taxes in determining the order in which tax attributes are utilized. As a result, we will only recognize a tax benefit from stock-based awards in additional paid-in capital if an incremental tax benefit is realized after all other tax attributes currently available to us have been utilized. In addition, we have elected to account for the indirect effects of stock-based awards on other tax attributes, such as the research tax credit, through the statement of operations. Stock-Based Compensation—Employee Stock Purchase Plan In December 2013, our board of directors approved the Employee Stock Purchase Plan ("ESPP"), which was approved by our stockholders at the annual meeting in June 2014. We estimate the fair value of shares to be issued under the ESPP on the first day of the offering period using the Black-Scholes valuation model. The determination of the fair value is affected by our stock price on the first date of the offering period, as well as other assumptions including the risk-free interest rate, the estimated volatility of our stock price over the term of the offering period, the expected term of the offering period and the expected dividend rate. Stock-based compensation expense related to the ESPP is recognized on a straight-line basis over the offering period, net of estimated forfeitures. Stock-Based Compensation—MSUs In March 2015, the compensation committee of the board of directors granted performance awards consisting of market stock units to certain key executives under our 2011 Plan. Specifically, MSUs measure Pandora’s total stockholder return ("TSR") performance against that of the Russell 2000 Index across three performance periods. We have determined the grant-date fair value of the MSUs using a Monte Carlo simulation performed by a third-party valuation specialist. The Monte Carlo simulation model utilizes multiple input variables to estimate the probability that market conditions will be achieved. The variables used in these models are reviewed on an annual basis and adjusted, as needed. We recognize stock-based compensation for the MSUs over the requisite service period using the accelerated attribution method. Stock-Based Compensation—PSUs We implemented a performance stock unit program in April 2016 for stock-settled performance-based RSUs to certain key executives. We have determined the grant-date fair value of the PSUs granted in 2016 using a Monte Carlo simulation performed by a third-party valuation firm. The Monte Carlo simulation model utilizes multiple input variables to estimate the probability that market conditions will be achieved. The variables used in these models are reviewed on an annual basis and adjusted, as needed. We recognize stock-based compensation for the PSUs over the requisite service period, which is approximately four years, using the accelerated attribution method.
Cost of Revenue	Cost of Revenue — Content Acquisition Costs Cost of revenue—content acquisition costs principally consist of licensing fees paid for streaming music or other content to our listeners. Content acquisition costs are currently calculated using negotiated rates documented in direct license agreements with major and independent record labels, music publishers and PROs. Prior to September 15, 2016, the majority of our content acquisition costs for sound recordings were based on a fee per public performance of a sound recording. Subsequent to September 15, 2016, depending on the applicable service, these license agreements generally require us to pay either a per-performance fee based on the number of sound recordings we transmit, a percentage of revenue associated with the service, or a per-subscriber minimum amount, all generally subject to certain discounts. Prior to January 1, 2016, the majority of our content acquisition costs for the underlying musical works contained in sound recording were based on a percentage of our revenue. From January 1, 2016 until September 15, 2016, the majority of our content acquisition costs for the underlying musical works were based on a percentage of content acquisition costs paid for sound recordings. Subsequent to September 15, 2016, the majority of our content acquisition costs for the underlying musical works contained in sound recordings are determined in the same manner they were prior to September 15, 2016, but this calculation only applies to the performance rights on our ad-supported service and content acquisition costs for the reproduction rights on our subscription services are determined in accordance with the statutory license set forth in 17 U.S.C. §115. Certain of our direct license agreements are also subject to minimum guarantee payments, some of which are paid in advance and amortized over the minimum guarantee period. For certain content acquisition arrangements, we accrue for estimated content acquisition costs based on the available facts and circumstances and adjust these estimates as more information becomes available. Several of our direct license agreements also include so-called "most favored nations" provisions, which, if triggered, could cause our payments under those agreements to escalate. We recognize an accrual when it is probable that we will make additional payments under these provisions. The expense related to these accruals is recognized in cost of revenue—content acquisition costs. Prepaid Content Acquisition Costs Prepaid content acquisition costs are primarily comprised of minimum guarantees under content acquisition agreements. In 2015 and 2016, we signed direct license agreements with major and independent labels, distributors and publishers. Certain of these license agreements include minimum guarantee payments, some of which are paid in advance. These minimum guarantees may take the form of either a contractually obligated minimum over a specified period of time that requires a true-up payment at the end of the specified period if the cumulative payments have not met or exceeded the specified minimum, or cash advance payments made at the beginning of, or at intervals during, the specified period, which cash payments are then recoupable against content acquisition costs over the specified period. On a quarterly basis, we record the greater of the cumulative actual content acquisition costs incurred or the cumulative minimum guarantee based on forecasted usage for the minimum guarantee period. The minimum guarantee period is the period of time that the minimum guarantee relates to, as specified in each agreement, which may be annual or a longer period. The cumulative minimum guarantee, based on forecasted usage considers factors such as listening hours, revenue, subscribers and other terms of each agreement that impact our expected attainment or recoupment of the minimum guarantees on a non-straight line basis. Cost of Revenue — Ticketing Service Cost of revenue—ticketing service consists primarily of ticketing revenue share costs, credit card fees and intangible amortization expense. The majority of the cost is related to revenue share costs which consist of royalties paid to clients for their share of convenience and order processing fees. Payments to clients are recorded as an expense to the extent that the fair value of the identifiable benefit received in the exchange exceeds the amount of the payment to the client. Intangible amortization expense is related to amortization of developed technology. Cost of Revenue — Other
Product Development	Product development consists primarily of employee-related, facilities and equipment costs, including salaries and benefits related to employees in software engineering, music analysis and product management departments, information technology and costs associated with supporting consumer connected-device manufacturers in implementing our service in their products. We incur product development expenses primarily for improvements to our website and the Pandora app, development of new advertising products and development and enhancement of our personalized station generating system. We have generally expensed product development as incurred. Certain website development and internal use software development costs are capitalized when specific criteria are met. In such cases, the capitalized amounts are amortized over the useful life of the related application once the application is placed in service.
Sales and Marketing, and General and Administrative	Sales and marketing consists primarily of employee-related and facilities and equipment costs, including salaries, commissions and benefits related to employees in sales, sales support, marketing, advertising and music maker group departments. In addition, sales and marketing expenses include transaction processing commissions on subscription purchases through mobile app stores, external sales and marketing expenses such as brand marketing, advertising, direct response and search engine marketing costs, public relations expenses, costs related to music events, agency platform and media measurement expenses, infrastructure costs and amortization expense related to acquired intangible assets. We expense the costs of producing advertisements as they are incurred and expense the cost of communicating advertisements at the time the advertisement airs or the event occurs, in each case as sales and marketing expense within the accompanying consolidated statements of operations. During the years ended December 31, 2014 , 2015 and 2016 , we recorded advertising expenses of $10.4 million , $35.1 million and $45.7 million , respectively. General and Administrative
Provision for (Benefit from) Income Taxes	Our provision for (benefit from) income taxes is computed using the asset and liability method, under which deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted statutory income tax rates in effect for the year in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce net deferred tax assets to the amount expected to b e realized. We recognize a tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such positions are then measured based on the largest benefit that has a greater than 50% likelihood of being realized upon settlement. We will recognize interest and penalties related to unrecognized tax benefits in the provision for (benefit from) income taxes in the accompanying statement of operations. We calculate the current and deferred income tax provision based on estimates and assumptions that could differ from the actual results reflected in income tax returns filed in subsequent years. Adjustments based on filed income tax returns are recorded when identified. The amount of income taxes paid is subject to examination by U.S. federal, state and international tax authorities. The estimate of the potential outcome of any uncertain tax issue is subject to management's assessment of relevant risks, facts and circumstances existing at that time. To the extent that the assessment of such tax positions change, the change in estimate is recorded in the period in which the determination is made.
Net Loss Per Share	Basic net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by giving effect to all potential shares of common stock, including stock options, restricted stock units, market stock units and performance-based RSUs, to the extent dilutive. Basic and diluted net loss per share were the same for each period presented as the inclusion of all potential common shares outstanding would have been anti-dilutive.
Recently Issued Accounting Standards and Recently Adopted Accounting Standards	In March 2016, the Financial Accounting Standards Board ("the FASB") issued Accounting Standards Update No. 2016-09, Compensation - Stock Compensation (Topic 718) ("ASU 2016-09"). ASU 2016-09 requires all income tax effects of awards to be recognized in the income statement when the awards vest or are settled. Additionally, it allows an employer to repurchase more of an employee's shares for tax withholding purposes without triggering liability accounting and to make a policy election to account for forfeitures as they occur. The guidance is effective for fiscal years beginning after December 15, 2016, and interim periods within that fiscal year, although early adoption is permitted. We have completed our initial assessment and expect to adopt ASU 2016-09 as of January 1, 2017 using the prospective method. We do not expect the impact of adopting ASU 2016-09 will be material to the consolidated financial statements and footnote disclosures. In May 2014, the FASB issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) ("ASU 2014-09"), which amends the existing accounting standards for revenue recognition. ASU 2014-09 outlines a single comprehensive model for entities to use in accounting for revenue. Under the guidance, revenue is recognized when a company transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. In March 2016, the FASB issued Accounting Standards Update No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) (ASU 2016-08) which clarifies the implementation guidance on principal versus agent considerations. The guidance includes indicators to assist an entity in determining whether it controls a specified good or service before it is transferred to the customers. The standard may be effective for public entities with annual and interim reporting periods beginning after December 15, 2017. Entities have the option of using either a full retrospective or a modified retrospective approach to adopt the guidance. We expect to adopt ASU 2014-09 as of January 1, 2018 using the full retrospective method. We have completed our initial assessment and do not believe there will be a material impact to our consolidated financial statements for the majority of our advertising and subscription revenue arrangements. We are currently continuing to evaluate the impact that the new principal versus agent guidance may have on certain of our advertising revenue arrangements and on our ticketing service revenue arrangements, and we are continuing to evaluate the expected impact on our business processes, systems and controls. We expect to complete our assessment of the effects of adopting ASU 2014-09 during 2017, and we will continue our evaluation of ASU 2014-09, including how it may impact new arrangements we enter into as well as new or emerging interpretations of the standard, through the date of adoption. In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases (Topic 842) ("ASU 2016-02"). ASU 2016-02 requires lessees to put most leases on their balance sheets but recognize expenses on their income statement and eliminates the real estate-specific provisions for all entities. The guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. We have completed our initial assessment and expect to adopt ASU 2016-02 as of January 1, 2018 using the modified retrospective method. We expect the potential impact of adopting ASU 2016-02 to be material to our lease liabilities and assets on our consolidated balance sheets. Recently Adopted Accounting Standards In August 2014, the FASB issued Accounting Standards Update No. 2014-15, Going Concern (Subtopic 205-40) ("ASU 2014-15"). ASU 2014-15 requires management of all entities to evaluate whether there are conditions and events that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the financial statements are issued (or available to be issued when applicable). The guidance is effective for annual periods ending after December 15, 2016 and for interim periods thereafter. The adoption of this guidance did not have a material effect on our consolidated financial statements during the year ended December 31, 2016.
Commitments and Contingencies	We record a liability when we believe that it is both probable that a loss has been incurred and the amount can be reasonably estimated. Our management periodically evaluates developments that could affect the amount, if any, of liability that we have previously accrued and make adjustments as appropriate. Determining both the likelihood and the estimated amount of a loss requires significant judgment, and management’s judgment may be incorrect.

Composition of Certain Financ23

Composition of Certain Financial Statement Captions (Tables)	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of cash, cash equivalents and investments	Cash, cash equivalents and investments consisted of the following: As of December 31, 2015 2016 (in thousands) Cash and cash equivalents Cash $ 104,361 $ 144,192 Money market funds 180,021 55,752 Commercial paper 31,089 — Corporate debt securities 2,000 — U.S. government and government agency debt securities 17,196 — Total cash and cash equivalents $ 334,667 $ 199,944 Short-term investments Commercial paper $ 4,792 $ — Corporate debt securities 31,052 37,109 Total short-term investments $ 35,844 $ 37,109 Long-term investments Corporate debt securities $ 46,369 $ 6,252 Total long-term investments $ 46,369 $ 6,252 Total cash, cash equivalents and investments $ 416,880 $ 243,305
Summary of available-for-sale securities' adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category	The following tables summarize our available-for-sale securities’ adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category as of December 31, 2015 and 2016 . As of December 31, 2015 Adjusted Cost Unrealized Gains Unrealized Losses Fair Value (in thousands) Cash equivalents and marketable securities Money market funds $ 180,021 $ — $ — $ 180,021 Commercial paper 35,881 — — 35,881 Corporate debt securities 79,760 8 (347 ) 79,421 U.S. government and government agency debt securities 17,198 — (2 ) 17,196 Total cash equivalents and marketable securities $ 312,860 $ 8 $ (349 ) $ 312,519 As of December 31, 2016 Adjusted Cost Unrealized Gains Unrealized Losses Fair Value (in thousands) Cash equivalents and marketable securities Money market funds $ 55,752 $ — $ — $ 55,752 Corporate debt securities 43,413 3 (55 ) 43,361 Total cash equivalents and marketable securities $ 99,165 $ 3 $ (55 ) $ 99,113
Schedule of available-for-sale investments by contractual maturity date	The following tables present available-for-sale investments by contractual maturity date as of December 31, 2015 and 2016 : As of December 31, 2015 Adjusted Cost Fair Value (in thousands) Due in one year or less $ 266,205 $ 266,150 Due after one year through three years 46,655 46,369 Total $ 312,860 $ 312,519 As of December 31, 2016 Adjusted Cost Fair Value (in thousands) Due in one year or less $ 92,914 $ 92,861 Due after one year through three years 6,251 6,252 Total $ 99,165 $ 99,113
Summary of available-for-sale securities' fair value and gross unrealized losses	The following tables summarize our available-for-sale securities’ fair value and gross unrealized losses aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position as of December 31, 2015 and 2016 : As of December 31, 2015 Twelve Months or Less More than Twelve Months Total Fair Gross Unrealized Losses Fair Gross Unrealized Losses Fair Gross Unrealized Losses (in thousands) Corporate debt securities $ 64,804 $ (293 ) $ 8,531 $ (54 ) $ 73,335 $ (347 ) U.S. government and government agency debt securities 16,241 (2 ) — — 16,241 (2 ) Total $ 81,045 $ (295 ) $ 8,531 $ (54 ) $ 89,576 $ (349 ) As of December 31, 2016 Twelve Months or Less More than Twelve Months Total Fair Gross Unrealized Losses Fair Gross Unrealized Losses Fair Gross Unrealized Losses (in thousands) Corporate debt securities $ 34,257 $ (52 ) $ 4,099 $ (3 ) $ 38,356 $ (55 ) Total $ 34,257 $ (52 ) $ 4,099 $ (3 ) $ 38,356 $ (55 )
Schedule of accounts receivable, net	Accounts receivable, net consisted of the following as of December 31, 2015 and 2016 : As of December 31, 2015 2016 (in thousands) Accounts receivable, net Accounts receivable $ 279,240 $ 312,900 Allowance for doubtful accounts (2,165 ) (3,633 ) Total accounts receivable, net $ 277,075 $ 309,267
Schedule of allowance for doubtful accounts	The following table summarizes our beginning allowance for doubtful accounts balance for each period, additions, write-offs net of recoveries and the balance at the end of each period for the years December 31, 2014 , 2015 and 2016 : Allowance for Doubtful Accounts Balance at Beginning of Period Additions Write-offs, Net of Recoveries Balance at End of Period (in thousands) For the year ended December 31, 2014 $ 1,272 1,064 (1,118 ) $ 1,218 For the year ended December 31, 2015 $ 1,218 2,085 (1,138 ) $ 2,165 For the year ended December 31, 2016 $ 2,165 3,508 (2,040 ) $ 3,633
Schedule of prepaid and other current assets	Prepaid and other current assets consisted of the following as of December 31, 2015 and 2016 : As of December 31, 2015 2016 (in thousands) Prepaid and other current assets Other current assets $ 15,821 $ 13,858 Prepaid expenses 13,908 13,533 Ticketing contract advances—short term, net 4,092 5,800 Total prepaid and other current assets $ 33,821 $ 33,191
Schedule of other long-term assets	Other long-term assets consisted of the following as of December 31, 2015 and 2016 : As of December 31, 2015 2016 (in thousands) Other long-term assets Ticketing contract advances—long-term $ 9,824 $ 15,395 Long-term security deposits 9,039 9,090 Other 10,929 7,048 Total other long-term assets $ 29,792 $ 31,533
Schedule of property and equipment, net	Property and equipment, net consisted of the following as of December 31, 2015 and 2016 : As of December 31, 2015 2016 (in thousands) Property and equipment, net Servers, computers and other related equipment $ 57,309 $ 85,541 Leasehold improvements 35,947 63,519 Office furniture and equipment 5,470 9,037 Construction in progress 12,550 20,393 Software developed for internal use 10,239 34,983 Total property and equipment $ 121,515 $ 213,473 Less accumulated depreciation and amortization (55,145 ) (89,385 ) Total property and equipment, net $ 66,370 $ 124,088
Schedule of other current liabilities	Other current liabilities consisted of the following as of December 31, 2015 and 2016 : As of December 31, 2015 2016 (in thousands) Other current liabilities Ticketing amounts due to clients $ 13,104 $ 20,666 Other 2,528 327 Total other current liabilities $ 15,632 $ 20,993
Schedule of other long-term liabilities	Other long-term liabilities consisted of the following as of December 31, 2015 and 2016 : As of December 31, 2015 2016 (in thousands) Other long-term liabilities Long-term deferred rent $ 23,662 $ 24,245 Other 7,200 9,942 Total other long-term liabilities $ 30,862 $ 34,187

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Schedule of fair value of financial assets and liabilities	The fair value of these financial assets and liabilities was determined using the following inputs at December 31, 2015 and 2016 : As of December 31, 2015 Fair Value Measurement Using Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Total (in thousands) Assets Commercial paper $ — $ 35,881 $ 35,881 Corporate debt securities — 79,421 79,421 U.S. government and government agency debt securities — 17,196 17,196 Total assets measured at fair value $ — $ 132,498 $ 132,498 As of December 31, 2016 Fair Value Measurement Using Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Total (in thousands) Assets Corporate debt securities $ — $ 43,361 $ 43,361 Total assets measured at fair value $ — $ 43,361 $ 43,361

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
Summary of the components of the purchase consideration transferred	The following table summarizes the components of the purchase consideration transferred based on the closing price of $12.18 per share of our common stock as of the acquisition date: (in thousands) Cash paid by Pandora $ 191,479 Cash paid by Ticketfly to option holders 7,238 Common stock (11,193,847 shares at $12.18 per share) issued by Pandora to selling shareholders 136,342 Fair value of stock options and restricted stock units assumed 10,514 Less: purchase price adjustments (6,995 ) Less: post-combination compensation expense (3,235 ) Purchase consideration $ 335,343
Summary of the estimated fair values of assets acquired and liabilities assumed	The following table summarizes the estimated fair values of assets acquired and liabilities assumed as of the date of acquisition: (in thousands) Current assets $ 39,809 Long-term assets 15,982 Current liabilities (21,853 ) Long-term liabilities (6,298 ) Deferred tax liability (1,738 ) Intangible assets 76,800 Goodwill 232,641 Total $ 335,343
Schedule of unaudited pro forma results	The unaudited pro forma results do not reflect any cost saving synergies from operating efficiencies or the effect of the incremental costs incurred in integrating the two companies. Accordingly, these unaudited pro forma results are presented for informational purpose only and are not necessarily indicative of what the actual results of operations of the combined company would have been if the acquisition had occurred at the beginning of the period presented, nor are they indicative of future results of operations: Year ended 2014 2015 (in thousands) Revenue $ 975,712 $ 1,222,452 Net loss $ (58,195 ) $ (210,111 )
Summary of the allocation of estimated fair values of net assets acquired including related estimated useful lives	The following table summarizes the allocation of estimated fair values of the net assets acquired during the year ended December 31, 2015 , including the related estimated useful lives, where applicable: Ticketfly Rdio Other Estimated fair value Estimated useful life in years Estimated fair value Estimated useful life in years Estimated fair value Estimated useful life in years (in thousands, except for estimated useful life) Intangible assets: Customer relationships—clients $ 37,300 8 $ — $ — Developed technology 28,100 5 26,400 2-5 1,550 4 Tradename 10,400 8 1,000 3 320 2 Customer relationships—users 1,000 2 — 940 2 FCC license—broadcast radio — — 193 Tangible assets acquired, net 27,640 1,969 (490 ) Deferred tax liabilities (1,738 ) — (49 ) Net assets acquired $ 102,702 $ 29,369 $ 2,464 Goodwill 232,641 48,131 23,103 Total fair value consideration $ 335,343 $ 77,500 $ 25,567

Goodwill and Other Intangible26

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of changes in the carrying amount of goodwill	The changes in the carrying amount of goodwill for the years ended December 31, 2015 and 2016 , are as follows: Goodwill (in thousands) Balance as of December 31, 2014 $ — Goodwill resulting from business combinations 303,875 Balance as of December 31, 2015 $ 303,875 Goodwill resulting from business combination and purchase price adjustments 2,816 Balance as of December 31, 2016 $ 306,691
Summary of gross carrying amounts and accumulated amortization of intangibles - finite lived	The following summarizes information regarding the gross carrying amounts and accumulated amortization of intangibles: As of December 31, 2015 As of December 31, 2016 Gross Carrying Amount Accumulated Amortization Net Carrying Value Gross Carrying Amount Accumulated Amortization Net Carrying Value (in thousands) Finite-lived intangible assets Patents $ 8,030 $ (1,824 ) $ 6,206 $ 8,030 $ (2,556 ) $ 5,474 Developed technology 56,050 (1,265 ) 54,785 56,162 (13,599 ) 42,563 Customer relationships — clients 37,300 (777 ) 36,523 37,399 (5,487 ) 31,912 Customer relationships — users 1,940 (318 ) 1,622 1,940 (1,288 ) 652 Trade names 11,720 (304 ) 11,416 11,735 (2,104 ) 9,631 Total finite-lived intangible assets $ 115,040 $ (4,488 ) $ 110,552 $ 115,266 $ (25,034 ) $ 90,232 Indefinite-lived intangible assets FCC license—broadcast radio $ 193 $ — $ 193 $ 193 $ — $ 193 Total intangible assets $ 115,233 $ (4,488 ) $ 110,745 $ 115,459 $ (25,034 ) $ 90,425
Summary of gross carrying amounts and accumulated amortization of intangibles - indefinite lived	The following summarizes information regarding the gross carrying amounts and accumulated amortization of intangibles: As of December 31, 2015 As of December 31, 2016 Gross Carrying Amount Accumulated Amortization Net Carrying Value Gross Carrying Amount Accumulated Amortization Net Carrying Value (in thousands) Finite-lived intangible assets Patents $ 8,030 $ (1,824 ) $ 6,206 $ 8,030 $ (2,556 ) $ 5,474 Developed technology 56,050 (1,265 ) 54,785 56,162 (13,599 ) 42,563 Customer relationships — clients 37,300 (777 ) 36,523 37,399 (5,487 ) 31,912 Customer relationships — users 1,940 (318 ) 1,622 1,940 (1,288 ) 652 Trade names 11,720 (304 ) 11,416 11,735 (2,104 ) 9,631 Total finite-lived intangible assets $ 115,040 $ (4,488 ) $ 110,552 $ 115,266 $ (25,034 ) $ 90,232 Indefinite-lived intangible assets FCC license—broadcast radio $ 193 $ — $ 193 $ 193 $ — $ 193 Total intangible assets $ 115,233 $ (4,488 ) $ 110,745 $ 115,459 $ (25,034 ) $ 90,425
Schedule of future amortization expense related to finite-lived intangible assets	The following is a schedule of future amortization expense related to finite-lived intangible assets as of December 31, 2016 . As of (in thousands) 2017 $ 20,116 2018 17,654 2019 17,129 2020 15,896 2021 6,690 Thereafter 12,747 Total future amortization expense $ 90,232

Debt Instruments (Tables)

Debt Instruments (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Schedule of long-term debt	Long-term debt, net consisted of the following: As of December 31, 2015 2016 (in thousands) 1.75% convertible senior notes due 2020 $ 345,000 $ 345,000 Credit facility — 90,000 Unamortized discount and deferred issuance costs (110,423 ) (92,753 ) Long-term debt, net $ 234,577 $ 342,247
Summary of the effective interest rate, contractually stated interest expense and costs related to amortization of discount for the Notes	The following table outlines the effective interest rate, contractually stated interest expense and costs related to the amortization of the discount for the Notes: Year ended December 31, 2015 2016 (in thousands except for effective interest rate) Effective interest rate 10.18 % 10.18 % Contractually stated interest expense $ 369 $ 6,046 Amortization of discount $ 1,084 $ 18,315

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Schedule of future minimum lease payments under operating leases	The following is a schedule of future minimum lease payments and future minimum sublease income under noncancelable operating leases as of December 31, 2016 : As of December 31, 2016 Future Minimum Lease Payments Future Minimum Sublease Income (in thousands) 2017 $ 26,035 $ 1,848 2018 25,023 907 2019 24,521 487 2020 21,996 501 2021 13,778 430 Thereafter 43,860 — Total $ 155,213 $ 4,173

Provision for Income Taxes (Tab

Provision for Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Schedule of loss before provision for income taxes by jurisdiction	Loss before provision for income taxes by jurisdiction consists of the following: Year ended December 31, 2014 2015 2016 (in thousands) Jurisdiction Domestic $ (24,230 ) $ (163,460 ) $ (328,414 ) Foreign (5,592 ) (7,751 ) (14,792 ) Loss before provision for income taxes $ (29,822 ) $ (171,211 ) $ (343,206 )
Schedule of provision for income taxes	The provision for income taxes consists of the following: Year ended December 31, 2014 2015 2016 (in thousands) Current Federal $ — $ — $ — State and local 353 9 26 International 231 214 443 Total current income tax expense $ 584 $ 223 $ 469 Deferred Federal (9,996 ) (17,943 ) (96,852 ) State and local (6,238 ) (2,174 ) (10,750 ) International — — (1,032 ) Valuation allowance 16,234 18,344 107,937 Total deferred income tax expense (benefit) $ — $ (1,773 ) $ (697 ) Total provision for (benefit from) income taxes $ 584 $ (1,550 ) $ (228 )
Schedule of reconciliation of the statutory federal rate and effective tax rate	The following table presents a reconciliation of the statutory federal rate and our effective tax rate: Year ended December 31, 2014 2015 2016 U.S. federal taxes at statutory rate 34 % 34 % 34 % State taxes, net of federal benefit (1 ) — — Permanent differences 4 3 2 Foreign rate differential (7 ) (1 ) (2 ) Federal and state credits, net of reserve 11 2 2 Impact of acquired DTAs and DTLs — 1 1 Change in valuation allowance (55 ) (33 ) (32 ) Change in rate 6 (1 ) — Deferred adjustments 6 (4 ) (5 ) Effective tax rate (2 )% 1 % — %
Schedule of major components of deferred tax assets and liabilities	The major components of deferred tax assets and liabilities consist of the following: As of December 31, 2015 2016 (in thousands) Deferred tax assets Net operating loss carryforwards $ 91,658 $ 167,961 Tax credit carryforwards 14,204 21,111 Allowances and other 21,802 27,729 Stock options 29,927 32,986 Depreciation and amortization — 3,704 Total deferred tax assets $ 157,591 $ 253,491 Valuation allowance (92,772 ) (200,797 ) Total deferred tax assets, net of valuation allowance $ 64,819 $ 52,694 Deferred tax liabilities Convertible debt (37,580 ) (31,592 ) Depreciation and amortization (27,252 ) (22,360 ) Total deferred tax liabilities $ (64,832 ) $ (53,952 ) Net deferred tax assets (liabilities) $ (13 ) $ (1,258 )
Schedule of reconciliation of beginning and ending amounts of unrecognized tax benefits	A reconciliation of the beginning and ending amounts of unrecognized tax benefits (excluding interest and penalties) is as follows: Year ended 2015 2016 (in thousands) Beginning balance $ 5,793 $ 6,864 Increases related to tax positions taken during a prior year — — Decreases related to tax positions taken during a prior year (74 ) (13 ) Increases related to tax positions taken during the current year 1,145 2,561 Ending balance $ 6,864 $ 9,412

Stock-based Compensation Plan30

Stock-based Compensation Plans and Awards (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of shares available for grant and activity	Shares available for grant as of December 31, 2016 and the activity during the year ended December 31, 2016 are as follows: Shares Available for Grant Equity Awards ESPP Total Balance as of December 31, 2015 11,723,327 3,319,337 15,042,664 Additional shares authorized 8,998,816 — 8,998,816 Restricted stock units granted (15,522,398 ) — (15,522,398 ) Performance stock units granted (1,835,250 ) — (1,835,250 ) ESPP shares issued — (1,254,910 ) (1,254,910 ) Options forfeited 1,592,289 — 1,592,289 Restricted stock units forfeited 2,587,203 — 2,587,203 Market stock units forfeited 185,714 — 185,714 Share adjustment 614,967 — 614,967 Balance as of December 31, 2016 8,344,668 2,064,427 10,409,095
Schedule of assumptions used for determining the per-share fair value of shares granted under the ESPP	The per-share fair value of shares to be granted under the ESPP is determined on the first day of the offering period using the Black-Scholes option pricing model using the following assumptions: Year Ended December 31, 2014 2015 2016 Expected life (in years) 0.5 0.5 0.5 Risk-free interest rate 0.06 % 0.12 % 0.36 % Expected volatility 42 % 52 % 44 % Expected dividend yield 0 % 0 % 0 %
Schedule of stock option activity	Stock option activity during the year ended December 31, 2016 was as follows: Options Outstanding Outstanding Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (1) (in thousands, except share and per share data) Balance as of December 31, 2015 12,815,891 $ 7.15 1.09 $ 101,151 Granted — — Exercised (1,588,781 ) 2.18 Forfeited (1,790,730 ) 19.02 Balance as of December 31, 2016 9,436,380 5.74 0.47 77,752 Vested and exercisable as of December 31, 2016 8,108,519 5.40 0.31 68,656 Expected to vest as of December 31, 2016 (2) 1,241,887 $ 7.94 1.50 $ 8,403 (1)Amounts represent the difference between the exercise price and the fair value of common stock at each period end for all in the money options outstanding based on the fair value per share of common stock of $13.41 and $13.04 as of December 31, 2015 and 2016. (2)Options expected to vest reflect an estimated forfeiture rate.
Schedule of assumptions used for estimating the per-share fair value of stock options	The per-share fair value of stock options granted during the years ended December 31, 2014 and 2015 was determined on the grant date using the Black-Scholes option pricing model with the following assumptions. No stock option grants were made during the year ended December 31, 2016 . Year Ended December 31, 2014 2015 2016 Expected life (in years) 6.08 6.08 N/A Risk-free interest rate 1.71% - 1.93% 1.75% - 1.92% N/A Expected volatility 58% - 59% 49% - 50% N/A Expected dividend yield 0 % 0 % N/A
Schedule of activities for RSUs and MSUs	The following table summarizes the activities for our PSUs for the year ended December 31, 2016 : Number of PSUs Weighted-Average Grant Date Fair Value Unvested as of December 31, 2015 — $ — Granted 1,835,250 5.33 Vested — — Forfeited — — Unvested as of December 31, 2016 1,835,250 5.33 Expected to vest as of December 31, 2016 (1) 1,658,031 $ 5.32 (1) PSUs expected to vest reflect an estimated forfeiture rate. year ended December 31, 2016 : Number of RSUs Weighted-Average Grant Date Fair Value Unvested as of December 31, 2015 17,272,085 $ 17.91 Granted 15,522,398 10.21 Vested (7,666,647 ) 16.94 Forfeited (2,723,419 ) 14.84 Unvested as of December 31, 2016 22,404,417 13.26 Expected to vest as of December 31, 2016 (1) 20,325,998 $ 13.33 (1) RSUs expected to vest reflect an estimated forfeiture rate. year ended December 31, 2016 : Number of MSUs Weighted-Average Grant Date Fair Value Unvested as of December 31, 2015 776,000 $ 5.60 Granted — — Vested (56,903 ) 2.57 Forfeited (185,714 ) 5.91 Unvested as of December 31, 2016 533,383 5.49 Expected to vest as of December 31, 2016 (1) 398,831 $ 5.52 (1) MSUs expected to vest reflect an estimated forfeiture rate.
Schedule of stock-based compensation expenses related to all employee and non-employee stock-based awards	Stock-based compensation expense related to all employee and non-employee stock-based awards was as follows: Year ended December 31, 2014 2015 2016 (in thousands) Stock-based compensation expense Cost of revenue—Other $ 4,414 $ 5,531 $ 6,108 Cost of revenue—Ticketing service — 40 188 Product development 17,546 23,671 30,975 Sales and marketing 42,165 52,747 58,118 General and administrative 22,930 29,656 43,069 Total stock-based compensation expense $ 87,055 $ 111,645 $ 138,458

Common Stock and Net Loss Per31

Common Stock and Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Schedule of the computation of historical basic and diluted net loss per share	The following table sets forth the computation of historical basic and diluted net loss per share: Year Ended December 31, 2014 2015 2016 (in thousands except per share amounts) Numerator Net loss $ (30,406 ) $ (169,661 ) $ (342,978 ) Denominator Weighted-average common shares outstanding used in computing basic and diluted net loss per share 205,273 213,790 230,693 Net loss per share, basic and diluted $ (0.15 ) $ (0.79 ) $ (1.49 )
Schedule of potential common shares that were excluded from the computation of diluted net loss per share	The following potential common shares outstanding were excluded from the computation of diluted net loss per share because including them would have been anti-dilutive: As of December 31, 2014 As of December 31, 2015 As of December 31, 2016 (in thousands) Options to purchase common stock 10,980 12,816 9,436 Restricted stock units 11,024 17,272 22,404 Performance awards* — 776 2,369 Total common stock equivalents 22,004 30,864 34,209 *Includes potential common shares outstanding for MSUs and PSUs

Segment Data and Revenue by G32

Segment Data and Revenue by Geographic Area (Tables)	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Schedule of Reportable Segments Information	The following table provides the financial performance of our reportable segments, including a reconciliation of gross profit from segment operations to gross profit from total operations: Year ended December 31, 2015 2016 Pandora Ticketfly (1) Total Pandora Ticketfly Total (in thousands) (in thousands) Revenues $ 1,153,876 $ 10,167 $ 1,164,043 $ 1,298,276 $ 86,550 $ 1,384,826 Cost of revenues 690,220 7,121 697,341 835,642 59,280 894,922 Gross profit $ 463,656 $ 3,046 $ 466,702 $ 462,634 $ 27,270 $ 489,904 Operating and other expenses (636,363 ) (832,882 ) Net loss $ (169,661 ) $ (342,978 ) (1) Includes two months of revenue and expense for Ticketfly from the acquisition date of October 31, 2015 to December 31, 2015. The following table provides depreciation and amortization costs included in costs of revenues by segment included in the consolidated statements of operations: Year ended December 31, 2015 2016 Pandora Ticketfly (1) Total Pandora Ticketfly Total (in thousands) (in thousands) Depreciation and amortization $ 7,231 $ 949 $ 8,180 $ 8,667 $ 5,729 $ 14,396 (1) Includes two months of depreciation and amortization expense for Ticketfly from the acquisition date of October 31, 2015 to December 31, 2015.
Schedule of Revenue by Geographic Area	The following table sets forth revenue by geographic area: Year ended December 31, 2014 2015 2016 (in thousands) Revenue by geographic area United States $ 917,008 $ 1,155,210 $ 1,366,330 International 3,794 8,833 18,496 Total revenue $ 920,802 $ 1,164,043 $ 1,384,826

Selected Quarterly Financial 33

Selected Quarterly Financial Data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Schedule of selected quarterly financial data (unaudited)	Quarter ended March 31, June 30, September 30, December 31, March 31, June 30, September 30, December 31, 2015 2015 2015 2015 2016 2016 2016 2016 (in thousands, except per share data) Total revenue (1) $ 230,764 $ 285,560 $ 311,562 $ 336,157 $ 297,305 $ 343,022 $ 351,901 $ 392,598 Cost of revenue Cost of revenue—Content acquisition costs 126,023 130,134 211,272 142,933 171,264 176,633 174,334 212,122 Cost of revenue—Other 16,233 20,043 21,414 22,168 20,999 24,833 25,556 29,901 Cost of revenue—Ticketing service (1) — — — 7,121 14,646 15,259 15,318 14,057 Total cost of revenue 142,256 150,177 232,686 172,222 206,909 216,725 215,208 256,080 Gross profit 88,508 135,383 78,876 163,935 90,396 126,297 136,693 136,518 Operating expenses Product development (1) 15,875 18,742 21,849 28,115 35,846 33,808 33,657 38,325 Sales and marketing (1) 84,274 94,035 107,286 112,574 117,622 123,812 116,475 133,546 General and administrative (1) 36,754 38,812 35,603 42,774 46,296 40,562 41,768 46,946 Total operating expenses 136,903 151,589 164,738 183,463 199,764 198,182 191,900 218,817 Loss from operations (48,395 ) (16,206 ) (85,862 ) (19,528 ) (109,368 ) (71,885 ) (55,207 ) (82,299 ) Net loss (48,257 ) (16,065 ) (85,930 ) (19,409 ) (115,102 ) (76,333 ) (61,534 ) (90,009 ) Net loss per share, basic (0.23 ) (0.08 ) (0.40 ) (0.09 ) (0.51 ) (0.33 ) (0.27 ) (0.38 ) Net loss per share, diluted $ (0.23 ) $ (0.08 ) $ (0.40 ) $ (0.09 ) $ (0.51 ) $ (0.33 ) $ (0.27 ) $ (0.38 ) (1) Includes two months of revenue and expense for Ticketfly from the acquisition date of October 31, 2015 to December 31, 2015.

Summary of Significant Accoun34

Summary of Significant Accounting Policies (Details)	1 Months Ended	3 Months Ended	12 Months Ended
	Mar. 31, 2015performance_period	Mar. 31, 2014USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Accounting Policies [Abstract]
Deferred revenue related to in-app mobile subscriptions subject to refund rights						$ 14,200,000
Increase related to in-app subscription revenue		$ 14,200,000
Concentration Risk [Line Items]
Actual credit losses			$ 2,000,000	$ 1,100,000	$ 1,100,000
Capitalized cost, net of amortization, related to internal use software and website development costs			7,500,000
Amortization expense on ticketing contract advances			5,700,000	700,000
Impairment of goodwill			$ 0
Service period over which company recognizes stock-based compensation (years)			4 years
Advertising expenses			$ 45,700,000	35,100,000	$ 10,400,000
MSUs
Concentration Risk [Line Items]
Service period over which company recognizes stock-based compensation (years)			1 year 1 month 17 days
Number of performance periods used for measurement | performance_period	3
Internal use software and website development
Concentration Risk [Line Items]
Capitalized cost, net of amortization, related to internal use software and website development costs			$ 25,700,000	$ 6,300,000
Minimum
Concentration Risk [Line Items]
Estimated useful lives of assets (years)			3 years
Life of ticketing contract term (years)			3 years
Finite-lived intangible asset, useful life (years)			2 years
Minimum | Internal use software and website development
Concentration Risk [Line Items]
Estimated useful lives of assets (years)			3 years
Maximum
Concentration Risk [Line Items]
Estimated useful lives of assets (years)			5 years
Life of ticketing contract term (years)			5 years
Finite-lived intangible asset, useful life (years)			11 years
Maximum | Internal use software and website development
Concentration Risk [Line Items]
Estimated useful lives of assets (years)			5 years

Composition of Certain Financ35

Composition of Certain Financial Statement Captions - Schedule of cash, cash equivalents and investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash, Cash Equivalents and Investments
Document Period End Date	Dec. 31, 2016
Total cash and cash equivalents	$ 199,944	$ 334,667	$ 175,957	$ 245,755
Total short-term investments	37,109	35,844
Total long-term investments	6,252	46,369
Total cash, cash equivalents and investments	243,305	416,880
Cash
Cash, Cash Equivalents and Investments
Total cash and cash equivalents	144,192	104,361
Money market funds
Cash, Cash Equivalents and Investments
Total cash and cash equivalents	55,752	180,021
Commercial paper
Cash, Cash Equivalents and Investments
Total cash and cash equivalents	0	31,089
Total short-term investments	0	4,792
Corporate debt securities
Cash, Cash Equivalents and Investments
Total cash and cash equivalents	0	2,000
Total short-term investments	37,109	31,052
Total long-term investments	6,252	46,369
U.S. government and government agency debt securities
Cash, Cash Equivalents and Investments
Total cash and cash equivalents	$ 0	$ 17,196

Composition of Certain Financ36

Composition of Certain Financial Statement Captions - Summary of available-for-sale securities' adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	$ 99,165	$ 312,860
Unrealized Gains	3	8
Unrealized Losses	(55)	(349)
Fair Value	99,113	312,519
Money market funds
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	55,752	180,021
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	55,752	180,021
Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost		35,881
Unrealized Gains		0
Unrealized Losses		0
Fair Value		35,881
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	43,413	79,760
Unrealized Gains	3	8
Unrealized Losses	(55)	(347)
Fair Value	$ 43,361	79,421
U.S. government and government agency debt securities
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost		17,198
Unrealized Gains		0
Unrealized Losses		(2)
Fair Value		$ 17,196

Composition of Certain Financ37

Composition of Certain Financial Statement Captions - Schedule of available-for-sale investments by contractual maturity date (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Adjusted Cost
Due in one year or less	$ 92,914	$ 266,205
Due after one year through three years	6,251	46,655
Total	99,165	312,860
Fair Value
Due in one year or less	92,861	266,150
Due after one year through three years	6,252	46,369
Total	$ 99,113	$ 312,519

Composition of Certain Financ38

Composition of Certain Financial Statement Captions - Summary of available-for-sale securities' fair value and gross unrealized losses (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, twelve months or less, fair value	$ 34,257	$ 81,045
Available-for-sale securities, continuous unrealized loss position, twelve months or less, gross unrealized losses	(52)	(295)
Available-for-sale securities, continuous unrealized loss position, more than twelve months, fair value	4,099	8,531
Available-for-sale securities, continuous unrealized loss position, more than twelve months, gross unrealized losses	(3)	(54)
Available-for-sale securities, continuous unrealized loss position, total, fair value	38,356	89,576
Available-for-sale securities, continuous unrealized loss position, total, gross unrealized losses	(55)	(349)
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, twelve months or less, fair value	34,257	64,804
Available-for-sale securities, continuous unrealized loss position, twelve months or less, gross unrealized losses	(52)	(293)
Available-for-sale securities, continuous unrealized loss position, more than twelve months, fair value	4,099	8,531
Available-for-sale securities, continuous unrealized loss position, more than twelve months, gross unrealized losses	(3)	(54)
Available-for-sale securities, continuous unrealized loss position, total, fair value	38,356	73,335
Available-for-sale securities, continuous unrealized loss position, total, gross unrealized losses	$ (55)	(347)
U.S. government and government agency debt securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, twelve months or less, fair value		16,241
Available-for-sale securities, continuous unrealized loss position, twelve months or less, gross unrealized losses		(2)
Available-for-sale securities, continuous unrealized loss position, more than twelve months, fair value		0
Available-for-sale securities, continuous unrealized loss position, more than twelve months, gross unrealized losses		0
Available-for-sale securities, continuous unrealized loss position, total, fair value		16,241
Available-for-sale securities, continuous unrealized loss position, total, gross unrealized losses		$ (2)

Composition of Certain Financ39

Composition of Certain Financial Statement Captions - Narrative (Details)	12 Months Ended
	Dec. 31, 2016USD ($)security	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Property, Plant and Equipment [Abstract]
Number of owned securities that were in an unrealized loss position | security	30
Unrealized losses deemed to be other-than-temporary	$ 0
Proceeds from sale of available-for-sale securities	3,507,000	$ 111,356,000	$ 0
Realized gain (loss) in connecting with sales of available-for-sale securities	0
Prepaid content acquisition costs	46,310,000	2,099,000
Property, Plant and Equipment [Line Items]
Depreciation	34,200,000	20,400,000	14,700,000
Capitalized cost related to internal use software and website development costs	7,500,000
Accumulated amortization	$ 89,385,000	55,145,000
Minimum
Property, Plant and Equipment [Line Items]
Expected useful lives (years)	3 years
Maximum
Property, Plant and Equipment [Line Items]
Expected useful lives (years)	5 years
Software developed for internal use
Property, Plant and Equipment [Line Items]
Capitalized cost related to internal use software and website development costs	$ 25,700,000	6,300,000
Accumulated amortization	9,300,000	4,000,000
Amortization expense	$ 5,300,000	2,200,000	$ 1,100,000
Software developed for internal use | Minimum
Property, Plant and Equipment [Line Items]
Expected useful lives (years)	3 years
Software developed for internal use | Maximum
Property, Plant and Equipment [Line Items]
Expected useful lives (years)	5 years
Other current assets
Property, Plant and Equipment [Line Items]
Receivables for the reimbursement of costs of leasehold improvements in connection with operating leases	$ 9,100,000	$ 12,900,000

Composition of Certain Financ40

Composition of Certain Financial Statement Captions - Schedule of accounts receivable, net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Document Period End Date	Dec. 31, 2016
Accounts receivable, net
Accounts receivable	$ 312,900	$ 279,240
Allowance for doubtful accounts	(3,633)	(2,165)	$ (1,218)	$ (1,272)
Total accounts receivable, net	$ 309,267	$ 277,075

Composition of Certain Financ41

Composition of Certain Financial Statement Captions - Schedule of allowance for doubtful accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for Doubtful Accounts
Balance at Beginning of Period	$ 2,165	$ 1,218	$ 1,272
Additions	3,508	2,085	1,064
Write-offs, Net of Recoveries	(2,040)	(1,138)	(1,118)
Balance at End of Period	$ 3,633	$ 2,165	$ 1,218

Composition of Certain Financ42

Composition of Certain Financial Statement Captions - Schedule of prepaid and other current assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Prepaid and other current assets
Other current assets	$ 13,858	$ 15,821
Prepaid expenses	13,533	13,908
Ticketing contract advances - short term, net	5,800	4,092
Total prepaid and other current assets	$ 33,191	$ 33,821

Composition of Certain Financ43

Composition of Certain Financial Statement Captions - Schedule of other long-term assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Other long-term assets
Ticketing contract advances - long-term	$ 15,395	$ 9,824
Long-term security deposits	9,090	9,039
Other	7,048	10,929
Total other long-term assets	$ 31,533	$ 29,792

Composition of Certain Financ44

Composition of Certain Financial Statement Captions - Schedule of property and equipment, net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Document Period End Date	Dec. 31, 2016
Property and equipment, net
Total property and equipment	$ 213,473	$ 121,515
Less accumulated depreciation and amortization	(89,385)	(55,145)
Total property and equipment, net	124,088	66,370
Servers, computers and other related equipment
Property and equipment, net
Total property and equipment	85,541	57,309
Leasehold improvements
Property and equipment, net
Total property and equipment	63,519	35,947
Office furniture and equipment
Property and equipment, net
Total property and equipment	9,037	5,470
Construction in progress
Property and equipment, net
Total property and equipment	20,393	12,550
Software developed for internal use
Property and equipment, net
Total property and equipment	34,983	10,239
Less accumulated depreciation and amortization	$ (9,300)	$ (4,000)

Composition of Certain Financ45

Composition of Certain Financial Statement Captions - Schedule of other current liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Document Period End Date	Dec. 31, 2016
Other current liabilities
Ticketing amounts due to clients	$ 20,666	$ 13,104
Other	327	2,528
Total other current liabilities	$ 20,993	$ 15,632

Composition of Certain Financ46

Composition of Certain Financial Statement Captions - Schedule of other long-term liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Document Period End Date	Dec. 31, 2016
Other long-term liabilities
Long-term deferred rent	$ 24,245	$ 23,662
Other	9,942	7,200
Total other long-term liabilities	$ 34,187	$ 30,862

Fair Value - Schedule of fair v

Fair Value - Schedule of fair value of financial assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 43,361	$ 132,498
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value		35,881
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	43,361	79,421
U.S. government and government agency debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value		17,196
Quoted Prices in Active Markets for Identical Instruments (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Quoted Prices in Active Markets for Identical Instruments (Level 1) | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value		0
Quoted Prices in Active Markets for Identical Instruments (Level 1) | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Quoted Prices in Active Markets for Identical Instruments (Level 1) | U.S. government and government agency debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value		0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	43,361	132,498
Significant Other Observable Inputs (Level 2) | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value		35,881
Significant Other Observable Inputs (Level 2) | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 43,361	79,421
Significant Other Observable Inputs (Level 2) | U.S. government and government agency debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value		$ 17,196

Fair Value - Narrative (Details

Fair Value - Narrative (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Money market funds | Fair value measured on a recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	$ 55,800,000	$ 180,000,000
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Liabilities measured at fair value	$ 0	$ 0

Business Combinations - Narrati

Business Combinations - Narrative (Details) $ / shares in Units, $ in Thousands	Dec. 23, 2015USD ($)	Oct. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2016company
Business Acquisition [Line Items]
Number of companies integrated | company			2
Ticketfly
Business Acquisition [Line Items]
Aggregate purchase price		$ 335,343
Shares issued in acquisition (in shares) | shares		11,193,847
Cash paid		$ 191,479
Share price (in dollars per share) | $ / shares		$ 12.18
Post-combination compensation expense		$ 3,235
Post-combination compensation expense (in shares) | shares		200,000
Post-combination compensation expense, cash		$ 1,900
Required service period (up to)		3 years
Estimated liabilities for indirect taxes and other liabilities		$ 5,100
Escrow receivable		$ 5,100
Rdio
Business Acquisition [Line Items]
Aggregate purchase price	$ 77,500
Cash paid	$ 2,500

Business Combinations - Summary

Business Combinations - Summary of the components of the purchase consideration transferred (Details) - Ticketfly $ / shares in Units, $ in Thousands	Oct. 31, 2015USD ($)$ / sharesshares
Business Acquisition [Line Items]
Cash paid by Pandora	$ 191,479
Cash paid by Ticketfly to option holders	7,238
Common stock (11,193,847 shares at $12.18 per share) issued by Pandora to selling shareholders	136,342
Fair value of stock options and restricted stock units assumed	10,514
Less: purchase price adjustments	(6,995)
Less: post-combination compensation expense	(3,235)
Purchase consideration	$ 335,343
Shares issued in acquisition (in shares) | shares	11,193,847
Share price (in dollars per share) | $ / shares	$ 12.18

Business Combinations - Summa51

Business Combinations - Summary of the estimated fair values of assets acquired and liabilities assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Oct. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 306,691	$ 303,875		$ 0
Ticketfly
Business Acquisition [Line Items]
Current assets			$ 39,809
Long-term assets			15,982
Current liabilities			(21,853)
Long-term liabilities			(6,298)
Deferred tax liability		(1,738)	(1,738)
Intangible assets			76,800
Goodwill		232,641	232,641
Total		$ 335,343	$ 335,343

Business Combinations - Schedul

Business Combinations - Schedule of unaudited pro forma results (Details) - Ticketfly - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Revenue	$ 1,222,452	$ 975,712
Net loss	$ (210,111)	$ (58,195)

Business Combinations - Summa53

Business Combinations - Summary of the allocation of estimated fair values of net assets acquired including related estimated useful lives (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016	Oct. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 303,875	$ 306,691		$ 0
Ticketfly
Business Acquisition [Line Items]
Tangible assets acquired, net	27,640
Deferred tax liability	(1,738)		$ (1,738)
Net assets acquired	102,702
Goodwill	232,641		232,641
Total	335,343		$ 335,343
Ticketfly | FCC license—broadcast radio
Business Acquisition [Line Items]
Estimated fair value	0
Ticketfly | Customer relationships - clients
Business Acquisition [Line Items]
Estimated fair value	$ 37,300
Estimated useful life in years	8 years
Ticketfly | Developed technology
Business Acquisition [Line Items]
Estimated fair value	$ 28,100
Estimated useful life in years	5 years
Ticketfly | Tradename
Business Acquisition [Line Items]
Estimated fair value	$ 10,400
Estimated useful life in years	8 years
Ticketfly | Customer relationships - users
Business Acquisition [Line Items]
Estimated fair value	$ 1,000
Estimated useful life in years	2 years
Rdio
Business Acquisition [Line Items]
Tangible assets acquired, net	$ 1,969
Deferred tax liability	0
Net assets acquired	29,369
Goodwill	48,131
Total	77,500
Rdio | FCC license—broadcast radio
Business Acquisition [Line Items]
Estimated fair value	0
Rdio | Customer relationships - clients
Business Acquisition [Line Items]
Estimated fair value	0
Rdio | Developed technology
Business Acquisition [Line Items]
Estimated fair value	$ 26,400
Rdio | Developed technology | Minimum
Business Acquisition [Line Items]
Estimated useful life in years	2 years
Rdio | Developed technology | Maximum
Business Acquisition [Line Items]
Estimated useful life in years	5 years
Rdio | Tradename
Business Acquisition [Line Items]
Estimated fair value	$ 1,000
Estimated useful life in years	3 years
Rdio | Customer relationships - users
Business Acquisition [Line Items]
Estimated fair value	$ 0
Other
Business Acquisition [Line Items]
Tangible assets acquired, net	(490)
Deferred tax liability	(49)
Net assets acquired	2,464
Goodwill	23,103
Total	25,567
Other | FCC license—broadcast radio
Business Acquisition [Line Items]
Estimated fair value	193
Other | Customer relationships - clients
Business Acquisition [Line Items]
Estimated fair value	0
Other | Developed technology
Business Acquisition [Line Items]
Estimated fair value	$ 1,550
Estimated useful life in years	4 years
Other | Tradename
Business Acquisition [Line Items]
Estimated fair value	$ 320
Estimated useful life in years	2 years
Other | Customer relationships - users
Business Acquisition [Line Items]
Estimated fair value	$ 940
Estimated useful life in years	2 years

Goodwill and Other Intangible54

Goodwill and Other Intangible Assets - Schedule of changes in the carrying amount of goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Goodwill
Beginning balance	$ 303,875	$ 0
Goodwill resulting from business combination and purchase price adjustments	2,816	303,875
Ending balance	$ 306,691	$ 303,875

Goodwill and Other Intangible55

Goodwill and Other Intangible Assets - Summary of gross carrying amounts and accumulated amortization of intangibles (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Finite-lived intangible assets
Gross Carrying Amount	$ 115,266	$ 115,040
Accumulated Amortization	(25,034)	(4,488)
Net Carrying Value	90,232	110,552
Total intangible assets, Gross Carrying Amount	115,459	115,233
Total intangible assets, Accumulated Amortization	(25,034)	(4,488)
Total intangible assets, Net Carrying Value	90,425	110,745
FCC license—broadcast radio
Indefinite-lived intangible assets
Indefinite-lived intangible assets	193	193
Patents
Finite-lived intangible assets
Gross Carrying Amount	8,030	8,030
Accumulated Amortization	(2,556)	(1,824)
Net Carrying Value	5,474	6,206
Total intangible assets, Accumulated Amortization	(2,556)	(1,824)
Developed technology
Finite-lived intangible assets
Gross Carrying Amount	56,162	56,050
Accumulated Amortization	(13,599)	(1,265)
Net Carrying Value	42,563	54,785
Total intangible assets, Accumulated Amortization	(13,599)	(1,265)
Customer relationships - clients
Finite-lived intangible assets
Gross Carrying Amount	37,399	37,300
Accumulated Amortization	(5,487)	(777)
Net Carrying Value	31,912	36,523
Total intangible assets, Accumulated Amortization	(5,487)	(777)
Customer relationships - users
Finite-lived intangible assets
Gross Carrying Amount	1,940	1,940
Accumulated Amortization	(1,288)	(318)
Net Carrying Value	652	1,622
Total intangible assets, Accumulated Amortization	(1,288)	(318)
Trade names
Finite-lived intangible assets
Gross Carrying Amount	11,735	11,720
Accumulated Amortization	(2,104)	(304)
Net Carrying Value	9,631	11,416
Total intangible assets, Accumulated Amortization	$ (2,104)	$ (304)

Goodwill and Other Intangible56

Goodwill and Other Intangible Assets - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense of intangible assets	$ 20.5	$ 3.4	$ 0.7

Goodwill and Other Intangible57

Goodwill and Other Intangible Assets - Schedule of future amortization expense related to finite-lived intangible assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
2,017	$ 20,116
2,018	17,654
2,019	17,129
2,020	15,896
2,021	6,690
Thereafter	12,747
Net Carrying Value	$ 90,232	$ 110,552

Debt Instruments - Schedule of

Debt Instruments - Schedule of long-term debt (Details) - USD ($)	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015	Dec. 09, 2015
Debt Instrument [Line Items]
Unamortized discount on long-term debt	$ (92,753,000)		$ (110,423,000)
Long-term debt, net	342,247,000		234,577,000
Line of credit
Debt Instrument [Line Items]
Credit facility	90,000,000		0
Interest rate (percent)		3.81%
Convertible debt | 1.75% convertible senior notes due 2020
Debt Instrument [Line Items]
1.75% convertible senior notes due 2020	$ 345,000,000		$ 345,000,000
Interest rate (percent)	1.75%			1.75%

Debt Instruments - Narrative (D

Debt Instruments - Narrative (Details) $ / shares in Units, shares in Millions	Dec. 09, 2015USD ($)day$ / shares$ / unitshares	Sep. 30, 2016USD ($)	Dec. 31, 2015USD ($)	May 31, 2011USD ($)	Dec. 31, 2016USD ($)$ / shares	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Debt Instruments
Payments for capped call transactions					$ 0	$ 43,160,000	$ 0
Debt instrument, conversion price (in dollars per share) | $ / shares	$ 16.42
Share price (in dollars per share) | $ / shares					$ 13.04
Line of credit
Debt Instruments
Interest rate (percent)		3.81%
Maximum borrowings available			$ 120,000,000			120,000,000
Credit facility financial covenant, minimum liquidity			10,000,000	$ 5,000,000
Line of credit facility, unused capacity, commitment fee percentage				0.375%
Borrowings from credit facility		$ 90,000,000
Credit facility			0		$ 90,000,000	0
Available borrowing capacity			118,900,000		$ 28,800,000	118,900,000
Debt issuance cost			400,000			400,000
Credit facility term remaining					2 years
Amortization of debt issuance costs					$ 400,000	200,000	$ 200,000
Line of credit | Minimum
Debt Instruments
Interest rate (percent)					2.00%
Line of credit | Maximum
Debt Instruments
Interest rate (percent)					2.25%
Line of credit | Alternate base rate | Minimum
Debt Instruments
Margin				1.00%
Line of credit | Alternate base rate | Maximum
Debt Instruments
Margin				1.25%
Line of credit | LIBOR | Minimum
Debt Instruments
Margin				2.00%
Line of credit | LIBOR | Maximum
Debt Instruments
Margin				2.25%
Letter of credit
Debt Instruments
Maximum borrowings available					$ 15,000,000
Outstanding amount			$ 1,100,000		$ 1,200,000	$ 1,100,000
Convertible debt | Notes
Debt Instruments
Aggregate principal amount	$ 345,000,000
Interest rate (percent)	1.75%				1.75%
Net proceeds from sale of debt	$ 336,500,000
Payments for capped call transactions	$ 43,200,000
Debt instrument, conversion ratio	0.060905
Debt instrument, conversion price (in dollars per share) | $ / shares	$ 16.42
Debt instrument, redemption price, percentage of principal	100.00%
Debt conversion, maximum number of shares of common stock convertible by notes (shares) | shares	27.3
Value of debt	$ 233,500,000				$ 357,200,000
Carrying amount of equity component reported in additional paid-in-capital	103,000,000
Debt fees and expenses	$ 2,600,000
Initial cap price (in dollars per share) | $ / unit	25.26
Convertible debt | Notes | Redemption, period 1
Debt Instruments
Debt instrument, threshold percentage of stock price trigger	130.00%
Debt instrument, threshold trading days | day	20
Debt instrument, threshold consecutive trading days	30 days
Debt instrument, threshold notice trading days | day	5
Convertible debt | Notes | Redemption, period 2
Debt Instruments
Debt instrument, threshold percentage of stock price trigger	130.00%
Debt instrument, threshold trading days | day	20
Debt instrument, threshold consecutive trading days	30 days
Convertible debt | Notes | Redemption, period 3
Debt Instruments
Debt instrument, threshold note trading days | day	5
Debt instrument, threshold principle amount of note trigger	$ 1,000
Debt instrument, threshold consecutive note trading days	10 days
Debt instrument, threshold percentage of note price trigger	98.00%

Debt Instruments - Summary of t

Debt Instruments - Summary of the effective interest rate, contractually stated interest expense and costs related to amortization of discount for the Notes (Details) - Convertible debt - Notes - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Effective interest rate	10.18%	10.18%
Contractually stated interest expense	$ 6,046	$ 369
Amortization of discount	$ 18,315	$ 1,084

Commitments and Contingencies -

Commitments and Contingencies - Schedule of future minimum lease payments under operating leases (Details) $ in Thousands	Dec. 31, 2016USD ($)
Future Minimum Lease Payments
2,017	$ 26,035
2,018	25,023
2,019	24,521
2,020	21,996
2,021	13,778
Thereafter	43,860
Total	155,213
Future Minimum Sublease Income
2,017	1,848
2,018	907
2,019	487
2,020	501
2,021	430
Thereafter	0
Total	$ 4,173

Commitments and Contingencies62

Commitments and Contingencies - Narrative (Details) - USD ($)	1 Months Ended	3 Months Ended								9 Months Ended	12 Months Ended
	Oct. 31, 2015	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Rent expenses											$ 20,500,000	$ 12,200,000	$ 8,600,000
Deferred rent		$ 27,600,000				$ 23,900,000					27,600,000	23,900,000
Content acquisition costs											163,800,000
Amortization of prepaid content acquisition costs											117,500,000
Total future minimum guarantee payments		763,000,000									763,000,000
Future minimum guarantee commitments to be paid this year		355,600,000									355,600,000
Loss Contingencies [Line Items]
Litigation settlement, expense		$ 212,122,000	$ 174,334,000	$ 176,633,000	$ 171,264,000	$ 142,933,000	$ 211,272,000	$ 130,134,000	$ 126,023,000		734,353,000	610,362,000	$ 446,377,000
Pre-1972 Copyright Litigation
Loss Contingencies [Line Items]
Settlement	$ 90,000,000
Expenses											$ 24,600,000
Pre-1972 Copyright Litigation | Cost of revenue - content acquisition costs
Loss Contingencies [Line Items]
Litigation settlement, expense												$ 65,400,000
Pre-1972 Copyright Litigation | Cost of revenue - content acquisition costs
Loss Contingencies [Line Items]
Litigation settlement, expense										$ 57,900,000

Provision for Income Taxes - Sc

Provision for Income Taxes - Schedule of loss before provision for income taxes by jurisdiction (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Jurisdiction
Domestic	$ (328,414)	$ (163,460)	$ (24,230)
Foreign	(14,792)	(7,751)	(5,592)
Loss before benefit from (provision for) income taxes	$ (343,206)	$ (171,211)	$ (29,822)

Provision for Income Taxes - 64

Provision for Income Taxes - Schedule of provision for income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current
Federal	$ 0	$ 0	$ 0
State and local	26	9	353
International	443	214	231
Total current income tax expense	469	223	584
Deferred
Federal	(96,852)	(17,943)	(9,996)
State and local	(10,750)	(2,174)	(6,238)
International	(1,032)	0	0
Valuation allowance	107,937	18,344	16,234
Total deferred income tax expense (benefit)	(697)	(1,773)	0
Total provision for (benefit from) income taxes	$ (228)	$ (1,550)	$ 584

Provision for Income Taxes - Na

Provision for Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Decrease in income tax provision	$ 1,300,000
Release of valuation allowance as a result of acquisitions	1,900,000	$ 1,800,000
Operating Loss Carryforwards [Line Items]
Increase in valuation allowance	$ (108,000,000)
Document Period End Date	Dec. 31, 2016
Unrecognized tax benefits	$ 9,412,000	6,864,000	$ 5,793,000
Income tax, penalties and interest expense	0	$ 0	$ 0
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	818,500,000
Tax credit carryforwards	14,800,000
Net operating loss carryforwards recognized through additional paid in capital, if realized	377,300,000
Federal | Acquisitions
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	62,400,000
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	552,200,000
Tax credit carryforwards that do not expire	15,800,000
Tax credit carryforwards that will expire beginning in 2024	5,700,000
State | Acquisitions
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	41,300,000
Foreign
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	8,200,000
Foreign | Acquisitions
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 3,800,000

Provision for Income Taxes - 66

Provision for Income Taxes - Schedule of reconciliation of the statutory federal rate and effective tax rate (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of the statutory federal rate and the company's effective tax rate
U.S. federal taxes at statutory rate	34.00%	34.00%	34.00%
State taxes, net of federal benefit	0.00%	0.00%	(1.00%)
Permanent differences	2.00%	3.00%	4.00%
Foreign rate differential	(2.00%)	(1.00%)	(7.00%)
Federal and state credits, net of reserve	2.00%	2.00%	11.00%
Impact of acquired DTAs and DTLs	1.00%	1.00%	0.00%
Change in valuation allowance	(32.00%)	(33.00%)	(55.00%)
Change in rate	0.00%	(1.00%)	6.00%
Deferred adjustments	(5.00%)	(4.00%)	6.00%
Effective tax rate	0.00%	1.00%	(2.00%)

Provision for Income Taxes - 67

Provision for Income Taxes - Schedule of major components of deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets
Net operating loss carryforwards	$ 167,961	$ 91,658
Tax credit carryforwards	21,111	14,204
Allowances and other	27,729	21,802
Stock options	32,986	29,927
Depreciation and amortization	3,704	0
Total deferred tax assets	253,491	157,591
Valuation allowance	(200,797)	(92,772)
Total deferred tax assets, net of valuation allowance	52,694	64,819
Deferred tax liabilities
Convertible debt	(31,592)	(37,580)
Depreciation and amortization	(22,360)	(27,252)
Total deferred tax liabilities	(53,952)	(64,832)
Net deferred tax assets (liabilities)	$ (1,258)	$ (13)

Provision for Income Taxes - 68

Provision for Income Taxes - Schedule of reconciliation of beginning and ending amounts of unrecognized tax benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, beginning balance	$ 6,864	$ 5,793
Increases related to tax positions taken during a prior year	0	0
Decreases related to tax positions taken during a prior year	(13)	(74)
Increases related to tax positions taken during the current year	2,561	1,145
Unrecognized tax benefits, ending balance	$ 9,412	$ 6,864

Stock-based Compensation Plan69

Stock-based Compensation Plans and Awards - Stock compensation plans narrative (Details) - USD ($)	Jun. 14, 2011	Dec. 31, 2013	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock previously reserved but unissued (in shares)			10,409,095	15,042,664
Employee stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for the issuance (in shares)		4,000,000
Percentage of payroll deductions of eligible employees to purchase shares of common stock (up to)		15.00%
Maximum amount of payroll deductions eligible employees can use per calendar year		$ 25,000
Offering period		6 months
Exercise price as a percentage of the fair market value of the common stock		85.00%
2011 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for the issuance (in shares)	12,000,000
Annual fixed increase alternative, increase in shares of common stock reserved for issuance (in shares)	10,000,000
Annual percentage increase alternative, increase in common stock reserved for issuance as a percentage of common stock outstanding	4.00%
2011 Plan | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
2011 Plan | Stock options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration term (no more than)	10 years
2004 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock previously reserved but unissued (in shares)	1,506,424

Stock-based Compensation Plan70

Stock-based Compensation Plans and Awards - Schedule of shares available for grant and activity (Details) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Shares Available for Grant
Beginning balance (in shares)	15,042,664
Additional shares authorized (in shares)	8,998,816
ESPP shares issued (in shares)	(1,254,910)
Options forfeited (in shares)	1,592,289
Share adjustment (in shares)	614,967
Ending balance (in shares)	10,409,095	15,042,664
Restricted stock units
Shares Available for Grant
Units granted (in shares)	(15,522,398)
Forfeited (in shares)	2,587,203
Performance stock units
Shares Available for Grant
Units granted (in shares)	(1,835,250)	0	0
Forfeited (in shares)	0
MSUs
Shares Available for Grant
Units granted (in shares)	0	(776,000)
Forfeited (in shares)	185,714
Equity Awards
Shares Available for Grant
Beginning balance (in shares)	11,723,327
Additional shares authorized (in shares)	8,998,816
ESPP shares issued (in shares)	0
Options forfeited (in shares)	1,592,289
Share adjustment (in shares)	614,967
Ending balance (in shares)	8,344,668	11,723,327
Equity Awards | Restricted stock units
Shares Available for Grant
Units granted (in shares)	(15,522,398)
Forfeited (in shares)	2,587,203
Equity Awards | Performance stock units
Shares Available for Grant
Units granted (in shares)	(1,835,250)
Equity Awards | MSUs
Shares Available for Grant
Forfeited (in shares)	185,714
ESPP
Shares Available for Grant
Beginning balance (in shares)	3,319,337
Additional shares authorized (in shares)	0
ESPP shares issued (in shares)	(1,254,910)
Options forfeited (in shares)	0
Share adjustment (in shares)	0
Ending balance (in shares)	2,064,427	3,319,337
ESPP | Restricted stock units
Shares Available for Grant
Units granted (in shares)	0
Forfeited (in shares)	0
ESPP | Performance stock units
Shares Available for Grant
Units granted (in shares)	0
ESPP | MSUs
Shares Available for Grant
Forfeited (in shares)	0

Stock-based Compensation Plan71

Stock-based Compensation Plans and Awards - Schedule of assumptions used for determining the per-share fair value of shares granted under the ESPP (Details) - Black-Scholes option pricing model - Employee stock	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (in years)	15 days	15 days	15 days
Risk-free interest rate (as a percent)	0.36%	0.12%	0.06%
Expected volatility (as a percent)	44.00%	52.00%	42.00%
Expected dividend yield (as a percent)	0.00%	0.00%	0.00%

Stock-based Compensation Plan72

Stock-based Compensation Plans and Awards - Employee stock purchase plan narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 138,458	$ 111,645	$ 87,055
ESPP shares issued (in shares)	1,254,910
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ESPP shares issued (in shares)	1,254,910
ESPP | Employee stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amounts withheld in contributions from employees	$ 9,700	7,600	6,400
Stock-based compensation expense	$ 3,400	$ 3,300	$ 2,100
ESPP shares issued (in shares)	1,254,910	538,398	149,378
Weighted average purchase price (in dollars per share)	$ 6.76	$ 17.80	$ 23.95

Stock-based Compensation Plan73

Stock-based Compensation Plans and Awards - Schedule of stock option activity (Details) - Stock options - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Outstanding Stock Options
Balance at the beginning of the period (in shares)	12,815,891
Granted (in shares)	0
Exercised (in shares)	(1,588,781)
Forfeited (in shares)	(1,790,730)
Balance at the end of the period (in shares)	9,436,380	12,815,891
Vested and exercisable at the end of the period (in shares)	8,108,519
Expected to vest at the end of the period (in shares)	1,241,887
Weighted-Average Exercise Price
Balance at the beginning of the period (in dollars per share)	$ 7.15
Granted (in dollars per share)	0
Exercised (in dollars per share)	2.18
Forfeited (in dollars per share)	19.02
Balance at the end of the period (in dollars per share)	5.74	$ 7.15
Vested and exercisable at the end of the period (in dollars per share)	5.40
Expected to vest at the end of the period (in dollars per share)	$ 7.94
Weighted-Average Remaining Contractual Term (in years)
Outstanding at the beginning of the period	14 days	1 year 1 month 2 days
Outstanding at the end of the period	14 days	1 year 1 month 2 days
Vested and exercisable at the end of the period	9 days
Expected to vest at the end of the period	1 year 6 months
Aggregate Intrinsic Value
Aggregate intrinsic value beginning of the period	$ 77,752	$ 101,151
Aggregate intrinsic value end of the period	77,752	$ 101,151
Vested and exercisable at the end of the period	68,656
Expected to vest at the end of the period	$ 8,403
Fair value per share of common stock (in dollars per share)	$ 13.04	$ 13.41

Stock-based Compensation Plan74

Stock-based Compensation Plans and Awards - Schedule of assumptions used for estimating the per-share fair value of stock options (Details) - Black-Scholes option pricing model - Stock options	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (in years)	6 years 29 days	6 years 29 days
Risk-free interest rate, minimum (as a percent)	1.75%	1.71%
Risk-free interest rate, maximum (as a percent)	1.92%	1.93%
Expected volatility, minimum (as a percent)	49.00%	58.00%
Expected volatility, maximum (as a percent)	50.00%	59.00%
Expected dividend yield (as a percent)	0.00%	0.00%

Stock-based Compensation Plan75

Stock-based Compensation Plans and Awards - Stock options narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 138,458	$ 111,645	$ 87,055
Service period over which company recognizes stock-based compensation (years)	4 years
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 13,800	$ 10,700	$ 14,700
Weighted-average fair value of stock option granted (in dollars per share)	$ 0	$ 9.08	$ 19.74
Aggregate intrinsic value of options exercised	$ 17,300	$ 9,500	$ 169,200
Total fair value of options vested	10,200	$ 17,600	$ 16,500
Employee stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 11,200
Service period over which company recognizes stock-based compensation (years)	1 year 6 months 18 days

Stock-based Compensation Plan76

Stock-based Compensation Plans and Awards - Restricted stock units narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 138,458	$ 111,645	$ 87,055
Service period over which company recognizes stock-based compensation (years)	4 years
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Stock-based compensation expense	$ 124,300	$ 96,100	$ 69,900
Compensation cost not yet recognized	$ 251,000
Service period over which company recognizes stock-based compensation (years)	2 years 8 months 23 days

Stock-based Compensation Plan77

Stock-based Compensation Plans and Awards - Schedule of activities for RSUs, MSUs and PSUs (Details) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
RSUs
Number
Unvested at the beginning of the period (in shares)	17,272,085
Granted (in shares)	15,522,398
Vested (in shares)	(7,666,647)
Forfeited (in shares)	(2,723,419)
Unvested at the end of the period (in shares)	22,404,417	17,272,085
Expected to vest at end of the period (in shares)	20,325,998
Weighted-Average Grant Date Fair Value
Unvested at the beginning of the period (in dollars per share)	$ 17.91
Granted (in dollars per share)	10.21
Vested (in dollars per share)	16.94
Forfeited (in dollars per share)	14.84
Unvested at the end of the period (in dollars per share)	13.26	$ 17.91
Expected to vest at end of the period (in dollars per share)	$ 13.33
MSUs
Number
Unvested at the beginning of the period (in shares)	776,000
Granted (in shares)	0	776,000
Vested (in shares)	(56,903)
Forfeited (in shares)	(185,714)
Unvested at the end of the period (in shares)	533,383	776,000
Expected to vest at end of the period (in shares)	398,831
Weighted-Average Grant Date Fair Value
Unvested at the beginning of the period (in dollars per share)	$ 5.60
Granted (in dollars per share)	0
Vested (in dollars per share)	2.57
Forfeited (in dollars per share)	5.91
Unvested at the end of the period (in dollars per share)	5.49	$ 5.60
Expected to vest at end of the period (in dollars per share)	$ 5.52
PSUs
Number
Unvested at the beginning of the period (in shares)	0
Granted (in shares)	1,835,250	0	0
Vested (in shares)	0
Forfeited (in shares)	0
Unvested at the end of the period (in shares)	1,835,250	0
Expected to vest at end of the period (in shares)	1,658,031
Weighted-Average Grant Date Fair Value
Unvested at the beginning of the period (in dollars per share)	$ 0
Granted (in dollars per share)	5.33
Vested (in dollars per share)	0
Forfeited (in dollars per share)	0
Unvested at the end of the period (in dollars per share)	5.33	$ 0
Expected to vest at end of the period (in dollars per share)	$ 5.32

Stock-based Compensation Plan78

Stock-based Compensation Plans and Awards - MSUs and PSUs narrative (Details)	1 Months Ended	7 Months Ended	12 Months Ended
	Mar. 31, 2015performance_period	Oct. 31, 2016$ / shares	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)shares	Dec. 31, 2014USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			$ 138,458,000	$ 111,645,000	$ 87,055,000
Service period over which company recognizes stock-based compensation (years)			4 years
MSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Requisite service period	3 years
Number of performance periods used for measurement | performance_period	3
Total stockholder return, duration period	90 days
Performance multiplier, percentage point decrease	3.00%
Performance multiplier, percentage point increase	2.00%
Grants in period (in shares) | shares			0	776,000
Total grant date fair value of stock options vested				$ 4,300,000
Stock-based compensation expense			$ 700,000	$ 1,500,000	$ 0
Compensation cost not yet recognized			$ 800,000
Service period over which company recognizes stock-based compensation (years)			1 year 1 month 17 days
MSUs | One-Year Performance Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percent	33.33%			22.00%
Decrease in shareholder return (percent)				26.00%
MSUs | Two-Year Performance Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percent	33.33%		0.00%
Decrease in shareholder return (percent)			48.00%
MSUs | Maximum | One and Two-Year Performance Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance multiplier	100.00%
MSUs | Maximum | Three-Year Performance Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance multiplier	200.00%
MSUs | Maximum | Two-Year Performance Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance multiplier	100.00%
PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Requisite service period		4 years
Total stockholder return, duration period		90 days
Grants in period (in shares) | shares			1,835,250	0	0
Total grant date fair value of stock options vested			$ 9,800,000
Stock-based compensation expense			$ 3,800,000	$ 0	$ 0
Service period over which company recognizes stock-based compensation (years)			3 years 1 month 28 days
Unrecognized compensation cost			$ 5,800,000
PSUs | One-Year Performance Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Requisite service period		1 year
Vesting percent		25.00%
PSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
90 Day trailing stock price to vest (usd per share) | $ / shares		$ 20

Stock-based Compensation Plan79

Stock-based Compensation Plans and Awards - Schedule of stock-based compensation expenses related to all employee and non-employee stock-based awards (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 138,458	$ 111,645	$ 87,055
Cost of revenue—Other
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	6,108	5,531	4,414
Cost of revenue—Ticketing service
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	188	40	0
Product development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	30,975	23,671	17,546
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	58,118	52,747	42,165
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 43,069	$ 29,656	$ 22,930

Stock-based Compensation Plan80

Stock-based Compensation Plans and Awards - Stock-based compensation expense narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Capitalized cost related to internal use software and website development costs	$ 7.5
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Accelerated awards in connection with executive severance	$ 8.7

Common Stock and Net Loss Per81

Common Stock and Net Loss Per Share - Narrative (Details)	12 Months Ended
	Dec. 31, 2016vote	Dec. 09, 2015$ / shares
Earnings Per Share [Abstract]
Number of voting rights per share | vote	1
Debt Instrument [Line Items]
Debt instrument, conversion price (in dollars per share)		$ 16.42
Convertible debt | 1.75% convertible senior notes due 2020
Debt Instrument [Line Items]
Interest rate (percent)	1.75%	1.75%
Debt instrument, conversion price (in dollars per share)		$ 16.42

Common Stock and Net Loss Per82

Common Stock and Net Loss Per Share - Schedule of the computation of historical basic and diluted net loss per share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Numerator
Net loss	$ (90,009)	$ (61,534)	$ (76,333)	$ (115,102)	$ (19,409)	$ (85,930)	$ (16,065)	$ (48,257)	$ (342,978)	$ (169,661)	$ (30,406)
Denominator
Weighted-average common shares outstanding used in computing basic and diluted net loss per share (in shares)									230,693	213,790	205,273
Net loss per share, basic and diluted (in dollars per share)									$ (1.49)	$ (0.79)	$ (0.15)

Common Stock and Net Loss Per83

Common Stock and Net Loss Per Share - Schedule of potential common shares that were excluded from the computation of diluted net loss per share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents (in shares)	34,209	30,864	22,004
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents (in shares)	9,436	12,816	10,980
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents (in shares)	22,404	17,272	11,024
Performance stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents (in shares)	2,369	776	0

Segment Data and Revenue by G84

Segment Data and Revenue by Geographic Area - Narrative (Details)	12 Months Ended
	Dec. 31, 2016segment
Segment Reporting [Abstract]
Number of operating segments	2
Number of reportable segments	2

Segment Data and Revenue by G85

Segment Data and Revenue by Geographic Area - Schedule of Reportable Segments Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Revenues	$ 392,598	$ 351,901	$ 343,022	$ 297,305	$ 336,157	$ 311,562	$ 285,560	$ 230,764	$ 1,384,826	$ 1,164,043	$ 920,802
Cost of revenues	256,080	215,208	216,725	206,909	172,222	232,686	150,177	142,256	894,922	697,341	508,004
Gross profit	136,518	136,693	126,297	90,396	163,935	78,876	135,383	88,508	489,904	466,702	412,798
Operating and other expenses									(832,882)	(636,363)
Net loss	$ (90,009)	$ (61,534)	$ (76,333)	$ (115,102)	$ (19,409)	$ (85,930)	$ (16,065)	$ (48,257)	(342,978)	(169,661)	(30,406)
Depreciation and amortization									14,396	8,180
United States
Segment Reporting Information [Line Items]
Revenues									1,366,330	1,155,210	917,008
International
Segment Reporting Information [Line Items]
Revenues									18,496	8,833	$ 3,794
Pandora
Segment Reporting Information [Line Items]
Revenues									1,298,276	1,153,876
Cost of revenues									835,642	690,220
Gross profit									462,634	463,656
Depreciation and amortization									8,667	7,231
Ticketfly
Segment Reporting Information [Line Items]
Revenues									86,550	10,167
Cost of revenues									59,280	7,121
Gross profit									27,270	3,046
Depreciation and amortization									$ 5,729	$ 949

Selected Quarterly Financial 86

Selected Quarterly Financial Data (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Total revenue	$ 392,598	$ 351,901	$ 343,022	$ 297,305	$ 336,157	$ 311,562	$ 285,560	$ 230,764	$ 1,384,826	$ 1,164,043	$ 920,802
Cost of revenue
Cost of revenue—Content acquisition costs	212,122	174,334	176,633	171,264	142,933	211,272	130,134	126,023	734,353	610,362	446,377
Cost of revenue—Other	29,901	25,556	24,833	20,999	22,168	21,414	20,043	16,233	101,289	79,858	61,627
Cost of revenue—Ticketing service	14,057	15,318	15,259	14,646	7,121	0	0	0	59,280	7,121	0
Total cost of revenue	256,080	215,208	216,725	206,909	172,222	232,686	150,177	142,256	894,922	697,341	508,004
Gross profit	136,518	136,693	126,297	90,396	163,935	78,876	135,383	88,508	489,904	466,702	412,798
Operating expenses
Product development	38,325	33,657	33,808	35,846	28,115	21,849	18,742	15,875	141,636	84,581	53,153
Sales and marketing	133,546	116,475	123,812	117,622	112,574	107,286	94,035	84,274	491,455	398,169	277,330
General and administrative	46,946	41,768	40,562	46,296	42,774	35,603	38,812	36,754	175,572	153,943	112,443
Total operating expenses	218,817	191,900	198,182	199,764	183,463	164,738	151,589	136,903	808,663	636,693	442,926
Loss from operations	(82,299)	(55,207)	(71,885)	(109,368)	(19,528)	(85,862)	(16,206)	(48,395)	(318,759)	(169,991)	(30,128)
Net loss	$ (90,009)	$ (61,534)	$ (76,333)	$ (115,102)	$ (19,409)	$ (85,930)	$ (16,065)	$ (48,257)	$ (342,978)	$ (169,661)	$ (30,406)
Net loss per share, basic (in dollars per share)	$ (0.38)	$ (0.27)	$ (0.33)	$ (0.51)	$ (0.09)	$ (0.40)	$ (0.08)	$ (0.23)
Net loss per share, diluted (in dollars per share)	$ (0.38)	$ (0.27)	$ (0.33)	$ (0.51)	$ (0.09)	$ (0.40)	$ (0.08)	$ (0.23)

Subsequent Event (Details)

Subsequent Event (Details) - Subsequent Event $ in Millions	Jan. 12, 2017USD ($)
Subsequent Event
Reduction in force (percent)	7.00%
Employee severance and benefits costs | Minimum
Subsequent Event
Expected cash expenditures	$ 5
Expected total reduction in force costs	4
Employee severance and benefits costs | Maximum
Subsequent Event
Expected cash expenditures	7
Expected total reduction in force costs	$ 6