Fitbit 10-Q 7 Aug 15 2015 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	6 Months Ended
	Jun. 30, 2015	Jul. 31, 2015
Entity Information [Line Items]
Entity Registrant Name	FITBIT INC
Entity Central Index Key	1,447,599
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q2
Amendment Flag	false
Common Class A [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		42,061,250
Common Class B [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		164,818,603

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 461,276	$ 195,626
Accounts receivable, net	252,023	238,859
Inventories	186,870	115,072
Deferred tax assets	49,625	33,555
Prepaid expenses and other current assets	18,163	13,614
Total current assets	967,957	596,726
Property and equipment, net	30,945	26,435
Goodwill	22,157	0
Intangible assets, net	13,263	0
Other assets	12,308	9,890
Total assets	1,046,630	633,051
Current liabilities:
Fitbit Force recall reserve	12,894	22,476
Accounts payable	193,594	195,666
Accrued liabilities	79,618	70,940
Deferred revenue	21,346	9,009
Income taxes payable	795	30,631
Long-term debt, current portion	0	132,589
Total current liabilities	308,247	461,311
Redeemable convertible preferred stock warrant liability	0	15,797
Other liabilities	15,031	12,867
Total liabilities	$ 323,278	$ 489,975
Commitments and contingencies (Note 7)
Redeemable convertible preferred stock, $0.0001 par value, no shares and 144,528,912 shares authorized as of June 30, 2015 and December 31, 2014, respectively; no shares and 139,851,483 shares issued and outstanding as of June 30, 2015 and December 31, 2014, respectively	$ 0	$ 67,814
Stockholders’ equity:
Additional paid-in capital	590,290	7,979
Accumulated other comprehensive income	122	37
Retained earnings	132,920	67,242
Total stockholders’ equity	723,352	75,262
Total liabilities, redeemable convertible preferred stock, and stockholders’ equity	1,046,630	633,051
Common Class A [Member]
Stockholders’ equity:
Common stock	4	0
Common Class B [Member]
Stockholders’ equity:
Common stock	$ 16	$ 4

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2015	Dec. 31, 2014
Redeemable convertible preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Redeemable convertible preferred stock authorized (in shares)	0	144,528,912
Redeemable convertible preferred stock issued (in shares)	0	139,851,483
Redeemable convertible preferred stock outstanding (in shares)	0	139,851,483
Common stock authorized (in shares)		230,400,000
Common stock issued (in shares)		40,875,583
Common stock outstanding (in shares)		40,875,583
Common Class A [Member]
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock authorized (in shares)	600,000,000	0
Common stock issued (in shares)	42,061,250	0
Common stock outstanding (in shares)	42,061,250	0
Common Class B [Member]
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock authorized (in shares)	350,000,000	230,400,000
Common stock issued (in shares)	164,625,960	40,875,583
Common stock outstanding (in shares)	164,625,960	40,875,583

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Revenue	$ 400,412	$ 113,572	$ 737,166	$ 222,387
Cost of revenue	212,870	55,183	380,415	119,229
Gross profit	187,542	58,389	356,751	103,158
Operating expenses:
Research and development	30,492	11,809	52,918	20,897
Sales and marketing	69,690	13,311	113,557	24,584
General and administrative	14,648	7,443	27,629	16,060
Change in contingent consideration	(7,704)	0	(7,704)	0
Total operating expenses	107,126	32,563	186,400	61,541
Operating income	80,416	25,826	170,351	41,617
Interest expense, net	(379)	(452)	(846)	(861)
Other expense, net	(45,308)	(3,687)	(58,385)	(4,906)
Income before income taxes	34,729	21,687	111,120	35,850
Income tax expense	17,048	6,934	45,442	12,225
Net income	17,681	14,753	65,678	23,625
Less: noncumulative dividends to preferred stockholders	(1,212)	(1,327)	(2,526)	(2,640)
Less: undistributed earnings to participating securities	(11,244)	(10,423)	(45,907)	(16,293)
Net income attributable to common stockholders—basic	5,225	3,003	17,245	4,692
Add: adjustments for undistributed earnings to participating securities	1,862	1,058	7,003	1,618
Net income attributable to common stockholders—diluted	$ 7,087	$ 4,061	$ 24,248	$ 6,310
Net income (loss) per share attributable to common stockholders, basic (in dollars per share)	$ 0.09	$ 0.07	$ 0.35	$ 0.12
Net income (loss) per share attributable to common stockholders, diluted (in dollars per share)	$ 0.07	$ 0.07	$ 0.29	$ 0.11
Shares used to compute net income (loss) per share attributable to common stockholders, basic (in shares)	58,548	40,193	49,922	40,174
Shares used to compute net income (loss) per share attributable to common stockholders, diluted (in shares)	95,190	60,487	82,841	59,983

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income Statement - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 17,681	$ 14,753	$ 65,678	$ 23,625
Other comprehensive income:
Change in foreign currency translation adjustment, net of tax	41	7	85	12
Comprehensive income	$ 17,722	$ 14,760	$ 65,763	$ 23,637

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash Flows from Operating Activities
Net income	$ 65,678	$ 23,625
Adjustments to reconcile net income to net cash provided by operating activities:
Recovery of doubtful accounts	(28)	(51)
Provision for inventory obsolescence	4,537	1,230
Depreciation and amortization	7,519	1,713
Amortization of intangible assets	655	0
Revaluation of redeemable convertible preferred stock warrant liability	56,655	5,194
Amortization of issuance costs and discount on debt	322	216
Stock-based compensation	12,650	975
Change in contingent consideration	(7,704)	0
Deferred income taxes	(20,111)	0
Changes in operating assets and liabilities, net of acquisition:
Accounts receivable	(12,834)	29,548
Inventories	(76,334)	976
Prepaid expenses and other assets	(2,495)	(3,186)
Fitbit Force recall reserve	(9,581)	(25,864)
Accounts payable	(5,561)	(27,107)
Accrued liabilities and other liabilities	8,830	(7,391)
Deferred revenue	11,789	1,914
Income taxes payable	(29,836)	(1,466)
Net cash provided by operating activities	4,151	326
Cash Flows from Investing Activities
Change in restricted cash	0	2,310
Purchase of property and equipment	(11,745)	(6,698)
Acquisitions, net of cash acquired	(11,037)	0
Net cash used in investing activities	(22,782)	(4,388)
Cash Flows from Financing Activities
Net proceeds from initial public offering	420,885	0
Proceeds from issuance of debt and revolving credit facility, net debt discount	160,000	30,000
Repayment of debt	(294,503)	(3,096)
Payment of debt issuance costs	0	(604)
Payments of offering costs	(2,522)	0
Proceeds from exercise of stock options	442	12
Net cash provided by financing activities	284,302	26,312
Net increase in cash and cash equivalents	265,671	22,250
Effect of exchange rate on cash and cash equivalents	(21)	12
Cash and cash equivalents at beginning of period	195,626	81,728
Cash and cash equivalents at end of period	461,276	103,990
Supplemental Disclosure
Cash paid for interest	103	820
Cash paid for income taxes	94,966	13,692
Supplemental Disclosure of Non-Cash Investing and Financing Activity
Conversion of redeemable convertible preferred stock into Class B common stock	67,814	0
Reclassification of redeemable convertible preferred stock warrant liability to additional paid-in capital	72,452	0
Issuance of redeemable convertible preferred stock upon net exercise of redeemable convertible preferred stock warrants	56,678	1,503
Purchase of property and equipment included in accounts payable	2,714	5,711
Deferred offering costs included in accounts payable and accruals	2,711	0
Issuance of common stock in connection with acquisitions	$ 13,317	$ 0

Business Overview

Business Overview	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business Overview	Business Overview Fitbit, Inc. (the “Company”) is transforming the way millions of people around the world achieve their health and fitness goals. The Fitbit platform combines connected health and fitness devices with software and services, including an online dashboard and mobile apps, data analytics, motivational and social tools, personalized insights, and virtual coaching through customized fitness plans and interactive workouts. The Company sells devices through diversified sales channels that include distributors, retailers, a corporate wellness offering, and Fitbit.com. The Company was incorporated in Delaware in 2007. The Company has established wholly-owned subsidiaries globally and its corporate headquarters are located in San Francisco, California. In June 2015, the Company completed its initial public offering (“IPO”) of Class A common stock, in which the Company sold 22,387,500 shares and certain of its stockholders sold 19,673,750 shares, including 5,486,250 shares pursuant to the underwriters’ over-allotment option. The shares were sold at an initial public offering price of $20.00 per share for net proceeds of $420.9 million to the Company, after deducting underwriting discounts and commissions of $26.9 million . Offering costs incurred by the Company were approximately $5.2 million . In addition, in connection with the IPO: • The Company authorized two new classes of common stock— Class A common stock and Class B common stock. All prior periods presented have been updated to reflect the new classes of common stock. The rights of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to ten votes per share. Each share of Class B common stock is convertible at any time at the option of the stockholder into one share of Class A common stock, generally automatically converts into Class A common stock upon a transfer, and has no expiration date. • All shares of the then-outstanding common stock, as well as options to purchase common stock and restricted stock units (“RSUs”), were reclassified into an equivalent number of shares of our Class B common stock. • All 139,851,483 shares of the then-outstanding redeemable convertible preferred stock were converted and reclassified into an equivalent number of shares of our Class B common stock. This resulted in a reclassification of the redeemable convertible preferred stock balance of $67.8 million to additional paid-in capital. • The Company issued 274,992 shares of Series B redeemable convertible preferred stock and 1,210,591 shares of Series C redeemable convertible preferred stock upon the net exercise of redeemable convertible preferred stock warrants, which occurred immediately prior to the completion of its IPO. These shares were sold as Class A common stock in the IPO. In addition, all of the remaining outstanding redeemable convertible preferred stock warrants automatically converted to Class B common stock warrants upon the closing of the IPO. As a result, the Company revalued the warrants as of the completion of the IPO and reclassified the redeemable convertible preferred stock warrant liability balance of $72.5 million to additional paid-in capital. • The Company recorded proceeds of $420.9 million to additional paid-in capital and reclassified $5.2 million of deferred offering costs previously recorded in other current assets as an offset to the proceeds from the IPO.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies The accompanying condensed consolidated financial statements are unaudited. The condensed consolidated balance sheet at December 31, 2014 has been derived from the audited financial statements of the Company. The accompanying condensed financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) for interim financial information, and in management’s opinion, includes all adjustments, consisting of only normal recurring adjustments, necessary for the fair statement of the Company’s financial position, its results of operations, and cash flows for the interim periods presented. The results of operations for the three and six months ended June 30, 2015 are not necessarily indicative of the results to be expected for the full fiscal year or any other period. The accompanying condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto contained in the Company’s prospectus filed pursuant to Rule 424(b) under the Securities Act of 1933, as amended, with the Securities and Exchange Commission (“SEC”) on June 18, 2015. There have been no significant changes in the Company’s accounting policies from those disclosed in its prospectus filed with the SEC on June 18, 2015. Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany transactions and balances have been eliminated. Stock Split In May 2015, the Company effected a 3 -for- 2 stock split of all outstanding shares of the Company’s capital stock, including common stock and redeemable convertible preferred stock. All share, option, RSU, warrant, and per share information presented in the condensed consolidated financial statements has been adjusted to reflect the stock split on a retroactive basis for all periods presented and all share information is rounded down to the nearest whole share after reflecting the stock split. Use of Estimates The preparation of condensed consolidated financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported and disclosed in the condensed consolidated financial statements and accompanying notes. The estimates and assumptions made by management related to revenue recognition, accruals for the Fitbit Force recall, reserves for sales returns and incentives, reserves for warranty, valuation of stock options, fair value of warrant liability and derivative assets and liabilities, allowance for doubtful accounts, inventory valuation, and the valuations of deferred income tax assets and uncertain tax positions. Actual results could differ from those estimates, and such differences may be material to the condensed consolidated financial statements. Comprehensive Income Comprehensive income consists of two components, net income and other comprehensive income, net of tax. Other comprehensive income refers to revenue, expenses, and gains and losses that are recorded as an element of stockholders’ equity but are excluded from net income. The Company’s other comprehensive income consists of foreign currency translation adjustments from those subsidiaries not using the U.S. dollar as their functional currency. Recent Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09 (ASC 606), Revenue from Contracts with Customers , which affects any entity that either enters into contracts with customers to transfer goods and services or enters into contracts for the transfer of nonfinancial assets. ASU 2014-09 will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. The standard’s core principle is that a company will recognize revenue when it 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 doing so, companies will need to use more judgment and make more estimates than under the currently effective guidance. These may include identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. In July 2015, the FASB approved a one-year deferral of the effective date of the standard. ASU 2014-09 will become effective for the Company on January 1, 2018 and can be adopted either retrospectively to each prior reporting period presented or as a cumulative effect adjustment as of the date of adoption. Early adoption is permitted but not before the original effective date of annual periods beginning after December 15, 2016. The Company is currently evaluating the impact of this guidance on its consolidated financial statements.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Assets and liabilities recorded at fair value on a recurring basis are categorized based upon the level of judgment associated with inputs used to measure their fair values. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the reporting date. The Company estimates fair value by applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement: Level 1 —Quoted prices in active markets for identical assets or liabilities; Level 2 —Observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and Level 3 —Inputs that are generally unobservable and typically reflect management’s estimate of assumptions that market participants would use in pricing the asset or liability. The carrying values of the Company’s financial instruments, including cash equivalents, accounts receivable, and accounts payable, approximated their fair values due to the short period of time to maturity or repayment. The carrying value of the Company’s long-term debt approximated its fair value as of December 31, 2014 as the debt carried a variable rate or market rates available to the Company and other assumptions had not changed significantly. The following tables set forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): June 30, 2015 Level 1 Level 2 Level 3 Total Assets: Derivative assets $ — $ 541 $ — $ 541 Liabilities: Derivative liabilities $ — $ 291 $ — $ 291 December 31, 2014 Level 1 Level 2 Level 3 Total Assets: Derivative assets $ — $ 316 $ — $ 316 Liabilities: Redeemable convertible preferred stock warrant liability $ — $ — $ 15,797 $ 15,797 Derivative liabilities — 105 — 105 Total $ — $ 105 $ 15,797 $ 15,902 Level 2 assets and liabilities are comprised of derivative financial instruments associated with hedging activity, which is further discussed in Note 4. Derivative financial instruments are initially measured at fair value on the contract date and are subsequently remeasured to fair value at each reporting date using inputs such as spot rates and forward rates. There is not an active market for each hedge contract, but the inputs used to calculate the value of the instruments are tied to active markets. The Company’s Level 3 liabilities, measured and recorded on a recurring basis, consist of the redeemable convertible preferred stock warrant liability and contingent consideration. Prior to the IPO, the fair value of the warrant liability was calculated using an option-pricing model as discussed in Note 8. Generally, increases or decreases in the fair value of the underlying redeemable convertible preferred stock would result in a directionally similar impact in the fair value measurement of the associated warrant liability. The unexercised warrants to purchase redeemable convertible preferred stock were converted into warrants to purchase shares of Class B common stock upon the closing of the IPO. As a result, the Company revalued and reclassified the redeemable convertible preferred stock liability to additional paid-in capital upon the closing of the IPO. The following table sets forth a summary of the changes in the fair value of the redeemable convertible preferred stock warrant liability (in thousands): Balance at December 31, 2014 $ 15,797 Change in fair value 56,655 Settlement of warrant liability upon exercise (56,678 ) Reclassification of unexercised warrants to additional paid-in capital upon the initial public offering (15,774 ) Balance at June 30, 2015 $ — The Company’s acquisition-related contingent consideration is determined using the Monte Carlo simulation method. The increases or decreases in the fair value of the contingent consideration payable could result from changes in the anticipated fair value of the Company’s common stock, stock price volatility, and probability of various market-based scenarios. As the fair value measure is based on significant inputs that are not observable in the market, they are categorized as Level 3. The following table sets forth a summary of the changes in the fair value of the acquisition-related contingent consideration (in thousands): Balance at December 31, 2014 $ — Addition from acquisition 7,704 Change in fair value of contingent consideration (7,704 ) Balance at June 30, 2015 $ — There have been no transfers between fair value measurement levels during the three and six months ended June 30, 2014 and June 30, 2015.

Derivative Financial Instrument

Derivative Financial Instruments	6 Months Ended
	Jun. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments The Company’s earnings and cash flows are subject to fluctuations due to changes in foreign currency exchange rates. The Company enters into foreign exchange contracts to hedge monetary assets and liabilities that are denominated in currencies other than the functional currency of its subsidiaries. The Company and its subsidiaries do not enter into derivative contracts for speculative purposes. These foreign exchange contracts are carried at fair value and do not qualify for hedge accounting treatment and are not designated as hedging instruments. Changes in the value of the foreign exchange contracts are recognized in other income (expense), net and offset the foreign currency gain or loss on the underlying net monetary assets or liabilities. The table below presents the notional amount of the foreign currency contracts as of June 30, 2015 (in thousands): Notional Amount Sold Functional Currency: Foreign Amount USD Equivalent AUD 35,260 $ 27,348 CAD 8,580 6,971 EUR 10,800 12,090 GBP 10,680 16,643 JPY 75,000 609 NZD 1,142 798 $ 64,459 The table below presents the notional amount of the foreign currency contracts as of December 31, 2014 (in thousands): Notional Amount Purchased Functional Currency: Foreign Amount USD Equivalent AUD 32,700 $ 26,810 CAD 3,200 2,782 EUR 2,700 3,355 GBP 2,100 3,295 NZD 1,200 930 $ 37,172 Currently, the Company does not have master netting agreements with its counterparties for its foreign currency contracts. As of December 31, 2014 and June 30, 2015 , the fair value of the derivative assets of $0.3 million and $0.5 million , respectively, were recorded in prepaid expenses and other current assets and the fair value of the derivative liability of $0.1 million and $0.3 million , respectively, were recorded in accrued liabilities on the condensed consolidated balance sheets. The gain recognized in other income (expense), net for non-designated foreign currency forward contracts was $0.5 million and $2.5 million for the three and six months ended June 30, 2015 , respectively. The Company did not enter into foreign exchange contracts during 2014 until December 2014.

Balance Sheet Components

Balance Sheet Components	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	Balance Sheet Components Revenue Reserve Revenue returns reserve activities were as follows (in thousands): Three Months Ended Six Months Ended 2015 2014 2015 2014 Beginning balances $ 26,362 $ 15,631 $ 26,559 $ 15,416 Increases 32,859 7,836 53,352 14,660 Returns taken (23,956 ) (6,318 ) (44,646 ) (12,927 ) Ending balances $ 35,265 $ 17,149 $ 35,265 $ 17,149 Inventories Inventories consisted of the following (in thousands): June 30, 2015 December 31, 2014 Components $ 60,217 $ 53,383 Finished goods 126,653 61,689 Total inventories $ 186,870 $ 115,072 Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): June 30, 2015 December 31, 2014 POP displays, net $ 6,700 $ 7,121 Prepaid expenses and other current assets 11,463 6,493 Total prepaid expenses and other current assets $ 18,163 $ 13,614 Property and Equipment, Net Property and equipment, net, consisted of the following (in thousands): June 30, 2015 December 31, 2014 Tooling and manufacturing equipment $ 38,559 $ 28,344 Furniture and office equipment 4,180 2,891 Purchased and internally-developed software 1,854 1,396 Leasehold improvements 3,661 3,594 Total property and equipment 48,254 36,225 Less: Accumulated depreciation and amortization (17,309 ) (9,790 ) Property and equipment, net $ 30,945 $ 26,435 Goodwill and Intangible Assets The changes in the carrying amount of goodwill for the six months ended June 30, 2015 were as follows (in thousands). See Note 13 for additional information. Goodwill Balance at December 31, 2014 $ — Goodwill acquired 22,562 Subsequent goodwill adjustments (405 ) Balance at June 30, 2015 $ 22,157 There were no intangible assets outstanding as of December 31, 2014. The carrying amounts of the intangible assets as of June 30, 2015 were as follows (in thousands, except useful life). See Note 13 for additional information. June 30, 2015 Weighted Average Remaining Useful Life (years) Gross Accumulated Amortization Net Developed technology $ 12,640 $ (558 ) $ 12,082 6.7 Trademarks and other 1,278 (97 ) 1,181 4.4 Total intangible assets, net $ 13,918 $ (655 ) $ 13,263 Total amortization expense related to intangible assets was $0.5 million and $0.7 million for the three and six months ended June 30, 2015, respectively. The estimated future amortization expense of acquired intangible assets to be charged to cost of revenue and operating expenses after June 30, 2015, is as follows (in thousands): Cost of Revenue Operating Expenses Total Remaining 2015 $ 883 $ 164 $ 1,047 2016 1,806 281 2,087 2017 1,806 230 2,036 2018 1,806 230 2,036 2019 1,806 230 2,036 Thereafter 3,975 46 4,021 Total intangible assets, net $ 12,082 $ 1,181 $ 13,263 Accrued Liabilities Accrued liabilities consisted of the following (in thousands): June 30, 2015 December 31, 2014 Product warranty $ 31,063 $ 20,098 Employee related liabilities 10,148 4,115 Accrued cooperative advertising and marketing development funds 10,132 7,679 Accrued sales incentives 4,034 2,355 Sales taxes and VAT payable 3,040 2,291 Accrued manufacturing expense 2,113 9,953 Customer deposits 1,864 6,391 Inventory received not billed — 6,242 Other 17,224 11,816 Accrued liabilities $ 79,618 $ 70,940 Product warranty reserve activities were as follows (in thousands) (1) : Three Months Ended Six Months Ended 2015 2014 2015 2014 Beginning balances $ 23,251 $ 6,740 $ 20,098 $ 8,480 Charged to cost of revenue 14,568 2,494 22,065 2,062 Settlement of claims (6,756 ) (1,609 ) (11,100 ) (2,917 ) Ending balances $ 31,063 $ 7,625 $ 31,063 $ 7,625 (1) Does not include reserves established as a result of the recall of the Fitbit Force. See the section titled “—Fitbit Force Recall Reserve” for additional information regarding such reserves. Fitbit Force Recall Reserve In March 2014, the Company announced a recall for one of its products, the Fitbit Force (“Fitbit Force Recall”). The product recall, which is regulated by the U.S. Consumer Product Safety Commission, covered all Fitbit Force units sold since the product was first introduced in October 2013. The product recall program has no expiration date. As a result of the product recall, the Company established reserves that include cost estimates for customer refunds, logistics and handling fees for managing product returns and processing refunds, obsolescence of on-hand inventory, cancellation charges for existing purchase commitments and rework of component inventory with the contract manufacturer, write-offs of tooling and manufacturing equipment, and legal settlement costs. Fitbit Force recall reserve activities were as follows (in thousands): Three Months Ended Six Months Ended 2015 2014 2015 2014 Beginning balances $ 15,104 $ 84,239 $ 22,476 $ 82,938 Charged to revenue — — — 11,561 Charged (benefit) to cost of revenue — — (2,040 ) 10,602 Charged (benefit) to general and administrative 69 — (73 ) 505 Settlement of claims (2,279 ) (27,165 ) (7,469 ) (48,532 ) Ending balances $ 12,894 $ 57,074 $ 12,894 $ 57,074

Long-Term Debt

Long-Term Debt	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt 2014 Credit Agreement In August 2014, the Company entered into an amended and restated credit agreement (“Asset-Based Credit Facility”), with a borrowing limit of $180.0 million . The Asset-Based Credit Facility allows the Company to borrow up to the lesser of (i) $180.0 million , including up to $50.0 million for the issuance of letters of credit and up to $25.0 million for swing line loans and (ii) the borrowing base then in effect less the amount then outstanding under letters of credit and loans. The borrowing base is determined by the Company’s collateral agents based on several variables, including percentages of the book value of certain eligible accounts receivable and a percentage of certain eligible inventories. Borrowings under the Asset-Based Credit Facility may be drawn as Alternate Base Rate or ABR loans or Eurodollar loans, and matures in August 2018. ABR loans bear interest at a variable rate equal to the applicable margin plus the highest of (i) the prime rate, (ii) the federal funds effective rate plus 0.5% , and (iii) the Eurodollar rate plus 1.0% , but in any case at a minimum rate of 3.25% per annum. Eurodollar loans bear interest at a variable rate based on the LIBOR rate and Euro currency reserve requirements. The Company is also required to pay an annual commitment fee on the average daily unused portion of the facility of 0.25% , 0.35% , or 0.45% , based on usage of the facility. As of December 31, 2014 and June 30, 2015 , the effective interest rate on the revolving line of credit was 4.25% . The Company has the option to repay its borrowings under the Asset-Based Credit Facility without penalty prior to maturity. The Asset-Based Credit Facility requires the Company to comply with certain financial covenants, including maintaining a consolidated fixed charge coverage ratio of at least 1. 1 :1, consolidated leverage ratios of between 3 :1 and 2 :1, and levels of liquidity of not less than $15.0 million . The Asset-Based Credit Facility also requires the Company to comply with certain non-financial covenants. The Company was in compliance with these covenants as of December 31, 2014 and June 30, 2015 . As of December 31, 2014 , the Company had $125.0 million of outstanding borrowings under the Asset-Based Credit Facility. In January 2015, the Company repaid $125.0 million of its indebtedness under the Asset-Based Credit Facility. As a result, the long-term debt that was repaid was classified as long-term debt, current portion, on the Company’s condensed consolidated balance sheet as of December 31, 2014 . As of June 30, 2015 , the Company had no outstanding borrowings under the Asset-Based Credit Facility. 2014 Revolving Credit and Guarantee Agreement In August 2014, the Company entered into a revolving credit and guarantee agreement (“Cash Flow Facility”). In October 2014, the Company amended the Cash Flow Facility to increase the borrowing limit under the Cash Flow Facility. The Cash Flow Facility allows the Company to borrow up to $50.0 million , including up to $10.0 million for the issuance of letters of credit and up to $10.0 million for swing line loans, and matures in August 2018. Borrowings under the Cash Flow Facility may also be drawn as ABR loans or Eurodollar loans. ABR loans under our Cash Flow Facility bear interest at a variable rate equal to the applicable margin plus the highest of (i) 3.5% , (ii) the prime rate, (iii) the federal funds effective rate plus 0.5% , and (iv) the adjusted LIBOR rate plus 1.0% . Eurodollar loans under the Cash Flow Facility bear interest at a variable rate for any day based on the LIBOR rate and Euro currency reserve requirements. The Company is also required to pay an annual commitment fee on the average daily unused portion of the facility of 0.375% or 0.5% , based on usage of the facility. As of December 31, 2014 , and June 30, 2015, the effective interest rate on the revolving line of credit was 3.59% . The Cash Flow Facility also requires the Company to comply with certain financial covenants, including maintaining certain consolidated leverage ratios of between 3 :1 and 2 :1, and other non-financial covenants. As of December 31, 2014 , the Company had $8.0 million of outstanding borrowings under the Cash Flow Facility. Subsequent to December 31, 2014 , the Company repaid $8.0 million of its indebtedness under the Cash Flow Facility. As of June 30, 2015 , the Company had no outstanding borrowings under the Cash Flow Facility. The fair value of warrants issued in connection with debt agreements prior to 2012 was recorded as a debt discount and is amortized over the term of the related financing arrangement to interest expense using the straight-line method. In addition, capitalized issuance costs are amortized to interest expense over the term of the related financing arrangement on a straight-line basis. Interest expense was $0.5 million and $0.4 million for the three months ended June 30, 2014 and 2015 , respectively, and $0.9 million and $0.9 million for the six months ended June 30, 2014 and 2015 , respectively. Letters of Credit As of December 31, 2014 and June 30, 2015 , the Company had outstanding letters of credit totaling $2.9 million and $3.5 million , respectively, issued to cover various security deposits on the Company’s facility leases.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases The Company’s principal facility is located in San Francisco, California. The Company also leases office space in various locations with expiration dates between 2015 and 2024. The lease agreements often include leasehold improvement incentives, escalating lease payments, renewal provisions and other provisions which require the Company to pay taxes, insurance, maintenance costs or defined rent increases. All of Company’s leases are accounted for as operating leases. Rent expense is recorded over the lease terms on a straight-line basis. Rent expense was $1.1 million and $1.5 million for the three months ended June 30, 2014 and 2015, respectively, and $2.2 million and $2.6 million for the six months ended June 30, 2014 and 2015 , respectively. In June 2015, the Company entered into a lease to expand the Company’s existing headquarters. The lease expires in 2024 and future minimum payments under the lease are included in the table below. Future minimum payments under the leases as of June 30, 2015 were as follows (in thousands): Amounts Remaining 2015 $ 3,633 2016 13,106 2017 16,905 2018 16,926 2019 16,263 Thereafter 56,294 Total $ 123,127 Purchase Commitments The aggregate amount of purchase orders open as of December 31, 2014 and June 30, 2015 was approximately $257.0 million and $344.1 million , respectively. The Company cannot determine the aggregate amount of such purchase orders that represent contractual obligations because purchase orders may represent authorizations to purchase rather than binding agreements. The Company’s purchase orders are based on its current needs and are fulfilled by its suppliers, contract manufacturers, and logistics providers within short periods of time. Legal Proceedings Fitbit Force In 2014, class action and personal injury lawsuits were filed against the Company based upon claims of allergic reactions from adhesives in the Fitbit Force, and alleged violations of various state false advertising and unfair competition statutes based on the Company’s sale and marketing of the Fitbit Force. The class action cases were settled in 2014. Certain personal injury complaints remain outstanding, including several complaints filed in 2015, but the Company believes that liabilities arising under these claims are covered by the Company’s commercial general liability insurance. Jawbone On May 27, 2015, Aliphcom, Inc. d/b/a Jawbone (“Jawbone”) filed a lawsuit against the Company and certain of its employees who were formerly employed by Jawbone in the Superior Court of the State of California in the County of San Francisco alleging trade secret misappropriation, breach of contract, breach of implied covenant of good faith and fair dealing, and unfair and unlawful business practices. The complaint alleges, among other things, that prior to leaving Jawbone at various times in 2015, the employees downloaded Jawbone company documents and materials, including allegedly confidential and trade secret information, and that these employees are using such information in the development of the Company’s products. The complaint also alleges that the Company recruited those employees with the intent of using Jawbone’s proprietary information. The complaint seeks unspecified damages, including punitive damages and injunctive relief. On June 26, 2015, the Company and the employee defendants filed demurrers seeking to dismiss Jawbone’s complaint. The demurrers are currently pending and a hearing is scheduled for August 21, 2015. On June 10, 2015, Jawbone and BodyMedia, Inc., a wholly-owned subsidiary of Jawbone (“BodyMedia”), filed a lawsuit against the Company in the United States District Court for the Northern District of California alleging that the Company infringes three U.S. patents held by them: U.S. Patent No. 8,446,275, titled “General Health and Wellness Management Method and Apparatus For A Wellness Application Using Data From a Data-Capable Band,” U.S. Patent No. 8,073,707, titled “System For Detecting, Monitoring, And Reporting An Individual’s Physiological Or Contextual Status,” and U.S. Patent No. 8,398,546, titled “System For Monitoring And Managing Body Weight And Other Physiological Conditions Including Iterative And Personalized Planning, Intervention And Reporting Capability.” Jawbone and BodyMedia allege that these patents have been infringed by a substantial majority of the Company’s products that it has sold historically, as well as several current products. The complaint seeks unspecified compensatory damages and attorney’s fees from the Company and to permanently enjoin the Company from making, manufacturing, using, selling, importing, or offering the Company’s products for sale. On July 3, 2015, Jawbone and BodyMedia amended their complaint to add three additional U.S. patents to the infringement claims against the Company: U.S. Patent No. 8,529,811, titled “Component Protective Overmolding Using Protective External Coatings,” U.S. Patent No. 8,793,522, titled “Power Management in a Data-Capable Strapband,” and U.S. Patent No. 8,961,413, titled “Wireless Communications Device and Personal Monitor.” On July 8, 2015, Jawbone and BodyMedia filed a complaint with the U.S. International Trade Commission (the “ITC”) requesting an investigation into purported violations of the Tariff Act of 1930 by the Company and Flextronics International Ltd. and Flextronics Sales and Marketing (A-P) Ltd. The complaint alleges that the Company’s products infringe the same six U.S. patents at issue in the District Court action. Furthermore, the complaint makes the same allegations of trade secret misappropriation, unfair competition and unfair acts as a result of the Company’s hiring of the former Jawbone employees, as in the State Court action. The complaint seeks a limited exclusion order and a cease and desist order halting the importation and sale of the Company’s products that allegedly infringe upon Jawbone’s patents and misappropriate Jawbone’s trade secrets. On July 24, 2015, Jawbone and BodyMedia filed a letter with the ITC seeking to amend and supplement their ITC complaint. In their letter, Jawbone and BodyMedia, among other things, purport to identify the trade secrets allegedly misappropriated by the employee defendants. The Company intends to vigorously defend each of the Jawbone litigation matters and, based on its review, the Company believes it has valid defenses with respect to each of these matters. However, litigation is inherently uncertain, and any judgment or injunctive relief entered against the Company or any adverse settlement could materially and adversely impact its business, financial condition, operating results, and prospects. Because the Company is in the early stages of these litigation matters, the Company is unable to estimate a reasonably possible range of loss, if any, that may result from this matter. In addition, these litigation matters are complex, likely to involve significant management time and attention, and the cost of defending these matters is likely to be expensive, regardless of outcome. Other The Company is and, from time to time, may in the future become, involved in other legal proceedings in the ordinary course of business. The Company currently believes that the outcome of any of these existing legal proceedings, either individually or in the aggregate, will not have a material impact on the operating results, financial condition or cash flows of the Company. With respect to existing legal proceedings, the Company has either determined that the existence of a material loss is not reasonably possible or that it is unable to estimate a reasonably possible range of loss. Indemnifications In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless and defend an indemnified parties for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third-party actions. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. To date, the Company has not incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. The Company has also entered into indemnification agreements with its directors and officers that may require the Company to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers to the fullest extent permitted by Delaware corporate law. The Company also currently has directors’ and officers’ insurance.

Redeemable Convertible Preferre

Redeemable Convertible Preferred Stock and Warrants	6 Months Ended
	Jun. 30, 2015
Temporary Equity Disclosure [Abstract]
Redeemable Convertible Preferred Stock and Warrants	Redeemable Convertible Preferred Stock and Warrants Redeemable Convertible Preferred Stock Upon the closing of the Company’s IPO, all shares of the Company’s then-outstanding redeemable convertible preferred stock, as shown in the table below, automatically converted on a one-for-one basis into an aggregate of 139,851,483 shares of Class B common stock. Redeemable convertible preferred stock outstanding as of December 31, 2014 and as of immediately prior to the conversion into Class B common stock consisted of the following (in thousands, except per share data): Shares Authorized Shares Outstanding Price per Share Net Carrying Value Liquidation Preference Series A 10,200 10,200 $ 0.04167 $ 421 $ 425 Series A-1 22,369 22,369 0.09165 2,000 2,050 Series B 42,360 42,052 0.21580 10,533 9,075 Series C 39,600 36,080 0.33452 12,049 12,069 Series D 30,000 29,150 1.47513 42,811 43,000 Total 144,529 139,851 $ 67,814 $ 66,619 Redeemable Convertible Preferred Stock Warrants As of December 31, 2014, and until immediately prior to the completion of the IPO, the Company had the following redeemable convertible preferred stock warrants issued and outstanding (in thousands, except per share data): Warrant Class Number of Shares Underlying Warrants Fair Value Issuance Date Exercise Price per Share Series B 278 $ 2,351 June 2011 $ 0.22 Series C 57 475 April 2012 0.33 Series C 1,215 9,728 September 2012 0.67 Series C (1) 405 3,243 September 2012 0.67 Total 1,955 $ 15,797 (1) Represents additional shares that may be exercised pursuant to the Series C redeemable convertible preferred stock warrant issued in September 2012 due to a draw down on a debt financing arrangement in March 2013. Prior to the IPO, as the redeemable convertible preferred stock warrants were exercisable into contingently redeemable preferred shares, the Company had recognized a liability for the fair value of its warrants upon issuance and subsequently remeasured the liability at the end of each reporting period. The Company estimated the fair values of the redeemable convertible preferred stock warrants using the Black-Scholes option-pricing model based on inputs as of the valuation measurement dates, including the fair values of our convertible preferred stock, the estimated volatility of the price of our convertible preferred stock, the expected term of the warrants, and the risk-free interest rates. Immediately prior to the completion of the IPO, the Company issued 274,992 shares of Series B redeemable convertible preferred stock and 1,210,591 shares of Series C redeemable convertible preferred stock upon the exercise of 277,992 and 1,251,357 of Series B and Series C redeemable convertible preferred stock warrants, respectively, after the forfeiture of 3,000 and 40,766 Series B and Series C redeemable convertible preferred stock warrants, respectively. The shares issued upon the net exercise were sold as Class A common stock in the IPO. In addition, all of the remaining outstanding redeemable convertible preferred stock warrants automatically converted to Class B common stock warrants upon closing of the IPO. As a result of the net exercise of redeemable convertible preferred stock warrants and automatic conversion of the remaining warrants to Class B common stock warrants, the Company revalued the warrants as of the completion of the IPO and reclassified the remaining redeemable convertible preferred stock warrant liability balance related to the unexercised warrants to additional paid-in capital. As of June 30, 2015, there were 425,643 Class B common stock warrants outstanding. These Class B common stock warrants expire in June 2025 and are exercisable at an exercise price of $0.67 per share.

Stock Plan

Stock Plan	6 Months Ended
	Jun. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Plan	Stock Plan Preferred Stock Upon completion of its IPO on June 22, 2015, the Company filed a Restated Certificate of Incorporation, which authorized the issuance of preferred stock with rights and preferences, including voting rights, designated from time to time by the board of directors. As of June 30, 2015, there were 10,000,000 shares of preferred stock authorized with a par value of $0.0001 per share, and no shares of preferred stock issued or outstanding. Common Stock As of December 31, 2014, the Company had 230,400,000 shares of common stock authorized for issuance and 40,875,583 shares issued and outstanding. In connection with the IPO, the Company established two classes of authorized common stock, Class A common stock and Class B common stock. All shares of common stock outstanding immediately prior to the IPO were converted into an equivalent amount of shares of Class B common stock. As of June 30, 2015, the Company had 600,000,000 shares of Class A common stock authorized with a par value of $0.0001 per share and 350,000,000 shares of Class B common stock authorized with a par value of $0.0001 per share. As of June 30, 2015, 42,061,250 shares of Class A common stock were issued and outstanding and 164,625,960 shares of Class B common stock were issued and outstanding. Holders of Class A common stock are entitled to one vote for each share of Class A common stock held on all matters submitted to a vote of stockholders and holders of Class B common stock are entitled to ten votes for each share of Class B common stock held on all matters submitted to a vote of stockholders. Except with respect to voting, the rights of the holders of Class A and Class B common stock are identical. Shares of Class B common stock are voluntarily convertible into shares of Class A common stock at the option of the holder and generally automatically convert into shares of our Class A common stock upon a transfer. 2007 Equity Incentive Plan In September 2007, the Company adopted the Amended and Restated 2007 Stock Plan (the “2007 Plan”), which was most recently amended in March 2015. The 2007 Plan provided for the grant of incentive and non-statutory stock options and RSUs to employees, directors, and consultants under terms and provisions established by the board of directors. The 2015 Equity Incentive Plan (the “2015 Plan”) became effective on June 16, 2015. As a result, the Company will not grant any additional stock options under the 2007 Plan and the 2007 Plan has terminated. Any outstanding stock options and RSUs granted under the 2007 Plan will remain outstanding, subject to the terms of the 2007 Plan and applicable award agreements, until such shares are issued under those awards, by exercise of stock options or settlement of RSUs, or until the awards terminate or expire by their terms. Stock options and RSUs granted under the 2007 Plan generally have terms similar to those described below with respect to stock options and RSUs granted under the 2015 Plan. 2015 Equity Incentive Plan In May 2015, the Company’s board of directors and stockholders adopted and approved the 2015 Plan. The 2015 Plan became effective on June 16, 2015 and serves as the successor to the 2007 Plan. The remaining shares available for issuance under the 2007 Plan became reserved for issuance under the 2015 Plan, and the Company ceased granting awards under the 2007 Plan. The number of shares reserved for issuance under the 2015 Plan will increase automatically on the first day of January of each year starting in 2016 through 2025 by the number of shares of Class A common stock equal to 5% of the total outstanding shares of common stock as of the immediately preceding December 31. The share reserve may also increase to the extent that outstanding awards expire or terminate un-exercised. As of June 30, 2015, 6,274,474 shares were reserved for issuance under the 2015 Plan. The 2015 Plan authorizes the award of stock options, restricted stock awards, stock appreciation rights, RSUs, performance awards, and stock bonuses to employees, directors, consultants, independent contractors, and advisors. In general, stock options and RSUs will vest over a four -year period, and have a maximum term of ten years . The exercise price of an option will be not less than 100% of the fair market value of the shares on the date of grant. 2015 Employee Stock Purchase Plan In May 2015, the Company’s board of directors adopted the 2015 Employee Stock Purchase Plan (“2015 ESPP”), which became effective on June 17, 2015. A total of 3,750,000 shares of Class A common stock were initially reserved for issuance under the 2015 ESPP. The 2015 ESPP allows eligible employees to purchase shares of the Company’s Class A common stock at a discount through payroll deductions of up to 15% of eligible compensation, subject to any plan limitations. Except for the initial offering period, the 2015 ESPP provides for 6-month offering periods beginning in May and November of each year. The initial offering period began June 17, 2015, and will end in May 2016. On each purchase date, eligible employees will purchase Class A common stock at a price per share equal to 85% of the lesser of the fair market value of the Company’s common stock (i) on the first trading day of the applicable offering period and (2) the last trading day of each purchase period in the applicable offering period. For the first offering period, which began on June 17, 2015, the fair market value of the common stock on the offering date was $20.00 , the price at which the Company’s Class A common stock was first sold to the public in its IPO, as specified in the final prospectus filed with the SEC on June 18, 2015, pursuant to Rule 424(b). Stock Options Stock option activity under the equity incentive plans was as follows: Options Outstanding Number of Shares Subject to Options Weighted– Average Exercise Price Aggregate Intrinsic Value (in thousands) (in thousands) Balance—December 31, 2014 44,009 $ 1.72 $ 207,863 Granted 6,844 10.27 Exercised (719 ) 0.62 $ 10,737 Forfeited or canceled (896 ) 3.34 Balance—June 30, 2015 49,238 2.90 $ 1,739,756 Options exercisable—June 30, 2015 20,528 0.51 $ 774,329 Options vested and expected to vest—June 30, 2015 46,462 2.81 $ 1,645,537 The aggregate intrinsic values of options outstanding, exercisable, vested and expected to vest as of June 30, 2015 were calculated as the difference between the exercise price of the options and the fair value of the Class A common stock of $38.23 as of June 30, 2015 . The total grant date fair value of options that vested during the three months ended June 30, 2014 and 2015 was $0.3 million and $4.7 million , respectively, and during the six months ended June 30, 2014 and 2015 was $0.5 million and $6.5 million , respectively. Restricted Stock Units RSU activity under the equity incentive plans was as follows: RSUs Outstanding Weighted- Average Grant Date Fair Value (in thousands) Unvested balance—December 31, 2014 — $ — Granted 504 15.70 Unvested balance—June 30, 2015 504 15.70 Stock-Based Compensation Expense Total stock-based compensation recognized was as follows (in thousands): Three Months Ended Six Months Ended 2015 2014 2015 2014 Cost of revenue $ 825 $ 129 $ 1,271 $ 188 Research and development 3,138 192 5,017 284 Sales and marketing 1,322 120 2,629 183 General and administrative 2,462 220 3,733 320 Total stock-based compensation expense $ 7,747 $ 661 $ 12,650 $ 975 As of June 30, 2015 , the total unrecognized compensation expense related to unvested options, net of estimated forfeitures, was $82.0 million , which the Company expects to recognize over an estimated weighted average period of 3.5 years. As of June 30, 2015 , the total unrecognized compensation expense related to unvested RSUs, net of estimated forfeitures, was $6.8 million , which the Company expects to recognize over an estimated weighted average period of 3.3 years. As of June 30, 2015 , the total unrecognized compensation expense related to unvested common stock issued in connection with the Company’s acquisition of FitStar, Inc. (“FitStar”), net of estimated forfeitures, was $3.1 million , which the Company expects to recognize over an estimated weighted average period of 2.7 years. See Note 13 for additional information on the acquisition. Stock-based compensation is measured at the grant date based on the fair value of the award and is recognized as expense, net of estimated forfeitures, over the requisite service period, which is generally the vesting period of the respective award. The fair value of RSUs is the fair value of the Company’s common stock on the grant date. In determining the fair value of the options and the 2015 ESPP, the Company uses the Black-Scholes option-pricing model and assumptions discussed below. Each of these inputs is subjective and generally requires significant judgment. Prior to the Company’s IPO, the fair value of the shares of common stock underlying stock options was historically established by the Company’s board of directors, and was based in part upon a valuation provided by an independent third-party valuation firm. Subsequent to the completion of the IPO, the Company uses the market closing price for Class A common stock as reported on the New York Stock Exchange. The Company has consistently used peer company volatilities for calculating the expected volatilities for employee stock options and the 2015 ESPP. The expected term of options granted to employees is based on the simplified method as the Company does not have sufficient historical exercise data, and the expected term of the 2015 ESPP is based on the contractual term. The risk-free interest rate for the expected term of the options and the 2015 ESPP is based on the U.S. Treasury yield curve in effect at the time of grant. The Company recognizes its stock-based compensation related to options using a straight-line method over the vesting term of the awards. The Company recognizes its stock-based compensation related to ESPP using a straight-line method over the offering period. In addition, the Company is required to estimate the amount of stock-based compensation that it expects to be forfeited based on historical experience. The assumptions used in calculating the fair value of the stock-based awards represent management judgment. As a result, if factors change and different assumptions are used, the stock-based compensation expense could be materially different in the future. The fair value of the stock option awards granted to employees was estimated at the date of grant using a Black-Scholes option-pricing model with the following assumptions: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Employee stock options Expected term in years 6.25 6.25 6.25 6.25 Volatility 52.7% - 55.1% 60.8% - 60.9% 52.7% - 56.9% 60.8% - 60.9% Risk-free interest rate 1.5% - 1.9% 1.9% - 2.0% 1.5% - 1.9% 1.9% - 2.0% Dividend yield —% —% —% —% Employee stock purchase plan Expected term in years 0.92 — 0.92 — Volatility 55% —% 55% —% Risk-free interest rate 0.3% —% 0.3% —% Dividend yield —% —% —% —%

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company is subject to income tax in the United States as well as other tax jurisdictions in which it conducts business. Earnings from non-U.S. activities are subject to local country income tax. The Company does not provide for federal income taxes on the undistributed earnings of its foreign subsidiaries as such earnings are to be reinvested indefinitely. For the three and six months ended June 30, 2015, the Company recorded an expense for income taxes of $17.0 million and $45.4 million , respectively, for an effective tax rate of 49.1% and 40.9% , respectively. The effective tax rate is higher than the statutory federal tax rate primarily due to certain permanent differences related to the change in fair value of the redeemable convertible preferred stock warrant liability and non-deductible stock-based compensation expense, partially offset by non-taxable income associated with contingent consideration from the FitStar acquisition and a permanent domestic production activities deduction. For the three and six months ended June 30, 2014, the Company recorded an expense for income taxes of $6.9 million and $12.2 million , respectively, for an effective tax rate of 32.0% and 34.1% , respectively. The tax expense for the three and six months ended June 30, 2014 reflect current income tax expense on earnings as the Company recorded a valuation allowance against its U.S. deferred tax assets as of June 30, 2014. At June 30, 2015, the total amount of gross unrecognized tax benefits was $13.5 million , all of which would affect the effective tax rate if recognized. The Company does not have any tax positions as of June 30, 2015 for which it is reasonably possible the total amount of gross unrecognized tax benefits will increase or decrease within the following 12 months. The Company’s policy is to record interest and penalties related to unrecognized tax benefits as income tax expense. During the three and six months ended June 30, 2015, the Company recorded $0.1 million and $0.4 million , respectively, related to the accrual of interest and penalties. During the three and six months ended June 30, 2014, the Company recorded a negligible amount related to the accrual of interest and penalties.

Net Income per Share Attributab

Net Income per Share Attributable to Common Stockholders	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Net Income per Share Attributable to Common Stockholders	Net Income per Share Attributable to Common Stockholders Basic and diluted net income per share attributable to common stockholders is presented in conformity with the two-class method required for participating securities. The Company considers its redeemable convertible preferred stock to be participating securities. In connection with the IPO, the Company established two classes of authorized common stock: Class A common stock and Class B common stock. As a result, all then-outstanding shares of common stock were converted into shares of Class B common stock. The rights of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to ten votes per share. Each share of Class B common stock is convertible at any time at the option of the stockholder into one share of Class A common stock, generally automatically converts into Class A common stock upon a transfer, and has no expiration date. Undistributed earnings allocated to participating securities are subtracted from net income in determining net income attributable to common stockholders. Basic net income per share attributable to common stockholders is computed by dividing the net income attributable to common stockholders by the weighted-average number of common shares outstanding during the period. All participating securities are excluded from basic weighted-average common shares outstanding. For the calculation of diluted EPS, net income attributable to common stockholders for basic EPS is adjusted by the effect of dilutive securities. Diluted net income per share attributable to common stockholders is computed by dividing the net income attributable to common stockholders by the weighted-average number of common shares outstanding, including all potentially dilutive common shares, if the effect of each class of potential shares of common stock is dilutive. The undistributed earnings are allocated based on the contractual participation rights of the Class A and Class B common shares as if the earnings for the year have been distributed. As the liquidation and dividend rights are identical, the undistributed earnings are allocated on a proportionate basis. The computation of the diluted net income per share of Class A common stock assumes the conversion of Class B common stock, while diluted net income per share of Class B common stock does not assume the conversion of Class A common stock as Class A common stock is not convertible into Class B common stock. The following table sets forth the computation of the Company’s basic and diluted net income per share attributable to common stockholders (in thousands, except per share amounts): Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Class A Class B Class B Class A Class B Class B Numerator: Net income $ 1,256 $ 16,425 $ 14,753 $ 2,752 $ 62,926 $ 23,625 Less: noncumulative dividends to preferred stockholders (86 ) (1,126 ) (1,327 ) (106 ) (2,420 ) (2,640 ) Less: undistributed earnings to participating securities (799 ) (10,445 ) (10,423 ) (1,924 ) (43,983 ) (16,293 ) Net income attributable to common stockholders—basic $ 371 $ 4,854 $ 3,003 $ 722 $ 16,523 $ 4,692 Add: adjustments to undistributed earnings to participating securities 1,862 1,731 1,058 7,003 6,717 1,618 Reallocation of net income as a result of conversion of Class B to Class A common stock 4,854 — — 16,523 — — Reallocation of net income to Class B common stock — 191 — — $ 392 — Net income attributable to common stockholders—diluted $ 7,087 $ 6,776 $ 4,061 $ 24,248 $ 23,632 $ 6,310 Denominator: Weighted-average shares of common stock—basic 4,160 54,388 40,193 2,091 47,831 40,174 Conversion of Class B to Class A common stock 54,388 — — 47,831 — — Effect of potentially dilutive stock options, RSUs, common stock warrants, and ESPP 36,642 36,618 20,294 32,919 32,907 19,809 Weighted-average shares of common stock—diluted 95,190 91,006 60,487 82,841 80,738 59,983 Net income per share attributable to common stockholders: Basic $ 0.09 $ 0.09 $ 0.07 $ 0.35 $ 0.35 $ 0.12 Diluted $ 0.07 $ 0.07 $ 0.07 $ 0.29 $ 0.29 $ 0.11 The following common stock equivalents were excluded from the computation of diluted net income per share for the periods presented because including them would have been anti-dilutive (in thousands): Three Months Six Months 2015 2014 2015 2014 Redeemable convertible preferred stock 126,020 139,504 132,898 139,504 Stock options to purchase common stock — 1,550 799 1,219 Redeemable convertible preferred stock warrants 1,808 2,303 1,808 1,794 Total 127,828 143,357 135,505 142,517

Significant Customer Informatio

Significant Customer Information and Other Information	6 Months Ended
	Jun. 30, 2015
Risks and Uncertainties [Abstract]
Significant Customer Information and Other Information	Significant Customer Information and Other Information Retailer and Distributor Concentration Retailers and distributors with revenue equal to or greater than 10% of total revenue for the three and six months ended June 30, 2014 and 2015 were as follows: Three Months Ended Six Months Ended 2015 2014 2015 2014 A 14 % 15 % 16 % 12 % B 14 * 12 13 C 13 15 12 14 D 11 * * * *Revenue was less than 10%. Retailers and distributors that accounted for equal to or greater than 10% of net accounts receivable at December 31, 2014 and June 30, 2015 were as follows: June 30, December 31, B 17 % 17 % D 17 13 C 16 14 A 11 * E * 10 * Accounts receivable were less than 10%. Geographic and Other Information Revenue by geographic region, based on ship-to destinations, was as follows (in thousands): Three Months Ended Six Months Ended 2015 2014 2015 2014 United States $ 312,666 $ 88,504 $ 577,975 $ 178,335 Americas excluding United States 16,799 7,177 30,228 10,893 Europe, Middle East, and Africa 39,712 9,915 74,768 18,639 APAC 31,235 7,976 54,195 14,520 Total $ 400,412 $ 113,572 $ 737,166 $ 222,387 As of December 31, 2014 and June 30, 2015 , long-lived assets, which represent property and equipment, located outside the United States were $20.0 million and $23.7 million , respectively.

Acquisition

Acquisition	6 Months Ended
	Jun. 30, 2015
Business Combinations [Abstract]
Acquisition	Acquisition In March 2015, the Company acquired all of the outstanding securities of FitStar, a provider of interactive video-based exercise experiences on mobile devices and computers that utilize proprietary algorithms to adjust and customize workouts for individual users, for aggregate acquisition consideration of $32.5 million ,. The aggregate acquisition consideration was comprised of $13.3 million related to the issuance of 1,059,688 shares of the Company’s Class B common stock, $11.5 million of cash, and $7.7 million of contingent consideration. The acquisition is expected to enhance the Company’s software and services offerings. As of the acquisition date, the Company was potentially obligated to issue additional common stock or pay cash to FitStar shareholders. The actual amount of any contingent consideration paid with respect to the FitStar acquisition, if any, was dependent on market-based events in the future. The Company determined the fair market value of this contingent consideration to be $7.7 million as of the acquisition date using the Monte Carlo simulation method. The fair value of this liability is adjusted at each reporting period, and the change in fair value is included in total operating expenses on the condensed consolidated statement of operations. As a result of the Company’s IPO, the Company recorded a change in fair value of $7.7 million as a benefit and as of June 30, 2015, the fair value of the contingent consideration liability was zero . In addition, the terms related to the contingent consideration have expired as of the date of this Report on Form 10-Q. The following table summarizes the fair value of assets acquired and liabilities assumed (in thousands): Goodwill $ 22,157 Developed and core technology 12,640 Customer relationships 128 Trademarks 1,150 Assumed liabilities, net of assets (3,552 ) Total $ 32,523 The amortization periods of the acquired developed technology, customer relationships, and trademarks are 7.0 years , 1.3 years , and 5.0 years , respectively. Goodwill is not deductible for tax purposes. In addition, upon acquisition, the Company issued 308,216 additional shares of common stock valued at $4.2 million . The Company is also obligated to make cash payments up to $1.2 million . Both the common stock and the cash payments are additional consideration which is contingent upon former employees of FitStar continuing to be employed by the Company. As such, this additional consideration was not part of the purchase price and is recognized as post-acquisition compensation expense over the related requisite service period of 3 years . The Company also recorded acquisition-related transaction costs of $0.3 million , which were included in general and administrative expenses in the condensed consolidated statement of operations during the six months ended June 30, 2015. The results of operations of FitStar are included in the accompanying condensed consolidated statements of operations from the date of acquisition. Pro forma results of operations for this acquisition have not been presented because they are not material to the Company’s condensed consolidated financial statements.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2015
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events In July 2015, the Company established a letter of credit of $13.3 million in connection with the security deposit required for the facility lease to expand the Company’s existing headquarters.

Basis of Presentation and Sum21

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	The accompanying condensed consolidated financial statements are unaudited. The condensed consolidated balance sheet at December 31, 2014 has been derived from the audited financial statements of the Company. The accompanying condensed financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) for interim financial information, and in management’s opinion, includes all adjustments, consisting of only normal recurring adjustments, necessary for the fair statement of the Company’s financial position, its results of operations, and cash flows for the interim periods presented. The results of operations for the three and six months ended June 30, 2015 are not necessarily indicative of the results to be expected for the full fiscal year or any other period.
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany transactions and balances have been eliminated.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported and disclosed in the condensed consolidated financial statements and accompanying notes. The estimates and assumptions made by management related to revenue recognition, accruals for the Fitbit Force recall, reserves for sales returns and incentives, reserves for warranty, valuation of stock options, fair value of warrant liability and derivative assets and liabilities, allowance for doubtful accounts, inventory valuation, and the valuations of deferred income tax assets and uncertain tax positions. Actual results could differ from those estimates, and such differences may be material to the condensed consolidated financial statements.
Comprehensive Income (Loss)	Comprehensive Income Comprehensive income consists of two components, net income and other comprehensive income, net of tax. Other comprehensive income refers to revenue, expenses, and gains and losses that are recorded as an element of stockholders’ equity but are excluded from net income. The Company’s other comprehensive income consists of foreign currency translation adjustments from those subsidiaries not using the U.S. dollar as their functional currency.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09 (ASC 606), Revenue from Contracts with Customers , which affects any entity that either enters into contracts with customers to transfer goods and services or enters into contracts for the transfer of nonfinancial assets. ASU 2014-09 will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. The standard’s core principle is that a company will recognize revenue when it 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 doing so, companies will need to use more judgment and make more estimates than under the currently effective guidance. These may include identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. In July 2015, the FASB approved a one-year deferral of the effective date of the standard. ASU 2014-09 will become effective for the Company on January 1, 2018 and can be adopted either retrospectively to each prior reporting period presented or as a cumulative effect adjustment as of the date of adoption. Early adoption is permitted but not before the original effective date of annual periods beginning after December 15, 2016. The Company is currently evaluating the impact of this guidance on its consolidated financial statements.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Schedule of fair value of assets and liabilities measured on recurring basis	The following tables set forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): June 30, 2015 Level 1 Level 2 Level 3 Total Assets: Derivative assets $ — $ 541 $ — $ 541 Liabilities: Derivative liabilities $ — $ 291 $ — $ 291 December 31, 2014 Level 1 Level 2 Level 3 Total Assets: Derivative assets $ — $ 316 $ — $ 316 Liabilities: Redeemable convertible preferred stock warrant liability $ — $ — $ 15,797 $ 15,797 Derivative liabilities — 105 — 105 Total $ — $ 105 $ 15,797 $ 15,902
Schedule of changes in fair value of redeemable convertible preferred stock warrant liability	The following table sets forth a summary of the changes in the fair value of the acquisition-related contingent consideration (in thousands): Balance at December 31, 2014 $ — Addition from acquisition 7,704 Change in fair value of contingent consideration (7,704 ) Balance at June 30, 2015 $ — The following table sets forth a summary of the changes in the fair value of the redeemable convertible preferred stock warrant liability (in thousands): Balance at December 31, 2014 $ 15,797 Change in fair value 56,655 Settlement of warrant liability upon exercise (56,678 ) Reclassification of unexercised warrants to additional paid-in capital upon the initial public offering (15,774 ) Balance at June 30, 2015 $ —

Derivative Financial Instrume23

Derivative Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of derivative instruments	The table below presents the notional amount of the foreign currency contracts as of June 30, 2015 (in thousands): Notional Amount Sold Functional Currency: Foreign Amount USD Equivalent AUD 35,260 $ 27,348 CAD 8,580 6,971 EUR 10,800 12,090 GBP 10,680 16,643 JPY 75,000 609 NZD 1,142 798 $ 64,459 The table below presents the notional amount of the foreign currency contracts as of December 31, 2014 (in thousands): Notional Amount Purchased Functional Currency: Foreign Amount USD Equivalent AUD 32,700 $ 26,810 CAD 3,200 2,782 EUR 2,700 3,355 GBP 2,100 3,295 NZD 1,200 930 $ 37,172

Balance Sheet Components (Table

Balance Sheet Components (Tables)	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of accounts receivable reserves	Revenue returns reserve activities were as follows (in thousands): Three Months Ended Six Months Ended 2015 2014 2015 2014 Beginning balances $ 26,362 $ 15,631 $ 26,559 $ 15,416 Increases 32,859 7,836 53,352 14,660 Returns taken (23,956 ) (6,318 ) (44,646 ) (12,927 ) Ending balances $ 35,265 $ 17,149 $ 35,265 $ 17,149
Schedule of inventories	Inventories consisted of the following (in thousands): June 30, 2015 December 31, 2014 Components $ 60,217 $ 53,383 Finished goods 126,653 61,689 Total inventories $ 186,870 $ 115,072
Schedule of prepaid expenses and other current asset	Prepaid expenses and other current assets consisted of the following (in thousands): June 30, 2015 December 31, 2014 POP displays, net $ 6,700 $ 7,121 Prepaid expenses and other current assets 11,463 6,493 Total prepaid expenses and other current assets $ 18,163 $ 13,614
Schedule of property and equipment	Property and equipment, net, consisted of the following (in thousands): June 30, 2015 December 31, 2014 Tooling and manufacturing equipment $ 38,559 $ 28,344 Furniture and office equipment 4,180 2,891 Purchased and internally-developed software 1,854 1,396 Leasehold improvements 3,661 3,594 Total property and equipment 48,254 36,225 Less: Accumulated depreciation and amortization (17,309 ) (9,790 ) Property and equipment, net $ 30,945 $ 26,435
Schedule of goodwill	The changes in the carrying amount of goodwill for the six months ended June 30, 2015 were as follows (in thousands). See Note 13 for additional information. Goodwill Balance at December 31, 2014 $ — Goodwill acquired 22,562 Subsequent goodwill adjustments (405 ) Balance at June 30, 2015 $ 22,157
Schedule of intangible assets (excluding goodwill)	The carrying amounts of the intangible assets as of June 30, 2015 were as follows (in thousands, except useful life). See Note 13 for additional information. June 30, 2015 Weighted Average Remaining Useful Life (years) Gross Accumulated Amortization Net Developed technology $ 12,640 $ (558 ) $ 12,082 6.7 Trademarks and other 1,278 (97 ) 1,181 4.4 Total intangible assets, net $ 13,918 $ (655 ) $ 13,263
Schedule of estimated future amortization expense	The estimated future amortization expense of acquired intangible assets to be charged to cost of revenue and operating expenses after June 30, 2015, is as follows (in thousands): Cost of Revenue Operating Expenses Total Remaining 2015 $ 883 $ 164 $ 1,047 2016 1,806 281 2,087 2017 1,806 230 2,036 2018 1,806 230 2,036 2019 1,806 230 2,036 Thereafter 3,975 46 4,021 Total intangible assets, net $ 12,082 $ 1,181 $ 13,263
Schedule of accrued liabilities	Accrued liabilities consisted of the following (in thousands): June 30, 2015 December 31, 2014 Product warranty $ 31,063 $ 20,098 Employee related liabilities 10,148 4,115 Accrued cooperative advertising and marketing development funds 10,132 7,679 Accrued sales incentives 4,034 2,355 Sales taxes and VAT payable 3,040 2,291 Accrued manufacturing expense 2,113 9,953 Customer deposits 1,864 6,391 Inventory received not billed — 6,242 Other 17,224 11,816 Accrued liabilities $ 79,618 $ 70,940
Schedule of product warranty reserves	Product warranty reserve activities were as follows (in thousands) (1) : Three Months Ended Six Months Ended 2015 2014 2015 2014 Beginning balances $ 23,251 $ 6,740 $ 20,098 $ 8,480 Charged to cost of revenue 14,568 2,494 22,065 2,062 Settlement of claims (6,756 ) (1,609 ) (11,100 ) (2,917 ) Ending balances $ 31,063 $ 7,625 $ 31,063 $ 7,625 (1) Does not include reserves established as a result of the recall of the Fitbit Force. See the section titled “—Fitbit Force Recall Reserve” for additional information regarding such reserves.
Schedule of product recall reserves	Fitbit Force recall reserve activities were as follows (in thousands): Three Months Ended Six Months Ended 2015 2014 2015 2014 Beginning balances $ 15,104 $ 84,239 $ 22,476 $ 82,938 Charged to revenue — — — 11,561 Charged (benefit) to cost of revenue — — (2,040 ) 10,602 Charged (benefit) to general and administrative 69 — (73 ) 505 Settlement of claims (2,279 ) (27,165 ) (7,469 ) (48,532 ) Ending balances $ 12,894 $ 57,074 $ 12,894 $ 57,074

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of future minimum rental payments for operating leases	Future minimum payments under the leases as of June 30, 2015 were as follows (in thousands): Amounts Remaining 2015 $ 3,633 2016 13,106 2017 16,905 2018 16,926 2019 16,263 Thereafter 56,294 Total $ 123,127

Redeemable Convertible Prefer26

Redeemable Convertible Preferred Stock and Warrants (Tables)	6 Months Ended
	Jun. 30, 2015
Temporary Equity Disclosure [Abstract]
Schedule of redeemable convertible preferred stock	Redeemable Convertible Preferred Stock Upon the closing of the Company’s IPO, all shares of the Company’s then-outstanding redeemable convertible preferred stock, as shown in the table below, automatically converted on a one-for-one basis into an aggregate of 139,851,483 shares of Class B common stock. Redeemable convertible preferred stock outstanding as of December 31, 2014 and as of immediately prior to the conversion into Class B common stock consisted of the following (in thousands, except per share data): Shares Authorized Shares Outstanding Price per Share Net Carrying Value Liquidation Preference Series A 10,200 10,200 $ 0.04167 $ 421 $ 425 Series A-1 22,369 22,369 0.09165 2,000 2,050 Series B 42,360 42,052 0.21580 10,533 9,075 Series C 39,600 36,080 0.33452 12,049 12,069 Series D 30,000 29,150 1.47513 42,811 43,000 Total 144,529 139,851 $ 67,814 $ 66,619
Schedule of redeemable convertible preferred stock warrants issued and outstanding	As of December 31, 2014, and until immediately prior to the completion of the IPO, the Company had the following redeemable convertible preferred stock warrants issued and outstanding (in thousands, except per share data): Warrant Class Number of Shares Underlying Warrants Fair Value Issuance Date Exercise Price per Share Series B 278 $ 2,351 June 2011 $ 0.22 Series C 57 475 April 2012 0.33 Series C 1,215 9,728 September 2012 0.67 Series C (1) 405 3,243 September 2012 0.67 Total 1,955 $ 15,797 (1) Represents additional shares that may be exercised pursuant to the Series C redeemable convertible preferred stock warrant issued in September 2012 due to a draw down on a debt financing arrangement in March 2013.

Stock Plan (Tables)

Stock Plan (Tables)	6 Months Ended
	Jun. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of stock option activity	ctivity under the equity incentive plans was as follows: Options Outstanding Number of Shares Subject to Options Weighted– Average Exercise Price Aggregate Intrinsic Value (in thousands) (in thousands) Balance—December 31, 2014 44,009 $ 1.72 $ 207,863 Granted 6,844 10.27 Exercised (719 ) 0.62 $ 10,737 Forfeited or canceled (896 ) 3.34 Balance—June 30, 2015 49,238 2.90 $ 1,739,756 Options exercisable—June 30, 2015 20,528 0.51 $ 774,329 Options vested and expected to vest—June 30, 2015 46,462 2.81 $ 1,645,537
Schedule of restricted stock unit activity	RSU activity under the equity incentive plans was as follows: RSUs Outstanding Weighted- Average Grant Date Fair Value (in thousands) Unvested balance—December 31, 2014 — $ — Granted 504 15.70 Unvested balance—June 30, 2015 504 15.70
Schedule of stock-based compensation expense	Total stock-based compensation recognized was as follows (in thousands): Three Months Ended Six Months Ended 2015 2014 2015 2014 Cost of revenue $ 825 $ 129 $ 1,271 $ 188 Research and development 3,138 192 5,017 284 Sales and marketing 1,322 120 2,629 183 General and administrative 2,462 220 3,733 320 Total stock-based compensation expense $ 7,747 $ 661 $ 12,650 $ 975
Schedule of options valuation assumptions	The fair value of the stock option awards granted to employees was estimated at the date of grant using a Black-Scholes option-pricing model with the following assumptions: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Employee stock options Expected term in years 6.25 6.25 6.25 6.25 Volatility 52.7% - 55.1% 60.8% - 60.9% 52.7% - 56.9% 60.8% - 60.9% Risk-free interest rate 1.5% - 1.9% 1.9% - 2.0% 1.5% - 1.9% 1.9% - 2.0% Dividend yield —% —% —% —% Employee stock purchase plan Expected term in years 0.92 — 0.92 — Volatility 55% —% 55% —% Risk-free interest rate 0.3% —% 0.3% —% Dividend yield —% —% —% —%

Net Income per Share Attribut28

Net Income per Share Attributable to Common Stockholders (Tables)	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Schedule of basic and diluted net income (loss) per share	The following table sets forth the computation of the Company’s basic and diluted net income per share attributable to common stockholders (in thousands, except per share amounts): Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Class A Class B Class B Class A Class B Class B Numerator: Net income $ 1,256 $ 16,425 $ 14,753 $ 2,752 $ 62,926 $ 23,625 Less: noncumulative dividends to preferred stockholders (86 ) (1,126 ) (1,327 ) (106 ) (2,420 ) (2,640 ) Less: undistributed earnings to participating securities (799 ) (10,445 ) (10,423 ) (1,924 ) (43,983 ) (16,293 ) Net income attributable to common stockholders—basic $ 371 $ 4,854 $ 3,003 $ 722 $ 16,523 $ 4,692 Add: adjustments to undistributed earnings to participating securities 1,862 1,731 1,058 7,003 6,717 1,618 Reallocation of net income as a result of conversion of Class B to Class A common stock 4,854 — — 16,523 — — Reallocation of net income to Class B common stock — 191 — — $ 392 — Net income attributable to common stockholders—diluted $ 7,087 $ 6,776 $ 4,061 $ 24,248 $ 23,632 $ 6,310 Denominator: Weighted-average shares of common stock—basic 4,160 54,388 40,193 2,091 47,831 40,174 Conversion of Class B to Class A common stock 54,388 — — 47,831 — — Effect of potentially dilutive stock options, RSUs, common stock warrants, and ESPP 36,642 36,618 20,294 32,919 32,907 19,809 Weighted-average shares of common stock—diluted 95,190 91,006 60,487 82,841 80,738 59,983 Net income per share attributable to common stockholders: Basic $ 0.09 $ 0.09 $ 0.07 $ 0.35 $ 0.35 $ 0.12 Diluted $ 0.07 $ 0.07 $ 0.07 $ 0.29 $ 0.29 $ 0.11
Schedule of antidilutive securities excluded from earnings per share	The following common stock equivalents were excluded from the computation of diluted net income per share for the periods presented because including them would have been anti-dilutive (in thousands): Three Months Six Months 2015 2014 2015 2014 Redeemable convertible preferred stock 126,020 139,504 132,898 139,504 Stock options to purchase common stock — 1,550 799 1,219 Redeemable convertible preferred stock warrants 1,808 2,303 1,808 1,794 Total 127,828 143,357 135,505 142,517

Significant Customer Informat29

Significant Customer Information and Other Information (Tables)	6 Months Ended
	Jun. 30, 2015
Risks and Uncertainties [Abstract]
Schedules of concentration of risk	Retailers and distributors with revenue equal to or greater than 10% of total revenue for the three and six months ended June 30, 2014 and 2015 were as follows: Three Months Ended Six Months Ended 2015 2014 2015 2014 A 14 % 15 % 16 % 12 % B 14 * 12 13 C 13 15 12 14 D 11 * * * *Revenue was less than 10%. Retailers and distributors that accounted for equal to or greater than 10% of net accounts receivable at December 31, 2014 and June 30, 2015 were as follows: June 30, December 31, B 17 % 17 % D 17 13 C 16 14 A 11 * E * 10 * Accounts receivable were less than 10%. Revenue by geographic region, based on ship-to destinations, was as follows (in thousands): Three Months Ended Six Months Ended 2015 2014 2015 2014 United States $ 312,666 $ 88,504 $ 577,975 $ 178,335 Americas excluding United States 16,799 7,177 30,228 10,893 Europe, Middle East, and Africa 39,712 9,915 74,768 18,639 APAC 31,235 7,976 54,195 14,520 Total $ 400,412 $ 113,572 $ 737,166 $ 222,387

Acquisition (Tables)

Acquisition (Tables)	6 Months Ended
	Jun. 30, 2015
Business Combinations [Abstract]
Schedule of fair value of assets acquired and liabilities assumed	The following table summarizes the fair value of assets acquired and liabilities assumed (in thousands): Goodwill $ 22,157 Developed and core technology 12,640 Customer relationships 128 Trademarks 1,150 Assumed liabilities, net of assets (3,552 ) Total $ 32,523

Business Overview - Narrative (

Business Overview - Narrative (Details) $ / shares in Units, $ in Thousands	Jun. 22, 2015classshares	Jun. 30, 2015USD ($)classvote$ / sharesshares	Jun. 30, 2015USD ($)classvote$ / shares	Jun. 30, 2014USD ($)
Class of Stock [Line Items]
Net proceeds from initial public offering | $		$ 420,900	$ 420,885	$ 0
Number of classes of stock | class	2	2	2
Common Stock [Member]
Class of Stock [Line Items]
Shares sold (in shares)		22,387,500
Common Class A [Member]
Class of Stock [Line Items]
Common stock, votes per share | vote		1	1
Common Class B [Member]
Class of Stock [Line Items]
Shares sold (in shares)	139,851,483
Common stock, votes per share | vote		10	10
Common Class B [Member] | Additional Paid-in Capital [Member]
Class of Stock [Line Items]
Reclassification | $		$ 67,800
Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock converted and reclassified into Class B Common Stock (in shares)		139,851,483
Series B [Member]
Class of Stock [Line Items]
Shares issued (in shares)	274,992
Series C [Member]
Class of Stock [Line Items]
Shares issued (in shares)	1,210,591
IPO [Member]
Class of Stock [Line Items]
Offering costs incurred | $			$ 5,200
IPO [Member] | Common Stock [Member]
Class of Stock [Line Items]
Share price (in dollars per share) | $ / shares		$ 20	$ 20
Underwriting discounts and commissions | $		$ 26,900
Offering costs incurred | $		$ 5,200
Over-Allotment Option [Member] | Common Stock [Member]
Class of Stock [Line Items]
Shares sold (in shares)		5,486,250
Select Stockholders [Member] | IPO [Member] | Common Stock [Member]
Class of Stock [Line Items]
Shares sold by certain shareholders (in shares)		19,673,750
Series B [Member] | Additional Paid-in Capital [Member]
Class of Stock [Line Items]
Reclassification | $		$ 72,500

Basis of Presentation and Sum32

Basis of Presentation and Summary of Significant Accounting Policies - Stock Split (Details)	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Stock split, conversion ratio	1.5

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Liabilities:
Redeemable convertible preferred stock warrant liability	$ 0	$ 15,797
Fair Value, Measurements, Recurring [Member]
Assets:
Derivative assets	541	316
Liabilities:
Redeemable convertible preferred stock warrant liability		15,797
Derivative liabilities	291	105
Total		15,902
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets:
Derivative assets	0	0
Liabilities:
Redeemable convertible preferred stock warrant liability		0
Derivative liabilities	0	0
Total		0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets:
Derivative assets	541	316
Liabilities:
Redeemable convertible preferred stock warrant liability		0
Derivative liabilities	291	105
Total		105
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets:
Derivative assets	0	0
Liabilities:
Redeemable convertible preferred stock warrant liability		15,797
Derivative liabilities	$ 0	0
Total		$ 15,797

Fair Value Measurements - Chang

Fair Value Measurements - Changes in fair value (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2015USD ($)
Redeemable Convertible Preferred Stock Warrant [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value of liability, beginning of period	$ 15,797
Change in fair value	56,655
Settlement of warrant liability upon exercise	(56,678)
Reclassification of unexercised warrants to additional paid-in capital upon the initial public offering	(15,774)
Fair value of liability, end of period	0
Acquisition Contingent Consideration [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value of liability, beginning of period	0
Addition from acquisition	7,704
Change in fair value	(7,704)
Fair value of liability, end of period	$ 0

Derivative Financial Instrume35

Derivative Financial Instruments (Details) - Not Designated as Hedging Instrument [Member] - Foreign Currency Contract [Member] € in Thousands, ¥ in Thousands, £ in Thousands, NZD in Thousands, CAD in Thousands, AUD in Thousands, $ in Thousands

Jun. 30, 2015USD ($)

Jun. 30, 2015AUD

Jun. 30, 2015CAD

Jun. 30, 2015EUR (€)

Jun. 30, 2015NZD

Jun. 30, 2015GBP (£)

Jun. 30, 2015JPY (¥)

Dec. 31, 2014USD ($)

Dec. 31, 2014AUD

Dec. 31, 2014CAD

Dec. 31, 2014EUR (€)

Dec. 31, 2014NZD

Dec. 31, 2014GBP (£)

Sold [Member]

Derivative [Line Items]

Notional amount

$ 64,459

Sold [Member] | AUD [Member]

Derivative [Line Items]

Notional amount

27,348

AUD 35,260

Sold [Member] | CAD [Member]

Derivative [Line Items]

Notional amount

6,971

CAD 8,580

Sold [Member] | EUR [Member]

Derivative [Line Items]

Notional amount

12,090

€ 10,800

Sold [Member] | GBP [Member]

Derivative [Line Items]

Notional amount

16,643

£ 10,680

Sold [Member] | JPY [Member]

Derivative [Line Items]

Notional amount

609

¥ 75,000

Sold [Member] | NZD [Member]

Derivative [Line Items]

Notional amount

$ 798

NZD 1,142

Purchased [Member]

Derivative [Line Items]

Notional amount

$ 37,172

Purchased [Member] | AUD [Member]

Derivative [Line Items]

Notional amount

26,810

AUD 32,700

Purchased [Member] | CAD [Member]

Derivative [Line Items]

Notional amount

2,782

CAD 3,200

Purchased [Member] | EUR [Member]

Derivative [Line Items]

Notional amount

3,355

€ 2,700

Purchased [Member] | GBP [Member]

Derivative [Line Items]

Notional amount

3,295

£ 2,100

Purchased [Member] | NZD [Member]

Derivative [Line Items]

Notional amount

$ 930

NZD 1,200

Derivative Financial Instrume36

Derivative Financial Instruments - Narrative (Details) - Foreign Currency Contract [Member] - Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Income (Expense), Net [Member]
Derivative [Line Items]
Gain on derivative instruments, net	$ 500	$ 2,500
Prepaid Expenses and Other Assets [Member]
Derivative [Line Items]
Derivative asset, notional amount	500	500	$ 300
Accrued Liabilities [Member]
Derivative [Line Items]
Derivative liability, notional amount	300	300	100
Purchased [Member]
Derivative [Line Items]
Notional amount			$ 37,172
Sold [Member]
Derivative [Line Items]
Notional amount	$ 64,459	$ 64,459

Balance Sheet Components - Acco

Balance Sheet Components - Account Receivable Reserves (Details) - Revenue Reserve [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balances	$ 26,362	$ 15,631	$ 26,559	$ 15,416
Increases	32,859	7,836	53,352	14,660
Returns taken	(23,956)	(6,318)	(44,646)	(12,927)
Ending balances	$ 35,265	$ 17,149	$ 35,265	$ 17,149

Balance Sheet Components - Inve

Balance Sheet Components - Inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Components	$ 60,217	$ 53,383
Finished goods	126,653	61,689
Total inventories	$ 186,870	$ 115,072

Balance Sheet Components - Prep

Balance Sheet Components - Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
POP displays, net	$ 6,700	$ 7,121
Prepaid expenses and other current assets	11,463	6,493
Total prepaid expenses and other current assets	$ 18,163	$ 13,614

Balance Sheet Components - Prop

Balance Sheet Components - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 48,254	$ 36,225
Less: Accumulated depreciation and amortization	(17,309)	(9,790)
Property and equipment, net	30,945	26,435
Tooling and manufacturing equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	38,559	28,344
Furniture and office equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	4,180	2,891
Purchased and internally-developed software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	1,854	1,396
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 3,661	$ 3,594

Balance Sheet Components - Good

Balance Sheet Components - Goodwill Rollfoward (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2015USD ($)
Goodwill [Roll Forward]
Balance at December 31, 2014	$ 0
Goodwill acquired	22,562
Subsequent goodwill adjustments	(405)
Balance at June 30, 2015	$ 22,157

Balance Sheet Components - Inta

Balance Sheet Components - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2015	Jun. 30, 2014
Finite-Lived Intangible Assets [Line Items]
Gross	$ 13,918	$ 13,918
Accumulated Amortization	(655)	(655)
Net	13,263	13,263
Amortization of intangible assets	549	655	$ 0
Developed technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	12,640	12,640
Accumulated Amortization	(558)	(558)
Net	12,082	$ 12,082
Weighted Average Remaining Useful Life (years)		6 years 8 months 12 days
Trademarks and other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	1,278	$ 1,278
Accumulated Amortization	(97)	(97)
Net	$ 1,181	$ 1,181
Weighted Average Remaining Useful Life (years)		4 years 4 months 24 days

Balance Sheet Components - Esti

Balance Sheet Components - Estimated Future Amortization Expense (Details) $ in Thousands	Jun. 30, 2015USD ($)
Finite-Lived Intangible Assets [Line Items]
Remaining 2,015	$ 1,047
2,016	2,087
2,017	2,036
2,018	2,036
2,019	2,036
Thereafter	4,021
Net	13,263
Cost of revenue [Member]
Finite-Lived Intangible Assets [Line Items]
Remaining 2,015	883
2,016	1,806
2,017	1,806
2,018	1,806
2,019	1,806
Thereafter	3,975
Net	12,082
Operating expenses [Member]
Finite-Lived Intangible Assets [Line Items]
Remaining 2,015	164
2,016	281
2,017	230
2,018	230
2,019	230
Thereafter	46
Net	$ 1,181

Balance Sheet Components - Accr

Balance Sheet Components - Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Product warranty	$ 31,063	$ 20,098
Employee related liabilities	10,148	4,115
Accrued cooperative advertising and marketing development funds	10,132	7,679
Accrued sales incentives	4,034	2,355
Sales taxes and VAT payable	3,040	2,291
Accrued manufacturing expense	2,113	9,953
Customer deposits	1,864	6,391
Inventory received not billed	0	6,242
Other	17,224	11,816
Accrued liabilities	$ 79,618	$ 70,940

Balance Sheet Components - Prod

Balance Sheet Components - Product Warranty (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
Beginning balances	$ 23,251	$ 6,740	$ 20,098	$ 8,480
Charged to cost of revenue	14,568	2,494	22,065	2,062
Settlement of claims	(6,756)	(1,609)	(11,100)	(2,917)
Ending balances	$ 31,063	$ 7,625	$ 31,063	$ 7,625

Balance Sheet Components - Rese

Balance Sheet Components - Reserve Accounts (Details) - Product Recall Reserves [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balances	$ 15,104	$ 84,239	$ 22,476	$ 82,938
Charged to revenue	0	0	0	11,561
Charged (benefit) to cost of revenue	0	0	(2,040)	10,602
Charged (benefit) to general and administrative	69	0	(73)	505
Settlement of claims	(2,279)	(27,165)	(7,469)	(48,532)
Ending balances	$ 12,894	$ 57,074	$ 12,894	$ 57,074

Long-Term Debt (Details)

Long-Term Debt (Details)	1 Months Ended			3 Months Ended		6 Months Ended
	Jan. 31, 2015USD ($)	Oct. 31, 2014USD ($)	Aug. 31, 2014USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2014USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2014USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013
Line of Credit Facility [Line Items]
Interest expense				$ 400,000	$ 500,000	$ 900,000	$ 900,000
Line of Credit [Member] | 2014 Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit facility, borrowing capacity			$ 180,000,000
Credit facility, amount outstanding				$ 0		$ 0		$ 125,000,000
Credit facility, minimal stated interest rate			3.25%
Credit facility, minimum fixed charge coverage ratio			1
Credit facility, maximum leverage ratio			3
Credit facility, minimum leverage ratio			2
Credit facility, minimum liquidity level			$ 15,000,000
Repayment of line of credit	$ 125,000,000
Line of Credit [Member] | 2014 Credit Facility [Member] | Federal Funds Effective Rate [Member]
Line of Credit Facility [Line Items]
Credit facility, basis spread on variable rate			0.50%
Line of Credit [Member] | 2014 Credit Facility [Member] | Eurodollar [Member]
Line of Credit Facility [Line Items]
Credit facility, basis spread on variable rate			1.00%
Line of Credit [Member] | 2014 Credit Facility [Member] | Commitment Fee, Scenario One [Member]
Line of Credit Facility [Line Items]
Credit facility, commitment fee rate			0.25%
Line of Credit [Member] | 2014 Credit Facility [Member] | Commitment Fee, Scenario Two [Member]
Line of Credit Facility [Line Items]
Credit facility, commitment fee rate			0.35%
Line of Credit [Member] | 2014 Credit Facility [Member] | Commitment Fee, Scenario Three [Member]
Line of Credit Facility [Line Items]
Credit facility, commitment fee rate			0.45%
Revolving Credit Facility [Member] | 2014 Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit facility, effective interest rate								4.25%	4.25%
Revolving Credit Facility [Member] | 2014 Revolving Credit And Guarantee Agreement [Member]
Line of Credit Facility [Line Items]
Credit facility, borrowing capacity		$ 50,000,000
Credit facility, effective interest rate				3.59%		3.59%		3.59%
Credit facility, amount outstanding				$ 0		$ 0		$ 8,000,000
Credit facility, maximum stated interest rate		3.50%
Credit facility, maximum leverage ratio		3
Credit facility, minimum leverage ratio		2
Repayment of line of credit						8,000,000
Revolving Credit Facility [Member] | 2014 Revolving Credit And Guarantee Agreement [Member] | Federal Funds Effective Rate [Member]
Line of Credit Facility [Line Items]
Credit facility, basis spread on variable rate		0.50%
Revolving Credit Facility [Member] | 2014 Revolving Credit And Guarantee Agreement [Member] | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Credit facility, basis spread on variable rate		1.00%
Revolving Credit Facility [Member] | 2014 Revolving Credit And Guarantee Agreement [Member] | Commitment Fee, Scenario One [Member]
Line of Credit Facility [Line Items]
Credit facility, commitment fee rate		0.375%
Revolving Credit Facility [Member] | 2014 Revolving Credit And Guarantee Agreement [Member] | Commitment Fee, Scenario Two [Member]
Line of Credit Facility [Line Items]
Credit facility, commitment fee rate		0.50%
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Credit facility, amount outstanding				$ 3,500,000		$ 3,500,000		$ 2,900,000
Letter of Credit [Member] | 2014 Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit facility, borrowing capacity			$ 50,000,000
Letter of Credit [Member] | 2014 Revolving Credit And Guarantee Agreement [Member]
Line of Credit Facility [Line Items]
Credit facility, borrowing capacity		$ 10,000,000
Swing Line Loan [Member] | 2014 Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit facility, borrowing capacity			$ 25,000,000
Swing Line Loan [Member] | 2014 Revolving Credit And Guarantee Agreement [Member]
Line of Credit Facility [Line Items]
Credit facility, borrowing capacity		$ 10,000,000

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Millions	Jul. 08, 2015patent	Jul. 03, 2015patent	Jun. 10, 2015patent	Jun. 30, 2015USD ($)	Jun. 30, 2014USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2014USD ($)	Dec. 31, 2014USD ($)
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Rent expense | $				$ 1.5	$ 1.1	$ 2.6	$ 2.2
Purchase Commitment [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Purchase commitment | $				$ 344.1		$ 344.1		$ 257
Jawbone Patent Litigation [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Loss contingency, patents allegedly infringed			3
Jawbone Patent Litigation [Member] | Subsequent Event [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Loss contingency, patents allegedly infringed	6
Loss contingency, additional patents allegedly infringed		3

Commitments and Contingencies49

Commitments and Contingencies - Future Minimum Payments (Details) $ in Thousands	Jun. 30, 2015USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Remaining 2,015	$ 3,633
2,016	13,106
2,017	16,905
2,018	16,926
2,019	16,263
Thereafter	56,294
Total	$ 123,127

Redeemable Convertible Prefer50

Redeemable Convertible Preferred Stock and Warrants - Preferred Shares (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Temporary Equity [Line Items]
Preferred stock authorized (in shares)	0	144,528,912
Preferred stock outstanding (in shares)	0	139,851,483
Preferred stock, net carrying value	$ 0	$ 67,814
Preferred stock, liquidation preference		$ 66,619
Series A [Member]
Temporary Equity [Line Items]
Preferred stock authorized (in shares)		10,200,000
Preferred stock outstanding (in shares)		10,200,000
Preferred stock, price (in dollars per share)		$ 0.04166666667
Preferred stock, net carrying value		$ 421
Preferred stock, liquidation preference		$ 425
Series A-1 [Member]
Temporary Equity [Line Items]
Preferred stock authorized (in shares)		22,369,000
Preferred stock outstanding (in shares)		22,369,000
Preferred stock, price (in dollars per share)		$ 0.09164666667
Preferred stock, net carrying value		$ 2,000
Preferred stock, liquidation preference		$ 2,050
Series B [Member]
Temporary Equity [Line Items]
Preferred stock authorized (in shares)		42,360,000
Preferred stock outstanding (in shares)		42,052,000
Preferred stock, price (in dollars per share)		$ 0.2158
Preferred stock, net carrying value		$ 10,533
Preferred stock, liquidation preference		$ 9,075
Series C [Member]
Temporary Equity [Line Items]
Preferred stock authorized (in shares)		39,600,000
Preferred stock outstanding (in shares)		36,080,000
Preferred stock, price (in dollars per share)		$ 0.33452
Preferred stock, net carrying value		$ 12,049
Preferred stock, liquidation preference		$ 12,069
Series D [Member]
Temporary Equity [Line Items]
Preferred stock authorized (in shares)		30,000,000
Preferred stock outstanding (in shares)		29,150,000
Preferred stock, price (in dollars per share)		$ 1.4751333333
Preferred stock, net carrying value		$ 42,811
Preferred stock, liquidation preference		$ 43,000

Redeemable Convertible Prefer51

Redeemable Convertible Preferred Stock and Warrants - Warrants Issued and Outstanding (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Class of Warrant or Right [Line Items]
Number of shares underlying warrants (in shares)		1,955
Fair value of warrants	$ 0	$ 15,797
Series B [Member]
Class of Warrant or Right [Line Items]
Number of shares underlying warrants (in shares)		278
Fair value of warrants		$ 2,351
Exercise price of warrants (in dollars per share)		$ 0.22
Series C Preferred Stock - April 2012 [Member]
Class of Warrant or Right [Line Items]
Number of shares underlying warrants (in shares)		57
Fair value of warrants		$ 475
Exercise price of warrants (in dollars per share)		$ 0.33
Series C Preferred Stock - September 2012 - Group One [Member]
Class of Warrant or Right [Line Items]
Number of shares underlying warrants (in shares)		1,215
Fair value of warrants		$ 9,728
Exercise price of warrants (in dollars per share)		$ 0.67
Series C Preferred Stock - September 2012 - Group Two [Member]
Class of Warrant or Right [Line Items]
Number of shares underlying warrants (in shares)		405
Fair value of warrants		$ 3,243
Exercise price of warrants (in dollars per share)		$ 0.67

Redeemable Convertible Prefer52

Redeemable Convertible Preferred Stock and Warrants - Narrative (Details) - $ / shares	Jun. 22, 2015	Jun. 30, 2015	Jun. 30, 2014
Common Class B [Member]
Temporary Equity [Line Items]
Shares issued in conversion of outstanding redeemable convertible preferred stock (in shares)	139,851,483
Series B [Member]
Temporary Equity [Line Items]
Shares issued (in shares)	274,992
Warrants exercised (in shares)	277,992
Warrants forfeited (in shares)	3,000
Series C [Member]
Temporary Equity [Line Items]
Shares issued (in shares)	1,210,591
Warrants exercised (in shares)	1,251,357
Warrants forfeited (in shares)	40,766
Class B, Common Stock Warrant [Member]
Temporary Equity [Line Items]
Warrants outstanding (in shares)		425,643
Exercise price of warrants (in dollars per share)			$ 0.67

Stock Plan - Narrative (Details

Stock Plan - Narrative (Details) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	May. 31, 2015shares	Jun. 30, 2015USD ($)classvote$ / sharesshares	Jun. 30, 2014USD ($)$ / shares	Jun. 30, 2015USD ($)classvote$ / sharesshares	Jun. 30, 2014USD ($)$ / shares	Dec. 31, 2012USD ($)	Jun. 22, 2015class$ / shares	Dec. 31, 2014$ / sharesshares
Class of Stock [Line Items]
Preferred stock, authorized (in shares)		10,000,000		10,000,000
Preferred stock, par value (in dollars per share) | $ / shares		$ 0.0001		$ 0.0001
Common stock issued (in shares)								40,875,583
Common stock outstanding (in shares)								40,875,583
Number of classes of stock | class		2		2			2
Common stock authorized (in shares)								230,400,000
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation | $		$ 7,747	$ 661	$ 12,650	$ 975
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value of options that vested during period | $		4,700	$ 300	6,500	$ 500
Unrecognized compensation expense related to unvested options | $		82,000		$ 82,000
Unrecognized compensation expense related to unvested options, estimated weighted average period				3 years 6 months
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to unvested options, net of estimated forfeitures | $		6,800		$ 6,800
Unrecognized compensation expense related to unvested options, estimated weighted average period				3 years 3 months 18 days
2015 Plan [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				4 years
Expiration period				10 years
2015 Plan [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				4 years
Expiration period				10 years
Common Stock [Member] | FitStar [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to unvested options, net of estimated forfeitures | $		$ 3,100		$ 3,100
Unrecognized compensation expense related to unvested options, estimated weighted average period				2 years 8 months 12 days
Common Class A [Member]
Class of Stock [Line Items]
Common stock issued (in shares)		42,061,250		42,061,250				0
Common stock outstanding (in shares)		42,061,250		42,061,250				0
Common stock authorized (in shares)		600,000,000		600,000,000				0
Common stock, par value (in dollars per share) | $ / shares		$ 0.0001		$ 0.0001				$ 0.0001
Common stock, votes per share | vote		1		1
Common Class A [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of exercise price (in dollars per share) | $ / shares			$ 38.23		$ 38.23
Common Class A [Member] | 2015 Plan [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, annual increase based on shares outstanding, percent	5.00%
Common stock reserved for future issuance (in shares)		6,274,474		6,274,474
Common Class A [Member] | 2015 Employee Stock Purchase Plan [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	3,750,000
Common stock discount available to employees	15.00%
Common stock, fair value of market value of stock, available to employees, percent	85.00%
Share price (in dollars per share) | $ / shares							$ 20
Common Class B [Member]
Class of Stock [Line Items]
Common stock issued (in shares)		164,625,960		164,625,960				40,875,583
Common stock outstanding (in shares)		164,625,960		164,625,960				40,875,583
Common stock authorized (in shares)		350,000,000		350,000,000				230,400,000
Common stock, par value (in dollars per share) | $ / shares		$ 0.0001		$ 0.0001				$ 0.0001
Common stock, votes per share | vote		10		10

Stock Plan - Stock Option Activ

Stock Plan - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance, beginning of period (in shares)	44,009
Granted (in shares)	6,844.158
Exercised (in shares)	(719.157)
Canceled (in shares)	(896)
Balance, end of period (in shares)	49,238
Options exercisable (in shares)	20,528
Options vested and expected to vest (in shares)	46,462
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Balance, weighted average exercise price, beginning of period (in dollars per share)	$ 1.72
Granted, weighted average exercise price (in dollars per share)	10.27
Exercised, weighted average exercise price (in dollars per share)	0.62
Canceled, weighted average exercise price (in dollars per share)	3.34
Balance, weighted average exercise price, end of period (in dollars per share)	2.90
Options exercisable, weighted average exercise price (in dollars per share)	0.51
Options vested and expected to vest, weighted average exercise price (in dollars per share)	$ 2.81
Options canceled, aggregate intrinsic value	$ 10,737
Options outstanding, aggregate intrinsic value	1,739,756	$ 207,863
Options exercisable, aggregate intrinsic value	774,329
Options vested and expected to vest, aggregate intrinsic value	$ 1,645,537

Stock Plan - Restricted Stock U

Stock Plan - Restricted Stock Unit Activity (Details) - 6 months ended Jun. 30, 2015 - Restricted Stock Units (RSUs) [Member] - $ / shares shares in Thousands	Total
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested balance—December 31, 2014 (in shares)	0
Granted (in shares)	504
Unvested balance—June 30, 2015 (in shares)	504
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Unvested balance—December 31, 2014 (in dollars per share)	$ 0
Granted (in dollars per share)	15.70
Unvested balance—June 30, 2015 (in dollars per share)	$ 15.70

Stock Plan - Stock Compensation

Stock Plan - Stock Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 7,747	$ 661	$ 12,650	$ 975
Cost of revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	825	129	1,271	188
Research and development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	3,138	192	5,017	284
Sales and marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	1,322	120	2,629	183
General and administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 2,462	$ 220	$ 3,733	$ 320

Stock Plan - Valuation Assumpti

Stock Plan - Valuation Assumptions (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	6 years 3 months	6 years 3 months	6 years 3 months	6 years 3 months
Minimum volatility rate	52.70%	60.80%	52.70%	60.80%
Maximum volatility rate	55.10%	60.90%	56.90%	60.90%
Minimum risk-free interest rate	1.50%	1.90%	1.50%	1.90%
Maximum risk-free interest rate	1.90%	2.00%	1.90%	2.00%
Dividend yield rate	0.00%	0.00%	0.00%	0.00%
Employee stock purchase plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	11 months 1 day		11 months 1 day
Volatility rate	55.00%	0.00%	55.00%	0.00%
Risk-free interest rate	0.30%	0.00%	0.30%	0.00%
Dividend yield rate	0.00%	0.00%	0.00%	0.00%

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Tax Disclosure [Abstract]
Income tax expense	$ 17,048	$ 6,934	$ 45,442	$ 12,225
Effective income tax rate	49.10%	32.00%	40.90%	34.10%
Unrecognized tax benefits	$ 13,500		$ 13,500
Unrecognized Tax Benefits, Interest on Income Taxes Expense	$ 100		$ 400

Net Income per Share Attribut59

Net Income per Share Attributable to Common Stockholders - Narrative (Details)	Jun. 30, 2015classvote	Jun. 22, 2015class
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Number of classes of stock | class	2	2
Common Class A [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Common stock, votes per share	1
Common Class B [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Common stock, votes per share	10

Net Income per Share Attribut60

Net Income per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 17,681	$ 14,753	$ 65,678	$ 23,625
Less: noncumulative dividends to preferred stockholders	(1,212)	(1,327)	(2,526)	(2,640)
Less: undistributed earnings to participating securities	(11,244)	(10,423)	(45,907)	(16,293)
Net income attributable to common stockholders—basic	5,225	3,003	17,245	4,692
Add: adjustments to undistributed earnings to participating securities	1,862	1,058	7,003	1,618
Net income attributable to common stockholders—diluted	$ 7,087	$ 4,061	$ 24,248	$ 6,310
Denominator:
Weighted-average shares of common stock—basic (in shares)	58,548	40,193	49,922	40,174
Weighted-average shares of common stock—diluted (in shares)	95,190	60,487	82,841	59,983
Net income (loss) per share attributable to common stockholders, basic (in dollars per share)	$ 0.09	$ 0.07	$ 0.35	$ 0.12
Net income (loss) per share attributable to common stockholders, diluted (in dollars per share)	$ 0.07	$ 0.07	$ 0.29	$ 0.11
Common Class A [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 1,256		$ 2,752
Less: noncumulative dividends to preferred stockholders	(86)		(106)
Less: undistributed earnings to participating securities	(799)		(1,924)
Net income attributable to common stockholders—basic	371		722
Add: adjustments to undistributed earnings to participating securities	1,862		7,003
Reallocation of net income as a result of conversion of Class B to Class A common stock	4,854		16,523
Reallocation of net income to Class B common stock	0		0
Net income attributable to common stockholders—diluted	$ 7,087		$ 24,248
Denominator:
Weighted-average shares of common stock—basic (in shares)	4,160		2,091
Conversion of Class B to Class A common stock (in shares)	54,388		47,831
Effect of potentially dilutive stock options, RSUs, common stock warrants, and ESPP (in shares)	36,642		32,919
Weighted-average shares of common stock—diluted (in shares)	95,190		82,841
Net income (loss) per share attributable to common stockholders, basic (in dollars per share)	$ 0.09		$ 0.35
Net income (loss) per share attributable to common stockholders, diluted (in dollars per share)	$ 0.07		$ 0.29
Common Class B [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 16,425	$ 14,753	$ 62,926	$ 23,625
Less: noncumulative dividends to preferred stockholders	(1,126)	(1,327)	(2,420)	(2,640)
Less: undistributed earnings to participating securities	(10,445)	(10,423)	(43,983)	(16,293)
Net income attributable to common stockholders—basic	4,854	3,003	16,523	4,692
Add: adjustments to undistributed earnings to participating securities	1,731	1,058	6,717	1,618
Reallocation of net income as a result of conversion of Class B to Class A common stock	0	0	0	0
Reallocation of net income to Class B common stock	191	0	392	0
Net income attributable to common stockholders—diluted	$ 6,776	$ 4,061	$ 23,632	$ 6,310
Denominator:
Weighted-average shares of common stock—basic (in shares)	54,388	40,193	47,831	40,174
Conversion of Class B to Class A common stock (in shares)	0	0	0	0
Effect of potentially dilutive stock options, RSUs, common stock warrants, and ESPP (in shares)	36,618	20,294	32,907	19,809
Weighted-average shares of common stock—diluted (in shares)	91,006	60,487	80,738	59,983
Net income (loss) per share attributable to common stockholders, basic (in dollars per share)	$ 0.09	$ 0.07	$ 0.35	$ 0.12
Net income (loss) per share attributable to common stockholders, diluted (in dollars per share)	$ 0.07	$ 0.07	$ 0.29	$ 0.11

Net Income per Share Attribut61

Net Income per Share Attributable to Common Stockholders - Antidilutive Securities (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	127,828	143,357	135,505	142,517
Redeemable convertible preferred stock and stock options to purchase common stock [Member] | Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	126,020	139,504	132,898	139,504
Redeemable convertible preferred stock and stock options to purchase common stock [Member] | Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	0	1,550	799	1,219
Redeemable Convertible Preferred Stock Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	1,808	2,303	1,808	1,794

Significant Customer Informat62

Significant Customer Information and Other Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Concentration Risk [Line Items]
Revenue	$ 400,412	$ 113,572	$ 737,166	$ 222,387
Geographic Concentration Risk [Member] | Non-US [Member]
Concentration Risk [Line Items]
Long-lived assets including property and equipment	$ 23,700		$ 23,700		$ 20,000
Revenue [Member] | Customer Concentration Risk [Member] | Customer A [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	14.00%	15.00%	16.00%	12.00%
Revenue [Member] | Customer Concentration Risk [Member] | Customer B [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	14.00%		12.00%	13.00%
Revenue [Member] | Customer Concentration Risk [Member] | Customer C [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	13.00%	15.00%	12.00%	14.00%
Revenue [Member] | Customer Concentration Risk [Member] | Customer D [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	11.00%
Revenue [Member] | Geographic Concentration Risk [Member]
Concentration Risk [Line Items]
Revenue	$ 400,412	$ 113,572	$ 737,166	$ 222,387
Revenue [Member] | Geographic Concentration Risk [Member] | United States [Member]
Concentration Risk [Line Items]
Revenue	312,666	88,504	577,975	178,335
Revenue [Member] | Geographic Concentration Risk [Member] | Americas excluding United States [Member]
Concentration Risk [Line Items]
Revenue	16,799	7,177	30,228	10,893
Revenue [Member] | Geographic Concentration Risk [Member] | Europe, Middle East, and Africa [Member]
Concentration Risk [Line Items]
Revenue	39,712	9,915	74,768	18,639
Revenue [Member] | Geographic Concentration Risk [Member] | APAC [Member]
Concentration Risk [Line Items]
Revenue	$ 31,235	$ 7,976	$ 54,195	$ 14,520
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Customer A [Member]
Concentration Risk [Line Items]
Concentration risk, percentage			11.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Customer B [Member]
Concentration Risk [Line Items]
Concentration risk, percentage			17.00%		17.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Customer C [Member]
Concentration Risk [Line Items]
Concentration risk, percentage			16.00%		14.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Customer D [Member]
Concentration Risk [Line Items]
Concentration risk, percentage			17.00%		13.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Customer E [Member]
Concentration Risk [Line Items]
Concentration risk, percentage					10.00%

Acquisition - Narrative (Detail

Acquisition - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	6 Months Ended
	Mar. 31, 2015	Jun. 30, 2015	Jun. 30, 2015	Jun. 30, 2014
Business Acquisition [Line Items]
Change in contingent consideration			$ (7,704)	$ 0
FitStar, Inc [Member]
Business Acquisition [Line Items]
Total consideration	$ 32,500
Cash paid for acquisition	11,500
Contingent consideration assumed in acquisition	7,700
Contingent consideration liability	7,700	$ 0	0
FitStar, Inc [Member] | Post Acquisition Compensation Expense [Member]
Business Acquisition [Line Items]
Business combination, contingent cash payments	$ 1,200
Requisite service period	3 years
FitStar, Inc [Member] | Other expense, net [Member]
Business Acquisition [Line Items]
Change in contingent consideration		$ 7,700
FitStar, Inc [Member] | General and administrative [Member] | Post Acquisition Compensation Expense [Member]
Business Acquisition [Line Items]
Transaction costs			$ 300
FitStar, Inc [Member] | Developed technology [Member]
Business Acquisition [Line Items]
Amortization period	7 years
FitStar, Inc [Member] | Customer relationships [Member]
Business Acquisition [Line Items]
Amortization period	1 year 3 months 18 days
FitStar, Inc [Member] | Trademarks [Member]
Business Acquisition [Line Items]
Amortization period	5 years
FitStar, Inc [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Shares issued, amount	$ 13,300
Shares issued (in shares)	1,059,688
FitStar, Inc [Member] | Common Stock [Member] | Post Acquisition Compensation Expense [Member]
Business Acquisition [Line Items]
Shares issued (in shares)	308,216
Shares repurchased, amount	$ 4,200

Acquisition - Assets Acquired a

Acquisition - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 22,157		$ 0
FitStar, Inc [Member]
Business Acquisition [Line Items]
Goodwill		$ 22,157
Assumed liabilities, net of assets		(3,552)
Total		32,523
FitStar, Inc [Member] | Developed and core technology [Member]
Business Acquisition [Line Items]
Intangibles acquired		12,640
FitStar, Inc [Member] | Customer relationships [Member]
Business Acquisition [Line Items]
Intangibles acquired		128
FitStar, Inc [Member] | Trademarks [Member]
Business Acquisition [Line Items]
Intangibles acquired		$ 1,150

Subsequent Events (Details)

Subsequent Events (Details)	Jul. 31, 2015USD ($)
Letter of Credit [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Credit facility, borrowings for security deposit on facility leases	$ 13,300,000