Arista Networks (ANET) 10-Q 7 Nov 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document	9 Months Ended
	Sep. 30, 2014	Oct. 31, 2014
Document and Entity Information [Abstract]	'	'
Entity Registrant Name	'Arista Networks, Inc.	'
Entity Central Index Key	'0001596532	'
Trading Symbol	'ANET	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Non-accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	64,425,460

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (Unaudited) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
CURRENT ASSETS:	'	'
Cash and cash equivalents	$408,596	$113,664
Accounts receivable, net of allowances of $3,196 and $2,339, respectively	84,063	77,999
Inventories	62,587	67,094
Deferred tax assets	8,696	12,356
Prepaid expenses and other current assets	16,409	7,653
Notes receivable	8,000	4,000
Total current assets	588,351	282,766
Property and equipment, net	66,991	67,204
Other Long-term Investments	15,000	'
Deferred tax assets	8,982	4,541
Other assets	27,559	10,009
TOTAL ASSETS	691,883	364,520
CURRENT LIABILITIES:	'	'
Accounts payable	19,845	14,741
Accrued liabilities	32,246	26,909
Deferred revenue	40,277	41,306
Convertible notes payable, related party	0	24,743
Accrued interest payable, related party	0	4,484
Convertible notes payable	0	74,050
Accrued interest payable	0	12,967
Other current liabilities	9,428	10,144
Total current liabilities	101,796	209,344
Income taxes payable	15,022	14,716
Lease financing obligations, non-current	42,831	43,152
Other long-term liabilities	39,312	19,576
TOTAL LIABILITIES	198,961	286,788
Commitments and contingencies (Note 6)	'	'
STOCKHOLDERS’ EQUITY:	'	'
Preferred stock	0	0
Common stock, $0.0001 par value—1,000,000 and 176,000 shares authorized as of September 30, 2014 and December 31, 2013; 64,425 and 31,927 shares issued and outstanding as of September 30, 2014 and December 31, 2013	7	3
Additional paid-in capital	394,186	28,737
Retained earnings	98,777	42,964
Accumulated other comprehensive income (loss)	-48	36
TOTAL STOCKHOLDERS’ EQUITY	492,922	77,732
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	691,883	364,520
Convertible Preferred Stock	'	'
STOCKHOLDERS’ EQUITY:	'	'
Preferred stock	$0	$5,992

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Allowances	$3,196	$2,339
Preferred stock, par value (usd per share)	$0.00	'
Preferred stock, shares authorized (in shares)	100,000,000	'
Preferred stock, shares issued (in shares)	0	'
Preferred stock, shares outstanding (in shares)	0	'
Common stock, par value (usd per share)	$0.00	$0.00
Common stock, shares authorized (in shares)	1,000,000,000	176,000,000
Common stock, shares issued (in shares)	64,425,000	31,927,000
Common stock, shares outstanding (in shares)	64,425,000	31,927,000
Convertible Preferred Stock	'	'
Preferred stock, par value (usd per share)	'	$0.00
Preferred stock, shares authorized (in shares)	'	24,000,000
Preferred stock, shares issued (in shares)	'	24,000,000
Preferred stock, shares outstanding (in shares)	'	24,000,000
Preferred stock, aggregate liquidation preference	'	$6,000

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Income (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]	'	'	'	'
Revenue	$155,463	$101,625	$410,617	$246,458
Cost of revenue	54,506	36,589	134,966	85,393
Gross profit	100,957	65,036	275,651	161,065
Operating expenses:	'	'	'	'
Research and development	36,231	26,635	104,565	67,235
Sales and marketing	20,956	14,523	60,322	37,703
General and administrative	9,896	5,242	24,253	12,484
Total operating expenses	67,083	46,400	189,140	117,422
Income from operations	33,874	18,636	86,511	43,643
Other income (expense), net:	'	'	'	'
Interest expense—related party	0	-439	-782	-1,300
Interest expense	-764	-1,358	-4,730	-4,020
Other income (expense), net	-824	-23	2,426	-123
Total other income (expense), net	-1,588	-1,820	-3,086	-5,443
Income before provision for income taxes	32,286	16,816	83,425	38,200
Provision for income taxes	10,420	4,960	27,612	9,482
Net income	21,866	11,856	55,813	28,718
Net income attributable to common stockholders:	'	'	'	'
Basic (usd per share)	21,185	5,838	40,556	13,874
Diluted (usd per share)	$21,255	$6,128	$41,909	$14,460
Net income per share attributable to common stockholders:	'	'	'	'
Basic (usd per share)	$0.34	$0.21	$0.93	$0.52
Diluted (usd per share)	$0.30	$0.20	$0.85	$0.49
Weighted-average shares used in computing net income per share attributable to common stockholders:	'	'	'	'
Basic (in shares)	62,402	27,557	43,453	26,927
Diluted (in shares)	69,737	30,412	49,323	29,241

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]	'	'	'	'
Net income	$21,866	$11,856	$55,813	$28,718
Other comprehensive income (loss), net of tax:	'	'	'	'
Change in foreign currency translation adjustments	-63	71	-84	6
Other comprehensive income (loss)	-63	71	-84	6
Comprehensive income	$21,803	$11,927	$55,729	$28,724

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Stockholders' Equity (USD $)

Total

Convertible notes payable

Convertible Preferred Stock

Convertible Preferred Stock

Convertible Preferred Stock

Common Stock

Common Stock

Common Stock

Additional Paid-In Capital

Additional Paid-In Capital

Additional Paid-In Capital

Retained Earnings

Accumulated Other Comprehensive Income

In Thousands, except Share data, unless otherwise specified

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Convertible notes payable

Convertible Preferred Stock

USD ($)

Convertible notes payable

Convertible Preferred Stock

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Beginning balance at Dec. 31, 2013

$77,732

'

'

$5,992

'

$3

'

'

$28,737

'

'

$42,964

$36

Beginning balance, shares at Dec. 31, 2013

'

'

'

24,000,000

'

31,927,000

'

'

'

'

'

'

'

Increase (Decrease) in Stockholders' Equity [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

Net income

55,813

'

'

'

'

'

'

'

'

'

'

55,813

'

Other comprehensive income, net of tax

-84

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock from initial public offering, net of offering costs, shares

'

'

'

'

'

6,038,000

'

'

'

'

'

'

'

Issuance of common stock from initial public offering, net of offering costs

238,904

'

'

'

'

1

'

'

238,903

'

'

'

'

Shares issued upon conversion

'

'

'

'

-24,000,000

'

1,543,000

24,000,000

'

'

'

'

'

Conversion of convertible preferred stock and notes payable into common stock upon initial public offering

'

66,338

0

'

-5,992

'

'

3

'

66,338

5,989

'

'

Conversion of notes payable and accrued interest, related party, into common stock upon initial public offering, shares

'

'

'

'

'

'

701,000

'

'

'

'

'

'

Conversion of notes payable and accrued interest, related party, into common stock upon initial public offering

30,153

'

'

'

'

'

'

'

30,153

'

'

'

'

Tax benefit for equity incentive plans

844

'

'

'

'

'

'

'

844

'

'

'

'

Stock-based compensation

19,569

'

'

'

'

'

'

'

19,569

'

'

'

'

Vesting of stock options and restricted stock

3,111

'

'

'

'

'

'

'

3,111

'

'

'

'

Exercise of stock options, net of repurchases, shares

'

'

'

'

'

216,000

'

'

'

'

'

'

'

Exercise of stock options, net of repurchases

542

'

'

'

'

'

'

'

542

'

'

'

'

Ending balance at Sep. 30, 2014

$492,922

'

'

$0

'

$7

'

'

$394,186

'

'

$98,777

($48)

Ending balance, shares at Sep. 30, 2014

'

'

'

0

'

64,425,000

'

'

'

'

'

'

'

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'
Net income	$55,813	$28,718
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation and amortization	7,366	2,505
Stock-based compensation	19,569	6,399
Deferred income taxes	-782	-2,965
Provision for bad debts	593	146
Unrealized gain on notes receivable	-4,000	0
Amortization of debt discount	527	832
Write-off of debt discount on notes payable	680	0
Excess tax benefit on stock based-compensation	-841	-340
Changes in operating assets and liabilities:	'	'
Accounts receivable	-6,657	-15,612
Inventories	4,507	-30,505
Prepaid expenses and other current assets	-8,755	-4,370
Other assets	-2,142	147
Accounts payable	5,600	15,848
Accrued liabilities	7,733	10,118
Deferred revenue	18,787	22,543
Interest payable	-1,630	3,366
Interest payable—related party	670	1,122
Income taxes payable	501	1,101
Other liabilities	1,165	1,562
Net cash provided by operating activities	98,704	40,615
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'
Purchases of property and equipment	-10,789	-15,496
Change in restricted cash	4,040	0
Payments for (Proceeds from) Other Investing Activities	-19,451	0
Net cash used in investing activities	-26,200	-15,496
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'
Proceeds from initial public offering, net of issuance cost	239,643	0
Repayment on notes payable	-20,000	0
Principal payments of lease financing obligations	-554	0
Proceeds from issuance of common stock upon exercising options, net of repurchases	2,578	5,914
Excess tax benefit on stock-based compensation	841	340
Net cash provided by financing activities	222,508	6,254
Effect of exchange rate changes	-80	-8
NET INCREASE IN CASH AND CASH EQUIVALENTS	294,932	31,365
CASH AND CASH EQUIVALENTS—Beginning of period	113,664	88,655
CASH AND CASH EQUIVALENTS—End of period	408,596	120,020
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:	'	'
Cash paid for income taxes	27,596	13,500
Cash paid for interest— lease financing obligation	2,048	0
Cash paid for interest— notes payable	3,639	0
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:	'	'
Increase (decrease) in accounts payable and accrued liabilities related to property and equipment	-3,634	4,557
Unpaid deferred offering costs	740	0
Acquisition of building with financing obligation	456	17,963
Convertible Notes Payable	'	'
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:	'	'
Conversion of stock upon initial public offering	66,338	0
Convertible notes payable—related party	'	'
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:	'	'
Conversion of stock upon initial public offering	30,153	0
Convertible Preferred Stock	'	'
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:	'	'
Conversion of stock upon initial public offering	$5,992	$0

Overview_and_Basis_of_Presenta

Overview and Basis of Presentation	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Overview and Basis of Presentation	'
	Overview and Basis of Presentation
	Organization
	Arista Networks, Inc. (together with our subsidiaries, “we,” “our” or “us”) is a supplier of cloud networking solutions that use software innovations to address the needs of large-scale Internet companies, cloud service providers and next-generation enterprise. Our cloud networking solutions consist of our Extensible Operating System, a set of network applications and our 10/40/100 Gigabit Ethernet switches. We were incorporated in October 2004 in the State of California under the name Arastra, Inc. In March 2008, we reincorporated in the State of Nevada and in October 2008 changed our name to Arista Networks, Inc. We reincorporated in the state of Delaware in March 2014. Our corporate headquarters are located in Santa Clara, California, and we have wholly-owned subsidiaries throughout the world, including North America, Europe, Asia and Australia.
	Initial Public Offering
	On June 6, 2014, we completed our initial public offering (the “IPO”) in which we sold 6,037,500 shares of our common stock at a public offering price of $43.00 per share, which included 787,500 shares of common stock issued pursuant to the exercise in full of the over-allotment option granted to the underwriters. The IPO resulted in proceeds of $238.9 million, net of underwriting discounts and commissions of $15.6 million and other estimated issuance costs of $5.1 million. In connection with the closing of the IPO, all of our outstanding convertible preferred stock automatically converted into 24,000,000 shares of common stock on a one-to-one basis.
	Upon the closing of our IPO, all noteholders with the exception of one noteholder converted the principal and accrued interest amount outstanding under their subordinated convertible promissory notes into shares of our common stock at the IPO price of $43.00 per share. The noteholder, who did not elect to so convert, was paid a total of $23.6 million which included principal and accrued interest less applicable withholding taxes of $1.1 million. The remainder of the noteholders converted the remaining debt balance of approximately $96.5 million including principal and accrued interest into 2.2 million shares of our common stock.
	Basis of Presentation
	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (" U.S. GAAP") and following the requirements of the U.S. Securities and Exchange Commission (the “SEC”) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP can be condensed or omitted. In management’s opinion, the unaudited condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and include all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of our financial information. The results for the three and nine months ended September 30, 2014, are not necessarily indicative of the results expected for the full fiscal year.
	The condensed consolidated balance sheet as of December 31, 2013 has been derived from the audited consolidated financial statements at that date but does not include all of the information and notes required by generally accepted accounting principles for complete financial statements.
	The accompanying unaudited condensed consolidated financial statements include the accounts of Arista Networks, Inc. and our wholly owned subsidiaries. All significant intercompany accounts and transactions have been eliminated.
	The accompanying unaudited condensed consolidated financial statements and related financial information should be read in conjunction with the audited consolidated financial statements and related footnotes included in our prospectus filed pursuant to Rule 424(b) under the Securities Act of 1933, as amended (the “Securities Act”), with the SEC on June 6, 2014 (the “Prospectus”).
	There have been no changes in our significant accounting policies from those that were disclosed in our audited consolidated financial statements for the year ended December 31, 2013 included in the Prospectus other than the following:
	New Accounting Policy
	Investments
	We have recorded our equity investment in a privately-held company under the cost method. Initial measurement of our investment under the cost method is recorded at historical cost which represents our initial investment in the privately-held company.  We will periodically assess and evaluate our cost method investment for impairment and perform an assessment based on evaluation of overall financial performance, industry and market conditions, and other relevant events or factors deemed necessary that may affect carrying value. If we determine that a decrease in the equity investment should be recognized given impairment that is considered “other than temporary” in nature, we will write-down the carrying amount to its revised new fair value.
	Use of Estimates
	The preparation of the accompanying unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires us to make estimates and assumptions that affect the amounts reported and disclosed in the unaudited condensed consolidated financial statements and accompanying notes. Those estimates and assumptions include, but are not limited to, revenue recognition and deferred revenue; determination of fair value for stock-based awards; accounting for income taxes, including the valuation allowance on deferred tax assets and reserves for uncertain tax positions; valuation of inventory; valuation of warranty accruals; and the recognition and measurement of contingent liabilities. We evaluate our estimates and assumptions on an ongoing basis using historical experience and other factors and adjust those estimates and assumptions when facts and circumstances dictate. As future events and their effects cannot be determined with precision, actual results could differ from these estimates, and those differences could be material to the unaudited condensed consolidated financial statements.
	Business Concentrations
	We work closely with third parties to manufacture and deliver our products. As of September 30, 2014 and December 31, 2013, two suppliers provided all of our electronic manufacturing services. Our products rely on key components, including certain integrated circuit components and power supplies some of which our contract manufacturers purchase on our behalf from a limited number of suppliers, including certain sole source providers. We do not have guaranteed supply contracts with any of our component suppliers, and our suppliers could delay shipments or cease manufacturing such products or selling them to us at any time. If we are unable to obtain a sufficient quantity of these components on commercially reasonable terms or in a timely manner, sales of our products could be delayed or halted entirely or we may be required to redesign our products. Quality or performance failures of our products or changes in our contractors’ or vendors’ financial or business condition could disrupt our ability to supply quality products to our customers. Any of these events could result in lost sales and damage to our end-customer relationships, which would adversely impact our business, financial condition and results of operations.
	Concentrations of Credit Risk
	Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash, cash equivalents, restricted cash, accounts receivable and notes receivable. Our cash, cash equivalents and restricted cash are invested in high quality financial instruments with banks and financial institutions. Such deposits may be in excess of insured limits provided on such deposits.
	Our accounts receivable are unsecured and represent amounts due to us based on contractual obligations of our customers. We mitigate credit risk in respect to accounts receivable by performing ongoing credit evaluations of our customers to assess the probability of accounts receivable collection based on a number of factors, including past transaction experience with the customer, evaluation of their credit history, the credit limits extended and review of the invoicing terms of the contract. We generally do not require our customers to provide collateral to support accounts receivable. We have recorded an allowance for doubtful accounts for those receivables that we have determined not to be collectible.
	Our notes receivable are secured and represent amounts due to us from a private company. We mitigate credit risk in respect to the notes receivable by performing ongoing credit evaluations of the borrower to assess the probability of collecting all amounts due to us under the existing contractual terms.
	We market and sell our products through both our direct sales force and our channel partners, including distributors, value-added resellers, system integrators and original equipment manufacturer (“OEM”) partners.
	Reclassifications
	As a result of a change in classification, we have reclassified our spare parts inventory from inventory to other current and non-current assets as of September 30, 2014. Spare parts inventory are used to satisfy our warranty obligations, and are not available for sale or used in the production process. Prior year balances have been adjusted to conform to this new classification for comparability purposes.
	Recent Accounting Pronouncements
	In May 2014, the FASB issued ASU No. 2014-09, Revenue From Contracts With Customers ("ASU 2014-09"), which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. ASU 2014-09 is effective for fiscal years (and interim reporting periods within those years) beginning after December 15, 2016. Early application is not permitted. ASU 2014-09 permits the use of either the retrospective or cumulative effect transition method. We are currently reviewing the provisions of ASU 2014-09 and have not yet selected a transition method nor have we determined the effect of the standard on our consolidated financial statements.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	Our assets and liabilities which require fair value measurement consist of cash and cash equivalents, restricted cash, accounts receivable, notes receivable, accounts payable and accrued liabilities. Cash equivalents, restricted cash, accounts receivable, accounts payable and accrued liabilities are stated at carrying amounts as reported in the consolidated financial statements, which approximates fair value due to their short term nature. Notes receivable are stated at fair value, as we have elected to fair value our notes receivable using the fair value option permitted to us.
	Assets and liabilities recorded at fair value on a recurring basis in the accompanying unaudited condensed consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair value. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of the inputs used to measure fair value instruments as follows:
	Level I - Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date;
	Level II - Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and
	Level III - Unobservable inputs that are supported by little or no market data for the related assets or liabilities and typically reflect management’s estimate of assumptions that market participants would use in pricing the asset or liability.
	Our financial instruments consist of Level I and Level III assets. Level I assets include highly liquid money market funds that are included in cash and cash equivalents. Level III assets that are measured on a recurring basis consist solely of our notes receivable. We classified the notes receivable as Level III, as we used unobservable inputs to the valuation methodology that were significant to the fair value measurement, and the valuation required management judgment due to the absence of quoted market prices. We measure the fair value of the notes receivable based upon the probability-weighted present value of expected future investment returns, considering each of the possible future outcomes available to us. The significant unobservable inputs used in the fair value measurement of the convertible notes are the scenario probabilities and the discount rate estimated at the valuation date. Generally, increases (decreases) in the discount rate would result in a directionally opposite impact to the fair value measurement of the notes. Also, changes in the probability scenarios would have had varying impacts depending on the weighting of each specific scenario. More weighting towards a change in control or an equity financing by the investee would result in an increase in fair value of the notes receivable.
	We measure and report our cash equivalents, restricted cash and notes receivable at fair value. The following table sets forth the fair value of our financial assets by level within the fair value hierarchy as noted above (in thousands):
		September 30, 2014
		Level I		Level II		Level III		Total
	Financial Assets
	Money market funds	$	244,187	$	—	$	—	$	244,187
	Notes receivable(2)	—		—		8,000		8,000
	Total financial assets	$	244,187	$	—	$	8,000	$	252,187
		December 31, 2013
		Level I		Level II		Level III		Total
	Financial Assets
	Money market funds	$	47,036	$	—	$	—	$	47,036
	Money market funds – restricted cash(1)	4,040		—		—		4,040
	Notes receivable(2)	—		—		4,000		4,000
	Total financial assets	$	51,076	$	—	$	4,000	$	55,076
	(1)Included in “Other assets" in the accompanying Condensed Consolidated Balance Sheets.
	(2)Included in “Notes receivable” in the accompanying Condensed Consolidated Balance Sheets. There were no changes in the fair value of the Level III assets during the year ended December 31, 2013. During the three and nine months ended September 30, 2014, we increased the fair value of our Notes receivable by $4.0 million (See “Note 4 – Notes Receivable”). During the nine months ended September 30, 2014 and the year ended December 31, 2013, we had no transfers between levels of the fair value hierarchy of its assets measured at fair value. In October 2014, we received payment in full from the borrower equal to two times our outstanding principal balance as well as the unpaid accrued interest through the payment date.

Balance_Sheet_Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2014
Balance Sheet Components [Abstract]	'
Balance Sheet Components	'
	Balance Sheet Components
	Accounts Receivable, net
	Accounts receivable, net consists of the following (in thousands):
		September 30,			December 31,
		2014			2013
	Accounts receivable	$	87,259		$	80,338
	Allowance for doubtful accounts	(945		)	(810		)
	Product sales return reserve	(2,251		)	(1,529		)
	Accounts receivable, net	$	84,063		$	77,999
	Inventories
	Inventories consist of the following (in thousands):
		September 30,			December 31,
		2014			2013
	Raw materials	$	15,470		$	18,286
	Finished goods	47,117			48,808
	Total inventories	$	62,587		$	67,094
	Property and Equipment, net
	Property and equipment, net consists of the following (in thousands):
		September 30,			December 31,
		2014			2013
	Equipment and machinery	$	17,243		$	13,733
	Computer hardware and software	6,890			3,688
	Furniture and fixtures	1,374			1,352
	Leasehold improvements	19,520			19,407
	Building	35,154			35,154
	Construction-in-process	1,127			1,056
	Property and equipment, gross	81,308			74,390
	Less: accumulated depreciation	(14,317		)	(7,186		)
	Property and equipment, net	$	66,991		$	67,204
	Building consists of capitalized construction costs of our leased building in Santa Clara, California. Based on the terms of the lease agreement and due to our involvement in certain aspects of the construction, such as our financial involvement in structural elements of asset construction, making decisions related to tenant improvement costs and purchasing insurance not reimbursable by the buyer-lessor (the Landlord), we are deemed the owner of the building (for accounting purposes only) during the construction period. We maintain continued involvement in the property after construction was completed and lack transferability of the risks and rewards of ownership, primarily due to our required maintenance of a $4.0 million letter of credit. Due to our continuing involvement in the property post construction and lack of transferability of related risks and rewards of ownership to the Landlord after construction is complete, we account for the building as a financing obligation. See “Note 6-Commitments and Contingencies”. Accordingly, as of September 30, 2014 and December 31, 2013, we have recorded assets of $53.4 million and $53.3 million, respectively, representing the total costs of the building and improvements incurred, including the costs paid by the Landlord. The building was completed in 2013.
	Depreciation expense was $2.7 million, $7.4 million, $1.0 million and $2.5 million for the three and nine months ended September 30, 2014 and 2013, respectively.
	Other Assets
	Other assets consist of the following (in thousands):
		September 30,			December 31,
		2014			2013
	Investments	$	18,000		$	—
	Restricted cash	—			4,040
	Deposits	2,578			2,581
	Spares	4,429			2,757
	Other assets	2,552			631
	Total other assets	$	27,559		$	10,009
	In September 2014, we made a $15.0 million equity investment in a privately held company which was accounted for under the cost method. In August 2014, we entered into a $3.0 million promissory note with a privately held company which was recorded as a notes receivable at cost. There were no impairments recognized on our investments for the three months ended September 30, 2014.
	Accrued Liabilities
	Accrued liabilities consist of the following (in thousands):
		September 30,			December 31,
		2014			2013
	Accrued payroll related costs	$	18,866		$	9,103
	Accrued warranty costs	3,464			5,075
	Accrued accounts payable	4,058			5,370
	Accrued manufacturing costs	1,724			3,835
	Accrued professional fees	1,422			1,220
	Accrued taxes	1,215			927
	Other	1,497			1,379
	Total accrued liabilities	$	32,246		$	26,909
	Warranty Accrual
	We offer a one-year warranty on all of our hardware products and a 90-day warranty against defects in the software embedded in the products. We accrue for potential warranty claims at the time of shipment as a component of cost of revenues based on historical experience and other relevant information. We accrue specifically identified reserves if and when we determine we have a systemic product failure. The accrued warranty liability is recorded in accrued liabilities in the accompanying unaudited condensed consolidated balance sheets.
	The following table summarizes the activity related to our accrued liability for estimated future warranty costs (in thousands):
		Nine Months Ended September 30,
		2014			2013
	Warranty accrual, beginning of period	$	5,075		$	5,314
	Liabilities accrued for warranties issued during the period	1,839			4,192
	Warranty costs incurred during the period	(1,689		)	(2,605		)
	Adjustments related to change in estimate	(1,761		)	—
Warranty accrual, end of period	$	3,464		$	6,901
During the nine months ended September 30, 2013, we identified specific products that were failing in the field prematurely at higher than expected rates due to various component issues. There were no significant specific product warranty reserves recorded in 2014.
Deferred Revenue
Deferred revenue consists of the following (in thousands):
	September 30,			December 31,
	2014			2013
Current portion of deferred revenue	$	40,277		$	41,306
Long-term portion of deferred revenue	37,415			17,598
Total deferred revenue	$	77,692		$	58,904
The long-term portion of deferred revenue is included in other long-term liabilities in the accompanying condensed consolidated balance sheets.

Notes_Receivable

Notes Receivable	9 Months Ended
	Sep. 30, 2014
Receivables [Abstract]	'
Notes Receivable	'
	Notes Receivable
	On December 31, 2012, we made a loan of $4.0 million to a private company. The interest rate on the notes receivable was 6.0% per annum. The notes are convertible into the private company’s preferred stock or any securities exchangeable for the private company’s preferred stock. All unpaid principal and accrued interest on the notes receivable was due and payable on the earlier of August 31, 2014, or upon default.
	On July 30, 2014, the borrower signed a definitive agreement to close a Corporate Transaction through a merger (i.e. a transaction in which 50% of the voting power is transferred) and the transaction is expected to close in the first quarter of 2015. Pursuant to this transaction and per the terms of our agreement, we have increased the value of our convertible notes receivable by $4.0 million to $8.0 million. In October 2014, we received payment in full from the borrower equal to two times our outstanding principal balance as well as the unpaid accrued interest through the payment date.
	In conjunction with the notes receivable, we also entered into an Exclusivity and Supply Agreement (“Supply Agreement”) with the borrower. Under the terms of the Supply Agreement, the borrower has agreed to develop and produce certain products for us at mutually agreed on supply terms and with best in class pricing rights to us. In addition, any exclusive features developed between us and the borrower cannot be sold by the borrower to other customers for 24 months following the commercial availability of such production versions. The Supply Agreement does not have a maturity date. We determined that the fair value of the Supply Agreement on its inception was insignificant as the borrower is still in the development stage and there is no certainty that a commercial product will be developed.

Debt_Obligations

Debt Obligations	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Debt Obligations	'
	Debt Obligations
	Our debt obligations consist of the following (in thousands):
		December 31,
		2013
	Convertible notes payable—related party	$	25,000
	Convertible notes payable	75,000
	Total	100,000
	Less: Unamortized discount on notes payable	1,207
	Less: Current portion	98,793
	Total long-term portion of debt	$	—
	In January 2011, we sold $55.0 million aggregate principal amount of subordinated convertible promissory notes (“Convertible Notes”) to outside investors and $25.0 million aggregate principal amount of Convertible Notes to two trusts that are related to two of our co-founders. In June 2011, we sold an additional $20.0 million in Convertible Notes to outside investors. The Convertible Notes were convertible into shares of our common stock upon a change of control, a qualified IPO, or immediately prior to when the notes are to be voluntarily prepaid. The interest rate on the Convertible Notes was 6.0% per annum, computed on the basis of the actual number of days elapsed and a year of 365 days. All unpaid principal and accrued interest on the Convertible Notes were due and payable on the earlier of December 31, 2014 or upon the occurrence of an event of default, defined as: (i) failure to pay principal or interest when due; (ii) breaches of covenants; (iii) breaches of representations and warranties; (iv) failure to make other payment obligations resulting in the acceleration of maturity of indebtedness in excess of $10.0 million; (v) voluntary bankruptcy; (vi) involuntary bankruptcy; or (vii) certain adverse judgments. We could have voluntarily prepaid the Convertible Notes, in whole or in part, before the maturity date by giving each investor 10 days’ prior written notice. We were also required to prepay the Convertible Notes upon a change of control unless the investor elected to convert its Convertible Note immediately prior to the closing of such change of control.
	Upon the closing of our IPO all noteholders with the exception of one noteholder converted the principal and accrued interest amount outstanding under their subordinated convertible promissory notes into shares of our common stock at the IPO price of $43.00 per share. The noteholder, who did not elect to so convert, was paid a total of $23.6 million which included principal and accrued interest less applicable withholding taxes of $1.1 million. The remainder of the noteholders converted the remaining debt balance of approximately $96.5 million including principal and accrued interest into 2.2 million shares of our common stock.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	Operating Leases
	We lease various operating spaces in North America, Europe, Asia and Australia under non-cancelable operating lease arrangements that expire on various dates through 2023. These arrangements require us to pay certain operating expenses, such as taxes, repairs, and insurance and contain renewal and escalation clauses. We recognize rent expense under these arrangements on a straight-line basis over the term of the lease.
	As of December 31, 2013, the aggregate future minimum payments under non-cancelable operating leases consist of the following (in thousands):
	Years Ending December 31,
	2014	$	825
	2015	540
	2016	507
	2017	411
	2018	161
	Total minimum future lease payments	$	2,444
	Rent expense for all operating leases amounted to $0.8 million, $2.5 million, $1.3 million and $3.0 million for the three and nine months ended September 30, 2014 and 2013, respectively.
	On July 30, 2014, we entered into an agreement to lease additional space to expand our headquarters in Santa Clara, California. The lease is expected to commence in phases on January 1, 2015 for a portion and subsequently on January 1, 2016 for the remainder and expiring on September 30, 2023. The minimum payments will be approximately $2.6 million per year.
	Financing Obligation—Build-to-Suit Lease
	In August 2012, we executed a lease for a building under construction in Santa Clara, California which will serve as our new headquarters. The lease term is 120 months and commenced in August 2013.
	Based on the terms of the lease agreement and due to our involvement in certain aspects of the construction such as our financial involvement in structural elements of asset construction, making decisions related to tenant improvement costs and purchasing insurance not reimbursable by the buyer-lessor (the Landlord), we are deemed the owner of the building (for accounting purposes only) during the construction period. We maintained continued involvement in the property after construction was completed and lack transferability of the risks and rewards of ownership, primarily due to our required maintenance of a $4.0 million letter of credit. Due to our continuing involvement in the property post construction and lack of transferability of related risks and rewards of ownership to the Landlord after construction is complete, we account for the building and related improvements as a lease financing obligation.
	Accordingly, as of September 30, 2014 and December 31, 2013, we have recorded assets of $53.4 million and $53.3 million, representing the total costs of the building and improvements incurred, including the costs paid by the lessor (the legal owner of the building) and additional improvement costs paid by us, and a corresponding financing obligation of $43.9 million and $44.0 million, respectively. As of September 30, 2014, $1.1 million and $42.8 million were recorded as short-term and long-term financing obligations, respectively. During the construction period, we continued to increase the asset and financing obligation as additional building and improvement costs were incurred until construction was completed.
	As of December 31, 2013, the future minimum payments due under the lease financing obligation were as follows (in thousands):
	Years Ending December 31,
	2014		$	4,991
	2015		5,601
	2016		5,769
	2017		5,948
	2018		6,128
	Thereafter		31,059
	Total payments		59,496
	Less: interest and land lease expense		(38,962		)
	Total payments under facility financing obligations		20,534
	Property reverting to landlord		23,436
	Present value of obligation		43,970
	Less current portion		(818		)
	Long-term portion of obligation		$	43,152
	Upon completion of construction in the third quarter of 2013, we evaluated the de-recognition of the asset and liability under the sale-leaseback accounting guidance. We concluded that we have forms of continued economic involvement in the facility, and therefore did not meet with the provisions for sale-leaseback accounting. Therefore, the lease is accounted for as a financing obligation and lease payments will be attributed to (1) a reduction of the principal financing obligation; (2) imputed interest expense; and (3) land lease expense (which is considered an operating lease and a component of cost of goods sold and operating expenses) representing an imputed cost to lease the underlying land of the building. In addition, the underlying building asset is depreciated over the building’s estimated useful life of 30 years. At the conclusion of the initial lease term, we will de-recognize both the net book values of the asset and the remaining financing obligation.
	Purchase Commitments
	Our products are manufactured, assembled and tested by third-party contract manufacturers in Asia who procure components and assemble products on our behalf based on our forecasts. These forecasts are based on estimates of future demand for our products, historical trend analysis provided by our sales and product marketing organizations and adjusted for overall market conditions. In order to reduce manufacturing lead times and plan for adequate component supply, we may issue purchase orders to these third-party contract manufacturers and vendors that may not be cancelable. As of September 30, 2014 and December 31, 2013, our contract manufacturer liability was $0.9 million and $1.8 million for non-cancelable purchase commitments issued to our vendors.
	We have provided restricted deposits to our third-party contract manufacturers and vendors to secure our obligations to purchase inventory. We had $2.3 million in restricted deposits as of September 30, 2014 and December 31, 2013. Restricted deposits are classified in deposits and other non-current assets in our accompanying unaudited condensed consolidated balance sheets.
	Guarantees
	We have entered into agreements with some of our direct customers and channel partners that contain indemnification provisions relating to potential situations where claims could be alleged that our products infringe the intellectual property rights of a third party. We have at our option and expense the ability to repair any infringement, replace product with a non-infringing equivalent-in-function product or refund our customers the unamortized value of the product based on its estimated useful life. Other guarantees or indemnification agreements include guarantees of product and service performance and standby letters of credit for lease facilities and corporate credit cards. We have not recorded a liability related to these indemnification and guarantee provisions and our guarantee and indemnification arrangements have not had any significant impact on our consolidated financial statements to date.
	Legal Proceedings
	OptumSoft, Inc. Matters
	On April 4, 2014, OptumSoft filed a lawsuit against us in the Superior Court of California, Santa Clara County titled OptumSoft, Inc. v. Arista Networks, Inc., in which it asserts (i) ownership of certain components of our EOS network operating system pursuant to the terms of a 2004 agreement between the companies and (ii) breaches of certain confidentiality and use restrictions in that agreement. Under the terms of the 2004 agreement, OptumSoft provided us with a non-exclusive, irrevocable, royalty-free license to software delivered by OptumSoft comprising a software tool used to develop certain components of EOS and a runtime library that is incorporated into EOS. The 2004 agreement places certain restrictions on our use and disclosure of the OptumSoft software and gives OptumSoft ownership of improvements, modifications and corrections to, and derivative works of, the OptumSoft software that we develop.
	In its lawsuit, OptumSoft has asked the Court to order us to (i) give OptumSoft copies of certain components of our software for evaluation by OptumSoft, (ii) cease all conduct constituting the alleged confidentiality and use restriction breaches, (iii) secure the return or deletion of OptumSoft’s alleged intellectual property provided to third parties, including our customers, (iv) assign ownership to OptumSoft of OptumSoft’s alleged intellectual property currently owned by us, and (v) pay OptumSoft’s alleged damages, attorney’s fees, and costs of the lawsuit. David Cheriton, one of our founders and a former member of our board of directors who resigned from our board of directors on March 1, 2014 and has no continuing role with us, is a founder and, we believe, the largest stockholder and director of OptumSoft. The 2010 David R. Cheriton Irrevocable Trust dtd July 27, 2010, a trust for the benefit of the minor children of Mr. Cheriton, is our largest stockholder.
	OptumSoft has identified in confidential documents certain software components it claims to own, which are generally applicable tools and utility subroutines and not networking specific code. We cannot assure which software components OptumSoft may ultimately claim to own in the litigation or whether such claimed components are material.
	On April 14, 2014, we filed a cross-complaint against OptumSoft, in which we assert our ownership of the software components at issue and our interpretation of the 2004 agreement. Among other things, we assert that the language of the 2004 agreement and the parties’ long course of conduct support our ownership of the disputed software components. We ask the Court to declare our ownership of those software components, all similarly-situated software components developed in the future and all related intellectual property. We also assert that, even if we are found not to own any particular components at issue, such components are licensed to us under the terms of the 2004 agreement. However, there can be no assurance that our assertions will ultimately prevail in litigation.
	On the same day, we also filed an answer to OptumSoft’s claims, as well as affirmative defenses based in part on OptumSoft’s failure to maintain the confidentiality of its claimed trade secrets, its authorization of the disclosures it asserts and its delay in claiming ownership of the software components at issue. We have also taken additional steps to respond to OptumSoft’s allegations that we improperly used and/or disclosed OptumSoft confidential information. While we believe we have strong defenses to these allegations, we believe we have (i) revised our software to remove the elements we understand to be the subject of the claims relating to improper use and disclosure of OptumSoft confidential information and made the revised software available to our customers and (ii) removed information from our website that OptumSoft asserted disclosed OptumSoft confidential information. The Court set a trial date for April 2016.
	We do not believe a loss is probable; however, it is a reasonable possibility. Due to the early stage of this matter, no estimate of the amount or range of possible amounts can be determined at this time.
	We intend to vigorously defend against any action brought against us by OptumSoft. However, we cannot be certain that, if litigated, any claims by OptumSoft would be resolved in our favor. For example, if it were determined that OptumSoft owned components of our EOS network operating system, we would be required to transfer ownership of those components and any related intellectual property to OptumSoft. If OptumSoft were the owner of those components, it could make them available to our competitors, such as through a sale or license. In addition, if OptumSoft were to bring actual litigation, it could assert additional or different claims against us, including claims that our license from OptumSoft is invalid. An adverse litigation ruling could result in a significant damages award against us and injunctive relief. In addition, if our license was ruled to have been terminated, and we were not able to negotiate a new license from OptumSoft on reasonable terms, we could be prohibited from selling products that incorporate OptumSoft intellectual property. Any such adverse ruling could materially adversely affect our business, prospects, results of operations and financial condition. Whether or not we prevail in a lawsuit, we expect that any litigation would be expensive, time-consuming and a distraction to management in operating our business.
	Net Navigation LLC Matters
	On April 23, 2014, Net Navigation LLC sued us for alleged infringement of U.S. Patent Nos. 5,901,147; 6,434,145; and 6,625,122 in U.S. District Court for the Eastern District of Texas. On June 30, 2014, we and Net Navigation LLC settled this dispute.
	In the ordinary course of business, we are a party to other claims and legal proceedings including matters relating to commercial, employee relations, business practices and intellectual property. We record a provision for contingent losses when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Based on currently available information, management does not believe that the ultimate outcome of these other unresolved matters is probable or estimable and not likely, individually and in the aggregate, to have a material adverse effect on our financial position, results of operations or cash flows. However, litigation is subject to inherent uncertainties and our view of these matters may change in the future. Were an unfavorable outcome to occur, there exists the possibility of a material adverse impact on our financial position, results of operations or cash flows for the period in which the unfavorable outcome occurs, and potentially in future periods.

Common_Stock_Reserved_for_Issu

Common Stock Reserved for Issuance	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Common Stock Reserved for Issuance	'
	Common Stock Reserved for Issuance
	We have reserved shares of common stock, on an as-converted basis, for future issuance as follows (in thousands):
		September 30,	December 31,
		2014	2013
	Conversion of convertible preferred stock outstanding (1)	—	24,000
	Outstanding stock options and RSAs	13,977	11,245
	Outstanding stock purchase rights	2	2
	Conversion of convertible debt and related interest expense (2)	—	3,949
	Shares reserved for future option and RSA grants	12,447	8,941
	Shares reserved under Employee Stock Purchase Plan	651	—
	Total	27,077	48,137
	(1) Upon the closing of our IPO, all shares of our convertible preferred stock were converted to 24 million shares of common stock on a one-for-one basis.
	(2) Upon the closing of our IPO, all noteholders with the exception of one noteholder converted the principal and accrued interest amount outstanding under their subordinated convertible promissory notes into shares of our common stock at the IPO price of $43.00 per share. The noteholder, who did not elect to so convert, was paid a total of $23.6 million which included principal and accrued interest less applicable withholding taxes of $1.1 million. The remainder of the noteholders converted the remaining debt balance of approximately $96.5 million including principal and accrued interest into 2.2 million shares of our common stock.

StockBased_Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock-Based Compensation	'
	Stock-Based Compensation
	Total stock-based compensation expense related to options, restricted stock awards, employee stock purchases, restricted stock units and stock purchase rights granted were allocated as follows (in thousands):
		Three Months Ended September 30,							Nine Months Ended September 30,
		2014			2013				2014			2013
	Cost of revenue	$	480		$	107			$	992		$	257
	Research and development	4,304			1,319				10,298			3,449
	Sales and marketing	2,387			765				5,746			1,859
	General and administrative	911			393				2,533			834
	Total stock-based compensation	$	8,082		$	2,584			$	19,569		$	6,399
	Allocations to cost of revenue, research and development, general and administrative and selling and marketing expense are based upon the department to which the associated employee reported.
	Equity Award Plans
	During the year ended December 31, 2004, we adopted the 2004 Equity Incentive Plan (the “2004 Plan”) for the purpose of granting stock based awards to employees, directors and consultants. Awards granted under the 2004 Plan could be in the form of Incentive Stock Options (“ISOs”), Nonstatutory Stock Options (“NSOs”) or Restricted Stock Awards (“RSAs”). With the establishment of the 2011 Plan (as defined below), the 2004 Plan was terminated with respect to the grant of future awards but the 2004 Plan continues to govern awards previously issued thereunder. During the year ended December 31, 2011, we adopted the 2011 Equity Incentive Plan (the “2011 Plan”) for the purpose of granting stock based awards to employees, directors, and consultants. Awards granted under the 2011 Plan could have been ISOs, NSOs, RSAs, Stock Appreciation Rights (“SARs”) or Restricted Stock Units (“RSUs”). With the establishment of the 2014 Plan (as defined below), the 2011 Plan terminated with respect to the grant of future awards but the 2011 Plan continues to govern awards previously issued thereunder.
	2014 Plan
	In April 2014, the board of directors and stockholders approved the 2014 Equity Incentive Plan (the “2014 Plan”), effective on the first day that our common stock was publicly traded. A total of 6,510,000 shares of our common stock were initially reserved for issuance under the 2014 Plan. In addition, the shares reserved for issuance under our 2014 Plan will also include (a) those shares reserved but unissued under the 2011 Plan and 2004 Plan as of the effective date and (b) shares returned to our 2011 Plan and 2004 Plan as the result of expiration or termination of options (provided that the maximum number of shares that may be added to the 2014 Plan pursuant to (a) and (b) is 20,025,189 shares). The number of shares available for grant and issuance under the 2014 Plan will be increased automatically on January 1 of each year commencing with 2016 by the number of shares equal to 3% of our shares outstanding on the immediately preceding December 31, but not to exceed 12,500,000 shares, unless the board of directors, in its discretion, determines to make a smaller increase.
	2014 Employee Stock Purchase Plan
	In April 2014, the board of directors and stockholders approved the 2014 Employee Stock Purchase Plan (the “ESPP”). The ESPP will become effective on the first day that our common stock is publicly traded. A total of 651,000 shares of our common stock are initially reserved for future issuance under the ESPP. The number of shares reserved for issuance under the ESPP will increase automatically on January 1 of each year commencing with 2015 by the number of shares equal to 1% of our shares outstanding immediately preceding December 31, but not to exceed 2,500,000 shares, unless the board of directors, in its discretion, determines to make a smaller increase.
	Determination of Fair Value
	Employee Stock Plans
	For the three and nine months ended September 30, 2014 and 2013, the fair value of each stock option granted under the 2011 Plan was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions and fair value per share:
		Three Months Ended September 30,					Nine Months Ended September 30,
		2014		2013			2014			2013
	Expected term (in years)	6.2		6.7			7.6			6.6
	Risk-free interest rate	1.9	%	2.2	%		2.3	%		1.7	%
	Expected volatility	49.1	%	50.5	%		47.8	%		50.8	%
	Dividend rate	—	%	—	%		—	%		—	%
	ESPP
	There were no stock purchases under the ESPP during the three and nine months ended September 30, 2014.  The following table summarizes the assumptions relating to our ESPP:
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014			2013
	Expected term (in years)	1.4		N/A		1.4			N/A
	Risk-free interest rate	0.3	%	N/A		0.3	%		N/A
	Expected volatility	36.3	%	N/A		36.3	%		N/A
	Dividend rate	—	%	N/A		—	%		N/A
	As of September 30, 2014, the total unrecognized stock-based compensation expense for unvested ESPP options, net of expected forfeitures, was $4.1 million, which is expected to be recognized over a weighted-average period of 1.9 years.
	Stock Option Activities
	The following table summarizes the option and RSA (Restricted Stock Award) activity under the 2004 Plan and 2011 Plan and related information:
				Options and RSAs Outstanding
		Shares		Number of			Weighted-				Weighted-	Aggregate
		Available for		Shares			Average				Average	Intrinsic
		Grant		Underlying			Exercise				Remaining	Value
		(in thousands)		Outstanding Options and RSAs			Price per Share				Contractual	of Stock
				(in thousands)							Term (Years) of	Options
											Stock Options	Outstanding
												(in thousands)
	Outstanding—December 31, 2013	8,941		11,245			$	6.82			8.8	$	254,319
	Authorized	6,510
	Options granted	(3,537	)	3,483			33.32
	Options exercised	—		(244	)		7.6
	Options canceled	507		(507	)		11.19
	Early exercised shares repurchased	26		—			4.05
	Outstanding—September 30, 2014	12,447		13,977			$	13.25			8.4	$	1,047,415
	Vested and exercisable—September 30, 2014			3,661			$	4.67			7.5	$	306,260
	Vested and expected to vest—September 30, 2014			12,338			$	12.2			8.3	$	939,302
	The weighted-average grant-date fair value of options granted during the nine months ended September 30, 2014 was $20.45 per share. The aggregate intrinsic value of options exercised for the nine months ended September 30, 2014 was $7.5 million.
	As of September 30, 2014, the total unrecognized stock-based compensation expense for unvested stock options, net of expected forfeitures, was $88.8 million, which is expected to be recognized over a weighted-average period of 3.9 years. The total fair value of options vested for the nine months ended September 30, 2014 was $8.4 million.
	Under the 2004 Plan and 2011 Plan, the options outstanding and vested and exercisable by exercise price at September 30, 2014 are as follows:
		Options Outstanding and Exercisable								Options Vested and Exercisable
	Range of Exercise Price	Number of		Weighted-		Weighted-				Number of		Weighted-
		Shares Underlying		Average		Average				Shares		Average
		Outstanding		Remaining		Exercise Price				Underlying		Exercise Price
		Options		Contractual		per Share				Outstanding		per Share
		(in thousands)		Life (Years)						Options
										(in thousands)
$3.33 - $4.16	4,076		7.2		$	3.65			2,463		$	3.6
$4.18 - $4.92	2,123		8.1		4.56				618		4.73
$7.76 - $8.77	1,971		8.6		8.26				447		8.29
$10.18	1,886		9		10.18				120		10.18
$22.49	1,041		9.2		22.49				4		22.49
$30.67	1,658		9.4		30.67				2		30.47
$34.12 - $38.00	1,072		9.6		36.92				7		35.26
$75.00 - $84.00	150		9.9		75.6				—		—
	13,977		8.4		$	13.25			3,661		$	4.67
Restricted Stock Unit (RSU) Activities
A summary of the activity under our stock plans and changes during the reporting period and a summary of information related to RSUs are presented below (in thousands, except years and per share amounts):
	Number of		Weighted-				Weighted-Average		Aggregate Intrinsic Value
	Shares		Average Grant				Remaining
			Date Fair Value Per Share				Contractual Term (in years)
Unvested balance—December 31, 2013	—		—				0		—
RSUs granted	54		$	76.76
RSUs vested	—		—
RSUs forfeited/canceled	—		—
Unvested balance—September 30, 2014	54		$	76.76			2.1		$	4,772
RSUs vested and expected to vest—September 30, 2014	54		$	76.76			2.1		$	4,772
As of September 30, 2014, there was $3.4 million of unrecognized compensation cost related to unvested RSUs, net of estimated forfeitures. This amount is expected to be recognized over a weighted-average period of 3.1 years.
Restricted Stock Award Activities
A summary of our RSA activity and related information is as follows (in thousands, except per share amounts):
	Number of		Weighted-
	RSA’s		Average Grant
	Outstanding		Date Fair Value Per Share
Unvested balance—December 31, 2013	142		$	2.42
Vested	(44	)	2.5
Unvested balance—September 30, 2014	98		$	2.5
There were no RSAs granted during the nine months ended September 30, 2014. As of September 30, 2014, the total unrecognized expense for outstanding RSAs, net of expected forfeitures, was $0.3 million, which is expected to be amortized over a weighted-average period of 2.0 years. As of September 30, 2014, the intrinsic value of the outstanding RSAs based on the estimated fair value of $88.33 per share was $8.4 million.
Early Exercise of Stock Options
We have typically allowed our employees and directors to exercise options granted under the 2011 Plan and the 2004 Plan prior to vesting. Upon an "early exercise" of these options, the unvested shares acquired through the exercise become options subject to our repurchase right that lapse in accordance with the original option vesting schedule. Upon termination of employment prior to our repurchase rights lapsing in full, we have a right to repurchase the unvested shares at the original purchase price (or the then-current fair market value, if lower). The proceeds initially are recorded in other liabilities from the early exercise of stock options and are reclassified to common stock and paid-in capital as our repurchase right lapse. For the nine months ended September 30, 2014, we repurchased 29,803 shares of common stock at the original exercise price due to the termination of the holders of the unvested shares. As of September 30, 2014, shares held by employees and directors that were subject to repurchase were 1.8 million with an aggregate price of $5.6 million.

Net_Income_Per_Share_Available

Net Income Per Share Available to Common Stock	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Net Income Per Share Available to Common Stock	'
	Net Income Per Share Available to Common Stock
	The following table sets forth the computation of our basic and diluted net income per share available to common stock (in thousands, except per share amounts):
		Three Months Ended September 30,							Nine Months Ended September 30,
		2014				2013			2014			2013
	Numerator:
	Basic:
	Net income	$	21,866			$	11,856		$	55,813		$	28,718
	Less: undistributed earnings allocated to participating securities	(681		)		(6,018		)	(15,257		)	(14,844		)
	Net income available to common stockholders, basic	$	21,185			$	5,838		$	40,556		$	13,874
	Diluted:
	Net income attributable to common stockholders, basic	$	21,185			$	5,838		$	40,556		$	13,874
	Add: undistributed earnings allocated to participating securities	70				290			1,353			586
	Net income attributable to common stockholders, diluted	$	21,255			$	6,128		$	41,909		$	14,460
	Denominator:
	Basic:
	Weighted-average shares used in computing net income per share available to common stockholders, basic	62,402				27,557			43,453			26,927
	Diluted:
	Weighted-average shares used in computing net income per share available to common stockholders, basic	62,402				27,557			43,453			26,927
	Add weighted-average effect of dilutive securities:
	Stock options and RSAs	7,161				2,848			5,795			2,308
	Employee stock purchase plan	174				—			75			—
	Stock purchase rights	—				7			—			6
	Weighted-average shares used in computing net income per share available to common stockholders, diluted	69,737				30,412			49,323			29,241
	Net income per share attributable to common stockholders:
	Basic	$	0.34			$	0.21		$	0.93		$	0.52
	Diluted	$	0.3			$	0.2		$	0.85		$	0.49
	The following outstanding shares of common stock equivalents were excluded from the computation of diluted net income per share available to common stockholders for the periods presented because including them would have been anti-dilutive (in thousands):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014		2013
	Stock options and RSAs to purchase common stock	120			1,396			1,480		1,416

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	Provision for income taxes was approximately $10.4 million and $5.0 million for the three months ended September 30, 2014 and 2013 respectively, and $27.6 million and $9.5 million for the nine months ended September 30, 2014 and 2013 respectively. The change in our provision for income taxes and effective tax rate was primarily due to increase in profit before income tax, the geographical distribution of the earnings, and the expiration of the federal research and development credit as of December 31, 2013.
	The effective tax rate as of December 31, 2013 included the impact of the passage of the American Tax Relief Act of 2012 signed into law on January 2, 2013, which reinstated 2012 and 2013 federal research and development credit. The impact of the 2012 federal research and development tax credit benefit was recorded in the three months ended March 31, 2013.
	We operate in a number of tax jurisdictions and are subject to taxes in each country or jurisdiction in which we conduct business. Earnings from our non-U.S. activities are subject to local country income tax and may be subject to U.S. income tax. Generally, the U.S. taxes are reduced by a credit for foreign income taxes paid on these earnings which avoids double taxation. Our tax expense to date consists of federal, state and foreign current and deferred income taxes. As we expand internationally, our marginal tax rate may decrease; however, there can be no certainty that our marginal tax rate will decrease, and we may experience changes in tax rates that are not reflective of actual changes in our business or operations.

Segment_Information

Segment Information	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Segment Information	'
	Segment Information
	We have determined that we operate as one reportable segment. The following table represents revenue based on the customer’s location, as determined by the customer’s shipping address (in thousands):
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
	United States	$	123,847	$	83,301	$	318,989	$	200,293
	Other Americas	1,581		2,350		5,797		3,797
	Europe, Middle East and Africa	21,485		10,922		53,827		28,333
	Asia Pacific	8,550		5,052		32,004		14,035
	Total revenue	$	155,463	$	101,625	$	410,617	$	246,458
	Long lived assets, excluding intercompany receivables, investments in subsidiaries, privately-held equity investment
	and deferred tax assets, net by location are summarized as follows (in thousands):
		September 30,		December 31,
		2014		2013
	United States	$	63,203	$	63,557
	International	3,788		3,647
	Total	$	66,991	$	67,204

Organization_and_Summary_of_Si

Organization and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of Accounting	'
	Basis of Presentation
	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (" U.S. GAAP") and following the requirements of the U.S. Securities and Exchange Commission (the “SEC”) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP can be condensed or omitted. In management’s opinion, the unaudited condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and include all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of our financial information. The results for the three and nine months ended September 30, 2014, are not necessarily indicative of the results expected for the full fiscal year.
Consolidation	'
	The condensed consolidated balance sheet as of December 31, 2013 has been derived from the audited consolidated financial statements at that date but does not include all of the information and notes required by generally accepted accounting principles for complete financial statements.
	The accompanying unaudited condensed consolidated financial statements include the accounts of Arista Networks, Inc. and our wholly owned subsidiaries. All significant intercompany accounts and transactions have been eliminated.
	The accompanying unaudited condensed consolidated financial statements and related financial information should be read in conjunction with the audited consolidated financial statements and related footnotes included in our prospectus filed pursuant to Rule 424(b) under the Securities Act of 1933, as amended (the “Securities Act”), with the SEC on June 6, 2014 (the “Prospectus”).
Significant Accounting Policies [Text Block]	'
	New Accounting Policy
	Investments
	We have recorded our equity investment in a privately-held company under the cost method. Initial measurement of our investment under the cost method is recorded at historical cost which represents our initial investment in the privately-held company.  We will periodically assess and evaluate our cost method investment for impairment and perform an assessment based on evaluation of overall financial performance, industry and market conditions, and other relevant events or factors deemed necessary that may affect carrying value. If we determine that a decrease in the equity investment should be recognized given impairment that is considered “other than temporary” in nature, we will write-down the carrying amount to its revised new fair value.
Use of Estimates	'
	Use of Estimates
	The preparation of the accompanying unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires us to make estimates and assumptions that affect the amounts reported and disclosed in the unaudited condensed consolidated financial statements and accompanying notes. Those estimates and assumptions include, but are not limited to, revenue recognition and deferred revenue; determination of fair value for stock-based awards; accounting for income taxes, including the valuation allowance on deferred tax assets and reserves for uncertain tax positions; valuation of inventory; valuation of warranty accruals; and the recognition and measurement of contingent liabilities. We evaluate our estimates and assumptions on an ongoing basis using historical experience and other factors and adjust those estimates and assumptions when facts and circumstances dictate. As future events and their effects cannot be determined with precision, actual results could differ from these estimates, and those differences could be material to the unaudited condensed consolidated financial statements.
Business Concentrations	'
	Business Concentrations
	We work closely with third parties to manufacture and deliver our products. As of September 30, 2014 and December 31, 2013, two suppliers provided all of our electronic manufacturing services. Our products rely on key components, including certain integrated circuit components and power supplies some of which our contract manufacturers purchase on our behalf from a limited number of suppliers, including certain sole source providers. We do not have guaranteed supply contracts with any of our component suppliers, and our suppliers could delay shipments or cease manufacturing such products or selling them to us at any time. If we are unable to obtain a sufficient quantity of these components on commercially reasonable terms or in a timely manner, sales of our products could be delayed or halted entirely or we may be required to redesign our products. Quality or performance failures of our products or changes in our contractors’ or vendors’ financial or business condition could disrupt our ability to supply quality products to our customers. Any of these events could result in lost sales and damage to our end-customer relationships, which would adversely impact our business, financial condition and results of operations.
Concentrations of Credit Risk	'
	Concentrations of Credit Risk
	Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash, cash equivalents, restricted cash, accounts receivable and notes receivable. Our cash, cash equivalents and restricted cash are invested in high quality financial instruments with banks and financial institutions. Such deposits may be in excess of insured limits provided on such deposits.
	Our accounts receivable are unsecured and represent amounts due to us based on contractual obligations of our customers. We mitigate credit risk in respect to accounts receivable by performing ongoing credit evaluations of our customers to assess the probability of accounts receivable collection based on a number of factors, including past transaction experience with the customer, evaluation of their credit history, the credit limits extended and review of the invoicing terms of the contract. We generally do not require our customers to provide collateral to support accounts receivable. We have recorded an allowance for doubtful accounts for those receivables that we have determined not to be collectible.
	Our notes receivable are secured and represent amounts due to us from a private company. We mitigate credit risk in respect to the notes receivable by performing ongoing credit evaluations of the borrower to assess the probability of collecting all amounts due to us under the existing contractual terms.
	We market and sell our products through both our direct sales force and our channel partners, including distributors, value-added resellers, system integrators and original equipment manufacturer (“OEM”) partners.
Reclassifications [Text Block]	'
	Reclassifications
	As a result of a change in classification, we have reclassified our spare parts inventory from inventory to other current and non-current assets as of September 30, 2014. Spare parts inventory are used to satisfy our warranty obligations, and are not available for sale or used in the production process. Prior year balances have been adjusted to conform to this new classification for comparability purposes.
Recently Issued and Adopted Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In May 2014, the FASB issued ASU No. 2014-09, Revenue From Contracts With Customers ("ASU 2014-09"), which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. ASU 2014-09 is effective for fiscal years (and interim reporting periods within those years) beginning after December 15, 2016. Early application is not permitted. ASU 2014-09 permits the use of either the retrospective or cumulative effect transition method. We are currently reviewing the provisions of ASU 2014-09 and have not yet selected a transition method nor have we determined the effect of the standard on our consolidated financial statements.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair value of financial assets by level	'
	The following table sets forth the fair value of our financial assets by level within the fair value hierarchy as noted above (in thousands):
		September 30, 2014
		Level I		Level II		Level III		Total
	Financial Assets
	Money market funds	$	244,187	$	—	$	—	$	244,187
	Notes receivable(2)	—		—		8,000		8,000
	Total financial assets	$	244,187	$	—	$	8,000	$	252,187
		December 31, 2013
		Level I		Level II		Level III		Total
	Financial Assets
	Money market funds	$	47,036	$	—	$	—	$	47,036
	Money market funds – restricted cash(1)	4,040		—		—		4,040
	Notes receivable(2)	—		—		4,000		4,000
	Total financial assets	$	51,076	$	—	$	4,000	$	55,076
	(1)Included in “Other assets" in the accompanying Condensed Consolidated Balance Sheets.
	(2)Included in “Notes receivable” in the accompanying Condensed Consolidated Balance Sheets. There were no changes in the fair value of the Level III assets during the year ended December 31, 2013. During the three and nine months ended September 30, 2014, we increased the fair value of our Notes receivable by $4.0 million (See “Note 4 – Notes Receivable”). During the nine months ended September 30, 2014 and the year ended December 31, 2013, we had no transfers between levels of the fair value hierarchy of its assets measured at fair value. In October 2014, we received payment in full from the borrower equal to two times our outstanding principal balance as well as the unpaid accrued interest through the payment date.

Balance_Sheet_Components_Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2014
Balance Sheet Components [Abstract]	'
Schedule of Accounts Receivable	'
	Accounts receivable, net consists of the following (in thousands):
		September 30,			December 31,
		2014			2013
	Accounts receivable	$	87,259		$	80,338
	Allowance for doubtful accounts	(945		)	(810		)
	Product sales return reserve	(2,251		)	(1,529		)
	Accounts receivable, net	$	84,063		$	77,999
Schedule of Inventories	'
	Inventories consist of the following (in thousands):
		September 30,			December 31,
		2014			2013
	Raw materials	$	15,470		$	18,286
	Finished goods	47,117			48,808
	Total inventories	$	62,587		$	67,094
Schedule of Property and Equipment, net	'
	Property and equipment, net consists of the following (in thousands):
		September 30,			December 31,
		2014			2013
	Equipment and machinery	$	17,243		$	13,733
	Computer hardware and software	6,890			3,688
	Furniture and fixtures	1,374			1,352
	Leasehold improvements	19,520			19,407
	Building	35,154			35,154
	Construction-in-process	1,127			1,056
	Property and equipment, gross	81,308			74,390
	Less: accumulated depreciation	(14,317		)	(7,186		)
	Property and equipment, net	$	66,991		$	67,204
Schedule of Accrued Liabilities	'
	Accrued liabilities consist of the following (in thousands):
		September 30,			December 31,
		2014			2013
	Accrued payroll related costs	$	18,866		$	9,103
	Accrued warranty costs	3,464			5,075
	Accrued accounts payable	4,058			5,370
	Accrued manufacturing costs	1,724			3,835
	Accrued professional fees	1,422			1,220
	Accrued taxes	1,215			927
	Other	1,497			1,379
	Total accrued liabilities	$	32,246		$	26,909
Schedule of Warranty Accrual	'
	The following table summarizes the activity related to our accrued liability for estimated future warranty costs (in thousands):
		Nine Months Ended September 30,
		2014			2013
	Warranty accrual, beginning of period	$	5,075		$	5,314
	Liabilities accrued for warranties issued during the period	1,839			4,192
	Warranty costs incurred during the period	(1,689		)	(2,605		)
	Adjustments related to change in estimate	(1,761		)	—
	Warranty accrual, end of period	$	3,464		$	6,901
Schedule of Deferred Revenue	'
	Deferred revenue consists of the following (in thousands):
		September 30,			December 31,
		2014			2013
	Current portion of deferred revenue	$	40,277		$	41,306
	Long-term portion of deferred revenue	37,415			17,598
	Total deferred revenue	$	77,692		$	58,904
Other Assets Disclosure [Text Block]	'
	Other assets consist of the following (in thousands):
		September 30,			December 31,
		2014			2013
	Investments	$	18,000		$	—
	Restricted cash	—			4,040
	Deposits	2,578			2,581
	Spares	4,429			2,757
	Other assets	2,552			631
	Total other assets	$	27,559		$	10,009

Debt_Obligations_Tables

Debt Obligations (Tables)	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Schedule of Debt Obligations	'
	Our debt obligations consist of the following (in thousands):
		December 31,
		2013
	Convertible notes payable—related party	$	25,000
	Convertible notes payable	75,000
	Total	100,000
	Less: Unamortized discount on notes payable	1,207
	Less: Current portion	98,793
	Total long-term portion of debt	$	—

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Schedule of Operating Leases	'
	As of December 31, 2013, the aggregate future minimum payments under non-cancelable operating leases consist of the following (in thousands):
	Years Ending December 31,
	2014	$	825
	2015	540
	2016	507
	2017	411
	2018	161
	Total minimum future lease payments	$	2,444
Schedule of Lease Financing Obligations	'
	As of December 31, 2013, the future minimum payments due under the lease financing obligation were as follows (in thousands):
	Years Ending December 31,
	2014		$	4,991
	2015		5,601
	2016		5,769
	2017		5,948
	2018		6,128
	Thereafter		31,059
	Total payments		59,496
	Less: interest and land lease expense		(38,962		)
	Total payments under facility financing obligations		20,534
	Property reverting to landlord		23,436
	Present value of obligation		43,970
	Less current portion		(818		)
	Long-term portion of obligation		$	43,152

Common_Stock_Reserved_for_Issu1

Common Stock Reserved for Issuance (Tables)	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Schedule of Common Stock Reserved for Issuance	'
	We have reserved shares of common stock, on an as-converted basis, for future issuance as follows (in thousands):
		September 30,	December 31,
		2014	2013
	Conversion of convertible preferred stock outstanding (1)	—	24,000
	Outstanding stock options and RSAs	13,977	11,245
	Outstanding stock purchase rights	2	2
	Conversion of convertible debt and related interest expense (2)	—	3,949
	Shares reserved for future option and RSA grants	12,447	8,941
	Shares reserved under Employee Stock Purchase Plan	651	—
	Total	27,077	48,137
	(1) Upon the closing of our IPO, all shares of our convertible preferred stock were converted to 24 million shares of common stock on a one-for-one basis.
	(2) Upon the closing of our IPO, all noteholders with the exception of one noteholder converted the principal and accrued interest amount outstanding under their subordinated convertible promissory notes into shares of our common stock at the IPO price of $43.00 per share. The noteholder, who did not elect to so convert, was paid a total of $23.6 million which included principal and accrued interest less applicable withholding taxes of $1.1 million. The remainder of the noteholders converted the remaining debt balance of approximately $96.5 million including principal and accrued interest into 2.2 million shares of our common stock.

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Schedule of Stock-based Compensation Expense	'
	Total stock-based compensation expense related to options, restricted stock awards, employee stock purchases, restricted stock units and stock purchase rights granted were allocated as follows (in thousands):
		Three Months Ended September 30,							Nine Months Ended September 30,
		2014			2013				2014			2013
	Cost of revenue	$	480		$	107			$	992		$	257
	Research and development	4,304			1,319				10,298			3,449
	Sales and marketing	2,387			765				5,746			1,859
	General and administrative	911			393				2,533			834
	Total stock-based compensation	$	8,082		$	2,584			$	19,569		$	6,399
Schedule of Stock Option Valuation Assumptions	'
	For the three and nine months ended September 30, 2014 and 2013, the fair value of each stock option granted under the 2011 Plan was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions and fair value per share:
		Three Months Ended September 30,					Nine Months Ended September 30,
		2014		2013			2014			2013
	Expected term (in years)	6.2		6.7			7.6			6.6
	Risk-free interest rate	1.9	%	2.2	%		2.3	%		1.7	%
	Expected volatility	49.1	%	50.5	%		47.8	%		50.8	%
	Dividend rate	—	%	—	%		—	%		—	%
Schedule of ESPP Valuation Assumptions	'
	There were no stock purchases under the ESPP during the three and nine months ended September 30, 2014.  The following table summarizes the assumptions relating to our ESPP:
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014			2013
	Expected term (in years)	1.4		N/A		1.4			N/A
	Risk-free interest rate	0.3	%	N/A		0.3	%		N/A
	Expected volatility	36.3	%	N/A		36.3	%		N/A
	Dividend rate	—	%	N/A		—	%		N/A
Schedule of Option and RSA Activity	'
	The following table summarizes the option and RSA (Restricted Stock Award) activity under the 2004 Plan and 2011 Plan and related information:
				Options and RSAs Outstanding
		Shares		Number of			Weighted-				Weighted-	Aggregate
		Available for		Shares			Average				Average	Intrinsic
		Grant		Underlying			Exercise				Remaining	Value
		(in thousands)		Outstanding Options and RSAs			Price per Share				Contractual	of Stock
				(in thousands)							Term (Years) of	Options
											Stock Options	Outstanding
												(in thousands)
	Outstanding—December 31, 2013	8,941		11,245			$	6.82			8.8	$	254,319
	Authorized	6,510
	Options granted	(3,537	)	3,483			33.32
	Options exercised	—		(244	)		7.6
	Options canceled	507		(507	)		11.19
	Early exercised shares repurchased	26		—			4.05
	Outstanding—September 30, 2014	12,447		13,977			$	13.25			8.4	$	1,047,415
	Vested and exercisable—September 30, 2014			3,661			$	4.67			7.5	$	306,260
	Vested and expected to vest—September 30, 2014			12,338			$	12.2			8.3	$	939,302
Schedule of Stock Options Outstanding and Vested and Exercisable by Exercise Price	'
	Under the 2004 Plan and 2011 Plan, the options outstanding and vested and exercisable by exercise price at September 30, 2014 are as follows:
		Options Outstanding and Exercisable								Options Vested and Exercisable
	Range of Exercise Price	Number of		Weighted-		Weighted-				Number of		Weighted-
		Shares Underlying		Average		Average				Shares		Average
		Outstanding		Remaining		Exercise Price				Underlying		Exercise Price
		Options		Contractual		per Share				Outstanding		per Share
		(in thousands)		Life (Years)						Options
										(in thousands)
	$3.33 - $4.16	4,076		7.2		$	3.65			2,463		$	3.6
	$4.18 - $4.92	2,123		8.1		4.56				618		4.73
	$7.76 - $8.77	1,971		8.6		8.26				447		8.29
	$10.18	1,886		9		10.18				120		10.18
	$22.49	1,041		9.2		22.49				4		22.49
	$30.67	1,658		9.4		30.67				2		30.47
	$34.12 - $38.00	1,072		9.6		36.92				7		35.26
	$75.00 - $84.00	150		9.9		75.6				—		—
		13,977		8.4		$	13.25			3,661		$	4.67
Schedule of Nonvested Restricted Stock Units Activity	'
	A summary of the activity under our stock plans and changes during the reporting period and a summary of information related to RSUs are presented below (in thousands, except years and per share amounts):
		Number of		Weighted-				Weighted-Average		Aggregate Intrinsic Value
		Shares		Average Grant				Remaining
				Date Fair Value Per Share				Contractual Term (in years)
	Unvested balance—December 31, 2013	—		—				0		—
	RSUs granted	54		$	76.76
	RSUs vested	—		—
	RSUs forfeited/canceled	—		—
	Unvested balance—September 30, 2014	54		$	76.76			2.1		$	4,772
	RSUs vested and expected to vest—September 30, 2014	54		$	76.76			2.1		$	4,772
Schedule of Restricted Stock Awards Activity	'
	A summary of our RSA activity and related information is as follows (in thousands, except per share amounts):
		Number of		Weighted-
		RSA’s		Average Grant
		Outstanding		Date Fair Value Per Share
	Unvested balance—December 31, 2013	142		$	2.42
	Vested	(44	)	2.5
	Unvested balance—September 30, 2014	98		$	2.5

Net_Income_Per_Share_Available1

Net Income Per Share Available to Common Stock (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Schedule of Basic and Diluted Net Income Per Share Available to Common Stock	'
	The following table sets forth the computation of our basic and diluted net income per share available to common stock (in thousands, except per share amounts):
		Three Months Ended September 30,							Nine Months Ended September 30,
		2014				2013			2014			2013
	Numerator:
	Basic:
	Net income	$	21,866			$	11,856		$	55,813		$	28,718
	Less: undistributed earnings allocated to participating securities	(681		)		(6,018		)	(15,257		)	(14,844		)
	Net income available to common stockholders, basic	$	21,185			$	5,838		$	40,556		$	13,874
	Diluted:
	Net income attributable to common stockholders, basic	$	21,185			$	5,838		$	40,556		$	13,874
	Add: undistributed earnings allocated to participating securities	70				290			1,353			586
	Net income attributable to common stockholders, diluted	$	21,255			$	6,128		$	41,909		$	14,460
	Denominator:
	Basic:
	Weighted-average shares used in computing net income per share available to common stockholders, basic	62,402				27,557			43,453			26,927
	Diluted:
	Weighted-average shares used in computing net income per share available to common stockholders, basic	62,402				27,557			43,453			26,927
	Add weighted-average effect of dilutive securities:
	Stock options and RSAs	7,161				2,848			5,795			2,308
	Employee stock purchase plan	174				—			75			—
	Stock purchase rights	—				7			—			6
	Weighted-average shares used in computing net income per share available to common stockholders, diluted	69,737				30,412			49,323			29,241
	Net income per share attributable to common stockholders:
	Basic	$	0.34			$	0.21		$	0.93		$	0.52
	Diluted	$	0.3			$	0.2		$	0.85		$	0.49
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	'
	The following outstanding shares of common stock equivalents were excluded from the computation of diluted net income per share available to common stockholders for the periods presented because including them would have been anti-dilutive (in thousands):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014		2013
	Stock options and RSAs to purchase common stock	120			1,396			1,480		1,416

Segment_Information_Tables

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Schedule of Net Revenue and Long Lived Assets, by Location	'
	The following table represents revenue based on the customer’s location, as determined by the customer’s shipping address (in thousands):
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
	United States	$	123,847	$	83,301	$	318,989	$	200,293
	Other Americas	1,581		2,350		5,797		3,797
	Europe, Middle East and Africa	21,485		10,922		53,827		28,333
	Asia Pacific	8,550		5,052		32,004		14,035
	Total revenue	$	155,463	$	101,625	$	410,617	$	246,458
	Long lived assets, excluding intercompany receivables, investments in subsidiaries, privately-held equity investment
	and deferred tax assets, net by location are summarized as follows (in thousands):
		September 30,		December 31,
		2014		2013
	United States	$	63,203	$	63,557
	International	3,788		3,647
	Total	$	66,991	$	67,204

Overview_and_Basis_of_Presenta1

Overview and Basis of Presentation - Narrative (Details) (USD $)	0 Months Ended	9 Months Ended				0 Months Ended		0 Months Ended
	Jun. 06, 2014	Sep. 30, 2014	Jun. 06, 2014	Sep. 30, 2014	Dec. 31, 2013	Jun. 06, 2014	Jun. 06, 2014	Jun. 06, 2014
			noteholder	Supplier Concentration Risk	Supplier Concentration Risk	Common Stock	Common Stock	Convertible Debt [Member]
				supplier	supplier			Common Stock
Class of Stock [Line Items]	'	'	'	'	'	'	'	'
Issuance of common stock during IPO (in shares)	'	'	'	'	'	6,037,500	'	'
Issue price (usd per share)	'	'	'	'	'	'	$43	'
Common stock issued pursuant to exercise of over-allotment option by underwriters	'	'	'	'	'	787,500	'	'
Proceeds from initial public offering, net of offering costs	$238,900,000	$238,904,000	'	'	'	'	'	'
Underwriting discounts and commissions	15,600,000	'	'	'	'	'	'	'
Issuance costs	5,100,000	'	'	'	'	'	'	'
Shares issued upon conversion	'	'	'	'	'	24,000,000	'	2,200,000
Ratio of shares issued upon conversion	'	'	1	'	'	'	1	'
Number of noteholders paid out upon closing of IPO	'	'	1	'	'	'	'	'
Repayment of Notes Payable and Accrued Interest	23,600,000	'	'	'	'	'	'	'
Withholding taxes	1,100,000	'	'	'	'	'	'	'
Converted debt amount	$96,500,000	'	'	'	'	'	'	'
Concentration Risk [Line Items]	'	'	'	'	'	'	'	'
Number of suppliers	'	'	'	2	2	'	'	'

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)

9 Months Ended

3 Months Ended

9 Months Ended

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Fair Value, Measurements, Recurring

Convertible Notes Receivable

Convertible Notes Receivable

Level 1

Level 1

Level 1

Level 1

Level 1

Level 2

Level 2

Level 2

Level 2

Level 2

Level 3

Level 3

Level 3

Level 3

Level 3

Total

Total

Total

Total

Total

Money market funds

Money market funds

Money market funds

Money market funds

Money market funds

Money market funds

Money market funds

Money market funds

Money market funds

Money market funds

Money market funds

Money market funds

Restricted cash

Restricted cash

Restricted cash

Restricted cash

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Money market funds

'

'

'

'

$244,187,000

$47,036,000

$4,040,000

[1]

'

'

$0

$0

$0

[1]

'

'

$0

$0

$0

[1]

'

'

$244,187,000

$47,036,000

$4,040,000

[1]

'

'

Notes receivable

8,000,000

0

0

[2]

0

[2]

'

'

'

0

[2]

0

[2]

'

'

'

8,000,000

[2]

4,000,000

[2]

'

'

'

8,000,000

[2]

4,000,000

[2]

'

'

'

'

'

Total financial assets

'

'

244,187,000

51,076,000

'

'

'

0

0

'

'

'

8,000,000

4,000,000

'

'

'

252,187,000

55,076,000

'

'

'

'

'

Increase in notes receivable

$4,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$4,000,000

$4,000,000

[1]

Included in “Other assets" in the accompanying Condensed Consolidated Balance Sheets.

[2]

Included in “Notes receivable” in the accompanying Condensed Consolidated Balance Sheets. There were no changes in the fair value of the Level III assets during the year ended December 31, 2013. During the three and nine months ended September 30, 2014, we increased the fair value of our Notes receivable by $4.0 million (See “Note 4 – Notes Receivable”). During the nine months ended September 30, 2014 and the year ended December 31, 2013, we had no transfers between levels of the fair value hierarchy of its assets measured at fair value. In October 2014, we received payment in full from the borrower equal to two times our outstanding principal balance as well as the unpaid accrued interest through the payment date.

Balance_Sheet_Components_Accou

Balance Sheet Components - Accounts Receivable, net (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Receivables [Abstract]	'	'
Accounts receivable	$87,259	$80,338
Allowance for doubtful accounts	-945	-810
Product sales return reserve	-2,251	-1,529
Accounts receivable, net	$84,063	$77,999

Balance_Sheet_Components_Inven

Balance Sheet Components - Inventories (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventories	'	'
Raw materials	$15,470	$18,286
Finished goods	47,117	48,808
Total inventories	$62,587	$67,094

Balance_Sheet_Components_Prope

Balance Sheet Components - Property and Equipment, net (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Property, Plant and Equipment [Line Items]	'	'	'	'	'
Property and equipment, gross	$81,308,000	'	$81,308,000	'	$74,390,000
Less: accumulated depreciation	-14,317,000	'	-14,317,000	'	-7,186,000
Property and equipment, net	66,991,000	'	66,991,000	'	67,204,000
Depreciation	2,700,000	1,000,000	7,400,000	2,500,000	'
Equipment and machinery	'	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'	'
Property and equipment, gross	17,243,000	'	17,243,000	'	13,733,000
Computer hardware and software	'	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'	'
Property and equipment, gross	6,890,000	'	6,890,000	'	3,688,000
Furniture and fixtures	'	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'	'
Property and equipment, gross	1,374,000	'	1,374,000	'	1,352,000
Leasehold improvements	'	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'	'
Property and equipment, gross	19,520,000	'	19,520,000	'	19,407,000
Building	'	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'	'
Property and equipment, gross	35,154,000	'	35,154,000	'	35,154,000
Construction-in-process	'	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'	'
Property and equipment, gross	1,127,000	'	1,127,000	'	1,056,000
Building and improvements	'	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'	'
Property and equipment, gross	53,400,000	'	53,400,000	'	53,300,000
Line of Credit | Letter of Credit	'	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'	'
Letter of credit	$4,000,000	'	$4,000,000	'	'

Balance_Sheet_Components_Accru

Balance Sheet Components - Accrued Liabilities (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Balance Sheet Components [Abstract]	'	'	'	'
Accrued payroll related costs	$18,866	$9,103	'	'
Accrued warranty costs	3,464	5,075	6,901	5,314
Accrued accounts payable	4,058	5,370	'	'
Accrued manufacturing costs	1,724	3,835	'	'
Accrued Professional Fees, Current	1,422	1,220	'	'
Accrued Income Taxes	1,215	927	'	'
Other	1,497	1,379	'	'
Total accrued liabilities	$32,246	$26,909	'	'

Balance_Sheet_Components_Warra

Balance Sheet Components - Warranty Accrual (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Warranty [Roll Forward]	'	'
Warranty accrual, beginning of period	$5,075	$5,314
Liabilities accrued for warranties issued during the period	1,839	4,192
Warranty costs incurred during the period	-1,689	-2,605
Adjustments related to change in estimate	-1,761	0
Warranty accrual, end of period	$3,464	$6,901
Hardware	'	'
Guarantor Obligations [Line Items]	'	'
Warranty Period	'1 year	'
Software embedded in products	'	'
Guarantor Obligations [Line Items]	'	'
Warranty Period	'90 days	'

Balance_Sheet_Components_Defer

Balance Sheet Components - Deferred Revenue (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Balance Sheet Components [Abstract]	'	'
Current portion of deferred revenue	$40,277	$41,306
Long-term portion of deferred revenue	37,415	17,598
Total deferred revenue	$77,692	$58,904

Balance_Sheet_Components_Priva

Balance Sheet Components - Privately-held Equity Investment (Details) (USD $)	Sep. 30, 2014
In Thousands, unless otherwise specified
Investments, All Other Investments [Abstract]	'
Other Long-term Investments	$15,000

Balance_Sheet_Components_Other

Balance Sheet Components Other assets (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]	'	'
Origination of Notes Receivable	$3,000	'
Other Investments	18,000	0
Restricted Cash and Investments, Noncurrent	0	4,040
Deposit Assets	2,578	2,581
Spares	4,429	2,757
Other Assets	2,552	631
Other Assets, Noncurrent	$27,559	$10,009

Notes_Receivable_Notes_Receiva

Notes Receivable Notes Receivable (Details) (USD $)	0 Months Ended	3 Months Ended	9 Months Ended		1 Months Ended	3 Months Ended	9 Months Ended
	Jul. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2014	Sep. 30, 2014	Jul. 31, 2012
					Convertible Notes Receivable	Convertible Notes Receivable	Convertible Notes Receivable	Convertible Notes Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'	'	'	'	'
Origination of notes receivable	'	$3,000,000	'	'	$4,000,000	'	'	'
Interest rate on notes receivable	'	'	'	'	'	'	'	6.00%
Minimum percentage of voting power transferred in corporate transaction	50.00%	'	'	'	'	'	'	'
Increase in notes receivable	'	'	4,000,000	'	'	4,000,000	4,000,000	'
Period borrower cannot sell exclusive features to other customers	'	'	'24 months	'	'	'	'	'
Fair value of convertible notes receivable	'	$8,000,000	$8,000,000	$0	'	'	'	'

Debt_Obligations_Schedule_of_D

Debt Obligations Schedule of Debt Obligations (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'
Long-term Debt, Gross	$100,000
Less: Unamortized discount on notes payable	1,207
Less: Current portion	98,793
Total long-term portion of debt	0
Convertible notes	'
Debt Instrument [Line Items]	'
Long-term Debt, Gross	75,000
Convertible notes payable—related party | Convertible notes	'
Debt Instrument [Line Items]	'
Long-term Debt, Gross	$25,000

Debt_Obligations_Additional_In

Debt Obligations - Additional Information (Details) (USD $)

0 Months Ended

9 Months Ended

9 Months Ended

0 Months Ended

0 Months Ended

Jun. 06, 2014

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Sep. 30, 2014

Jan. 31, 2011

Jun. 30, 2011

Jan. 31, 2011

Sep. 30, 2014

Sep. 30, 2014

Jun. 06, 2014

Jun. 06, 2014

Jun. 06, 2014

Convertible notes

Convertible notes

Convertible notes

Trusts related to two co-founders

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Convertible notes issued January 2011

Convertible debt issued June 2011

Convertible notes

Convertible notes payable

Convertible notes payable

Related party convertible notes issued January 2011

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate principal amount

'

'

'

'

'

$55,000,000

$20,000,000

$25,000,000

'

'

'

'

'

Issuance of common stock during IPO (in shares)

'

'

'

'

'

'

'

'

6,038,000

'

6,037,500

'

'

Issuance of common stock from initial public offering, net of offering costs

238,900,000

238,904,000

'

'

'

'

'

'

1,000

'

'

'

'

Unamortized debt discount

'

'

'

1,207,000

'

'

'

'

'

'

'

'

'

Interest rate

'

'

'

'

6.00%

'

'

'

'

'

'

'

'

Minimum amount of indebtedness not subject to acceleration of maturity after failure to make other payment obligations

'

'

'

'

10,000,000

'

'

'

'

'

'

'

'

Prepay notice period

'

'10 days

'

'

'

'

'

'

'

'

'

'

'

Issue price (usd per share)

'

'

'

'

'

'

'

'

'

'

'

$43

'

Repayment of Notes Payable and Accrued Interest

23,600,000

'

'

'

'

'

'

'

'

'

'

'

'

Repayment on notes payable

'

20,000,000

0

'

'

'

'

'

'

'

'

'

'

Withholding taxes

1,100,000

'

'

'

'

'

'

'

'

'

'

'

'

Converted debt amount

$96,500,000

'

'

'

'

'

'

'

'

'

'

'

'

Shares issued upon conversion

'

'

'

'

'

'

'

'

'

1,543,000

24,000,000

'

2,200,000

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Long-term Purchase Commitment [Line Items]	'	'	'	'	'	'
Rent expense	'	$800,000	$1,300,000	$2,500,000	$3,000,000	'
Lease term	'120 months	'	'	'	'	'
Recorded assets	'	81,308,000	'	81,308,000	'	74,390,000
Lease financing obligation	'	43,900,000	'	43,900,000	'	44,000,000
Lease financing obligation, current	'	1,100,000	'	1,100,000	'	'
Lease financing obligations, non-current	'	42,831,000	'	42,831,000	'	43,152,000
Contract manufacturer liability	'	900,000	'	900,000	'	1,800,000
Deposits and other assets	'	'	'	'	'	'
Long-term Purchase Commitment [Line Items]	'	'	'	'	'	'
Restricted deposits	'	2,300,000	'	2,300,000	'	2,300,000
Line of Credit | Letter of Credit	'	'	'	'	'	'
Long-term Purchase Commitment [Line Items]	'	'	'	'	'	'
Letter of credit	'	4,000,000	'	4,000,000	'	'
Building and improvements	'	'	'	'	'	'
Long-term Purchase Commitment [Line Items]	'	'	'	'	'	'
Recorded assets	'	53,400,000	'	53,400,000	'	53,300,000
Building	'	'	'	'	'	'
Long-term Purchase Commitment [Line Items]	'	'	'	'	'	'
Recorded assets	'	$35,154,000	'	$35,154,000	'	$35,154,000
Estimated useful life	'	'	'	'30 years	'	'

Commitments_and_Contingencies_2

Commitments and Contingencies - Operating Leases (Details) (USD $)	9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'	'
Operating Leases, Rent Expense, Minimum Rentals	$2,600,000	'
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]	'	'
2014	'	825,000
2015	'	540,000
2016	'	507,000
2017	'	411,000
2018	'	161,000
Total minimum future lease payments	'	$2,444,000

Commitments_and_Contingencies_3

Commitments and Contingencies - Lease Financing Obligation (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Lease Financing Obligation, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]	'	'
2014	'	$4,991
2015	'	5,601
2016	'	5,769
2017	'	5,948
2018	'	6,128
Thereafter	'	31,059
Total payments	'	59,496
Less: interest and land lease expense	'	-38,962
Total payments under facility financing obligations	'	20,534
Property reverting to landlord	'	23,436
Present value of obligation	'	43,970
Less current portion	'	-818
Long-term portion of obligation	$42,831	$43,152

Common_Stock_Reserved_for_Issu2

Common Stock Reserved for Issuance (Details) (USD $)	0 Months Ended	9 Months Ended
	Jun. 06, 2014	Sep. 30, 2014		Sep. 30, 2013	Jun. 06, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'	'
Common stock reserved for issuance (in shares)	'	27,077,000		'	'	48,137,000
Ratio of shares issued upon conversion	'	'		'	1	'
Repayment of Notes Payable and Accrued Interest	$23,600,000	'		'	'	'
Repayment on notes payable	'	20,000,000		0	'	'
Withholding taxes	1,100,000	'		'	'	'
Converted debt amount	$96,500,000	'		'	'	'
Conversion of convertible preferred stock outstanding	'	'		'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'	'
Common stock reserved for issuance (in shares)	'	0	[1]	'	'	24,000,000	[1]
Outstanding stock options and RSAs	'	'		'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'	'
Common stock reserved for issuance (in shares)	'	13,977,000		'	'	11,245,000
Outstanding stock purchase rights	'	'		'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'	'
Common stock reserved for issuance (in shares)	'	2,000		'	'	2,000
Convertible notes payable	'	'		'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'	'
Common stock reserved for issuance (in shares)	'	0	[2]	'	'	3,949,000	[2]
Shares reserved for future option and RSA grants	'	'		'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'	'
Common stock reserved for issuance (in shares)	'	12,447,000		'	'	8,941,000
Employee Stock Purchase Plan	'	'		'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'	'
Common stock reserved for issuance (in shares)	'	651,000		'	'	0
Convertible Preferred Stock	'	'		'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'	'
Shares issued upon conversion	24,000,000	'		'	'	'
Common Stock	'	'		'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'	'
Shares issued upon conversion	24,000,000	'		'	'	'
Ratio of shares issued upon conversion	'	'		'	1	'
Issue price (usd per share)	'	'		'	43	'
Convertible notes payable | Common Stock	'	'		'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'	'
Shares issued upon conversion	2,200,000	'		'	'	'
[1]	Upon the closing of our IPO, all shares of our convertible preferred stock were converted to 24 million shares of common stock on a one-for-one basis.
[2]	Upon the closing of our IPO, all noteholders with the exception of one noteholder converted the principal and accrued interest amount outstanding under their subordinated convertible promissory notes into shares of our common stock at the IPO price of $43.00 per share. The noteholder, who did not elect to so convert, was paid a total of $23.6 million which included principal and accrued interest less applicable withholding taxes of $1.1 million. The remainder of the noteholders converted the remaining debt balance of approximately $96.5 million including principal and accrued interest into 2.2 million shares of our common stock.

Convertible_Preferred_Stock_De

Convertible Preferred Stock (Details)	Jun. 06, 2014	Jun. 06, 2014	Sep. 30, 2014
		Convertible Preferred Stock	Common Stock
			Convertible Preferred Stock
Class of Stock [Line Items]	'	'	'
Shares issued upon conversion	'	24,000,000	24,000,000
Ratio of shares issued upon conversion	1	'	'

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation	$8,082	$2,584	$19,569	$6,399
Cost of revenue	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation	480	107	992	257
Research and development	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation	4,304	1,319	10,298	3,449
Sales and marketing	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation	2,387	765	5,746	1,859
General and administrative	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation	$911	$393	$2,533	$834

StockBased_Compensation_Fair_V

Stock-Based Compensation - Fair Value Assumptions - Stock Options (Details) (Stock Option)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Stock Option	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Expected term (in years)	'6 years 2 months 12 days	'6 years 8 months 19 days	'7 years 7 months 13 days	'6 years 7 months 6 days
Risk-free interest rate	1.90%	2.20%	2.30%	1.70%
Expected volatility	49.10%	50.50%	47.80%	50.80%
Expected dividend rate	0.00%	0.00%	0.00%	0.00%

StockBased_Compensation_Fair_V1

Stock-Based Compensation - Fair Value Assumptions - ESPP (Details) (ESPP)	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
ESPP	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Expected term (in years)	'1 year 4 months 24 days	'1 year 4 months 24 days
Risk-free interest rate	0.30%	0.30%
Expected volatility	36.30%	36.30%
Expected dividend rate	0.00%	0.00%

StockBased_Compensation_Option

Stock-Based Compensation - Option and RSA Activity Rollforward (Details) (USD $)	9 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Shares Available for Grant	'	'
Shares available for grant beginning balance (in shares)	8,941	'
Shares available for grant, authorized (in shares)	6,510	'
Early exercised shares repurchased (in shares)	26	'
Shares available for grant ending balance (in shares)	12,447	8,941
ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodsharesavailableforgrant	3,537	'
Number of Shares Underlying Outstanding Options and RSAs (in thousands)	'	'
Beginning balance, options (in shares)	11,245	'
Options granted (in shares)	3,483	'
Options exercised (in shares)	-244	'
Options canceled (in shares)	-507	'
Ending balance, options (in shares)	13,977	11,245
Vested and exercisable (in shares)	3,661	'
Vested and expected to vest (in shares)	12,338	'
Weighted- Average Exercise Price per Share	'	'
Outstanding beginning balance (usd per share)	$6.82	'
Options granted (usd per share)	$33.32	'
Options exercised (usd per share)	$7.60	'
Options canceled (usd per share)	$11.19	'
Early exercised shares repurchased	$4.05	'
Outstanding ending balance (usd per share)	$13.25	$6.82
Vested and exercisable (usd per share)	$4.67	'
Vested and expected to vest (usd per share)	$12.20	'
Weighted- Average Remaining Contractual Term and Aggregate Intrinsic Value of Stock Options Outstanding	'	'
Weighted-average remaining contractual term of stock options outstanding	'8 years 4 months 24 days	'8 years 9 months 18 days
Weighted-average remaining contractual term of stock options vested and exercisable	'7 years 6 months 7 days	'
Weighted-average remaining contractual term of stock options vested and expected to vest	'8 years 3 months 22 days	'
Aggregate intrinsic value of stock options outstanding	$1,047,415	$254,319
Aggregate intrinsic value of stock options outstanding vested and exercisable	306,260	'
Aggregate intrinsic value of stock options outstanding vested and expected to vest	$939,302	'

StockBased_Compensation_Stock_

Stock-Based Compensation - Stock Options by Exercise Price (Details) (USD $)	9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number of Shares Underlying Outstanding Options (in shares)	13,977
Weighted- Average Remaining Contractual Life (Years)	'8 years 4 months 24 days
Weighted- Average Exercise Price per Share (usd per share)	$13.25
Number of Shares Underlying Outstanding Options (in shares)	3,661
Weighted- Average Exercise Price per Share (usd per share)	$4.67
$3.33 - $4.16	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$4.16
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$3.33
Number of Shares Underlying Outstanding Options (in shares)	4,076
Weighted- Average Remaining Contractual Life (Years)	'7 years 2 months 27 days
Weighted- Average Exercise Price per Share (usd per share)	$3.65
Number of Shares Underlying Outstanding Options (in shares)	2,463
Weighted- Average Exercise Price per Share (usd per share)	$3.60
$4.18 - $4.92	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$4.92
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$4.18
Number of Shares Underlying Outstanding Options (in shares)	2,123
Weighted- Average Remaining Contractual Life (Years)	'8 years 1 month 6 days
Weighted- Average Exercise Price per Share (usd per share)	$4.56
Number of Shares Underlying Outstanding Options (in shares)	618
Weighted- Average Exercise Price per Share (usd per share)	$4.73
$7.76 - $8.77	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$8.77
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$7.76
Number of Shares Underlying Outstanding Options (in shares)	1,971
Weighted- Average Remaining Contractual Life (Years)	'8 years 7 months 6 days
Weighted- Average Exercise Price per Share (usd per share)	$8.26
Number of Shares Underlying Outstanding Options (in shares)	447
Weighted- Average Exercise Price per Share (usd per share)	$8.29
$10.18	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$10.18
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$10.18
Number of Shares Underlying Outstanding Options (in shares)	1,886
Weighted- Average Remaining Contractual Life (Years)	'8 years 11 months 19 days
Weighted- Average Exercise Price per Share (usd per share)	$10.18
Number of Shares Underlying Outstanding Options (in shares)	120
Weighted- Average Exercise Price per Share (usd per share)	$10.18
$22.49	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$22.49
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$22.49
Number of Shares Underlying Outstanding Options (in shares)	1,041
Weighted- Average Remaining Contractual Life (Years)	'9 years 2 months 23 days
Weighted- Average Exercise Price per Share (usd per share)	$22.49
Number of Shares Underlying Outstanding Options (in shares)	4
Weighted- Average Exercise Price per Share (usd per share)	$22.49
$30.67	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$30.67
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$30.67
Number of Shares Underlying Outstanding Options (in shares)	1,658
Weighted- Average Remaining Contractual Life (Years)	'9 years 4 months 10 days
Weighted- Average Exercise Price per Share (usd per share)	$30.67
Number of Shares Underlying Outstanding Options (in shares)	2
Weighted- Average Exercise Price per Share (usd per share)	$30.47
$34.12 - $38.00	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$38
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$34.12
Number of Shares Underlying Outstanding Options (in shares)	1,072
Weighted- Average Remaining Contractual Life (Years)	'9 years 6 months 26 days
Weighted- Average Exercise Price per Share (usd per share)	$36.92
Number of Shares Underlying Outstanding Options (in shares)	7
Weighted- Average Exercise Price per Share (usd per share)	$35.26
$75.00 - $84.00	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$84
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$75
Number of Shares Underlying Outstanding Options (in shares)	150
Weighted- Average Remaining Contractual Life (Years)	'9 years 10 months 21 days
Weighted- Average Exercise Price per Share (usd per share)	$75.60
Number of Shares Underlying Outstanding Options (in shares)	0
Weighted- Average Exercise Price per Share (usd per share)	$0

StockBased_Compensation_Restri

Stock-Based Compensation - Restricted Stock Awards (Details) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value	$0	'
Restricted Stock Units (RSUs)	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms	'2 years 1 month 6 days	'0 years
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	$76.76	'
Restricted Stock Awards, Number of Shares [Roll Forward]	'	'
Unvested beginning balance (in shares)	0	'
Vested (in shares)	0	'
Unvested ending balance (in shares)	54,000	0
Restricted Stock Awards, Weighted Average Grant Date Fair Value	'	'
Unvested beginning balance (usd per share)	$0	'
Vested (unaudited) (usd per share)	$0	'
Unvested ending balance (usd per share)	$76.76	$0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Intrinsic Value	$4,772,000	$0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested and Expected to Vest, Outstanding, Number	54,000	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price	$76.76	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested and Expected to Vest, Weighted Average Remaining Contractual Term	'2 years 1 month 6 days	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	$4,772,000	'
Restricted Stock Award	'	'
Restricted Stock Awards, Number of Shares [Roll Forward]	'	'
Unvested beginning balance (in shares)	142,000	'
Vested (in shares)	-44,000	'
Unvested ending balance (in shares)	98,000	'
Restricted Stock Awards, Weighted Average Grant Date Fair Value	'	'
Unvested beginning balance (usd per share)	$2.42	'
Vested (unaudited) (usd per share)	$2.50	'
Unvested ending balance (usd per share)	$2.50	'

StockBased_Compensation_Narrat

Stock-Based Compensation - Narrative (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Apr. 30, 2014

Sep. 30, 2014

Apr. 30, 2014

Sep. 30, 2014

Apr. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

2014 Plan

2014 Plan

2014 Plan

2014 Plan

2014 Employee Stock Purchase Plan

2014 Employee Stock Purchase Plan

2014 Employee Stock Purchase Plan

Stock Option

Stock Option

Restricted Stock Award

Restricted Stock Award

ESPP

ESPP

Restricted Stock Units (RSUs)

Restricted Stock Units (RSUs)

Maximum

Maximum

Maximum

Common Stock

2011 Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise price as percent of fair value of common stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100.00%

Common stock reserved for issuance (in shares)

27,077,000

27,077,000

48,137,000

'

6,510,000

'

20,025,189

'

651,000

'

'

'

'

'

651,000

0

'

'

Percent of shares outstanding to increase number of shares available for grant and issuance

'

'

'

3.00%

'

'

'

1.00%

'

'

'

'

'

'

'

'

'

'

Number of shares available for grant

12,447,000

12,447,000

8,941,000

'

'

12,500,000

'

'

'

2,500,000

'

'

'

'

'

'

'

'

Unrecognized stock-based compensation expense for unvested options, net of expected forfeitures

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$4,100,000

'

$3,400,000

'

Weighted-average grant-date fair value of options granted (usd per share)

'

$20.45

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate intrinsic value of options exercised

'

7,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrecognized stock-based compensation expense

88,800,000

88,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted-average amortization period

'

'

'

'

'

'

'

'

'

'

'3 years 10 months 24 days

'

'2 years

'

'1 year 10 months 17 days

'

'3 years 1 month 6 days

'

Fair value of options vested

8,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrecognized expense

'

'

'

'

'

'

'

'

'

'

'

'

300,000

'

'

'

'

'

Fair value unvested restricted stock awards (usd per share)

'

'

'

'

'

'

'

'

'

'

'

'

$88.33

$29.44

'

'

'

'

Intrinsic value of unvested restricted stock awards

'

'

'

'

'

'

'

'

'

'

'

'

8,400,000

'

'

'

'

'

Repurchased shares of common stock (in shares)

'

'

'

'

'

'

'

'

'

'

'

29,803

'

'

'

'

'

'

Shares subject to repurchase (in shares)

1,800,000

1,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate price of shares subject to repurchase

$5,600,000

$5,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

StockBased_Compensation_Restri1

Stock-Based Compensation - Restricted stock units (Details) (Restricted Stock Units (RSUs), USD $)	9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Restricted Stock Units (RSUs)	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	54,000	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	54,000	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	0	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	0	'
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	'3 years 1 month 6 days	'
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$3.40	'

Net_Income_Per_Share_Available2

Net Income Per Share Available to Common Stock - Basic and Diluted Net Income Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Net income	$21,866	$11,856	$55,813	$28,718
Less: undistributed earnings allocated to participating securities	-681	-6,018	-15,257	-14,844
Net income attributable to common stockholders, basic	21,185	5,838	40,556	13,874
Add: undistributed earnings allocated to participating securities	70	290	1,353	586
Net income attributable to common stockholders, diluted	$21,255	$6,128	$41,909	$14,460
Weighted-average shares used in computing net income per share available to common stockholders, basic (in shares)	62,402	27,557	43,453	26,927
Add weighted-average effect of dilutive securities:	'	'	'	'
Stock options and RSAs (in shares)	7,161	2,848	5,795	2,308
Incremental Common Shares Attributable to Dilutive Effect of Employee Stock Purchase Plan	174	0	75	0
Stock purchase rights (in shares)	0	7	0	6
Weighted-average shares used in computing net income per share available to common stockholders, diluted (in shares)	69,737	30,412	49,323	29,241
Net income per share attributable to common stockholders:	'	'	'	'
Basic (usd per share)	$0.34	$0.21	$0.93	$0.52
Diluted (usd per share)	$0.30	$0.20	$0.85	$0.49

Net_Income_Per_Share_Available3

Net Income Per Share Available to Common Stock - Antidilutive Securities Excluded from Earnings Per Share (Details) (Stock options and RSAs)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Stock options and RSAs	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Antidilutive securities excluded from earnings per share	120,000	1,396,000	1,480,000	1,416,000

Income_Taxes_Income_Taxes_Narr

Income Taxes Income Taxes - Narrative (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'	'	'	'
Income Tax Expense (Benefit)	$10,420	$4,960	$27,612	$9,482

Segment_Information_Details

Segment Information (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
			segment
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'
Number of reportable segments	'	'	1	'	'
Revenue	$155,463	$101,625	$410,617	$246,458	'
Long lived assets	66,991	'	66,991	'	67,204
United States	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'
Revenue	123,847	83,301	318,989	200,293	'
Long lived assets	63,203	'	63,203	'	63,557
Other Americas	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'
Revenue	1,581	2,350	5,797	3,797	'
Europe, Middle East and Africa	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'
Revenue	21,485	10,922	53,827	28,333	'
Asia Pacific	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'
Revenue	8,550	5,052	32,004	14,035	'
International	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'
Long lived assets	$3,788	'	$3,788	'	$3,647