Violin Memory (VMEMQ) 10-K 8 Apr 15 2015 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Jan. 31, 2015	Mar. 31, 2015	Jul. 31, 2014
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Jan-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	FY
Trading Symbol	VMEM
Entity Registrant Name	Violin Memory Inc
Entity Central Index Key	1407190
Current Fiscal Year End Date	-30
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		95,789,619
Entity Public Float			$363,862,216

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Jan. 31, 2015	Jan. 31, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$93,432	$40,273
Restricted cash	2,300
Short-term investments	60,483	59,106
Accounts receivable, net (including amounts due from a related party of $232 and $565 as of January 31, 2015 and 2014, respectively)	15,080	21,055
Inventory	10,322	39,653
Other current assets	5,949	6,154
Total current assets	187,566	166,241
Property and equipment, net	9,863	13,653
Intangibles and other assets	10,806	4,769
Total assets	208,235	184,663
Current liabilities:
Line of credit	10,000
Accounts payable (including amounts due to a related party of $2,432 and $12,208 as of January 31, 2015 and 2014, respectively)	11,065	18,389
Accrued liabilities (including amounts due to a related party of $0 and $6,875 as of January 31, 2015 and 2014, respectively)	18,024	37,315
Deferred revenue	15,635	13,480
Total current liabilities	54,724	69,184
Convertible senior notes, net	120,000
Deferred revenue	10,398	11,755
Long-term liabilities	1,707
Total liabilities	186,829	80,939
Commitments and contingencies (Note 9)
Stockholders' equity:
Preferred stock, $0.0001 par value, 10,000 shares authorized as of January 31, 2015; no shares issued and outstanding as of January 31, 2015 and 2014
Common stock, $0.0001 par value, 1,000,000 shares authorized as of January 31, 2015; 93,872 and 83,057 shares issued and outstanding as of January 31, 2015 and 2014, respectively	9	8
Additional paid-in capital	482,674	456,223
Accumulated other comprehensive income	248	115
Accumulated deficit	-461,525	-352,622
Total stockholders' equity	21,406	103,724
Total liabilities and stockholders' equity	$208,235	$184,663

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Jan. 31, 2015	Jan. 31, 2014
In Thousands, except Per Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Accounts receivable, amounts due from a related party	$232	$565
Accounts payable, amounts due to a related party	2,432	12,208
Accrued liabilities, amounts due to a related party	$0	$6,875
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	10,000	10,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	1,000,000	1,000,000
Common stock, shares issued	93,872	83,057
Common stock, shares outstanding	93,872	83,057

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jan. 31, 2015		Jan. 31, 2014		Jan. 31, 2013
Revenue:
Product revenue (including related party sales of $1,527, $7,128 and $5,242 for the years ended January 31, 2015, 2014 and 2013, respectively)	$58,378		$88,321		$69,584
Service revenue (including related party sales of $1,102, $6,360 and $332 for the years ended January 31, 2015, 2014 and 2013, respectively)	20,597		19,335		4,214
Total revenue	78,975		107,656		73,798
Cost of revenue:
Cost of product revenue (including related party purchases of $9,190, $38,239 and $27,510 for the years ended January 31, 2015, 2014 and 2013, respectively)	50,378	[1]	56,927	[1]	38,180	[1]
Cost of service revenue	8,389	[1]	7,846	[1]	4,474	[1]
Total cost of revenue	58,767		64,773		42,654
Gross profit	20,208		42,883		31,144
Operating expenses:
Sales and marketing	61,871	[1]	81,104	[1]	61,094	[1]
Research and development	52,091	[1]	73,743	[1]	57,840	[1]
General and administrative	20,645	[1]	29,622	[1]	21,105	[1]
Gain on sale of PCIe product line	-17,448
Restructuring charges	3,062		4,869
Litigation settlement	652		350
Total operating expenses	120,873		189,688		140,039
Loss from operations	-100,665		-146,805		-108,895
Other expense, net	-4,910		-1,389		-79
Interest and other financing expense	-3,205		-1,539		-31
Loss before income taxes	-108,780		-149,733		-109,005
Income taxes	123		76		97
Net loss	($108,903)		($149,809)		($109,102)
Net loss per share of common stock, basic and diluted	($1.20)		($3.88)		($8.01)
Shares used to compute net loss per share of common stock, basic and diluted	90,959		38,591		13,624
[1]	Includes stock-based compensation expense as follows (Note 7): Cost of product revenue $ 718 $ 100 $ 150 Cost of service revenue 658 889 474 Sales and marketing 4,792 10,344 4,061 Research and development 9,570 6,900 3,228 General and administrative 7,228 18,166 10,010 $ 22,966 $ 36,399 $ 17,923

Consolidated_Statements_of_Ope1

Consolidated Statements of Operations (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Cost of product revenue, related party purchases	$9,190	$38,239	$27,510
Stock-based compensation expense	22,966	36,399	17,923
Product Revenue [Member]
Revenue from related party sales	1,527	7,128	5,242
Services Revenue [Member]
Revenue from related party sales	1,102	6,360	332
Cost of Product Revenue [Member]
Stock-based compensation expense	718	100	150
Cost of Service Revenue [Member]
Stock-based compensation expense	658	889	474
Sales and Marketing [Member]
Stock-based compensation expense	4,792	10,344	4,061
Research and Development [Member]
Stock-based compensation expense	9,570	6,900	3,228
General and Administrative [Member]
Stock-based compensation expense	$7,228	$18,166	$10,010

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Loss (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Statement of Comprehensive Income [Abstract]
Net loss	($108,903)	($149,809)	($109,102)
Foreign currency translation adjustments, net of tax	123	111	81
Unrealized holding gains on investments, net of tax	10	11
Comprehensive loss	($108,770)	($149,687)	($109,021)

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	IPO [Member]	Series D Preferred Stock [Member]	Restricted Stock Units (RSUs) [Member]	Convertible Preferred Stock [Member]	Convertible Preferred Stock [Member]	Common Stock [Member]	Common Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member]	Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
In Thousands, except Share data	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	Series D Preferred Stock [Member]	USD ($)	IPO [Member]	Restricted Stock Units (RSUs) [Member]	USD ($)	IPO [Member]	Series D Preferred Stock [Member]	Restricted Stock Units (RSUs) [Member]	USD ($)	USD ($)
						USD ($)		USD ($)			USD ($)	USD ($)	USD ($)
Beginning balance at Jan. 31, 2012	$44,151				$8		$4			$137,938				($88)	($93,711)
Beginning balance, shares at Jan. 31, 2012					75,942,000		15,324,000
Issuance of stock			89,728			1						89,727
Conversion of convertible notes into common stock			9,415
Issuance of stock, shares						15,428,000
Conversion of convertible notes into common stock, shares			1,569,000
Issuance of stock units in settlement of liabilities			1,400									1,400
Issuance of stock units in settlement of liabilities, shares						200,000
Issuance of common stock upon exercise of stock options	543									543
Issuance of common stock upon exercise of stock options, shares	353,000						353,000
Repurchase of unvested portion of common stock, shares							-63,000
Stock-based compensation	17,923									17,923
Translation adjustment	81													81
Net loss	-109,102														-109,102
Ending balance at Jan. 31, 2013	44,724				9		4			247,531				-7	-202,813
Ending balance, shares at Jan. 31, 2013					91,570,000		15,614,000
Conversion of convertible preferred stock into common stock					-10		2			8
Conversion of convertible preferred stock into common stock, shares					-95,145,000		47,735,000
Issuance of stock		145,820	20,953			1		2			145,818	20,952
Conversion of convertible notes into common stock	5,203									5,203
Issuance of stock, shares						3,575,000		18,000,000
Conversion of convertible notes into common stock, shares							585,000
Common stock warrants	309									309
Issuance of common stock upon exercise of stock options	732									732
Issuance of common stock upon exercise of stock options, shares	1,008,000						1,008,000
Issuance of common stock for settlement of RSUs, shares							250,000
Shares withheld related to net share settlement of RSUs	-341									-341
Shares withheld related to net share settlement of RSUs, shares							-38,000
Repurchase of unvested portion of common stock, value	-388									-388
Repurchase of unvested portion of common stock, shares							-97,000
Stock-based compensation	36,399									36,399
Translation adjustment	111													111
Unrealized gain on investments	11													11
Net loss	-149,809														-149,809
Ending balance at Jan. 31, 2014	103,724						8			456,223				115	-352,622
Ending balance, shares at Jan. 31, 2014							83,057,000
Issuance of stock units in settlement of liabilities				3,380									3,380
Issuance of stock units in settlement of liabilities, shares									715,000
Issuance of common stock upon exercise of stock options	1,930									1,930
Issuance of common stock upon exercise of stock options, shares	1,648,000						1,648,000
Issuance of common stock for settlement of RSUs							1			-1
Issuance of common stock for settlement of RSUs, shares							8,611,000
Issuance of common stock under the employee stock purchase plan	1,239									1,239
Issuance of common stock under the employee stock purchase plan, shares							431,000
Sale of common stock	908									908
Sale of common stock, shares							200,000
Shares withheld related to net share settlement of RSUs	-3,971									-3,971
Shares withheld related to net share settlement of RSUs, shares							-790,000
Stock-based compensation	22,966									22,966
Translation adjustment	123													123
Unrealized gain on investments	10													10
Net loss	-108,903														-108,903
Ending balance at Jan. 31, 2015	$21,406						$9			$482,674				$248	($461,525)
Ending balance, shares at Jan. 31, 2015							93,872,000

Consolidated_Statements_of_Sto1

Consolidated Statements of Stockholders' Equity (Parenthetical) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jan. 31, 2014	Jan. 31, 2013
Series D Preferred Stock [Member]
Issuance of convertible preferred stock, price per share	$6	$7
Common stock, issuance costs	$498	$3,200
IPO [Member]
Common stock, issuance costs	$16,180
Minimum [Member] | Series D Preferred Stock [Member]
Issuance of convertible preferred stock, price per share		$6
Maximum [Member] | Series D Preferred Stock [Member]
Issuance of convertible preferred stock, price per share		$7

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Cash flows from operating activities:
Net loss	($108,903)	($149,809)	($109,102)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	10,961	12,552	9,013
Amortization of debt issuance costs	639	175
Gain on sale of PCIe product line	-17,448
Provision for excess and obsolete inventory	20,961	10,973	1,052
Loss on extinguishment of debt	372		31
Impairment of assets	3,470	1,965
Stock-based compensation	22,966	36,399	17,923
Changes in operating assets and liabilities, net:
Accounts receivable	5,975	957	-6,354
Inventory	9,076	-24,339	-6,538
Other assets	531	-932	733
Accounts payable	-11,804	2,881	-1,930
Accrued liabilities	-17,097	15,413	7,540
Deferred revenue	798	12,217	10,722
Net cash used in operating activities	-79,503	-81,548	-76,910
Cash flows from investing activities:
Purchase of property and equipment	-11,745	-9,300	-10,554
Purchase of cost method investments		-604	-4,986
Proceeds from sale of PCIe product line	23,000
Increase in restricted cash	-2,300
Purchase of investments	-57,396	-66,224
Proceeds from maturity of investments	56,017	7,129
Net cash provided by (used in) investing activities	7,576	-68,999	-15,540
Cash flows from financing activities:
Proceeds from issuance of convertible notes, net of issuance costs	115,397	5,160	2,698
Proceeds from issuance of convertible preferred stock, net of issuance costs		20,953	86,316
Proceeds from debt and lines of credit, net of issuance costs	46,776	20,078
Repayment of debt and lines of credit	-37,326	-20,500
Proceeds from issuance of common stock, net of related costs	908	147,870	-2,050
Proceeds from exercise of common stock options and stock purchase plan	3,169	610	260
Repurchase of unvested portion of common stock		-388
Taxes paid related to net share settlement of equity awards	-3,971	-341
Net cash provided by financing activities	124,953	173,442	87,224
Effect of exchange rates on cash and cash equivalents	133
Net increase (decrease) in cash and cash equivalents	53,159	22,895	-5,226
Cash and cash equivalents at beginning of year	40,273	17,378	22,604
Cash and cash equivalents at end of year	93,432	40,273	17,378
Supplemental disclosure of other cash flow information:
Taxes paid	115	47	10
Interest paid	419	972
Supplemental disclosure of non-cash investing and financing activities:
Conversion of convertible notes to common stock		5,203
Transfer of inventory to property and equipment	707	4,418	3,574
Conversion of notes payable and accrued interest to convertible preferred stock			3,415
Settlement of loan receivable from officer in lieu of bonus payment			1,000
Issuance of Series D convertible preferred stock in connection with litigation			1,400
Payables related to purchases of fixed assets	2,234
Issuance of common stock in settlement of liabilities	$3,379

Organization_and_Summary_of_Si

Organization and Summary of Significant Accounting Policies	12 Months Ended
	Jan. 31, 2015
Accounting Policies [Abstract]
Organization and Summary of Significant Accounting Policies	1. Organization and Summary of Significant Accounting Policies
	Description of Business
	Violin Memory, Inc. (the “Company”) was incorporated in the State of Delaware on March 9, 2005 under the name Violin Technologies, Inc. The Company re-incorporated as Violin Memory, Inc. in the State of Delaware on April 11, 2007. The Company is a developer and supplier of high-performance, persistent memory-based storage systems that are designed to bring storage performance in line with high-speed applications, servers and networks. These All Flash Arrays are specifically designed at each level of the system architecture, starting with memory and optimized through the array, to leverage the inherent capabilities of flash memory. The Company also recently introduced the Flash Storage Platform, the industry’s first vertically integrated design of software, firmware and hardware that delivers the highest performance, resiliency and availability at the same cost as legacy enterprise-class primary storage. The Flash Storage Platform runs the Company’s Concerto OS 7, a single operating system with integrated continuous data protection, in-line block de-duplication and compression, stretch metro cluster and LUN mirroring as well as its suite of other Enterprise Data Services. With Violin’s Flash Storage Platform, all active data (Tiers 0, 1, and 2) can be consolidated onto a single tier, simplifying storage administration. Additionally, with Violin’s release of Symphony Management Suite Version 3.0, the entire software functionality can all be controlled in 1, 2 or 3 clicks, with management of the entire storage estate, through a single pane of glass. The Company sells its products through its global direct sales force, systems vendors, resellers and other channel partners. The Company operates in a single business segment.
	Basis of Presentation and Consolidation
	We prepared the consolidated financial statements in accordance with U.S. generally accepted accounting principles (GAAP). The consolidated financial statements include the accounts of Violin Memory, Inc. and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated.
	Reclassifications
	Certain prior year amounts have been reclassified for consistency with the current period presentation. These reclassifications had no effect on the previously reported financial position, results of operations or cash flows.
	Foreign Currency Translations and Remeasurement
	The local currency is the functional currency for each of the Company’s subsidiaries. Assets and liabilities are translated into U.S. dollars at exchange rates in effect at the balance sheet date. Income and expense items are translated at average exchange rates for the respective period.
	Gains and losses from foreign currency transactions are included in other expense, net. Foreign currency translation adjustments are included in other comprehensive loss.
	Use of Estimates
	The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. On an on-going basis, the Company evaluates its significant estimates, including those related to estimated selling prices for elements sold in multiple-element revenue arrangements, product warranty, determination of the fair value of stock options, carrying values of inventories, liabilities for unrecognized tax benefits and deferred income tax asset valuation allowances. The Company also uses estimates in determining the useful lives of property and equipment and in its provision for doubtful accounts. Actual results could differ from those estimates.
	Concentrations of Market, Credit Risk, Significant Customers and Manufacturing
	The Company participates in the business of developing and manufacturing scalable All Flash Arrays and believes that changes in any of the following areas could have a material adverse effect on the Company’s future financial position, results of operations or cash flows: advances and trends in new technologies and industry standards; competitive pressures in the form of new products or price reduction on current products; changes in the overall demand for products offered by the Company; changes in certain strategic relationships or customer relationships; litigation or claims against the Company based on intellectual property, patent, product, regulatory or other factors; and risks associated with changes in domestic and international economic and international and/or political conditions or regulations.
	Financial instruments that potentially subject the Company to concentrations of credit risk primarily consist of cash, cash equivalents, investments and accounts receivable. The Company places its cash and cash equivalents and investments with high credit quality financial institutions which the Company believes are creditworthy. Deposits may exceed the insured limits provided on them.
	The Company generally requires no collateral from its customers. The Company mitigates its credit risk with associated with its accounts receivable by performing ongoing credit evaluations of its customers and establishes an allowance for doubtful accounts for estimated losses based on management’s assessment of the collectability of customer accounts.
	Customers that represented more than 10% of total revenue and gross accounts receivable are as follows:
			Year Ended January 31,
			2015			2014			2013
	Percent of revenue:
	Enterprise Vision Technology			10	%		*			*
	Toshiba (Note 10)			*			12	%		*
	CompSec			*			*			12	%
		*	Less than 10%
			January 31,
			2015			2014
	Percent of gross accounts receivable:
	Arrow ECS			19	%		*
	Commtech Innovative Solutions			*			27	%
	Avnet, Inc.			*			15
		*	Less than 10%
	The Company sells to a limited number of large systems vendors, resellers and end-customers and, as a result, maintains individually significant receivable balances with such customers. The Company’s systems vendor customers and certain large resellers tend to be well-capitalized, multi-national companies, while other customers may not be as well capitalized. Sales of products to large systems vendors and resellers are expected to account for a majority of the Company’s revenues in the foreseeable future, and the Company’s financial results will depend in part upon the success of these customers. The composition of the Company’s major customer base may change as the market demand for its products changes, and the Company expects this variability will continue in the future. The loss of, or a significant reduction in purchases by, any of the major customers may harm the Company’s business, financial condition and results of operations.
	The Company relies on a limited number of suppliers for its contract manufacturing and certain raw material components. The Company believes that other vendors would be able to provide similar products and services; however, the qualification of such vendors may require substantial start-up time. In order to mitigate any adverse impacts from disruption of supply, the Company attempts to maintain an adequate supply of critical single-sourced raw materials.
	Cash and Cash Equivalents
	Cash consists of deposits with financial institutions. The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Cash equivalents consist of money market funds, which are readily convertible into cash and are stated at cost, which approximates fair market value. Cash and cash equivalents were $93.4 million and $40.3 million as of January 31, 2015 and 2014, respectively.
	Restricted Cash
	In connection with the sale of its PCIe product line, the Company is obligated to maintain a balance of $2.3 million with an escrow agent for one year. Such amount will be held for the purpose of securing certain of the Company’s indemnification obligations and to compensate the buyer for damages for which they are indemnified pursuant to the asset purchase agreement. No claims for indemnification have been filed to date. The agreement expires on July 24, 2015.
	Investments
	The Company classifies its investments as available-for-sale at the time of purchase since it is the Company’s intent that these investments are available for current operations and includes these investments on the consolidated balance sheet as short-term or long-term investments depending on their maturity and management’s intention with regard to the utilization of these investments, as needed, to fund current operations. As of January 31, 2015, all investments have been classified as short-term.
	Investments are considered impaired when a decline in fair value is judged to be other-than-temporary. The Company consults with its investment managers and considers available quantitative and qualitative evidence in evaluating potential impairment of its investments on a quarterly basis. If the cost of an individual investment exceeds its fair value, the Company evaluates, among other factors, general market conditions, the duration and extent to which the fair value is less than cost, and its intent and ability to hold the investment. Once a decline in fair value is determined to be other-than-temporary, an impairment charge is recorded and a new cost basis in the investment is established.
	Fair Value Measurements and Disclosures
	The Company records its financial assets and liabilities at fair value. The accounting guidance for fair value provides a framework for measuring fair value, clarifies the definition of fair value and expands disclosures regarding fair value measurements. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value:
	Level 1 – Quoted prices in active markets for identical assets or liabilities.
	Level 2 – Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices 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 assets or liabilities.
	Level 3 – Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
	The Company recognizes transfers among Level 1, Level 2 and Level 3 classifications as of the actual date of the events or change in circumstances that caused the transfers.
	The Company’s financial instruments, including cash equivalents, accounts receivable, accounts payable and accrued liabilities have carrying amounts which approximate fair value due to the short-term maturity of these instruments.
	Accounts Receivable
	Trade accounts receivable are recorded at the invoiced amount and do not bear interest. The Company maintains an allowance for doubtful accounts for estimated losses inherent in its accounts receivable portfolio. In establishing the required allowance, management considers expected losses after taking into account current market conditions, customers’ financial condition, current receivable aging and current payment patterns. Account balances are charged off against the allowance after all means of collection have been exhausted and the potential for recovery is considered remote. As of January 31, 2015 and 2014, the Company’s allowance for doubtful accounts was insignificant.
	Inventory
	Inventory consists of raw materials and finished goods and is stated at the lower of cost, determined on a first-in, first-out (“FIFO”) basis, or market. The Company periodically assesses the recoverability of all inventory, including raw materials and finished goods to determine whether adjustments are required to record inventory at the lower of cost or market. Inventory that the Company determines to be obsolete or in excess of forecasted usage is reduced to its estimated realizable value based on assumptions about future and current market conditions. In the case of inventory which has been written down below cost through the use of a reserve, such reduced amount is considered the cost for subsequent accounting purposes.
	Revenue Recognition
	The Company derives revenue primarily from sales of its All Flash Arrays, software and related support and professional services. Revenue is recognized when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price is fixed and determinable and collectability is reasonably assured. Evidence of an arrangement exists when there is a customer contract or purchase order. The Company considers delivery complete when title and risk of loss transfer to the customer, which is generally upon shipment, but no later than physical receipt by the customer.
	The Company sells its products and support services directly to end-customers, systems vendors and resellers. The Company currently does not provide price protection, rebates or other sales incentives to customers. The Company generally does not allow a right of return to its customers, including resellers.
	The Company’s multiple-element arrangements typically include two elements: hardware, which includes embedded software, and support services. Beginning in the second quarter of fiscal 2014, following introduction of the Violin Symphony Management Software Suite, the Company’s multiple-element arrangements also may include software elements. The Company has determined that its hardware and the embedded software are considered a single unit of accounting, because the hardware and software individually do not have standalone value and are not sold separately. Standalone software, professional services and support services are each considered a separate unit of accounting as they can be sold separately and have standalone value.
	When more than one element, such as hardware, software and services, are contained in a single arrangement, the Company first allocates consideration to the software deliverables as a group and non-software deliverables based on the relative selling price method. The Company’s appliance products, embedded software and certain other services are considered to be non-software deliverables in such arrangements. The Company allocates revenue within the software group based upon fair value using vendor-specific objective evidence, or VSOE, with the residual revenue allocated to the delivered element. If VSOE of fair value cannot be objectivity determined for any undelivered software elements, we defer revenue until all elements are delivered and services have been performed, or until fair value can objectively be determined for any remaining undelivered elements. The Company allocates revenue within the non-software group to each element based upon its relative selling price in accordance with the selling price hierarchy, which includes: (1) VSOE, if available; (2) third-party evidence, or TPE, if VSOE is not available; and (3) best estimate of selling price, or BESP, if neither VSOE nor TPE is available. The Company establishes BESP considering multiple factors including, but not limited to, historical prices of products sold on a stand-alone basis, cost and gross margin objectives, competitive pricing practices and customer and market specific considerations.
	The Company then recognizes revenue on each deliverable in accordance with its policies for product and service revenue recognition. Revenue allocated to the Company’s products is recognized upon shipment or delivery. Revenue allocated to support services is recognized over the term, which is generally one or three years.
	The Company’s policy is to record revenue net of any applicable sales, use or excise tax.
	Property and Equipment
	Property and equipment consist primarily of capitalized equipment and computer hardware and software, which are stated at cost and depreciated using the straight-line method over the estimated useful lives of two years and three years, respectively. Leasehold improvements are amortized using the straight-line method over the shorter of the lease term or the estimated useful life of the asset. Costs of maintenance and repairs that do not improve or extend the lives of the respective assets are expensed as incurred. Upon retirement or sale, the cost and related accumulated depreciation are removed from the balance sheet and the resulting gain or loss is reflected in operating expenses.
	Research and Development
	Research and development costs are expensed as incurred. Research and development costs consist primarily of personnel costs, prototype expenses, software tools, consulting services and allocated facilities costs.
	Software Development Costs
	The Company expenses software development costs as incurred until technological feasibility is attained, including research and development costs associated with stand-alone software products and software embedded in hardware products. Technological feasibility is attained when the Company has completed the planning, design and testing phase of development of its software and the software has been determined viable for its intended use, which typically occurs when beta testing commences. The period of time between when beta testing commences and when the software is available for general release to customers has historically been short with immaterial amounts of software development costs incurred during this period. Accordingly, the Company has not capitalized any internal software development costs to date.
Advertising Expenses
All advertising costs are expensed as incurred. The Company recognized advertising expenses of $1.6 million, $0.6 million and $1.0 million for the years ended January 31, 2015, 2014 and 2013, respectively.
Income Taxes
Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income (or loss) in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Valuation allowances are established for deferred tax assets to the extent it is more likely than not that the deferred tax assets may not be realized.
The Company evaluates uncertain tax positions taken or expected to be taken in the course of preparing an enterprise’s tax return to determine whether the tax positions are more likely than not of being sustained upon challenge by the applicable tax authority. Tax positions with respect to any potential income tax for the Company not deemed to meet the more likely than not threshold would be recorded as a tax expense in the current year.
Net Loss Per Share
Basic net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock outstanding for each fiscal period presented.
Diluted net loss per share is computed by giving effect to all potential shares of common stock, including stock options, warrants and convertible preferred stock, to the extent dilutive. Basic and diluted net loss per share was the same for each period presented as the inclusion of all potential shares of common stock outstanding would have been anti-dilutive.
Stock-Based Compensation
The Company records stock-based compensation expense related to employee stock-based awards on a straight-line basis based on the estimated fair value of the awards as determined on the date of grant. The Company utilizes the Black-Scholes option pricing model to estimate the fair value of employee stock options and Employee Stock Purchase Plan (ESPP). The Black-Scholes model requires the input of highly subjective and complex assumptions, including the expected term of the stock option, the expected volatility of the Company’s common stock over the period equal to the expected term of the grant and forfeitures. The Company estimates forfeitures at the date of grant and revises the estimates, if necessary, in subsequent periods if actual forfeitures differ from those estimates.
The Company accounts for stock options that are issued to non-employees based on the estimated fair value of such awards using the Black-Scholes option pricing model. The measurement of stock-based compensation expense for these awards is variable and subject to periodic adjustments to the estimated fair value until the awards vest and the resulting change in the estimated fair value is recognized in the Company’s consolidated statements of operations during the period in which the related services are rendered.
The Company grants restricted stock units (RSUs) to employees. Stock-based compensation expense related to these grants is based on the grant date fair value of the RSUs and is recognized on a straight-line basis over the applicable service period, which is generally four years.
Impairment of Long-Lived Assets
Long-lived assets, such as property and equipment, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group be tested for possible impairment, the Company first compares undiscounted cash flows expected to be generated by that asset or asset group to its carrying value. If the carrying value of the long-lived asset or asset group is not recoverable on an undiscounted cash flow basis, an impairment charge is recognized to the extent that the carrying value exceeds its fair value. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values and third-party independent appraisals, as considered necessary.
Investment in Privately-held Companies
The Company analyzes equity investments in privately held companies to determine if it should be accounted for under the cost or equity method of accounting based on such factors as the percentage ownership of the voting stock outstanding and our ability to exert significant influence over these companies. For the cost method investments, the Company determines at each reporting period whether a decline in fair value has occurred and whether such decline is considered to be an other-than-temporary impairment. If a decline in fair value is determined to be other-than-temporary, the Company would recognize an impairment to reduce the investment to the lower of cost or fair value.
For the year ended January 31, 2015 and 2014, the Company recorded an impairment on its cost-method investments in the amount of $3.5 million and $0.7 million, respectively, in other expense, net in the consolidated statements of operations. There was no impairment recorded for the year ended January 31, 2013. As of January 31, 2015, the net carrying value of the Company’s investments in privately-held companies was nil.
Commitments and Contingencies
Liabilities for loss contingencies arising from claims, assessments, litigation, fines and penalties and other sources are recorded when it is probable that a liability has been incurred and the amount can be reasonably estimated. Legal costs incurred in connection with loss contingencies are expensed as incurred.
Product Warranties
The Company generally provides a three-year warranty on all of its products. The Company accrues for potential liability claims as a component of cost of revenue based upon performance of equipment in the Company’s test and support labs, historical data and trends of product reliability and costs of repairing and replacing defective products. The accrued warranty balance is reviewed periodically for adequacy and is included in accrued liabilities in the consolidated balance sheets.
Recent Accounting Pronouncements
In August 2014, the FASB issued Accounting Standards Update (ASU) No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, which requires management to assess a company’s ability to continue as a going concern and to provide related footnote disclosures in certain circumstances. Before this new standard, there was minimal guidance in U.S. GAAP specific to going concern. Under the new standard, disclosures are required when conditions give rise to substantial doubt about a company’s ability to continue as a going concern within one year from the financial statement issuance date. The new standard applies to all companies and is effective for the annual period ending after December 15, 2016, and all annual and interim periods thereafter. The Company has determined that this pronouncement is not likely to have a material impact on the Company’s consolidated financial statements.
In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, a converged standard on revenue recognition. The new pronouncement requires revenue recognition to depict the transfer of promised goods or services to customer in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance also specifies the accounting for some costs to obtain or fulfil a contract with a customer, as well as enhanced disclosure requirements. ASU 2014-9 is effective for annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting periods. Early adoption is not permitted. The Company is currently in the process of evaluating the impact of the adoption will have on its consolidated financial statements.
In April 2014, the FASB issued ASU No. 2014-08, Presentation of Financial Statements (Topic 2015) and Property Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an entity, an accounting standard update that changes the criteria for reporting discontinued operations. Under the accounting standard update, a disposal of a component of an entity or a group of components of an entity is required to be reported in discontinued operations if the disposal represents a strategic shift that has, or will have, a major effect on an entity’s operations and financial results when either it qualifies as held for sale, disposed of by sale, or disposed of other than by sale. This accounting standard update became effective for the Company on February 1, 2015. The Company anticipates that this pronouncement will not have a material impact on the Company’s consolidated financial statements.
In July 2013, the FASB issued ASU No. 2013-11, Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carry-forward, a Similar Tax Loss, or a Tax Credit Carry-forward Exists, which is effective for the periods beginning after December 15, 2013. The new guidance provides that a liability related to an unrecognized tax benefit would be presented as a reduction of a deferred tax asset for a net operating loss carryforward, a similar tax loss or a tax credit carryforward if such settlement is required or expected in the event the uncertain tax position is disallowed. The new guidance became effective for the Company on February 1, 2014, and was applied prospectively to unrecognized tax benefits that existed at the effective date. The adoption of this new guidance did not have a material impact on the Company’s consolidated financial statements.
In March 2013, the FASB issued an accounting standard update requiring an entity to release into net income the entire amount of a cumulative translation adjustment related to its investment in a foreign entity when as a parent it either sells a part or all of its investment in a foreign entity or no longer holds a controlling financial interest in a subsidiary or group of assets within a foreign entity. This accounting standard update was effective prospectively for the Company on February 1, 2014. The adoption of this accounting standard update did not have a material impact on the Company’s consolidated financial statements.

Balance_Sheet_Components

Balance Sheet Components	12 Months Ended
	Jan. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	2. Balance Sheet Components
	Accounts Receivable
	The following table shows the components of accounts receivable, net (in thousands):
		January 31,
		2015			2014
	Accounts receivable	$	15,680		$	21,248
	Allowance for doubtful accounts		(39	)		—
	Allowance for sales returns		(561	)		(193	)
		$	15,080		$	21,055
	The following table shows a rollforward of our allowance for doubtful accounts for the years ended January 31, 2015, 2014 and 2013 (in thousands):
		Balance at			Additions			Deductions			Balance at
		Beginning of			Charged to						End of Year
		Year			Expense or
					Other Accounts
	Year ended January 31, 2015	$	—		$	80		$	(41	)	$	39
	Year ended January 31, 2014		350			—			(350	)		—
	Year ended January 31, 2013		32			357			(39	)		350
	Inventory
	The following table shows the components of inventory (in thousands):
		January 31,
		2015			2014
	Raw materials	$	3,677		$	15,326
	Finished goods		6,645			24,327
		$	10,322		$	39,653
	Included in the components of inventory are reserves of $23.2 million and $6.7 million as of January 31, 2015 and 2014, respectively. In the fourth quarter of fiscal 2015, the Company incurred a provision for excess and obsolete inventory of approximately $19.9 million in connection with its transition from its 6000 Series All Flash Array to its 7000 Series Flash Storage Platform. This provision resulted in an increase in inventory reserves of $17.6 million and an increase in accrued liabilities of $2.3 million for non-cancellable purchase orders related to the 6000 Series parts. In December 2013, the Company decided to pursue strategic alternatives for its PCIe card business and to stop selling its PCIe cards. In light of this decision, the Company recorded a PCIe card inventory provision of $9.2 million. This provision resulted in an increase in inventory reserves of $3.4 million and an increase in accrued liabilities of $5.8 million for non-cancellable purchase orders related to PCIe card components. For the year ended January 31, 2014, the Company also recorded a provision for excess inventory of $1.8 million of which $1.2 million was recorded in the fourth quarter of that year.
	Property and Equipment
	The following table shows the components of property and equipment (in thousands):
		January 31,
		2015			2014
	Laboratory equipment	$	25,589		$	22,854
	Computer hardware and software		12,165			11,440
	Leasehold improvements		691			310
	Office furniture		326			305
			38,771			34,909
	Less: accumulated depreciation		(28,908	)		(21,256	)
		$	9,863		$	13,653
	Depreciation expense (including amortization of leasehold improvements) was $11.0 million, $12.6 million and $9.0 million for fiscal 2015, 2014 and 2013, respectively.
	Intangibles and Other Assets
	The following table shows the components of intangibles and other assets (in thousands):
		January 31,
		2015			2014
	Licensed OEM software	$	6,086		$	604
	Deferred borrowing costs		4,032			—
	Cost method investments		—			3,470
	Other		688			695
		$	10,806		$	4,769
	During the year we capitalized $6.0 million in licensed OEM software which we are amortizing over the greater of an estimated useful life of ten years on a straight line basis, or in proportion of the actual revenue to date over the expected revenue from our Flash Storage Platform product over the ten year estimated life of the product.
	Accrued Liabilities
	The following table shows the components of accrued liabilities (in thousands):
		January 31,
		2015			2014
	Compensation and benefits	$	9,036		$	10,805
	Purchase commitments		2,328			6,661
	Accrued interest		1,700			—
	Warranty		1,262			1,223
	Restructuring charges		313			3,248
	Professional fees		101			4,635
	Customer advance from Toshiba (Note 10)		—			6,875
	Other		3,284			3,868
		$	18,024		$	37,315
	Accrued Warranty
	The following table is a reconciliation of the changes in the Company’s aggregate product warranty liability (in thousands):
		Year ended January 31,
		2015			2014
Balance, beginning of year	$	1,223		$	994
Additions		1,301			1,663
Settlements		(1,262	)		(1,434	)
Balance, end of period	$	1,262		$	1,223

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Jan. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements
	The following tables present, for assets or liabilities measured at fair value, the respective fair value and the classification by level of input within the fair value hierarchy (in thousands):
		January 31, 2015
		Level 1		Level 2		Level 3		Total
	Cash equivalents:
	Commercial paper	$	—	$	34,395	$	—	$	34,395
	Money market funds		24,534		—		—		24,534
	Corporate debt securities		—		6,116		—		6,116
	Total cash equivalents		24,534		40,511		—		65,045
	Short-term investments:
	Corporate debt securities		—		44,711		—		44,711
	U.S. government and agency obligations		—		7,808		—		7,808
	Municipal obligations		—		4,967		—		4,967
	Commercial paper		—		2,997		—		2,997
	Total short-term investments		—		60,483		—		60,483
		$	24,534	$	100,994	$	—	$	125,528
		January 31, 2014
		Level 1		Level 2		Level 3		Total
	Cash equivalents:
	Money market funds	$	15,229	$	—	$	—	$	15,229
	Commercial paper		—		11,099		—		11,099
	Municipal obligations		—		4,601		—		4,601
	Total cash equivalents		15,229		15,700		—		30,929
	Short-term investments:
	U.S. government and agency obligations		—		29,132		—		29,132
	Municipal obligations		—		13,841		—		13,841
	Corporate debt securities		—		8,135		—		8,135
	Commercial paper		—		7,998		—		7,998
	Total short-term investments		—		59,106		—		59,106
		$	15,229	$	74,806	$	—	$	90,035
	The Company measures its cash equivalents and marketable securities at fair value. Money market funds are valued primarily using quoted market prices utilizing market observable inputs. The Company’s investments in commercial paper, treasury bills, corporate debt securities and federal and municipal obligations are classified within Level 2 as the market inputs to value these instruments consist of market yields, reported trades and broker/dealer quotes.
	No financial assets and liabilities measured at fair value on a recurring basis were held by the Company as of January 31, 2013. There have been no transfers between Level 1 and 2 during fiscal 2015 or 2014.
	No assets or liabilities measured at fair value on a nonrecurring basis were held by the Company as of January 31, 2015 or 2014.
	The carrying amounts of the Company’s accounts receivable, accounts payable, accrued liabilities and other liabilities approximate their fair value due to their short term maturities.

Investments

Investments	12 Months Ended
	Jan. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Investments	4. Investments
	Short term investments as of January 31, 2015 and 2014 consist of U.S. corporate debt securities, U.S. government and municipal debt, agency obligations and commercial paper. All marketable securities are deemed by management to be available-for-sale and are reported at fair value. Net unrealized gains or losses that are not determined to be other-than-temporary are reported within stockholders’ equity on the Company’s consolidated balance sheets as a component of accumulated comprehensive loss. Realized gains or losses are recorded based on the specific identification method. The Company’s investments are detailed in the tables below (in thousands):
		January 31, 2015
		Amortized		Unrealized		Unrealized			Estimated
		Cost		Gains		Losses			Fair Value
	Corporate debt securities	$	44,705	$	14	$	(8	)	$	44,711
	U.S. government and agency obligations		7,807		2		(1	)		7,808
	Municipal obligations		4,964		3		—			4,967
	Commercial paper		2,997		—		—			2,997
		$	60,473	$	19	$	(9	)	$	60,483
		31-Jan-14
		Amortized		Unrealized		Unrealized			Estimated
		Cost		Gains		Losses			Fair Value
	U.S. government and agency obligations	$	29,130	$	5	$	(3	)	$	29,132
	Municipal obligations		13,833		8		—			13,841
	Corporate debt securities		8,134		4		(3	)		8,135
	Commercial paper		7,998		—		—			7,998
		$	59,095	$	17	$	(6	)	$	59,106
	The amortized cost and fair value of investments held as of January 31, 2015 and 2014, by contractual years-to-maturity, are as follows (in thousands):
		January 31,
		2015				2014
		Amortized		Fair		Amortized			Fair
		Cost		Value		Cost			Value
	Due within one year	$	60,473	$	60,483	$	47,707		$	47,712
	Due within one to two years		—		—		11,388			11,394
		$	60,473	$	60,483	$	59,095		$	59,106

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Jan. 31, 2015
Equity [Abstract]
Stockholders' Equity	5. Stockholders’ Equity
	Stock Split
	The Company effected a two-for-one reverse stock split to its common stock for all stockholders of record as of September 12, 2013 with an automatic adjustment to the conversion ratio of the outstanding shares of convertible preferred stock to reflect the same reverse stock split ratio upon conversion of the convertible preferred stock into common stock. Based on the adjusted conversion ratio, two outstanding shares of preferred stock converted into one share of common stock, except for Series D convertible preferred stock for which every two shares converted into 1.016998402 shares of common stock. All information related to common stock, stock options, RSUs and earnings per share for prior periods has been retroactively adjusted to give effect to the two-for-one reverse stock split.
	Initial Public Offering
	On October 2, 2013, the Company closed its initial public offering, or IPO, of 18,000,000 shares of common stock. The public offering price of the shares sold in the IPO was $9.00 per share. The total gross proceeds were $162 million. After deducting underwriting discounts and commissions and IPO expenses, the aggregate net proceeds totaled $145.8 million.
	Convertible Preferred Stock
	Upon the closing of the Company’s IPO, all shares of our then-outstanding convertible preferred stock, as shown on the table below, automatically converted into an aggregate of 47.7 million shares of its common stock. The following table summarizes the convertible preferred stock authorized, issued and outstanding, and the rights and preferences of the respective series immediately prior to the conversion into common stock (in thousands, except per share data):
		Shares				Liquidation		Dividend		Conversion
						Preference		Per Share		Ratio Per
		Authorized		Issued and		Per Share		Per Annum		Share
				Outstanding
	Series 1		8,797		8,796		1.28	$	0.068		0.5
	Series A		35,357		35,357		0.9		0.048		0.5
	Series B		18,265		18,264		3		0.16		0.5
	Series C		13,525		13,525		6		0.32		0.5
	Series D		35,056		19,203		8.75		0.56		0.508499
			111,000		95,145
	Common Stock
	The Company is authorized to issue 1 billion shares of common stock at a par value of $0.0001 per share. As of January 31, 2015 and 2014, the Company had 93.9 million and 83.1 million shares of common stock issued and outstanding, respectively. Holders of common stock are entitled to one vote per share on all matters to be voted upon by the shareholders of the Company.
	Warrants
	In August 2014, the Company entered into a secured $40.0 million credit facility with Silicon Valley Bank (“SVB”). Pursuant to this arrangement, the Company agreed to issue SVB a warrant to purchase 79,323 shares of its common stock, $0.0001 par value per share, at a price per share of $3.782. The warrant expires in August 2019.
	During the second quarter of fiscal 2014, the Company issued warrants to purchase 131,875 shares of Series D convertible preferred stock at $6.00 per share. These warrants were issued to TriplePoint in conjunction with the TriplePoint debt facility and to several investors in conjunction with the Company’s sale of convertible notes. In conjunction with the Company’s IPO, the warrants converted to warrants to purchase 84,278 shares of common stock at $11.80 per share. The warrants will expire during the second quarter of fiscal year ended January 31, 2018.

Equity_Award_and_Employee_Comp

Equity Award and Employee Compensation Plans	12 Months Ended
	Jan. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Award and Employee Compensation Plans	6. Equity Award and Employee Compensation Plans
	2005 Stock Plan
	The 2005 Stock Plan (the “2005 Plan”) expired October 2, 2013 upon closing of the Company’s IPO and was replaced by the 2012 Stock Incentive Plan. Under the 2005 Plan, the Company was able to directly sell or award restricted shares, restricted stock units and options to employees, directors and consultants. The share awards and options were granted at prices no less than the estimated fair value at the date of grant and generally vest ratably over three to four years. The options generally expire ten years from the date of grant.
	2012 Stock Plan
	In November 2012, the Company’s stockholders approved the adoption of the 2012 Stock Incentive Plan (the “2012 Plan”) as the successor plan to the 2005 Plan, which became effective at the completion of the Company’s initial public offering (“IPO”). Unexercised options or restricted stock units under the 2005 Plan that cancel due to a grantee’s termination may be reissued under the 2012 Plan. Under the 2012 Plan, stock options, restricted shares, restricted stock units and stock appreciation rights may be granted to employees, outside directors and consultants at not less than 100% of the fair value on the date of grant and generally vest ratably over four years. Options generally expire seven years from the date of grant.
	As of January 31, 2015, shares authorized under the 2012 Plan include 11,652,856 and any shares forfeited from the 2005 Plan. The reserve will automatically increase on the first day of each fiscal year in an amount equal to the lesser of (i) 5% of the outstanding shares of common stock on the last day of the immediately preceding fiscal year or (ii) a lesser amount determined by the Board of Directors. On February 1, 2015, the share reserve increased by 4,699,362 shares to an aggregate of 16,352,218 shares authorized under the plan. The 2012 Stock Plan is administered by the Compensation Committee of the Board of Directors (the “Compensation Committee”), and the Compensation Committee may terminate or amend the plan at any time.
	Inducement Awards
	During fiscal 2015, the Company issued inducement awards totaling 6,250,000 shares outside of the 2012 Plan under the employee inducement award exemption under the New York Stock Exchange Listed Company Manual Rule 303A.08, to the Company’s CEO and certain key executives. In February 2015, 1,250,000 shares were forfeited.
	Stock Options
	The following table summarizes the stock option activity related to shares of common stock under the Company’s 2005 and 2012 Plans and the inducement awards (in thousands, except per share data):
						Outstanding Options
											Weighted-Average
			Shares						Weighted-		Remaining		Aggregate
			Available			Number of			Average		Contractual Life		Intrinsic
			for Grant			Options			Exercise Price ($)		(in years)		Value (1)
	Balances, January 31, 2012			2,594			7,061			0.94		9.29	$	12,792
	Shares authorized			10,020
	RSUs granted			(9,018	)
	RSUs forfeited			555
	Options exercised			—			(353	)		0.72
	Options forfeited			641			(641	)		1.08
	Repurchase of shares			66			—			0.2
	Balances, January 31, 2013			4,858			6,067			0.94		8.31	$	42,096
	Shares authorized			7,500
	RSUs granted			(10,496	)
	Recovery of RSUs from net settlement			39
	RSUs forfeited			3,632
	Options granted			(1,320	)		1,320			5
	Options exercised						(1,008	)		0.61
	Options forfeited			1,149			(1,149	)		2.13
	Repurchase of shares			97			—
	Balances, January 31, 2014			5,459			5,230			1.43		7.23	$	19,770
	Shares authorized, including 6,250 shares from inducement awards			10,403
	RSUs granted			(4,572	)
	Recovery of RSUs from net settlement			790
	RSUs forfeited			3,601
	Options granted			(9,371	)		9,371			3.99
	Options exercised			—			(1,648	)		1.02
	Options forfeited			304			(304	)		0.25
	Balances, January 31, 2015			6,614			12,649			3.35		7.25	$	34,255
	Options vested and expected to vest - January 31, 2015						6,475		$	4.02		7.28	$	390
	Options exercisable – January 31, 2015						4,368		$	2.08		7.25	$	7,710
	-1	Aggregate intrinsic value is based on the common stock price at each respective date presented.
	The weighted average grant date fair value of options granted during the year ended January 31, 2015 was $1.74 per share. The total intrinsic value of options exercised during the year ended January 31, 2015 was $5.0 million. The following table summarizes additional information regarding outstanding and exercisable options under the Stock Plans at January 31, 2015 (in thousands, except per share data):
			Options Outstanding
	Weighted-Average		Number			Weighted-			Number
	Exercise Price($)		Outstanding			Average Remaining			Exercisable
						Contractual Life (years)
	0.002			30			4.45			30
	0.14			844			5.86			844
	0.5			30			6.23			30
	1.42			1,755			6.54			1,754
	3.07 - 3.75			5,548			8.33			1,710
	4.28			4,442			6.47			—
				12,649						4,368
	Restricted Stock Units
	The table below summarizes the RSU activity under the Company’s 2005 and 2012 Plans (in thousands, except per share data):
			Number			Weighted-			Aggregate
			of RSUs			Average			Intrinsic
			Outstanding			Grant Date			Value (1)
						Fair Value
	Balance, January 31, 2012			—		$	—		$	—
	RSUs granted			9,018			6.2
	RSUs forfeited			(555	)		4.88
Balance, January 31, 2013			8,463			6.52		$	63,469
RSUs granted			10,496			6.35
RSUs vested			(250	)		6.87
RSUs forfeited			(3,632	)		7.46
Balance, January 31, 2014			15,077			6.09		$	56,990
RSUs granted			4,572			4.16
RSUs vested			(9,199	)		6.12
RSUs forfeited			(3,601	)		5.57
Balance, January 31, 2015			6,849		$	4.71		$	26,299
	-1	Aggregate intrinsic value is based on the common stock price at each respective date presented.
The aggregate intrinsic value of RSUs that vested during the year ended January 31, 2015, amounted to $37.0 million.
Non-employee Stock Options and Awards
During the years ended January 31, 2015, 2014 and 2013, the Company granted stock options to purchase 0, 5,000 and 0 shares, respectively, to non-employees. The Company granted 230,098, 6,000 and 177,500 restricted stock units to non-employees in fiscal 2015, 2014 and 2013, respectively.
Employee Stock Purchase Plan
In November 2012, the Company’s stockholders approved the adoption of the 2012 Employee Stock Purchase Plan (the “2012 Purchase Plan”). Upon adoption, a total of 1,000,000 shares were reserved for issuance under the 2012 Purchase Plan. The number of shares available for issuance under the 2012 Purchase Plan automatically increases on February 1 each year, beginning in 2014, by the lesser of 0.75% of the shares of common stock then outstanding or 1,000,000 shares. On February 1, 2014, pursuant to the provisions of the plan, the share reserved was increased by 600,000 shares to an aggregate of 1,600,000 shares reserved under the plan. The 2012 Purchase Plan permits eligible employees to purchase common stock on favorable terms via payroll deductions of up to 15% of the employee’s salary, subject to certain share and statutory dollar limits. Two overlapping offering periods commence during each calendar year, on each June 1 and December 1 or such other periods or dates as determined by the Compensation Committee from time to time, and the offering periods last up to 24 months with a purchase date every six months. The price of each share purchased is 85% of the lower of a) the fair value per share of common stock on the last trading day before the commencement of the applicable offering period, or b) the fair value per share of common stock on the purchase date. The 2012 Purchase Plan is administered by the Compensation Committee, and the Compensation Committee may terminate or amend the plan.
Employee 401(k) Plan
The Company sponsors the Violin Memory, Inc. 401(k) Plan (“401(k) Plan”), which qualifies under Section 401(k) of the Internal Revenue Code and is designed to provide retirement benefits for its eligible employees through tax-deferred salary deductions.
Employees may elect to contribute up to 90% of their eligible compensation to the 401(k) Plan. Employee contributions are limited to a maximum annual amount as set periodically by the Internal Revenue Service (“IRS”). The Company does not currently match employee contributions.

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Jan. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	7. Stock-Based Compensation
	As of January 31, 2015, total stock-based compensation cost related to unvested equity awards not yet recognized, net of estimated forfeitures, totaled $29.3 million. The Company expects to amortize $14.7 million in fiscal 2016, $8.4 million in fiscal 2017, $4.9 million in fiscal 2018 and $1.3 million in fiscal 2019. Capitalized stock-based compensation expense was not material for any period presented.
	The Company used the following assumptions for its employee stock option and ESPP grants:
			Year Ended January 31,
	Employee stock options		2015	2014		2013 (1)
	Expected life of options (in years)		4.6 - 7.0	3.5 - 4.6			—
	Expected volatility		47% - 49%	45% - 50%			—
	Risk-free interest rate		1.4% - 2.1%	0.9% - 1.5%			—
	Dividend yield		—	—  %			—
		-1	No stock options were granted during fiscal 2013.
			Year Ended January 31,
	Employee stock purchase plan		2015	2014				2013 (1)
	Expected life (in years)		0.5		2.18				—
	Expected volatility		44% - 51%		45.6	%			—
	Risk-free interest rate		0.1% - 0.2%		0.12	%			—
	Dividend yield		—  %		—	%			—
		-1	The ESPP plan was established in fiscal 2014.
	During the year ended January 31, 2015 and 2014, the Company recognized stock-based compensation associated with its ESPP plan of $0.8 million and $0.4 million, respectively.
	Stock-based compensation associated with non-employee awards was approximately $0.8 million, $0.8 million and $2.5 million for fiscal 2015, 2014 and 2013, respectively.
	Award Modification and Accelerations
	During fiscal 2014, the Company modified 225,000 options issued to a non-employee, accelerating the vesting of the award. The Company recognized a charge of $2.0 million within general and administrative expenses in the accompanying consolidated statement of operations for fiscal 2014 relating to this modification.
	In January 2014, as part of its retention program, the Company repriced approximately 377,000 stock options originally granted to 51 non-executive employees in September and November 2013 at exercise prices ranging from $5.97 to $8.82 per share to $3.49 per share, the fair market value of the Company’s common stock as of the date of the modification. The incremental compensation charged recognized in fiscal 2014 for these awards was not significant. Total incremental charge relating to this modification, approximately $0.3 million, net of forfeitures, will be recognized using the straight-line attribution method over the remaining service period.
	During the fourth quarter of fiscal 2014, as result of the Company’s strategic restructuring initiatives, the Company accelerated the vesting of certain stock options and RSU awards as result of the termination of certain former executives of the Company. Under the terms of the former employees’ executed employment agreements, accelerated vesting of certain awards was granted in the event of involuntary termination which was not ‘for cause’, as defined in such agreements. As a result, the Company recognized incremental charges relating to equity awards impacted by such accelerations of approximately $14.6 million in the consolidated statement of operations for the year ended January 31, 2014. Given that the acceleration was contemplated in the original employment agreements of these employees, modification accounting was not required.

Income_Taxes

Income Taxes	12 Months Ended
	Jan. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	8. Income Taxes
	The components of loss before provision for income taxes are as follows (in thousands):
		Year Ended January 31,
		2015			2014			2013
	United States	$	(109,342	)	$	(150,146	)	$	(109,311	)
	Foreign		562			413			306
	Total	$	(108,780	)	$	(149,733	)	$	(109,005	)
	The Company’s tax provision for the years ended January 31, 2015, 2014 and 2013 consists of state and foreign taxes. Income tax expense differed from the amounts computed by applying the federal statutory income tax rate of 35% to pretax loss for the years ended January 31, 2015, 2014 and 2013, respectively, as result of the following (in thousands):
		Year Ended January 31,
		2015			2014			2013
	Federal tax at statutory rate	$	(38,073	)	$	(52,406	)	$	(37,021	)
	Loss not being benefited		32,422			55,506			37,320
	Nondeductible expenses		7,601			470			1,559
	State taxes		7			11			6
	Nondeductible interest on convertible notes		—			(1,751	)		10
	Research credits		(1,834	)		(1,754	)		(1,777	)
		$	123		$	76		$	97
	The tax effects of temporary differences and carryforwards that give rise to significant portions of the Company’s deferred tax assets and liabilities related to the following (in thousands):
		January 31,
		2015			2014
	Net operating loss carryforwards	$	84,222		$	56,529
	Depreciation and amortization		49,251			39,700
	Tax credits and other		12,441			7,755
	Inventory valuations		8,730			3,854
	Accrual and reserve		7,476			5,516
	Stock-based compensation		4,856			18,031
	Gross deferred tax assets		166,976			131,385
	Valuation allowance		(166,976	)		(131,385	)
	Net deferred tax assets (liabilities)	$	—		$	—
	Management believes that, based on available evidence, both positive and negative, it is more likely than not that the net deferred tax assets will not be utilized, such that a full valuation allowance has been recorded. The valuation allowance for deferred tax assets was $167.0 million and $131.4 million as of January 31, 2015 and 2014, respectively. The net change in the total valuation allowance for the year ended January 31, 2015 and 2014 was an increase of $35.6 million and $58.2 million, respectively.
	As of January 31, 2015, the Company had approximately $232.7 million and $87.7 million of net operating loss carry forwards available to offset future taxable income for both Federal and State purposes, respectively. If not utilized, these carry forward losses will expire in various amounts for Federal and State tax purposes beginning in 2025 and 2015, respectively. The Company also has Federal and State research and development tax credit carryforwards of approximately $9.0 million and $10.0 million, respectively. The Federal tax credits will expire at various dates beginning in the year 2030 unless previously utilized. The State tax credits do not expire and will carry forward indefinitely until utilized.
	Utilization of the net operating loss carry forwards and credits may be subject to substantial annual limitation due to the ownership change limitations provided by the Internal Revenue Code of 1986, as amended, and similar state provisions. The annual limitation may result in the expiration of net operating losses and credits before utilization.
	The following table reflects changes in the gross unrecognized tax benefits (in thousands):
		January 31,
		2015			2014			2013
	Gross unrecognized tax benefits-beginning of year	$	4,048		$	2,444		$	932
	Net decreases related to prior year tax positions		(8	)		(122	)		(106	)
	Increases related to current year tax positions		1,649			1,726			1,618
	Gross unrecognized tax benefits-end of year	$	5,689		$	4,048		$	2,444
	None of the unrecognized tax benefits would have a net impact to income tax expense if subsequently recognized since the recognition of such benefits would result in a corresponding increase to the Company’s valuation allowance.
	Income taxes payable of $116,000 and $115,000 are included within accrued liabilities in the Company’s consolidated balance sheets as and January 31, 2015 and 2014, respectively.
	The Company’s policy is to classify interest and penalties associated with unrecognized tax benefits as income tax expense. The Company had no interest or penalty accruals associated with uncertain tax benefits.
	The Company is subject to taxation in the United States and in California and New Jersey among other states, and in certain foreign jurisdictions. As of January 31, 2015, the Company’s federal and state returns for the years ended 2010 through the current period are still open to examination. Net operating losses and research and development carryforwards that may be used in future years are still subject to inquiry given that the statute of limitation for these items would be from the year of the utilization. There are no tax years under examination by any jurisdiction at this time.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Jan. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. Commitments and Contingencies
	Legal Disclosure
	Beginning on November 26, 2013, four putative class action lawsuits were filed in the United States District Court for the Northern District of California, naming as defendants the Company, a number of the Company’s present or former directors and officers, and several underwriters of the Company’s September 27, 2013 IPO. The four complaints have been consolidated into a single, putative class action, and co-lead plaintiffs have been appointed by the court. On March 28, 2014, a consolidated complaint was filed. The complaint purports to assert claims under the federal securities laws on behalf of purchasers of our common stock issued in the IPO, based on seven categories of alleged omissions. The complaint seeks damages in an unspecified amount and other relief. On April 18, 2014, the defendants filed motions to dismiss the complaint. On October 31, 2014, the court granted in part and denied in part defendants’ motions to dismiss. The court’s order dismissed all except one category of alleged omissions, and gave plaintiffs the opportunity to amend the complaint. On November 21, 2014, the plaintiffs filed an amended complaint. In so doing, the plaintiffs chose not to amend their claims against the Company or the present or former directors and officers. Pending further developments regarding plaintiffs’ claims against the underwriters, the case will proceed to the discovery phase on the remaining allegations against the Company and the present or former directors and officers.
	A purported stockholder derivative action also is pending before the same federal district court judge to whom the putative class action has been assigned. In the derivative action, the plaintiffs allege that certain of the Company’s current and former officers and directors breached their fiduciary duties to the Company by violating the federal securities laws and exposing the Company to possible financial liability. Pursuant to a stipulation by the parties, the derivative action currently is stayed pending further developments in the putative class action. The stay may be lifted at any time.
	The Company intends to defend itself vigorously in both securities actions.
	Indemnification
	The Company indemnifies certain of its officers and directors for certain events or occurrences, subject to certain limits, while the officer or director is or was serving at the Company’s request in such capacity. The Company’s certificate of incorporation and bylaws require that it indemnify its officers and directors against expenses, judgments, fines, settlements and other amounts actually and reasonably incurred in connection with any proceedings arising out of their services to the Company. In addition, the Company has entered into separate indemnification agreements with each of its directors and executive officers, which provide for indemnification of these individuals under certain circumstances. The maximum amount of potential future indemnification is unlimited; however, the Company has a Directors and Officers insurance policy that enables the Company to recover a portion of any future amounts paid. Historically, the Company has not been obligated to make any payments for these obligations and no liabilities have been recorded for these obligations on the consolidated balance sheets as of January 31, 2015 and 2014.
	The Company may, in the ordinary course of business, agree to defend and indemnify some customers against legal claims that the Company’s products infringe on certain U.S. patents or copyrights. The terms of such obligations may vary. To date, the Company has not been required to make any payments resulting from such infringement indemnifications and no amounts have been accrued for such matters.
	Other Contingencies
	From time to time, the Company may become involved in legal proceeding or other claims and assessments arising in the ordinary course of business. The Company is not currently a party to any litigation matters, except as discussed above, which, individually or in the aggregate, are expected to have a material adverse effect on the Company’s business, financial condition or results of operations.
	Operating Lease Commitments
	The Company leases office space under various non-cancelable operating leases that expire at various dates through fiscal 2018. Rent expense related to operating leases was $2.4 million, $2.5 million and $2.0 million for the years ended January 31, 2015, 2014 and 2013, respectively. Future minimum lease payments under the Company’s operating leases as of January 31, 2015, are as follows (in thousands):
		Amount
	Fiscal years ending January 31:
	2016	$	3,896
	2017		3,615
	2018		294
		$	7,805
	Purchase Commitments
	The Company depends entirely upon a contract manufacturer to manufacture its products and provide test services. Due to the lengthy lead times, the Company must order from its contract manufacturer well in advance and is obligated to pay for the materials when received and services once they are completed. As of January 31, 2015, the Company had approximately $2.3 million of outstanding purchase commitments to such contract manufacturer and other vendors.
	In July 2012, we entered into an OEM agreement with a software vendor, which obligates us to pay an aggregate of $5.0 million in minimum royalty fees over a three-year period beginning after the first commercial shipment of the related product. The Company made the first commercial shipment in April 2013 and began paying royalties. As of January 31, 2015, the remaining purchase commitment was $3.2 million.
	Advertising Commitment
	In June 2012, the Company entered into an agreement with the Forty Niners SC Stadium Company LLC, which was amended in April 2014. As part of the amended agreement, the Company will receive advertising and related benefits at the stadium in Santa Clara, California from 2014 through 2023 for $1.75 million per year over the 10-year term. The Company recognized $1.2 million in advertising expenses related to this agreement for the year ended January 31, 2015.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Jan. 31, 2015
Related Party Transactions [Abstract]
Related Party Transactions	10. Related Party Transactions
	Toshiba
	As of January 31, 2015, Toshiba Corporation and its affiliates, including Toshiba America Electronic Components, Inc. (collectively Toshiba), owned 9.2 million shares of the Company’s common stock or 10% of the Company’s total common stock outstanding.
	In June 2011, the Company entered into a Sales Agreement with Toshiba pursuant to which the Company agreed to purchase at least 70% of its annual flash memory requirement from Toshiba. Our Sales Agreement with Toshiba expired in June 2014 and automatically renews for successive one-year periods unless terminated by either party.
	In July 2013, the Company signed an agreement with Toshiba for the development of PCIe cards and the sale of sample cards and received a prepayment of $16 million. The $16 million prepayment consisted of $8 million for services to be performed for the development of the PCIe cards and $8 million for the sale of sample PCIe cards and related support services. The Company retains all ownership of the intellectual property developed under the agreement. The Company applied ASC 605-25, Revenue Recognition – Multiple Element Arrangements to identify the deliverables. The Company concluded that the deliverables are development services, sample PCIe cards and support services for the sample PCIe cards. The Company recognized $6.0 million of revenue related to development services of PCIe cards and $3.1 million of revenue related to sample products during fiscal 2014 as determined on a relative fair value basis. For the year ended January 31, 2015, the Company recognized an additional $1.0 million under the agreement related to development services performed. The remaining $5.8 million advance payment was repaid to Toshiba in May 2014 pursuant to a Mutual Termination of Contract Agreement between Toshiba and the Company. Any incremental research and development expense related to this arrangement was recognized as cost of services. During fiscal 2015 and 2014, the Company recognized incremental cost of services of $0 and $1.0 million, respectively.
	In addition to the development agreement, the Company recognized revenue of $1.6 million, $4.0 million and $3.6 million related to the sale of All Flash Arrays and services to Toshiba during fiscal 2015, 2014 and 2013, respectively.
	The Company purchased $9.2 million, $38.2 million and $27.5 million of NAND flash memory from Toshiba during fiscal 2015, 2014 and 2013, respectively.
	RiverMeadow Software, Inc.
	In August 2012, the Company purchased 866,325 shares of Series A-1 convertible preferred stock of RiverMeadow Software, Inc., or RiverMeadow, for consideration of $3.0 million representing 9% of the outstanding stock of RiverMeadow. During fiscal 2013, we had product sales to RiverMeadow of $1.4 million. In September 2013, the Company purchased 118,204 shares of Series B convertible preferred stock for consideration of $0.5 million. Mr. Rosenblatt, a former member of our board of directors, previously served as a member of the Board of Directors of RiverMeadow, and Mr. Newman, a former director of Violin Memory serves as the Chairman of the Board of RiverMeadow. From April 2012 to August 2013, Mr. Basile, a former executive and director of Violin Memory served as a director of RiverMeadow.
	As part of the Company’s annual review of its long-lived assets for impairment, the Company evaluated the near-term prospects of its cost method investment, including performing a probability-weighted assessment of potential outcomes with the assistance of independent investment bankers. Based on that evaluation, the Company considered the investment to be other-than-temporarily impaired at January 31, 2015. For the year ended January 31, 2015, the Company recorded an impairment on its RiverMeadow investment in the amount of $3.5 million, which was included in other expense, net in the consolidated statements of operations.

Restructuring_Charges

Restructuring Charges	12 Months Ended
	Jan. 31, 2015
Restructuring and Related Activities [Abstract]
Restructuring Charges	11. Restructuring Charges
	During the fourth quarter of fiscal 2014, the Company initiated a restructuring plan focused on accelerating growth and increasing operating leverage, including a reorganization of its sales, marketing and engineering functions in order to better focus on the core segments of the flash-based storage market and improve operating and financial efficiency. In connection with the Company’s restructuring activities and decision to focus on its core All Flash Array market, the Company sold its PCIe Flash Memory Card product line in July 2014 and realized proceeds of $23.0 million and a gain of $17.4 million thereon.
	The Company’s restructuring and transition charges consist primarily of severance, facility costs and other related charges. Severance generally includes severance payments, payments for pro-rata share of earned incentive pay and health insurance coverage. Facility costs include rent expense and related common area maintenance charges attributable to a leased facility that will not utilized over the remaining lease term. Other related charges primarily consist of write-off of purchased software, which will not be utilized and consulting charges associated with the reorganization of the Company. A summary of the restructuring activities is as follows (in thousands):
		Severance			Excess Facility			Impairment			Other			Total
		and Related			Charges			of Assets			Restructuring
		Charges									Charges
	Balance January 31, 2013	$	—		$	—		$	—		$	—		$	—
	Restructuring provision		2,728			511			1,231			399			4,869
	Payments and other adjustments		(357	)		—			(1,231	)		(33	)		(1,621	)
	Balance January 31, 2014		2,371			511			—			366			3,248
	Restructuring provision		1,185			1,810			—			67			3,062
	Payments		(3,556	)		(1,057	)		—			(433	)		(5,046	)
	Balance January 31, 2015	$	—		$	1,264		$	—		$	—			1,264
	Less: non-current portion														(951	)
	Current portion of restructuring accrual													$	313

Segment_Information

Segment Information	12 Months Ended
	Jan. 31, 2015
Segment Reporting [Abstract]
Segment Information	12. Segment Information
	Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision maker, the Company’s chief executive officer. The Company’s chief executive officer reviews financial information presented on a consolidated basis, accompanied by information about revenue by geographic region for purposes of allocating resources and evaluating financial performance. The Company has one business activity, and there are no segment managers who are held accountable for operations, operating results and plans for levels or components below the consolidated unit level. Accordingly, the Company considers itself to be in a single reportable segment and operating unit structure.
	Revenue by geography is based on the billing address of the customer. The following table sets forth revenue and property and equipment by geographic area (in thousands):
		Year Ended January 31,
		2015		2014		2013
	Revenue
	Americas:
	United States	$	48,247	$	66,502	$	56,229
	Other Americas		402		425		543
			48,649		66,927		56,772
	Europe:
	United Kingdom		5,807		7,491		5,270
	Other Europe		12,796		9,003		4,356
			18,603		16,494		9,626
	Asia Pacific:		11,723		24,235		7,400
		$	78,975	$	107,656	$	73,798
		January 31,
		2015		2014
	Property and Equipment
	United States	$	9,653	$	13,232
	Europe		204		415
	Asia Pacific		6		6
		$	9,863	$	13,653

Net_Loss_Per_Share

Net Loss Per Share	12 Months Ended
	Jan. 31, 2015
Earnings Per Share [Abstract]
Net Loss Per Share	13. Net Loss Per Share
	Basic net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, less the weighted-average unvested common stock subject to repurchase or forfeiture. Diluted net loss per share is computed by giving effect to all potential shares of common stock, including preferred stock, stock options and warrants, to the extent dilutive. Basic and diluted net loss per share was the same for each period presented as the inclusion of all potential common shares outstanding would have been anti-dilutive. The following table sets forth the computation of historical basic and diluted net loss per share (in thousands, except per share data):
		Year Ended January 31,
		2015			2014			2013
	Numerator:
	Net loss	$	(108,903	)	$	(149,809	)	$	(109,102	)
	Denominator:
	Weighted average common shares outstanding		90,994			38,804			15,443
	Less: Weighted average unvested common shares subject to repurchase		35			213			1,819
	Weighted average shares used to compute net loss per share of common stock, basic and diluted		90,959			38,591			13,624
	Net loss per share of common stock, basic and diluted	$	(1.20	)	$	(3.88	)	$	(8.01	)
	Since the Company experienced losses for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods. The following potential common stock equivalents that could potentially dilute net loss per share in the future were excluded from the computation of diluted net loss per share because including them would have been anti-dilutive for the periods presented (in thousands):
		Year Ended January 31,
		2015			2014			2013
	Convertible senior notes (on an as-converted basis)		21,352			—			—
	Shares subject to outstanding common stock options and restricted stock units		19,498			20,307			14,529
	Warrants related to common stock		164			84			—
	Convertible preferred stock (on an as converted basis)		—			—			45,858
	Common stock subject to repurchase		—			70			356
			41,014			20,461			60,743

Convertible_Senior_Notes_Line_

Convertible Senior Notes, Line of Credit and Debt Facility	12 Months Ended
	Jan. 31, 2015
Debt Disclosure [Abstract]
Convertible Senior Notes, Line of Credit and Debt Facility	14. Convertible Senior Notes, Line of Credit and Debt Facility
	Convertible Senior Notes
	On September 19, 2014, the Company issued $120 million aggregate principal amount of Convertible Senior Notes (the “Notes”), which included $15 million issued pursuant to an over-allotment option granted to the initial purchasers. The aggregate principal amount of the Notes is due on October 1, 2019, unless earlier repurchased, redeemed or converted. The Company received net proceeds of $115.4 million after deducting offering costs.
	Interest on the outstanding Notes accrues at a rate of 4.25% per annum and is payable semi-annually on April 1 and October 1 of each year beginning on April 1, 2015. Interest began to accrue on September 24, 2014. The Notes are unsecured senior obligations of Violin. These Notes were offered and sold only to qualified institutional investors, as defined in Rule 144 under the Securities Act of 1933 (“Securities Act”), and the Notes and the shares of the Company’s common stock issuable upon conversion of the Notes have not been registered under the Securities Act.
	The Company used the net proceeds to repay all amounts outstanding and owed under its credit agreement with SVB and intends to use the remaining net proceeds for general corporate purposes, including working capital. In addition, the Company believes that the issuance of the Notes provides greater financial flexibility to the Company and should provide its customers and/or potential customers with greater confidence in the Company’s liquidity.
	The Company may redeem the Notes, at its option, in whole or in part on or after October 1, 2017, if the last reported sale price per share of its common stock equals or exceeds 130% of the applicable conversion price for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period ending on the trading day immediately prior to the date on which the Company delivers notice of the redemption.
	Holders of the Notes may convert all or any portion of their notes, in multiples of $1,000 principal amount, at their option at any time prior to the close of business on the business day immediately preceding the maturity date. The Notes are convertible at an initial conversion rate of 177.8489 shares of our common stock per $1,000 principal amount of notes. This is equivalent to an initial conversion price of approximately $5.62 per share of the Company’s common stock, subject to adjustment upon the occurrence of certain dilutive events, or, if the Company obtains the required consent from its shareholders, into shares of the Company’s common stock, cash or a combination of cash and shares of its common stock, at the Company’s election. The conversion rate will be increased in the case of corporate events that constitute a “Make-Whole Fundamental Change” (as defined in the indenture governing the notes). As of January 31, 2015, the Notes are not convertible.
	The holders of the Notes will have the ability to require the Company to repurchase the notes in whole or in part upon the occurrence of an event that constitutes a “Fundamental Change” (as defined in the indenture governing the notes including such events as a “change in control” or “termination of trading”). In such case, the repurchase price would be 100% of the principal amount of the notes plus accrued and unpaid interest, if any. Certain events are also considered “Events of Default,” which may result in the acceleration of the maturity of the Notes, as described in the indenture governing the Notes, including, among other events, the Company’s failure to timely file with the SEC the reports required pursuant to Section 13 or 15(d) of the Securities Exchange of 1934, as amended. There were no “Fundamental Changes” or “Events of Default” that occurred for the year ended January 31, 2015. The Company was in compliance with its covenants under the notes as of January 31, 2015.
	During the time that the Notes are outstanding, the Company may not at any time incur any indebtedness other than permitted debt, which is defined as: (a) revolving debt secured by the Company’s accounts receivable and the proceeds therefrom in a principal amount not to exceed $50 million; (b) unsecured indebtedness (including the Notes) in a principal amount not to exceed (when combined with any indebtedness incurred under clause (c) below) $150 million; (c) secured indebtedness secured by the Company’s intellectual property in a principal amount not to exceed (when combined with any indebtedness incurred under clause (b) above) $150 million; and (d) unsecured subordinated indebtedness in a principal amount not to exceed $50 million. Furthermore, the Company may incur indebtedness if (a) the Company is not in default and such additional debt would not put it into default and (ii) the consolidated leverage ratio, as defined, after taking the additional debt into account does not exceed 5:1.
	The conversion option of the Notes cannot be settled in cash prior to obtaining the necessary approval of the Company’s shareholders. In accordance with guidance in ASC 470-20, Debt with Conversion and Other Options and ASC 815-15, Embedded Derivatives, the Company determined that until shareholder approval that allows for settlement by issuing shares of the Company’s common stock, cash or a combination of cash and shares of its common stock, the embedded conversion components of the Notes do not require bifurcation and separate accounting. The $120 million principal amount of the Notes has been recorded as debt on the Company’s accompanying condensed consolidated balance sheet as of January 31, 2015.
	The deferred debt issuance costs are recorded in other assets and are being amortized to interest and other financing expense using the effective interest method over the Notes’ five-year term. The deferred debt issuance costs have been classified as long-term as the underlying debt instrument is classified as a long-term liability in the Company’s accompanying condensed consolidated balance sheet. For the year ended January 31, 2015, the Company amortized debt issuance costs of $0.6 million to interest and other financing expenses. The Company also accrued interest of $1.7 million related to the Notes.
	Silicon Valley Bank Credit Agreements
	In August 2014, the Company entered into a $40.0 million credit facility with SVB that provides for a term loan of $10.0 million and a line of credit with a maximum commitment of $30.0 million. The Company’s obligations under the agreement were secured by a first priority security interest in substantially all of its assets. Pursuant to this arrangement, the Company agreed to issue SVB a warrant to purchase 79,323 shares of its common stock, $0.0001 par value per share, at a price per share of $3.782. The warrant expires in August 2019.
	In connection with the Notes offering, the Company terminated the credit facility and repaid the loan. In addition, the Company recorded a loss on extinguishment on the term loan amounting to $0.4 million, which relates to the write-off of debt issuance costs, including the warrant issued with the term loan. The loss on extinguishment is reflected as a part of interest and other financing expense in the accompanying consolidated statements of operations.
	In October 2014, the Company entered into a new $20.0 million secured revolving line of credit with SVB. The Company’s obligations under the agreement are secured by a first priority security interest in the Company’s accounts receivable and proceeds therefrom. Borrowings under this facility will bear interest at a rate per annum of either (a) the sum of (i) the Eurodollar rate plus (ii) 5.00%, or (b) the sum of (i) ABR plus (ii) 2.00%. The Company borrowed $10.0 million on this facility in January 2015. The line of credit expires on October 24, 2016, subject to acceleration upon certain specified events of defaults.
	An event of default under the Company’s Credit Agreement with SVB occurred solely because the Company did not satisfy a financial condition covenant requiring it to generate revenue for the fourth quarter of fiscal 2015 in an amount not less than 80% of the amount of revenue the Company forecasted for the quarter in the annual operating plan. The Company requested, and SVB agreed, subject to certain terms and conditions, to waive the event of default. The Company and SVB agreed, subject to the same terms and conditions, to amend the Credit Agreement to provide that its revenue forecast for fiscal 2016 will be based upon the annual operating plan the Company delivered to SVB on March 11, 2015.
	After the loss on extinguishment of $0.4 million, the remaining debt issuance costs associated with these two transactions are reflected in other assets and are being amortized to interest and other financing expense using the straight line method over the facility’s two-year term.
	TriplePoint Capital Debt Facility
	During May 2013, the Company entered into a $50.0 million debt arrangement with TriplePoint Capital LLC, or TriplePoint. The facility had first secured interest in substantially all of the Company’s assets and intellectual property other than $7.5 million of accounts receivable. The Company had one year to utilize the facility, which has a number of borrowing options ranging in duration from three months up to five years. Depending on the loan option, annualized interest rates range from 7.00% to 13.50%. In addition, the loans had an end-of-term payment, ranging from 0.50% to 14.00% of the principal amount depending on the duration of the loan. As of January 31, 2014, the Company had repaid all amounts outstanding on this facility. The facility was terminated in May 2014.
	Convertible Notes
	In fiscal 2014, the Company issued and sold convertible promissory notes for an aggregate amount of $5.2 million pursuant to a note and warrant purchase agreement. The notes had an interest rate of 10%. The outstanding principal and accrued interest converted, upon completion of the IPO, into Company’s common stock at $9.00 per share.
	The Company also issued $8.7 million in convertible notes during the year ended January 31, 2013, which were converted into preferred stock upon completion of the equity financing. The convertible notes bore 6% interest per annum.
	The following table is a reconciliation of the changes in the Company’s aggregate convertible notes payable liability (in thousands, except for per share data):
		Notes Value			Shares		Conversion
							Price per Share
	Balance at January 31, 2012	$	688
	Issued		8,698
	Accrued interest		29
	Converted into Series D convertible preferred stock		(9,415	)		1569		6
	Balance at January 31, 2013		—
	Issued		5,165
	Accrued interest		43
	Converted into common stock		(5,203	)		585		9
	Balance at January 31, 2014	$	—
	Other Short-term Borrowings
	Line of Credit: In July 2013, the Company entered into a $7.5 million line of credit with Comerica Bank. The Company could borrow up to 80% of its current U.S.-based receivables, or $7.5 million, whichever is lower. The line was secured against the Company’s accounts receivable and collections thereof as well as its intellectual property. The line had a two-year term and bore interest of prime plus 1%. In August 2014, the Company repaid all outstanding amounts under the line of credit and terminated the Loan and Security Agreement with Comerica.
	Product Financing Arrangement: In July 2014, the Company entered into a managed inventory program to run through December 2014. Under the agreement, the Company gave title to 194,000 units of product to the counterparty for approximately $2.3 million. The Company is obligated to repurchase the product in five equal monthly installments, including predetermined transaction fees of between 4.5% and 6%. As of January 31, 2015, the Company had settled this liability in full.

Organization_and_Summary_of_Si1

Organization and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Jan. 31, 2015
Accounting Policies [Abstract]
Description of Business	Description of Business
	Violin Memory, Inc. (the “Company”) was incorporated in the State of Delaware on March 9, 2005 under the name Violin Technologies, Inc. The Company re-incorporated as Violin Memory, Inc. in the State of Delaware on April 11, 2007. The Company is a developer and supplier of high-performance, persistent memory-based storage systems that are designed to bring storage performance in line with high-speed applications, servers and networks. These All Flash Arrays are specifically designed at each level of the system architecture, starting with memory and optimized through the array, to leverage the inherent capabilities of flash memory. The Company also recently introduced the Flash Storage Platform, the industry’s first vertically integrated design of software, firmware and hardware that delivers the highest performance, resiliency and availability at the same cost as legacy enterprise-class primary storage. The Flash Storage Platform runs the Company’s Concerto OS 7, a single operating system with integrated continuous data protection, in-line block de-duplication and compression, stretch metro cluster and LUN mirroring as well as its suite of other Enterprise Data Services. With Violin’s Flash Storage Platform, all active data (Tiers 0, 1, and 2) can be consolidated onto a single tier, simplifying storage administration. Additionally, with Violin’s release of Symphony Management Suite Version 3.0, the entire software functionality can all be controlled in 1, 2 or 3 clicks, with management of the entire storage estate, through a single pane of glass. The Company sells its products through its global direct sales force, systems vendors, resellers and other channel partners. The Company operates in a single business segment.
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation
	We prepared the consolidated financial statements in accordance with U.S. generally accepted accounting principles (GAAP). The consolidated financial statements include the accounts of Violin Memory, Inc. and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated.
Reclassifications	Reclassifications
	Certain prior year amounts have been reclassified for consistency with the current period presentation. These reclassifications had no effect on the previously reported financial position, results of operations or cash flows.
Foreign Currency Translations and Remeasurement	Foreign Currency Translations and Remeasurement
	The local currency is the functional currency for each of the Company’s subsidiaries. Assets and liabilities are translated into U.S. dollars at exchange rates in effect at the balance sheet date. Income and expense items are translated at average exchange rates for the respective period.
	Gains and losses from foreign currency transactions are included in other expense, net. Foreign currency translation adjustments are included in other comprehensive loss.
Use of Estimates	Use of Estimates
	The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. On an on-going basis, the Company evaluates its significant estimates, including those related to estimated selling prices for elements sold in multiple-element revenue arrangements, product warranty, determination of the fair value of stock options, carrying values of inventories, liabilities for unrecognized tax benefits and deferred income tax asset valuation allowances. The Company also uses estimates in determining the useful lives of property and equipment and in its provision for doubtful accounts. Actual results could differ from those estimates.
Concentrations of Market, Credit Risk, Significant Customers and Manufacturing	Concentrations of Market, Credit Risk, Significant Customers and Manufacturing
	The Company participates in the business of developing and manufacturing scalable All Flash Arrays and believes that changes in any of the following areas could have a material adverse effect on the Company’s future financial position, results of operations or cash flows: advances and trends in new technologies and industry standards; competitive pressures in the form of new products or price reduction on current products; changes in the overall demand for products offered by the Company; changes in certain strategic relationships or customer relationships; litigation or claims against the Company based on intellectual property, patent, product, regulatory or other factors; and risks associated with changes in domestic and international economic and international and/or political conditions or regulations.
	Financial instruments that potentially subject the Company to concentrations of credit risk primarily consist of cash, cash equivalents, investments and accounts receivable. The Company places its cash and cash equivalents and investments with high credit quality financial institutions which the Company believes are creditworthy. Deposits may exceed the insured limits provided on them.
	The Company generally requires no collateral from its customers. The Company mitigates its credit risk with associated with its accounts receivable by performing ongoing credit evaluations of its customers and establishes an allowance for doubtful accounts for estimated losses based on management’s assessment of the collectability of customer accounts.
	The Company sells to a limited number of large systems vendors, resellers and end-customers and, as a result, maintains individually significant receivable balances with such customers. The Company’s systems vendor customers and certain large resellers tend to be well-capitalized, multi-national companies, while other customers may not be as well capitalized. Sales of products to large systems vendors and resellers are expected to account for a majority of the Company’s revenues in the foreseeable future, and the Company’s financial results will depend in part upon the success of these customers. The composition of the Company’s major customer base may change as the market demand for its products changes, and the Company expects this variability will continue in the future. The loss of, or a significant reduction in purchases by, any of the major customers may harm the Company’s business, financial condition and results of operations.
	The Company relies on a limited number of suppliers for its contract manufacturing and certain raw material components. The Company believes that other vendors would be able to provide similar products and services; however, the qualification of such vendors may require substantial start-up time. In order to mitigate any adverse impacts from disruption of supply, the Company attempts to maintain an adequate supply of critical single-sourced raw materials.
Cash and Cash Equivalents	Cash and Cash Equivalents
	Cash consists of deposits with financial institutions. The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Cash equivalents consist of money market funds, which are readily convertible into cash and are stated at cost, which approximates fair market value. Cash and cash equivalents were $93.4 million and $40.3 million as of January 31, 2015 and 2014, respectively.
Restricted Cash	Restricted Cash
	In connection with the sale of its PCIe product line, the Company is obligated to maintain a balance of $2.3 million with an escrow agent for one year. Such amount will be held for the purpose of securing certain of the Company’s indemnification obligations and to compensate the buyer for damages for which they are indemnified pursuant to the asset purchase agreement. No claims for indemnification have been filed to date. The agreement expires on July 24, 2015.
Investments	Investments
	The Company classifies its investments as available-for-sale at the time of purchase since it is the Company’s intent that these investments are available for current operations and includes these investments on the consolidated balance sheet as short-term or long-term investments depending on their maturity and management’s intention with regard to the utilization of these investments, as needed, to fund current operations. As of January 31, 2015, all investments have been classified as short-term.
	Investments are considered impaired when a decline in fair value is judged to be other-than-temporary. The Company consults with its investment managers and considers available quantitative and qualitative evidence in evaluating potential impairment of its investments on a quarterly basis. If the cost of an individual investment exceeds its fair value, the Company evaluates, among other factors, general market conditions, the duration and extent to which the fair value is less than cost, and its intent and ability to hold the investment. Once a decline in fair value is determined to be other-than-temporary, an impairment charge is recorded and a new cost basis in the investment is established.
Fair Value Measurements and Disclosures	Fair Value Measurements and Disclosures
	The Company records its financial assets and liabilities at fair value. The accounting guidance for fair value provides a framework for measuring fair value, clarifies the definition of fair value and expands disclosures regarding fair value measurements. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value:
	Level 1 – Quoted prices in active markets for identical assets or liabilities.
	Level 2 – Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices 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 assets or liabilities.
	Level 3 – Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
	The Company recognizes transfers among Level 1, Level 2 and Level 3 classifications as of the actual date of the events or change in circumstances that caused the transfers.
	The Company’s financial instruments, including cash equivalents, accounts receivable, accounts payable and accrued liabilities have carrying amounts which approximate fair value due to the short-term maturity of these instruments.
Accounts Receivable	Accounts Receivable
	Trade accounts receivable are recorded at the invoiced amount and do not bear interest. The Company maintains an allowance for doubtful accounts for estimated losses inherent in its accounts receivable portfolio. In establishing the required allowance, management considers expected losses after taking into account current market conditions, customers’ financial condition, current receivable aging and current payment patterns. Account balances are charged off against the allowance after all means of collection have been exhausted and the potential for recovery is considered remote. As of January 31, 2015 and 2014, the Company’s allowance for doubtful accounts was insignificant.
Inventory	Inventory
	Inventory consists of raw materials and finished goods and is stated at the lower of cost, determined on a first-in, first-out (“FIFO”) basis, or market. The Company periodically assesses the recoverability of all inventory, including raw materials and finished goods to determine whether adjustments are required to record inventory at the lower of cost or market. Inventory that the Company determines to be obsolete or in excess of forecasted usage is reduced to its estimated realizable value based on assumptions about future and current market conditions. In the case of inventory which has been written down below cost through the use of a reserve, such reduced amount is considered the cost for subsequent accounting purposes.
Revenue Recognition	Revenue Recognition
	The Company derives revenue primarily from sales of its All Flash Arrays, software and related support and professional services. Revenue is recognized when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price is fixed and determinable and collectability is reasonably assured. Evidence of an arrangement exists when there is a customer contract or purchase order. The Company considers delivery complete when title and risk of loss transfer to the customer, which is generally upon shipment, but no later than physical receipt by the customer.
	The Company sells its products and support services directly to end-customers, systems vendors and resellers. The Company currently does not provide price protection, rebates or other sales incentives to customers. The Company generally does not allow a right of return to its customers, including resellers.
	The Company’s multiple-element arrangements typically include two elements: hardware, which includes embedded software, and support services. Beginning in the second quarter of fiscal 2014, following introduction of the Violin Symphony Management Software Suite, the Company’s multiple-element arrangements also may include software elements. The Company has determined that its hardware and the embedded software are considered a single unit of accounting, because the hardware and software individually do not have standalone value and are not sold separately. Standalone software, professional services and support services are each considered a separate unit of accounting as they can be sold separately and have standalone value.
	When more than one element, such as hardware, software and services, are contained in a single arrangement, the Company first allocates consideration to the software deliverables as a group and non-software deliverables based on the relative selling price method. The Company’s appliance products, embedded software and certain other services are considered to be non-software deliverables in such arrangements. The Company allocates revenue within the software group based upon fair value using vendor-specific objective evidence, or VSOE, with the residual revenue allocated to the delivered element. If VSOE of fair value cannot be objectivity determined for any undelivered software elements, we defer revenue until all elements are delivered and services have been performed, or until fair value can objectively be determined for any remaining undelivered elements. The Company allocates revenue within the non-software group to each element based upon its relative selling price in accordance with the selling price hierarchy, which includes: (1) VSOE, if available; (2) third-party evidence, or TPE, if VSOE is not available; and (3) best estimate of selling price, or BESP, if neither VSOE nor TPE is available. The Company establishes BESP considering multiple factors including, but not limited to, historical prices of products sold on a stand-alone basis, cost and gross margin objectives, competitive pricing practices and customer and market specific considerations.
	The Company then recognizes revenue on each deliverable in accordance with its policies for product and service revenue recognition. Revenue allocated to the Company’s products is recognized upon shipment or delivery. Revenue allocated to support services is recognized over the term, which is generally one or three years.
	The Company’s policy is to record revenue net of any applicable sales, use or excise tax.
Property and Equipment	Property and Equipment
	Property and equipment consist primarily of capitalized equipment and computer hardware and software, which are stated at cost and depreciated using the straight-line method over the estimated useful lives of two years and three years, respectively. Leasehold improvements are amortized using the straight-line method over the shorter of the lease term or the estimated useful life of the asset. Costs of maintenance and repairs that do not improve or extend the lives of the respective assets are expensed as incurred. Upon retirement or sale, the cost and related accumulated depreciation are removed from the balance sheet and the resulting gain or loss is reflected in operating expenses.
Research and Development	Research and Development
	Research and development costs are expensed as incurred. Research and development costs consist primarily of personnel costs, prototype expenses, software tools, consulting services and allocated facilities costs.
Software Development Costs	Software Development Costs
	The Company expenses software development costs as incurred until technological feasibility is attained, including research and development costs associated with stand-alone software products and software embedded in hardware products. Technological feasibility is attained when the Company has completed the planning, design and testing phase of development of its software and the software has been determined viable for its intended use, which typically occurs when beta testing commences. The period of time between when beta testing commences and when the software is available for general release to customers has historically been short with immaterial amounts of software development costs incurred during this period. Accordingly, the Company has not capitalized any internal software development costs to date.
Advertising Expenses	Advertising Expenses
	All advertising costs are expensed as incurred. The Company recognized advertising expenses of $1.6 million, $0.6 million and $1.0 million for the years ended January 31, 2015, 2014 and 2013, respectively.
Income Taxes	Income Taxes
	Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income (or loss) in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Valuation allowances are established for deferred tax assets to the extent it is more likely than not that the deferred tax assets may not be realized.
	The Company evaluates uncertain tax positions taken or expected to be taken in the course of preparing an enterprise’s tax return to determine whether the tax positions are more likely than not of being sustained upon challenge by the applicable tax authority. Tax positions with respect to any potential income tax for the Company not deemed to meet the more likely than not threshold would be recorded as a tax expense in the current year.
Net Loss Per Share	Net Loss Per Share
	Basic net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock outstanding for each fiscal period presented.
	Diluted net loss per share is computed by giving effect to all potential shares of common stock, including stock options, warrants and convertible preferred stock, to the extent dilutive. Basic and diluted net loss per share was the same for each period presented as the inclusion of all potential shares of common stock outstanding would have been anti-dilutive.
Stock-Based Compensation	Stock-Based Compensation
	The Company records stock-based compensation expense related to employee stock-based awards on a straight-line basis based on the estimated fair value of the awards as determined on the date of grant. The Company utilizes the Black-Scholes option pricing model to estimate the fair value of employee stock options and Employee Stock Purchase Plan (ESPP). The Black-Scholes model requires the input of highly subjective and complex assumptions, including the expected term of the stock option, the expected volatility of the Company’s common stock over the period equal to the expected term of the grant and forfeitures. The Company estimates forfeitures at the date of grant and revises the estimates, if necessary, in subsequent periods if actual forfeitures differ from those estimates.
	The Company accounts for stock options that are issued to non-employees based on the estimated fair value of such awards using the Black-Scholes option pricing model. The measurement of stock-based compensation expense for these awards is variable and subject to periodic adjustments to the estimated fair value until the awards vest and the resulting change in the estimated fair value is recognized in the Company’s consolidated statements of operations during the period in which the related services are rendered.
	The Company grants restricted stock units (RSUs) to employees. Stock-based compensation expense related to these grants is based on the grant date fair value of the RSUs and is recognized on a straight-line basis over the applicable service period, which is generally four years.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets
	Long-lived assets, such as property and equipment, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group be tested for possible impairment, the Company first compares undiscounted cash flows expected to be generated by that asset or asset group to its carrying value. If the carrying value of the long-lived asset or asset group is not recoverable on an undiscounted cash flow basis, an impairment charge is recognized to the extent that the carrying value exceeds its fair value. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values and third-party independent appraisals, as considered necessary.
Investment in Privately-held Companies	Investment in Privately-held Companies
	The Company analyzes equity investments in privately held companies to determine if it should be accounted for under the cost or equity method of accounting based on such factors as the percentage ownership of the voting stock outstanding and our ability to exert significant influence over these companies. For the cost method investments, the Company determines at each reporting period whether a decline in fair value has occurred and whether such decline is considered to be an other-than-temporary impairment. If a decline in fair value is determined to be other-than-temporary, the Company would recognize an impairment to reduce the investment to the lower of cost or fair value.
	For the year ended January 31, 2015 and 2014, the Company recorded an impairment on its cost-method investments in the amount of $3.5 million and $0.7 million, respectively, in other expense, net in the consolidated statements of operations. There was no impairment recorded for the year ended January 31, 2013. As of January 31, 2015, the net carrying value of the Company’s investments in privately-held companies was nil.
Commitments and Contingencies	Commitments and Contingencies
	Liabilities for loss contingencies arising from claims, assessments, litigation, fines and penalties and other sources are recorded when it is probable that a liability has been incurred and the amount can be reasonably estimated. Legal costs incurred in connection with loss contingencies are expensed as incurred.
Product Warranties	Product Warranties
	The Company generally provides a three-year warranty on all of its products. The Company accrues for potential liability claims as a component of cost of revenue based upon performance of equipment in the Company’s test and support labs, historical data and trends of product reliability and costs of repairing and replacing defective products. The accrued warranty balance is reviewed periodically for adequacy and is included in accrued liabilities in the consolidated balance sheets.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In August 2014, the FASB issued Accounting Standards Update (ASU) No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, which requires management to assess a company’s ability to continue as a going concern and to provide related footnote disclosures in certain circumstances. Before this new standard, there was minimal guidance in U.S. GAAP specific to going concern. Under the new standard, disclosures are required when conditions give rise to substantial doubt about a company’s ability to continue as a going concern within one year from the financial statement issuance date. The new standard applies to all companies and is effective for the annual period ending after December 15, 2016, and all annual and interim periods thereafter. The Company has determined that this pronouncement is not likely to have a material impact on the Company’s consolidated financial statements.
	In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, a converged standard on revenue recognition. The new pronouncement requires revenue recognition to depict the transfer of promised goods or services to customer in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance also specifies the accounting for some costs to obtain or fulfil a contract with a customer, as well as enhanced disclosure requirements. ASU 2014-9 is effective for annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting periods. Early adoption is not permitted. The Company is currently in the process of evaluating the impact of the adoption will have on its consolidated financial statements.
	In April 2014, the FASB issued ASU No. 2014-08, Presentation of Financial Statements (Topic 2015) and Property Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an entity, an accounting standard update that changes the criteria for reporting discontinued operations. Under the accounting standard update, a disposal of a component of an entity or a group of components of an entity is required to be reported in discontinued operations if the disposal represents a strategic shift that has, or will have, a major effect on an entity’s operations and financial results when either it qualifies as held for sale, disposed of by sale, or disposed of other than by sale. This accounting standard update became effective for the Company on February 1, 2015. The Company anticipates that this pronouncement will not have a material impact on the Company’s consolidated financial statements.
	In July 2013, the FASB issued ASU No. 2013-11, Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carry-forward, a Similar Tax Loss, or a Tax Credit Carry-forward Exists, which is effective for the periods beginning after December 15, 2013. The new guidance provides that a liability related to an unrecognized tax benefit would be presented as a reduction of a deferred tax asset for a net operating loss carryforward, a similar tax loss or a tax credit carryforward if such settlement is required or expected in the event the uncertain tax position is disallowed. The new guidance became effective for the Company on February 1, 2014, and was applied prospectively to unrecognized tax benefits that existed at the effective date. The adoption of this new guidance did not have a material impact on the Company’s consolidated financial statements.
	In March 2013, the FASB issued an accounting standard update requiring an entity to release into net income the entire amount of a cumulative translation adjustment related to its investment in a foreign entity when as a parent it either sells a part or all of its investment in a foreign entity or no longer holds a controlling financial interest in a subsidiary or group of assets within a foreign entity. This accounting standard update was effective prospectively for the Company on February 1, 2014. The adoption of this accounting standard update did not have a material impact on the Company’s consolidated financial statements.
Fair Value of Financial Instruments	The Company measures its cash equivalents and marketable securities at fair value. Money market funds are valued primarily using quoted market prices utilizing market observable inputs. The Company’s investments in commercial paper, treasury bills, corporate debt securities and federal and municipal obligations are classified within Level 2 as the market inputs to value these instruments consist of market yields, reported trades and broker/dealer quotes.
	No financial assets and liabilities measured at fair value on a recurring basis were held by the Company as of January 31, 2013. There have been no transfers between Level 1 and 2 during fiscal 2015 or 2014.
	No assets or liabilities measured at fair value on a nonrecurring basis were held by the Company as of January 31, 2015 or 2014.
	The carrying amounts of the Company’s accounts receivable, accounts payable, accrued liabilities and other liabilities approximate their fair value due to their short term maturities.
Restructuring Charges	The Company’s restructuring and transition charges consist primarily of severance, facility costs and other related charges. Severance generally includes severance payments, payments for pro-rata share of earned incentive pay and health insurance coverage. Facility costs include rent expense and related common area maintenance charges attributable to a leased facility that will not utilized over the remaining lease term. Other related charges primarily consist of write-off of purchased software, which will not be utilized and consulting charges associated with the reorganization of the Company.
Operating segments	Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision maker, the Company’s chief executive officer. The Company’s chief executive officer reviews financial information presented on a consolidated basis, accompanied by information about revenue by geographic region for purposes of allocating resources and evaluating financial performance. The Company has one business activity, and there are no segment managers who are held accountable for operations, operating results and plans for levels or components below the consolidated unit level. Accordingly, the Company considers itself to be in a single reportable segment and operating unit structure.

Organization_and_Summary_of_Si2

Organization and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Jan. 31, 2015
Accounting Policies [Abstract]
Summary of Customers Accounted as Percentage of Total Revenue and Accounts Receivable	Customers that represented more than 10% of total revenue and gross accounts receivable are as follows:
			Year Ended January 31,
			2015			2014			2013
	Percent of revenue:
	Enterprise Vision Technology			10	%		*			*
	Toshiba (Note 10)			*			12	%		*
	CompSec			*			*			12	%
		*	Less than 10%
			January 31,
			2015			2014
	Percent of gross accounts receivable:
	Arrow ECS			19	%		*
	Commtech Innovative Solutions			*			27	%
	Avnet, Inc.			*			15
		*	Less than 10%

Balance_Sheet_Components_Table

Balance Sheet Components (Tables)	12 Months Ended
	Jan. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Components of Accounts Receivable	The following table shows the components of accounts receivable, net (in thousands):
		January 31,
		2015			2014
	Accounts receivable	$	15,680		$	21,248
	Allowance for doubtful accounts		(39	)		—
	Allowance for sales returns		(561	)		(193	)
		$	15,080		$	21,055
Schedule of Allowance for Doubtful Accounts	The following table shows a rollforward of our allowance for doubtful accounts for the years ended January 31, 2015, 2014 and 2013 (in thousands):
		Balance at			Additions			Deductions			Balance at
		Beginning of			Charged to						End of Year
		Year			Expense or
					Other Accounts
	Year ended January 31, 2015	$	—		$	80		$	(41	)	$	39
	Year ended January 31, 2014		350			—			(350	)		—
	Year ended January 31, 2013		32			357			(39	)		350
Schedule of Inventory Components	The following table shows the components of inventory (in thousands):
		January 31,
		2015			2014
	Raw materials	$	3,677		$	15,326
	Finished goods		6,645			24,327
		$	10,322		$	39,653
Schedule of Components of Property and Equipment	The following table shows the components of property and equipment (in thousands):
		January 31,
		2015			2014
	Laboratory equipment	$	25,589		$	22,854
	Computer hardware and software		12,165			11,440
	Leasehold improvements		691			310
	Office furniture		326			305
			38,771			34,909
	Less: accumulated depreciation		(28,908	)		(21,256	)
		$	9,863		$	13,653
Components of Intangibles and Other Assets	The following table shows the components of intangibles and other assets (in thousands):
		January 31,
		2015			2014
	Licensed OEM software	$	6,086		$	604
	Deferred borrowing costs		4,032			—
	Cost method investments		—			3,470
	Other		688			695
		$	10,806		$	4,769
Schedule of Components of Accrued Liabilities	The following table shows the components of accrued liabilities (in thousands):
		January 31,
		2015			2014
	Compensation and benefits	$	9,036		$	10,805
	Purchase commitments		2,328			6,661
	Accrued interest		1,700			—
	Warranty		1,262			1,223
	Restructuring charges		313			3,248
	Professional fees		101			4,635
	Customer advance from Toshiba (Note 10)		—			6,875
	Other		3,284			3,868
		$	18,024		$	37,315
Schedule of Reconciliation of Product Warranty Liability	The following table is a reconciliation of the changes in the Company’s aggregate product warranty liability (in thousands):
		Year ended January 31,
		2015			2014
	Balance, beginning of year	$	1,223		$	994
	Additions		1,301			1,663
	Settlements		(1,262	)		(1,434	)
	Balance, end of period	$	1,262		$	1,223

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Jan. 31, 2015
Fair Value Disclosures [Abstract]
Summary of Assets or Liabilities Measured at Fair Value	The following tables present, for assets or liabilities measured at fair value, the respective fair value and the classification by level of input within the fair value hierarchy (in thousands):
		January 31, 2015
		Level 1		Level 2		Level 3		Total
	Cash equivalents:
	Commercial paper	$	—	$	34,395	$	—	$	34,395
	Money market funds		24,534		—		—		24,534
	Corporate debt securities		—		6,116		—		6,116
	Total cash equivalents		24,534		40,511		—		65,045
	Short-term investments:
	Corporate debt securities		—		44,711		—		44,711
	U.S. government and agency obligations		—		7,808		—		7,808
	Municipal obligations		—		4,967		—		4,967
	Commercial paper		—		2,997		—		2,997
	Total short-term investments		—		60,483		—		60,483
		$	24,534	$	100,994	$	—	$	125,528
		January 31, 2014
		Level 1		Level 2		Level 3		Total
	Cash equivalents:
	Money market funds	$	15,229	$	—	$	—	$	15,229
	Commercial paper		—		11,099		—		11,099
	Municipal obligations		—		4,601		—		4,601
	Total cash equivalents		15,229		15,700		—		30,929
	Short-term investments:
	U.S. government and agency obligations		—		29,132		—		29,132
	Municipal obligations		—		13,841		—		13,841
	Corporate debt securities		—		8,135		—		8,135
	Commercial paper		—		7,998		—		7,998
	Total short-term investments		—		59,106		—		59,106
		$	15,229	$	74,806	$	—	$	90,035

Investments_Tables

Investments (Tables)	12 Months Ended
	Jan. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Schedule of Investments	The Company’s investments are detailed in the tables below (in thousands):
		January 31, 2015
		Amortized		Unrealized		Unrealized			Estimated
		Cost		Gains		Losses			Fair Value
	Corporate debt securities	$	44,705	$	14	$	(8	)	$	44,711
	U.S. government and agency obligations		7,807		2		(1	)		7,808
	Municipal obligations		4,964		3		—			4,967
	Commercial paper		2,997		—		—			2,997
		$	60,473	$	19	$	(9	)	$	60,483
		31-Jan-14
		Amortized		Unrealized		Unrealized			Estimated
		Cost		Gains		Losses			Fair Value
	U.S. government and agency obligations	$	29,130	$	5	$	(3	)	$	29,132
	Municipal obligations		13,833		8		—			13,841
	Corporate debt securities		8,134		4		(3	)		8,135
	Commercial paper		7,998		—		—			7,998
		$	59,095	$	17	$	(6	)	$	59,106
Amortized Cost and Fair Value of Investments by Contractual Years-to-Maturity	The amortized cost and fair value of investments held as of January 31, 2015 and 2014, by contractual years-to-maturity, are as follows (in thousands):
		January 31,
		2015				2014
		Amortized		Fair		Amortized			Fair
		Cost		Value		Cost			Value
	Due within one year	$	60,473	$	60,483	$	47,707		$	47,712
	Due within one to two years		—		—		11,388			11,394
		$	60,473	$	60,483	$	59,095		$	59,106

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	12 Months Ended
	Jan. 31, 2015
Equity [Abstract]
Summary of Convertible Preferred Stock Authorized, Issued and Outstanding, and Rights and Preferences of Respective Series Immediately Prior to Conversion into Common Stock	The following table summarizes the convertible preferred stock authorized, issued and outstanding, and the rights and preferences of the respective series immediately prior to the conversion into common stock (in thousands, except per share data):
		Shares				Liquidation		Dividend		Conversion
						Preference		Per Share		Ratio Per
		Authorized		Issued and		Per Share		Per Annum		Share
				Outstanding
	Series 1		8,797		8,796		1.28	$	0.068		0.5
	Series A		35,357		35,357		0.9		0.048		0.5
	Series B		18,265		18,264		3		0.16		0.5
	Series C		13,525		13,525		6		0.32		0.5
	Series D		35,056		19,203		8.75		0.56		0.508499
			111,000		95,145

Equity_Award_and_Employee_Comp1

Equity Award and Employee Compensation Plans (Tables)	12 Months Ended
	Jan. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Activity	The following table summarizes the stock option activity related to shares of common stock under the Company’s 2005 and 2012 Plans and the inducement awards (in thousands, except per share data):
						Outstanding Options
											Weighted-Average
			Shares						Weighted-		Remaining		Aggregate
			Available			Number of			Average		Contractual Life		Intrinsic
			for Grant			Options			Exercise Price ($)		(in years)		Value (1)
	Balances, January 31, 2012			2,594			7,061			0.94		9.29	$	12,792
	Shares authorized			10,020
	RSUs granted			(9,018	)
	RSUs forfeited			555
	Options exercised			—			(353	)		0.72
	Options forfeited			641			(641	)		1.08
	Repurchase of shares			66			—			0.2
	Balances, January 31, 2013			4,858			6,067			0.94		8.31	$	42,096
	Shares authorized			7,500
	RSUs granted			(10,496	)
	Recovery of RSUs from net settlement			39
	RSUs forfeited			3,632
	Options granted			(1,320	)		1,320			5
	Options exercised						(1,008	)		0.61
	Options forfeited			1,149			(1,149	)		2.13
	Repurchase of shares			97			—
	Balances, January 31, 2014			5,459			5,230			1.43		7.23	$	19,770
	Shares authorized, including 6,250 shares from inducement awards			10,403
	RSUs granted			(4,572	)
	Recovery of RSUs from net settlement			790
	RSUs forfeited			3,601
	Options granted			(9,371	)		9,371			3.99
	Options exercised			—			(1,648	)		1.02
	Options forfeited			304			(304	)		0.25
	Balances, January 31, 2015			6,614			12,649			3.35		7.25	$	34,255
	Options vested and expected to vest - January 31, 2015						6,475		$	4.02		7.28	$	390
	Options exercisable – January 31, 2015						4,368		$	2.08		7.25	$	7,710
	-1	Aggregate intrinsic value is based on the common stock price at each respective date presented.
Summary of Outstanding and Exercisable Options under Stock Plans	The following table summarizes additional information regarding outstanding and exercisable options under the Stock Plans at January 31, 2015 (in thousands, except per share data):
			Options Outstanding
	Weighted-Average		Number			Weighted-			Number
	Exercise Price($)		Outstanding			Average Remaining			Exercisable
						Contractual Life (years)
	0.002			30			4.45			30
	0.14			844			5.86			844
	0.5			30			6.23			30
	1.42			1,755			6.54			1,754
	3.07 - 3.75			5,548			8.33			1,710
	4.28			4,442			6.47			—
				12,649						4,368
Summary of Restricted Stock Units Activity	The table below summarizes the RSU activity under the Company’s 2005 and 2012 Plans (in thousands, except per share data):
			Number			Weighted-			Aggregate
			of RSUs			Average			Intrinsic
			Outstanding			Grant Date			Value (1)
						Fair Value
	Balance, January 31, 2012			—		$	—		$	—
	RSUs granted			9,018			6.2
	RSUs forfeited			(555	)		4.88
	Balance, January 31, 2013			8,463			6.52		$	63,469
	RSUs granted			10,496			6.35
	RSUs vested			(250	)		6.87
	RSUs forfeited			(3,632	)		7.46
	Balance, January 31, 2014			15,077			6.09		$	56,990
	RSUs granted			4,572			4.16
	RSUs vested			(9,199	)		6.12
	RSUs forfeited			(3,601	)		5.57
	Balance, January 31, 2015			6,849		$	4.71		$	26,299
		-1	Aggregate intrinsic value is based on the common stock price at each respective date presented.

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Jan. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Assumptions to Estimated Fair Value of Options and Purchase Rights under ESPP	The Company used the following assumptions for its employee stock option and ESPP grants:
			Year Ended January 31,
	Employee stock options		2015	2014		2013 (1)
	Expected life of options (in years)		4.6 - 7.0	3.5 - 4.6			—
	Expected volatility		47% - 49%	45% - 50%			—
	Risk-free interest rate		1.4% - 2.1%	0.9% - 1.5%			—
	Dividend yield		—	—  %			—
		-1	No stock options were granted during fiscal 2013.
			Year Ended January 31,
	Employee stock purchase plan		2015	2014				2013 (1)
	Expected life (in years)		0.5		2.18				—
	Expected volatility		44% - 51%		45.6	%			—
	Risk-free interest rate		0.1% - 0.2%		0.12	%			—
	Dividend yield		—  %		—	%			—
		-1	The ESPP plan was established in fiscal 2014.

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Jan. 31, 2015
Income Tax Disclosure [Abstract]
Components of Loss before Provision for Income Taxes	The components of loss before provision for income taxes are as follows (in thousands):
		Year Ended January 31,
		2015			2014			2013
	United States	$	(109,342	)	$	(150,146	)	$	(109,311	)
	Foreign		562			413			306
	Total	$	(108,780	)	$	(149,733	)	$	(109,005	)
Components of Income Tax Expense Computed by Federal Statutory Income Tax Rate	The Company’s tax provision for the years ended January 31, 2015, 2014 and 2013 consists of state and foreign taxes. Income tax expense differed from the amounts computed by applying the federal statutory income tax rate of 35% to pretax loss for the years ended January 31, 2015, 2014 and 2013, respectively, as result of the following (in thousands):
		Year Ended January 31,
		2015			2014			2013
	Federal tax at statutory rate	$	(38,073	)	$	(52,406	)	$	(37,021	)
	Loss not being benefited		32,422			55,506			37,320
	Nondeductible expenses		7,601			470			1,559
	State taxes		7			11			6
	Nondeductible interest on convertible notes		—			(1,751	)		10
	Research credits		(1,834	)		(1,754	)		(1,777	)
		$	123		$	76		$	97
Schedule of Tax Effects of Temporary Differences and Carryforwards that Give Rise to Significant Portions of Deferred Tax Assets and Liabilities	The tax effects of temporary differences and carryforwards that give rise to significant portions of the Company’s deferred tax assets and liabilities related to the following (in thousands):
		January 31,
		2015			2014
	Net operating loss carryforwards	$	84,222		$	56,529
	Depreciation and amortization		49,251			39,700
	Tax credits and other		12,441			7,755
	Inventory valuations		8,730			3,854
	Accrual and reserve		7,476			5,516
	Stock-based compensation		4,856			18,031
	Gross deferred tax assets		166,976			131,385
	Valuation allowance		(166,976	)		(131,385	)
	Net deferred tax assets (liabilities)	$	—		$	—
Gross Unrecognized Tax Benefits	The following table reflects changes in the gross unrecognized tax benefits (in thousands):
		January 31,
		2015			2014			2013
	Gross unrecognized tax benefits-beginning of year	$	4,048		$	2,444		$	932
	Net decreases related to prior year tax positions		(8	)		(122	)		(106	)
	Increases related to current year tax positions		1,649			1,726			1,618
	Gross unrecognized tax benefits-end of year	$	5,689		$	4,048		$	2,444

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Jan. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Lease Payments under Operating Leases	Future minimum lease payments under the Company’s operating leases as of January 31, 2015, are as follows (in thousands):
		Amount
	Fiscal years ending January 31:
	2016	$	3,896
	2017		3,615
	2018		294
		$	7,805

Restructuring_Charges_Tables

Restructuring Charges (Tables)	12 Months Ended
	Jan. 31, 2015
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Charges	A summary of the restructuring activities is as follows (in thousands):
		Severance			Excess Facility			Impairment			Other			Total
		and Related			Charges			of Assets			Restructuring
		Charges									Charges
	Balance January 31, 2013	$	—		$	—		$	—		$	—		$	—
	Restructuring provision		2,728			511			1,231			399			4,869
	Payments and other adjustments		(357	)		—			(1,231	)		(33	)		(1,621	)
	Balance January 31, 2014		2,371			511			—			366			3,248
	Restructuring provision		1,185			1,810			—			67			3,062
	Payments		(3,556	)		(1,057	)		—			(433	)		(5,046	)
	Balance January 31, 2015	$	—		$	1,264		$	—		$	—			1,264
	Less: non-current portion														(951	)
	Current portion of restructuring accrual													$	313

Segment_Information_Tables

Segment Information (Tables)	12 Months Ended
	Jan. 31, 2015
Segment Reporting [Abstract]
Schedule of Revenue and Property and Equipment by Geographic Area	Revenue by geography is based on the billing address of the customer. The following table sets forth revenue and property and equipment by geographic area (in thousands):
		Year Ended January 31,
		2015		2014		2013
	Revenue
	Americas:
	United States	$	48,247	$	66,502	$	56,229
	Other Americas		402		425		543
			48,649		66,927		56,772
	Europe:
	United Kingdom		5,807		7,491		5,270
	Other Europe		12,796		9,003		4,356
			18,603		16,494		9,626
	Asia Pacific:		11,723		24,235		7,400
		$	78,975	$	107,656	$	73,798
		January 31,
		2015		2014
	Property and Equipment
	United States	$	9,653	$	13,232
	Europe		204		415
	Asia Pacific		6		6
		$	9,863	$	13,653

Net_Loss_Per_Share_Tables

Net Loss Per Share (Tables)	12 Months Ended
	Jan. 31, 2015
Earnings Per Share [Abstract]
Schedule of Computation of Historical Basic and Diluted Net Loss Per Share	The following table sets forth the computation of historical basic and diluted net loss per share (in thousands, except per share data):
		Year Ended January 31,
		2015			2014			2013
	Numerator:
	Net loss	$	(108,903	)	$	(149,809	)	$	(109,102	)
	Denominator:
	Weighted average common shares outstanding		90,994			38,804			15,443
	Less: Weighted average unvested common shares subject to repurchase		35			213			1,819
	Weighted average shares used to compute net loss per share of common stock, basic and diluted		90,959			38,591			13,624
	Net loss per share of common stock, basic and diluted	$	(1.20	)	$	(3.88	)	$	(8.01	)
Schedule of Common Stock Equivalents Excluded from Computation of Diluted Net Loss Per Share	Since the Company experienced losses for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods. The following potential common stock equivalents that could potentially dilute net loss per share in the future were excluded from the computation of diluted net loss per share because including them would have been anti-dilutive for the periods presented (in thousands):
		Year Ended January 31,
		2015			2014			2013
	Convertible senior notes (on an as-converted basis)		21,352			—			—
	Shares subject to outstanding common stock options and restricted stock units		19,498			20,307			14,529
	Warrants related to common stock		164			84			—
	Convertible preferred stock (on an as converted basis)		—			—			45,858
	Common stock subject to repurchase		—			70			356
			41,014			20,461			60,743

Convertible_Senior_Notes_Line_1

Convertible Senior Notes, Line of Credit and Debt Facility (Tables) (Convertible Notes Payable [Member])	12 Months Ended
	Jan. 31, 2015
Convertible Notes Payable [Member]
Reconciliation of Aggregate Convertible Notes Payable Liability	The following table is a reconciliation of the changes in the Company’s aggregate convertible notes payable liability (in thousands, except for per share data):
		Notes Value			Shares		Conversion
							Price per Share
	Balance at January 31, 2012	$	688
	Issued		8,698
	Accrued interest		29
	Converted into Series D convertible preferred stock		(9,415	)		1569		6
	Balance at January 31, 2013		—
	Issued		5,165
	Accrued interest		43
	Converted into common stock		(5,203	)		585		9
	Balance at January 31, 2014	$	—

Organization_and_Summary_of_Si3

Organization and Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Cash and cash equivalents	$93,432,000	$40,273,000	$17,378,000	$22,604,000
Sale of PCIe product line, obligated to maintain escrow balance	2,300,000
Escrow deposit, term	1 year
Capitalized internal software development costs	0
Advertising expenses recognized	1,600,000	600,000	1,000,000
Impairment on cost-method investments	3,500,000	700,000	0
Net carrying value of investments
Products warranty period	3 years
Minimum [Member] | Support Services [Member]
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Revenue recognition term	1 year
Maximum [Member] | Support Services [Member]
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Revenue recognition term	3 years
Restricted Stock Units (RSUs) [Member]
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Restricted stock units vesting period	4 years
Capitalized Equipment [Member]
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives	2 years
Computer Hardware and Software [Member]
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives	3 years
Total Revenue [Member]
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Revenue by major customer	10.00%
Gross Accounts Receivable [Member]
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Revenue by major customer	10.00%

Organization_and_Summary_of_Si4

Organization and Summary of Significant Accounting Policies - Summary of Customers Accounted as Percentage of Total Revenue and Accounts Receivable (Detail)	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Total Revenue [Member]
Concentration Risk [Line Items]
Percentage of customers accounted for total revenue and accounts receivable	10.00%
Total Revenue [Member] | Enterprise Vision Technology [Member]
Concentration Risk [Line Items]
Percentage of customers accounted for total revenue and accounts receivable	10.00%
Total Revenue [Member] | Toshiba Corporation [Member]
Concentration Risk [Line Items]
Percentage of customers accounted for total revenue and accounts receivable		12.00%
Total Revenue [Member] | CompSec [Member]
Concentration Risk [Line Items]
Percentage of customers accounted for total revenue and accounts receivable			12.00%
Gross Accounts Receivable [Member]
Concentration Risk [Line Items]
Percentage of customers accounted for total revenue and accounts receivable	10.00%
Gross Accounts Receivable [Member] | Arrow ECS [Member]
Concentration Risk [Line Items]
Percentage of customers accounted for total revenue and accounts receivable	19.00%
Gross Accounts Receivable [Member] | Commtech Innovative Solutions [Member]
Concentration Risk [Line Items]
Percentage of customers accounted for total revenue and accounts receivable		27.00%
Gross Accounts Receivable [Member] | Avnet, Inc. [Member]
Concentration Risk [Line Items]
Percentage of customers accounted for total revenue and accounts receivable		15.00%

Balance_Sheet_Components_Sched

Balance Sheet Components - Schedule of Components of Accounts Receivable (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Receivables [Abstract]
Accounts receivable	$15,680	$21,248
Allowance for doubtful accounts	-39		-350	-32
Allowance for sales returns	-561	-193
Accounts receivable, net	$15,080	$21,055

Balance_Sheet_Components_Sched1

Balance Sheet Components - Schedule of Allowance for Doubtful Accounts (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at Beginning of Year		$350	$32
Additions Charged to Expense or Other Accounts	80		357
Deductions	-41	-350	-39
Balance at End of Year	$39		$350

Balance_Sheet_Components_Sched2

Balance Sheet Components - Schedule of Inventory Components (Detail) (USD $)	Jan. 31, 2015	Jan. 31, 2014
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]
Raw materials	$3,677	$15,326
Finished goods	6,645	24,327
Inventory	$10,322	$39,653

Balance_Sheet_Components_Addit

Balance Sheet Components - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended		12 Months Ended
	Dec. 31, 2013	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Balance Sheet Details [Line Items]
Inventory reserves		$23,200,000	$6,700,000	$23,200,000	$6,700,000
Inventory provision	9,200,000
Increase in inventory reserve	3,400,000
Increase in accrued liabilities	5,800,000	2,300,000		-17,097,000	15,413,000	7,540,000
Provision for excess inventory			1,200,000		1,800,000
Provision for excess and obsolete inventory		19,900,000		20,961,000	10,973,000	1,052,000
Increase in inventory reserve		17,600,000
Depreciation expense				11,000,000	12,600,000	9,000,000
Capitalized amount		6,086,000	604,000	6,086,000	604,000
Minimum [Member] | Flash Storage Platform Product [Member]
Balance Sheet Details [Line Items]
Estimated useful life of product				10 years
Licensed OEM software [Member]
Balance Sheet Details [Line Items]
Capitalized amount		$6,000,000		$6,000,000
Licensed OEM software [Member] | Minimum [Member]
Balance Sheet Details [Line Items]
Estimated useful life of intangible assets				10 years

Balance_Sheet_Components_Sched3

Balance Sheet Components - Schedule of Components of Property and Equipment (Detail) (USD $)	Jan. 31, 2015	Jan. 31, 2014
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$38,771	$34,909
Less: accumulated depreciation	-28,908	-21,256
Property and Equipment, Net	9,863	13,653
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	25,589	22,854
Computer Hardware and Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	12,165	11,440
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	691	310
Office Furniture [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$326	$305

Balance_Sheet_Components_Compo

Balance Sheet Components - Components of Intangibles and Other Assets (Detail) (USD $)	Jan. 31, 2015	Jan. 31, 2014
In Thousands, unless otherwise specified
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Licensed OEM software	$6,086	$604
Deferred borrowing costs	4,032
Cost method investments		3,470
Other	688	695
Intangibles and other assets	$10,806	$4,769

Balance_Sheet_Components_Sched4

Balance Sheet Components - Schedule of Components of Accrued Liabilities (Detail) (USD $)	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
In Thousands, unless otherwise specified
Payables and Accruals [Abstract]
Compensation and benefits	$9,036	$10,805
Purchase commitments	2,328	6,661
Accrued interest	1,700
Warranty	1,262	1,223	994
Restructuring charges	313	3,248
Professional fees	101	4,635
Customer advance from Toshiba (Note 10)	0	6,875
Other	3,284	3,868
Accrued liabilities	$18,024	$37,315

Balance_Sheet_Components_Sched5

Balance Sheet Components - Schedule of Reconciliation of Product Warranty Liability (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014
Payables and Accruals [Abstract]
Balance, beginning of year	$1,223	$994
Additions	1,301	1,663
Settlements	-1,262	-1,434
Balance, end of period	$1,262	$1,223

Fair_Value_Measurements_Summar

Fair Value Measurements - Summary of Assets or Liabilities Measured at Fair Value (Detail) (USD $)	Jan. 31, 2015	Jan. 31, 2014
In Thousands, unless otherwise specified
Cash equivalents:
Total cash equivalents	$65,045	$30,929
Short-term investments:
Total short term investments	60,483	59,106
Total assets measured at fair value	125,528	90,035
Money Market Funds [Member]
Cash equivalents:
Total cash equivalents	24,534	15,229
Commercial Paper [Member]
Cash equivalents:
Total cash equivalents	34,395	11,099
Short-term investments:
Total short term investments	2,997	7,998
Municipal Obligations [Member]
Cash equivalents:
Total cash equivalents		4,601
Short-term investments:
Total short term investments	4,967	13,841
Corporate Debt Securities [Member]
Cash equivalents:
Total cash equivalents	6,116
Short-term investments:
Total short term investments	44,711	8,135
U.S. Government and Agency Obligations [Member]
Short-term investments:
Total short term investments	7,808	29,132
Level 1 [Member]
Cash equivalents:
Total cash equivalents	24,534	15,229
Short-term investments:
Total assets measured at fair value	24,534	15,229
Level 1 [Member] | Money Market Funds [Member]
Cash equivalents:
Total cash equivalents	24,534	15,229
Level 2 [Member]
Cash equivalents:
Total cash equivalents	40,511	15,700
Short-term investments:
Total short term investments	60,483	59,106
Total assets measured at fair value	100,994	74,806
Level 2 [Member] | Commercial Paper [Member]
Cash equivalents:
Total cash equivalents	34,395	11,099
Short-term investments:
Total short term investments	2,997	7,998
Level 2 [Member] | Municipal Obligations [Member]
Cash equivalents:
Total cash equivalents		4,601
Short-term investments:
Total short term investments	4,967	13,841
Level 2 [Member] | Corporate Debt Securities [Member]
Cash equivalents:
Total cash equivalents	6,116
Short-term investments:
Total short term investments	44,711	8,135
Level 2 [Member] | U.S. Government and Agency Obligations [Member]
Short-term investments:
Total short term investments	$7,808	$29,132

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Detail) (USD $)	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Fair Value Disclosures [Abstract]
Financial assets measured at fair value on a recurring basis			$0
Financial liabilities measured at fair value on a recurring basis			0
Transfer of assets measured at fair value between Level 1 and Level 2	0	0
Transfer of liabilities measured at fair value between Level 1 and Level 2	0	0
Financial assets measured at fair value on a nonrecurring basis	0	0
Financial liabilities measured at fair value on a nonrecurring basis	$0	$0

Investments_Schedule_of_Invest

Investments - Schedule of Investments (Detail) (USD $)	Jan. 31, 2015	Jan. 31, 2014
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$60,473	$59,095
Unrealized Gains	19	17
Unrealized Losses	-9	-6
Estimated Fair Value	60,483	59,106
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,997	7,998
Estimated Fair Value	2,997	7,998
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	44,705	8,134
Unrealized Gains	14	4
Unrealized Losses	-8	-3
Estimated Fair Value	44,711	8,135
U.S. Government and Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	7,807	29,130
Unrealized Gains	2	5
Unrealized Losses	-1	-3
Estimated Fair Value	7,808	29,132
Municipal Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	4,964	13,833
Unrealized Gains	3	8
Estimated Fair Value	$4,967	$13,841

Investments_Amortized_Cost_and

Investments - Amortized Cost and Fair Value of Investments by Contractual Years-to-Maturity (Detail) (USD $)	Jan. 31, 2015	Jan. 31, 2014
In Thousands, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]
Amortized Cost, Due within one year	$60,473	$47,707
Amortized Cost, Due within one to two years		11,388
Amortized Cost	60,473	59,095
Fair Value, Due within one year	60,483	47,712
Fair Value, Due within one to two years		11,394
Fair Value	$60,483	$59,106

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Detail) (USD $)	12 Months Ended	1 Months Ended	0 Months Ended
	Jan. 31, 2015	Aug. 31, 2014	Sep. 12, 2013	Oct. 02, 2013	Jan. 31, 2014	Jul. 31, 2013
Class of Stock [Line Items]
Reverse stock split	Two-for-one reverse stock split to its common stock for all stockholders of record as of September 12, 2013 with an automatic adjustment to the conversion ratio of the outstanding shares of convertible preferred stock to reflect the same reverse stock split ratio upon conversion of the convertible preferred stock into common stock. Based on the adjusted conversion ratio, two outstanding shares of preferred stock converted into one share of common stock, except for Series D convertible preferred stock for which every two shares converted into 1.016998402 shares of common stock. All information related to common stock, stock options, RSUs and earnings per share for prior periods has been retroactively adjusted to give effect to the two-for-one reverse stock split.
Common stock, shares issued	93,872,000				83,057,000
Common stock, shares authorized	1,000,000,000				1,000,000,000
Common stock, par value	$0.00				$0.00
Common stock, shares outstanding	93,872,000				83,057,000
Voting rights	One vote per share
Warrants expiration date	31-Jan-18
Silicon Valley Bank [Member]
Class of Stock [Line Items]
Common stock, par value		$0.00
Credit facility		$40,000,000
Warrants to purchase common stock		79,323
Warrant, exercise price per share		$3.78
Warrant, expiration date		2019-08
Common Stock [Member]
Class of Stock [Line Items]
Conversion of preferred stock, shares issued			1
Common Stock [Member] | Secondary Offering [Member]
Class of Stock [Line Items]
Conversion of preferred stock, shares issued			1.016998402
Series D [Member]
Class of Stock [Line Items]
Warrant, exercise price per share						$6
Warrants issued						131,875
Series D Preferred Stock [Member]
Class of Stock [Line Items]
Convertible preferred stock converted to common stock			2
Convertible Preferred Stock [Member] | Secondary Offering [Member]
Class of Stock [Line Items]
Convertible preferred stock converted to common stock			2
Common Stock [Member]
Class of Stock [Line Items]
Convertible preferred stock converted to common stock	47,700,000
IPO [Member]
Class of Stock [Line Items]
Common stock, shares issued				18,000,000
Initial public offering, price per share				$9
Total gross proceeds from initial public offering				162,000,000
Aggregate net proceeds from initial public offering				$145,800,000
IPO [Member] | Common Stock [Member]
Class of Stock [Line Items]
Warrant, exercise price per share						$11.80
Warrants issued						84,278

Stockholders_Equity_Summary_of

Stockholders' Equity - Summary of Convertible Preferred Stock Authorized, Issued and Outstanding, and Rights and Preferences of Respective Series Immediately Prior to Conversion into Common Stock (Detail) (USD $)	Jan. 31, 2015	Jan. 31, 2014	Oct. 02, 2013
In Thousands, except Per Share data, unless otherwise specified
Temporary Equity [Line Items]
Preferred stock, shares authorized	10,000	10,000
Convertible preferred stock, Conversion Ratio Per Share	$0.00	$0.00
Series 1 [Member]
Temporary Equity [Line Items]
Preferred stock, shares authorized			8,797
Convertible preferred stock, Shares, Issued and Outstanding			8,796
Convertible preferred stock, Liquidation Preference Per Share			$1.28
Convertible preferred stock, Dividend Per Share Per Annum			$0.07
Convertible preferred stock, Conversion Ratio Per Share			$0.50
Series A [Member]
Temporary Equity [Line Items]
Preferred stock, shares authorized			35,357
Convertible preferred stock, Shares, Issued and Outstanding			35,357
Convertible preferred stock, Liquidation Preference Per Share			$0.90
Convertible preferred stock, Dividend Per Share Per Annum			$0.05
Convertible preferred stock, Conversion Ratio Per Share			$0.50
Series B [Member]
Temporary Equity [Line Items]
Preferred stock, shares authorized			18,265
Convertible preferred stock, Shares, Issued and Outstanding			18,264
Convertible preferred stock, Liquidation Preference Per Share			$3
Convertible preferred stock, Dividend Per Share Per Annum			$0.16
Convertible preferred stock, Conversion Ratio Per Share			$0.50
Series C [Member]
Temporary Equity [Line Items]
Preferred stock, shares authorized			13,525
Convertible preferred stock, Shares, Issued and Outstanding			13,525
Convertible preferred stock, Liquidation Preference Per Share			$6
Convertible preferred stock, Dividend Per Share Per Annum			$0.32
Convertible preferred stock, Conversion Ratio Per Share			$0.50
Series D [Member]
Temporary Equity [Line Items]
Preferred stock, shares authorized			35,056
Convertible preferred stock, Shares, Issued and Outstanding			19,203
Convertible preferred stock, Liquidation Preference Per Share			$8.75
Convertible preferred stock, Dividend Per Share Per Annum			$0.56
Convertible preferred stock, Conversion Ratio Per Share			$0.51
Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Preferred stock, shares authorized			111,000
Convertible preferred stock, Shares, Issued and Outstanding			95,145

Equity_Award_and_Employee_Comp2

Equity Award and Employee Compensation Plans - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended
In Millions, except Share data, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013	Feb. 28, 2015	Jan. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding	12,649,000	5,230,000	6,067,000		7,061,000
Shares forfeited	304,000	1,149,000	641,000
Weighted average grant date fair value of options granted	$1.74
Total intrinsic value of options exercised	$5
Aggregate intrinsic value of vested RSUs	$37
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increased share reserve	600,000
Shares authorized	1,600,000
Employee Stock Purchase Plan, shares have been reserved for issuance under the 2012 Purchase Plan	1,000,000
Employee Stock Purchase Plan, increase in number of shares available for issuance under the 2012 Purchase Plan	0.75%
Employee Stock Purchase Plan, maximum percentage of annual salary that an employee is permitted to utilize	15.00%
Employee Stock Purchase Plan, number of offering periods	2
Employee Stock Purchase Plan, price of each shares issued is lower of the fair value per share of common stock	85.00%
2005 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share awards and options expiration period	10 years
Stock plan expiration date	2-Oct-13
2012 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share awards and options expiration period	7 years
Share awards and options vesting period	4 years
Shares outstanding	11,652,856
Increase in shares authorized reserve, description	The reserve will automatically increase on the first day of each fiscal year in an amount equal to the lesser of (i) 5% of the outstanding shares of common stock on the last day of the immediately preceding fiscal year or (ii) a lesser amount determined by the Board of Directors.
Increased share reserve	4,699,362
Shares authorized	16,352,218
Inducement Grant Stock Option Agreements [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares related to options issued	6,250,000
Subsequent Events [Member] | Inducement Grant Stock Option Agreements [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares forfeited				1,250,000
Minimum [Member] | 2005 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share awards and options vesting period	3 years
Minimum [Member] | 2012 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of stock appreciation rights granted	100.00%
Maximum [Member] | Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Stock Purchase Plan, duration of offering period	24 months
Employee Stock Purchase Plan, frequency of purchase date	6 months
Maximum [Member] | 2005 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share awards and options vesting period	4 years
Employee 401(k) Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee compensation plan, percentage of maximum contribution by employees	90.00%
Non-Employee Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, Company granted option to purchase common stock	0	5,000	0
Share based compensation, Company granted option to purchase restricted stock	230,098	6,000	177,500

Equity_Award_and_Employee_Comp3

Equity Award and Employee Compensation Plans - Summary of Stock Option Activity (Detail) (USD $)	1 Months Ended	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Jan. 31, 2014	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Available for Grant, Beginning balance		5,459,000	4,858,000	2,594,000
Weighted-Average Exercise Price, Options granted		$3.99	$5
Shares Available for Grant, Ending balance	5,459,000	6,614,000	5,459,000	4,858,000	2,594,000
Number of Options, Beginning balance		5,230,000	6,067,000	7,061,000
Number of Options, RSUs granted		-4,572,000	-10,496,000	-9,018,000
Number of Options, RSUs forfeited		3,601,000	3,632,000	555,000
Number of Options, Options granted	377,000	9,371,000	1,320,000
Number of Options, Options exercised		-1,648,000	-1,008,000	-353,000
Number of Options, Options forfeited		-304,000	-1,149,000	-641,000
Number of Options, Ending balance	5,230,000	12,649,000	5,230,000	6,067,000	7,061,000
Weighted-Average Exercise Price, Beginning balance		$1.43	$0.94	$0.94
Number of Options, Options vested and expected to vest		6,475,000
Number of Options, Options exercisable		4,368,000
Weighted-Average Exercise Price, Options exercised		$1.02	$0.61	$0.72
Weighted-Average Exercise Price, Options forfeited		$0.25	$2.13	$1.08
Weighted-Average Exercise Price, Repurchase of shares				$0.20
Weighted-Average Exercise Price, Ending balance	$1.43	$3.35	$1.43	$0.94	$0.94
Aggregate Intrinsic Value, Beginning balance		$19,770	$42,096	$12,792
Weighted-Average Exercise Price, Options vested and expected to vest		$4.02
Aggregate Intrinsic Value, Ending balance	19,770	34,255	19,770	42,096	12,792
Weighted-Average Exercise Price, Options exercisable		$2.08
Aggregate Intrinsic Value, Options vested and expected to vest		390
Weighted-Average Remaining Contractual Life (in years)		7 years 3 months	7 years 2 months 23 days	8 years 3 months 22 days	9 years 3 months 15 days
Aggregate Intrinsic Value, Options exercisable		$7,710
Weighted-Average Remaining Contractual Life (in years), Options vested and expected to vest		7 years 3 months 11 days
Weighted-Average Remaining Contractual Life (in years), Options exercisable		7 years 3 months
Shares Available for Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Available for Grant, Shares authorized			7,500,000	10,020,000
Number of Options, Shares authorized		10,403,000
Number of Options, Options granted		9,371,000	1,320,000
Shares Available for Grant, Options forfeited		304,000	1,149,000	641,000
Number of Options, Repurchase of shares			97,000	66,000
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Recovery of RSUs from net settlement		0	0
Restricted Stock Units (RSUs) [Member] | Shares Available for Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, RSUs granted		-4,572,000	-10,496,000	-9,018,000
Shares Available for Grant, Recovery of RSUs from net settlement		790,000	39,000
Number of Options, RSUs forfeited		3,601,000	3,632,000	555,000

Equity_Award_and_Employee_Comp4

Equity Award and Employee Compensation Plans - Summary of Stock Option Activity (Parenthetical) (Detail) (Inducement Grant Stock Option Agreements [Member])	Jan. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Available for Grant, Shares from inducement awards	6,250,000
Shares Available for Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Available for Grant, Shares from inducement awards	6,250,000

Equity_Award_and_Employee_Comp5

Equity Award and Employee Compensation Plans - Summary of Outstanding and Exercisable Options under Stock Plans (Detail) (USD $)	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-average exercise prices	$3.35	$1.43	$0.94	$0.94
Options outstanding, Number outstanding	12,649,000	5,230,000	6,067,000	7,061,000
Options outstanding, Weighted-average remaining contractual life (years)	7 years 3 months	7 years 2 months 23 days	8 years 3 months 22 days	9 years 3 months 15 days
Number exercisable	4,368,000
0.002 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-average exercise prices	$0.00
Options outstanding, Number outstanding	30,000
Options outstanding, Weighted-average remaining contractual life (years)	4 years 5 months 12 days
Number exercisable	30,000
0.14 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-average exercise prices	$0.14
Options outstanding, Number outstanding	844,000
Options outstanding, Weighted-average remaining contractual life (years)	5 years 10 months 10 days
Number exercisable	844,000
0.5 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-average exercise prices	$0.50
Options outstanding, Number outstanding	30,000
Options outstanding, Weighted-average remaining contractual life (years)	6 years 2 months 23 days
Number exercisable	30,000
1.42 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-average exercise prices	$1.42
Options outstanding, Number outstanding	1,755,000
Options outstanding, Weighted-average remaining contractual life (years)	6 years 6 months 15 days
Number exercisable	1,754,000
3.07 - 3.75 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, Number outstanding	5,548,000
Options outstanding, Weighted-average remaining contractual life (years)	8 years 3 months 29 days
Number exercisable	1,710,000
4.28 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-average exercise prices	$4.28
Options outstanding, Number outstanding	4,442,000
Options outstanding, Weighted-average remaining contractual life (years)	6 years 5 months 19 days
Minimum [Member] | 3.07 - 3.75 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-average exercise prices	$3.07
Maximum [Member] | 3.07 - 3.75 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-average exercise prices	$3.75

Equity_Award_and_Employee_Comp6

Equity Award and Employee Compensation Plans - Summary of Restricted Stock Units Activity (Detail) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of RSUs Outstanding, Beginning balance	15,077	8,463
Number of RSUs Outstanding, granted	4,572	10,496	9,018
Number of RSUs Outstanding, vested	-9,199	-250
Number of RSUs Outstanding, forfeited	-3,601	-3,632	-555
Number of RSUs Outstanding, Ending balance	6,849	15,077	8,463
Weighted-Average Grant Date Fair Value, Beginning balance	$6.09	$6.52
Weighted-Average Grant Date Fair Value, granted	$4.16	$6.35	$6.20
Weighted-Average Grant Date Fair Value, vested	$6.12	$6.87
Weighted-Average Grant Date Fair Value, forfeited	$5.57	$7.46	$4.88
Weighted-Average Grant Date Fair Value, Ending balance	$4.71	$6.09	$6.52
Aggregate Intrinsic Value	$26,299	$56,990	$63,469

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
	Jan. 31, 2014	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation not yet recognized		$29,300,000
Stock-based compensation not yet recognized, expects to amortize in fiscal 2016		14,700,000
Stock-based compensation not yet recognized, expects to amortize in fiscal 2017		8,400,000
Stock-based compensation not yet recognized, expects to amortize in fiscal 2018		4,900,000
Stock-based compensation not yet recognized, expects to amortize in fiscal 2019		1,300,000
Capitalized stock-based compensation expense		0
Recognized stock based compensation of ESPP		800,000	400,000
Stock-based compensation of non-employee awards		800,000	800,000	2,500,000
Stock-based compensation expense		22,966,000	36,399,000	17,923,000
Stock options grants in period	377,000	9,371,000	1,320,000
Incremental charge related to modification			300,000
Exercise Price $5.97 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise prices range	5.97
Exercise Price $8.82 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise prices range	8.82
Exercise Price $3.49 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise prices range	3.49
Non-Executive Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options originally granted, number of employees	51		51
Non-Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional share-based compensation expense			14,600,000
Non-Employee Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options issued			225,000
Stock-based compensation expense			$2,000,000

StockBased_Compensation_Schedu

Stock-Based Compensation - Schedule of Assumptions to Estimated Fair Value of Options and Purchase Rights under ESPP (Detail)	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Employee Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of options (in years)			0 years
Expected volatility, Minimum	47.00%	45.00%
Expected volatility, Maximum	49.00%	50.00%
Risk-free interest rate, Minimum	1.40%	0.90%
Risk-free interest rate, Maximum	2.10%	1.50%
Dividend yield	0.00%	0.00%	0.00%
Employee Stock Options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of options (in years)	4 years 7 months 6 days	3 years 6 months
Employee Stock Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of options (in years)	7 years	4 years 7 months 6 days
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of options (in years)	6 months	2 years 2 months 5 days	0 years
Expected volatility		45.60%
Expected volatility, Minimum	44.00%
Expected volatility, Maximum	51.00%
Risk-free interest rate		0.12%
Risk-free interest rate, Minimum	0.10%
Risk-free interest rate, Maximum	0.20%
Dividend yield	0.00%	0.00%	0.00%

StockBased_Compensation_Schedu1

Stock-Based Compensation - Schedule of Assumptions to Estimated Fair Value of Options and Purchase Rights under ESPP (Parenthetical) (Detail)	1 Months Ended	12 Months Ended
	Jan. 31, 2014	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options grants in period	377,000	9,371,000	1,320,000
Employee Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options grants in period				0

Income_Taxes_Components_of_Los

Income Taxes - Components of Loss before Provision for Income Taxes (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Income Tax Disclosure [Abstract]
United States	($109,342)	($150,146)	($109,311)
Foreign	562	413	306
Loss before income taxes	($108,780)	($149,733)	($109,005)

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Operating Loss Carryforwards [Line Items]
Federal statutory income tax rate	35.00%	35.00%	35.00%
Valuation allowance	$166,976,000	$131,385,000
Net change in valuation allowance	35,600,000	58,200,000
Income taxes payable	116,000	115,000
Federal [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carry forwards	232,700,000
Research and development tax credit carryforwards	9,000,000
State [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carry forwards	87,700,000
Research and development tax credit carryforwards	$10,000,000

Income_Taxes_Components_of_Inc

Income Taxes - Components of Income Tax Expense Computed by Federal Statutory Income Tax Rate (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Income Tax Disclosure [Abstract]
Federal tax at statutory rate	($38,073)	($52,406)	($37,021)
Loss not being benefited	32,422	55,506	37,320
Nondeductible expenses	7,601	470	1,559
State taxes	7	11	6
Nondeductible interest on convertible notes		-1,751	10
Research credits	-1,834	-1,754	-1,777
Income taxes	$123	$76	$97

Income_Taxes_Components_of_Com

Income Taxes - Components of Company's Deferred Tax Assets and Liabilities (Detail) (USD $)	Jan. 31, 2015	Jan. 31, 2014
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$84,222	$56,529
Depreciation and amortization	49,251	39,700
Tax credits and other	12,441	7,755
Inventory valuations	8,730	3,854
Accrual and reserve	7,476	5,516
Stock-based compensation	4,856	18,031
Gross deferred tax assets	166,976	131,385
Valuation allowance	-166,976	-131,385
Net deferred tax assets (liabilities)	$0	$0

Income_Taxes_Gross_Unrecognize

Income Taxes - Gross Unrecognized Tax Benefits (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Income Tax Disclosure [Abstract]
Gross unrecognized tax benefits-beginning of year	$4,048	$2,444	$932
Net decreases related to prior year tax positions	-8	-122	-106
Increases related to current year tax positions	1,649	1,726	1,618
Gross unrecognized tax benefits-end of year	$5,689	$4,048	$2,444

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended
	Nov. 26, 2013	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013	Jul. 31, 2012
	Lawsuits
Loss Contingencies [Line Items]
Number of lawsuits filed	4
Class action filing date		11/26/13
Rent expense related to operating leases		$2,400,000	$2,500,000	$2,000,000
Outstanding purchase commitments		2,300,000
Purchase commitments obligations					5,000,000
Advertising Commitment description		In June 2012, the Company entered into an agreement with the Forty Niners SC Stadium Company LLC, which was amended in April 2014. As part of the amended agreement, the Company will receive advertising and related benefits at the stadium in Santa Clara, California from 2014 through 2023 for $1.75 million per year over the 10-year term.
Advertising commitment		1,750,000
Advertising commitment agreement term		10 years
Advertising expenses recognized		1,600,000	600,000	1,000,000
Indemnification Agreement [Member]
Loss Contingencies [Line Items]
Liabilities recorded for indemnification agreements		0	0
Forty Niners SC Stadium Company LLC [Member]
Loss Contingencies [Line Items]
Advertising expenses recognized		1,200,000
Other Software Vendor [Member]
Loss Contingencies [Line Items]
Remaining purchase commitment		$3,200,000

Commitments_and_Contingencies_2

Commitments and Contingencies - Future Minimum Lease Payments under Operating Leases (Detail) (USD $)	Jan. 31, 2015
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]
2016	$3,896
2017	3,615
2018	294
Total	$7,805

Related_Party_Transactions_Add

Related Party Transactions - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013	Jul. 31, 2013	Jun. 30, 2011	Aug. 31, 2012	Sep. 30, 2013	31-May-14
Related Party Transaction [Line Items]
Common stock outstanding	93,872,000	83,057,000
Remaining contract value	$2,432,000	$12,208,000
Impairment on cost-method investments	3,500,000	700,000	0
Toshiba Corporation [Member]
Related Party Transaction [Line Items]
Common stock outstanding	9,200,000
Percentage of common stock outstanding	10.00%
Sales Agreement expiration period	2014-06
Sales Agreement renewal period	1 year
Prepayment received from related party				16,000,000
Revenue recognized related to development services	1,000,000
Remaining contract value								5,800,000
Recognized incremental cost	0	1,000,000
Toshiba Corporation [Member] | Flash Memory [Member]
Related Party Transaction [Line Items]
Sales agreement purchase percentage					70.00%
Toshiba Corporation [Member] | Development of PCIe Cards [Member]
Related Party Transaction [Line Items]
Prepayment received from related party				8,000,000
Revenue recognized related to development services		6,000,000
Toshiba Corporation [Member] | Sample PCIe Cards [Member]
Related Party Transaction [Line Items]
Prepayment received from related party				8,000,000
Revenue recognized related to development services		3,100,000
Toshiba Corporation [Member] | All Flash Array and services [Member]
Related Party Transaction [Line Items]
Revenue recognized from related party	1,600,000	4,000,000	3,600,000
Toshiba Corporation [Member] | NAND Flash Memory [Member]
Related Party Transaction [Line Items]
Purchases from related party	9,200,000	38,200,000	27,500,000
RiverMeadow Software, Inc. [Member]
Related Party Transaction [Line Items]
Revenue recognized from related party			1,400,000
Impairment on cost-method investments	3,500,000
RiverMeadow Software, Inc. [Member] | Series A-1 Convertible Preferred Stock [Member]
Related Party Transaction [Line Items]
Number of shares purchased						866,325
Consideration transferred						3,000,000
Percentage of outstanding stock purchased						9.00%
RiverMeadow Software, Inc. [Member] | Series B [Member]
Related Party Transaction [Line Items]
Number of shares purchased							118,204
Consideration transferred							$500,000

Restructuring_Charges_Addition

Restructuring Charges - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Jul. 31, 2014	Jan. 31, 2015
Reorganizations [Abstract]
Proceeds from sale of PCIe product line	$23,000	$23,000
Gain on sale of PCIe product line	$17,400	$17,448

Restructuring_Charges_Schedule

Restructuring Charges - Schedule of Restructuring Charges (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring and transition charges, beginning balance	$3,248
Restructuring provision	3,062	4,869
Payments and other adjustments		-1,621
Payments	-5,046
Restructuring and transition charges, ending balance	1,264	3,248
Less: non-current portion	-951
Current portion of restructuring accrual	313	3,248
Severance and Related Charges [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and transition charges, beginning balance	2,371
Restructuring provision	1,185	2,728
Payments and other adjustments		-357
Payments	-3,556
Restructuring and transition charges, ending balance		2,371
Excess Facility Charges [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and transition charges, beginning balance	511
Restructuring provision	1,810	511
Payments	-1,057
Restructuring and transition charges, ending balance	1,264	511
Impairment of Assets [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring provision		1,231
Payments and other adjustments		-1,231
Other Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and transition charges, beginning balance	366
Restructuring provision	67	399
Payments and other adjustments		-33
Payments	-433
Restructuring and transition charges, ending balance		$366

Segment_Information_Additional

Segment Information - Additional Information (Detail)	12 Months Ended
	Jan. 31, 2015
	Segment
Segment Reporting [Abstract]
Number of reportable segment	1
Number of operating segment	1

Segment_Information_Schedule_o

Segment Information - Schedule of Revenue and Property and Equipment by Geographic Area (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Segment Reporting Information [Line Items]
Total Revenue	$78,975	$107,656	$73,798
Property and equipment, net	9,863	13,653
United States [Member]
Segment Reporting Information [Line Items]
Total Revenue	48,247	66,502	56,229
Property and equipment, net	9,653	13,232
Other Americas [Member]
Segment Reporting Information [Line Items]
Total Revenue	402	425	543
Americas [Member]
Segment Reporting Information [Line Items]
Total Revenue	48,649	66,927	56,772
United Kingdom [Member]
Segment Reporting Information [Line Items]
Total Revenue	5,807	7,491	5,270
Other Europe [Member]
Segment Reporting Information [Line Items]
Total Revenue	12,796	9,003	4,356
Europe [Member]
Segment Reporting Information [Line Items]
Total Revenue	18,603	16,494	9,626
Property and equipment, net	204	415
Asia Pacific [Member]
Segment Reporting Information [Line Items]
Total Revenue	11,723	24,235	7,400
Property and equipment, net	$6	$6

Net_Loss_Per_Share_Schedule_of

Net Loss Per Share - Schedule of Computation of Historical Basic and Diluted Net Loss Per Share (Detail) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Dec. 31, 2013	Jan. 31, 2013
Numerator:
Net loss	($108,903)	($149,809)	($109,102)	($109,102)
Denominator:
Weighted average common shares outstanding	90,994	38,804	15,443
Less: Weighted average unvested common shares subject to repurchase	35	213	1,819
Weighted average shares used to compute net loss per share of common stock, basic and diluted	90,959	38,591	13,624	13,624
Net loss per share of common stock, basic and diluted	($1.20)	($3.88)	($8.01)	($8.01)

Net_Loss_Per_Share_Schedule_of1

Net Loss Per Share - Schedule of Common Stock Equivalents Excluded from Computation of Diluted Net Loss Per Share (Detail)	12 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from computation of diluted net loss per share	41,014	20,461	60,743
Convertible Senior Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from computation of diluted net loss per share	21,352
Shares Subject to Outstanding Common Stock Options and Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from computation of diluted net loss per share	19,498	20,307	14,529
Warrants Related to Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from computation of diluted net loss per share	164	84
Common Stock Subject to Repurchase [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from computation of diluted net loss per share		70	356
Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from computation of diluted net loss per share			45,858

Convertible_Senior_Notes_Line_2

Convertible Senior Notes, Line of Credit and Debt Facility - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended		3 Months Ended	1 Months Ended		0 Months Ended	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013	Aug. 31, 2014	Oct. 31, 2014	Jan. 31, 2015	Jul. 31, 2014	Jul. 31, 2013	Sep. 19, 2014	Oct. 31, 2014	31-May-13
							Unit		D
Debt Instrument [Line Items]
Convertible notes issued		$5,165,000	$8,698,000
Convertible notes, interest rate	6.00%					6.00%
Convertible senior notes, net	120,000,000					120,000,000
Interest and other financing expenses related to amortization of debt issuance costs	639,000	175,000
Common stock, par value	$0.00	$0.00				0.0001
Loss on extinguishment	372,000		31,000
Issuance of notes payable			8,700,000
Silicon Valley Bank [Member]
Debt Instrument [Line Items]
Credit facility				40,000,000
Warrants to purchase common stock				79,323
Warrant, expiration date				2019-08
Common stock, par value				$0.00
Warrant, exercise price per share				$3.78
Loss on extinguishment	400,000
Debt facility period	2 years
Silicon Valley Bank [Member] | Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility					20,000,000					20,000,000
Line of credit facility, interest rate description	Borrowings under this facility will bear interest at a rate per annum of either (a) the sum of (i) the Eurodollar rate plus (ii) 5.00%, or (b) the sum of (i) ABR plus (ii) 2.00%. The line of credit expires on October 24, 2016, subject to acceleration upon certain specified events of defaults.
Line of credit facility, expiration date					24-Oct-16
TriplePoint Capital LLC [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Credit facility											50,000,000
Debt facility period	1 year
Debt facility, collateral description	The facility had first secured interest in substantially all of the Company's assets and intellectual property other than $7.5 million of accounts receivable.
Debt instrument, interest rate, minimum	7.00%
Debt instrument, interest rate, maximum	13.50%
Eurodollar [Member] | Silicon Valley Bank [Member] | Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, interest rate spread					5.00%
ABR [Member] | Silicon Valley Bank [Member] | Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, interest rate spread					2.00%
Maximum [Member]
Debt Instrument [Line Items]
Percentage of revenue						80.00%
Maximum [Member] | TriplePoint Capital LLC [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Borrowing options, expiration period	5 years
Debt instrument, interest rate at period end	14.00%					14.00%
Minimum [Member] | TriplePoint Capital LLC [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Borrowing options, expiration period	3 months
Debt instrument, interest rate at period end	0.50%					0.50%
Term Loan [Member] | Silicon Valley Bank [Member]
Debt Instrument [Line Items]
Credit facility	10,000,000			10,000,000		10,000,000
Product Financing Arrangement [Member]
Debt Instrument [Line Items]
Units of product							194,000
Product financing							2,300,000
Inventory repurchase description	Five equal monthly installments
Product Financing Arrangement [Member] | Maximum [Member]
Debt Instrument [Line Items]
Transaction fees	6.00%					6.00%
Product Financing Arrangement [Member] | Minimum [Member]
Debt Instrument [Line Items]
Transaction fees	4.50%					4.50%
Line of Credit [Member] | Silicon Valley Bank [Member]
Debt Instrument [Line Items]
Credit facility				30,000,000
Line of Credit [Member] | Comerica Bank [Member]
Debt Instrument [Line Items]
Credit facility								7,500,000
Line of credit facility, interest rate spread								1.00%
Debt facility period	2 years
Line of credit, borrowing capacity description	The Company could borrow up to 80% of its current U.S.-based receivables, or $7.5 million, whichever is lower.
Line of Credit [Member] | Maximum [Member] | Comerica Bank [Member]
Debt Instrument [Line Items]
Percentage of receivable								80.00%
Convertible Notes Payable [Member]
Debt Instrument [Line Items]
Convertible notes issued		5,200,000
Convertible notes, interest rate		10.00%
Accrued interest converted into common stock, price per share		$9
Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Convertible notes issued									120,000,000
Convertible notes, issuance date	19-Sep-14
Convertible notes, maturity date	1-Oct-19
Proceeds from notes issued net of offering expenses									115,400,000
Convertible notes, interest rate									4.25%
Convertible notes, periodicity of payment	Semi-annually
Convertible notes, periodic payment start date	1-Apr-15
Convertible notes, redemption start date	1-Oct-17
Convertible notes, redemption description	The Company may redeem the Notes, at its option, in whole or in part on or after October 1, 2017, if the last reported sale price per share of its common stock equals or exceeds 130% of the applicable conversion price for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period ending on the trading day immediately prior to the date on which the Company delivers notice of the redemption.
Convertible notes, percentage of applicable conversion price required for redemption									130.00%
Number of trading days									20
Number of consecutive trading days									30 days
Convertible notes, initial conversion rate									$5.62
Convertible notes, common stock conversion rate per $1,000 principal amount										177.8489
Convertible notes, principal amount per conversion					1,000					1,000
Convertible senior note repurchase price as percentage of principal amount	100.00%
Indebtedness description	During the time that the Notes are outstanding, the Company may not at any time incur any indebtedness other than permitted debt, which is defined as: (a) revolving debt secured by the Companybs accounts receivable and the proceeds therefrom in a principal amount not to exceed $50 million; (b) unsecured indebtedness (including the Notes) in a principal amount not to exceed (when combined with any indebtedness incurred under clause (c) below) $150 million; (c) secured indebtedness secured by the Companybs intellectual property in a principal amount not to exceed (when combined with any indebtedness incurred under clause (b) above) $150 million; and (d) unsecured subordinated indebtedness in a principal amount not to exceed $50 million. Furthermore, the Company may incur indebtedness if (a) the Company is not in default and such additional debt would not put it into default and (ii) the consolidated leverage ratio, as defined, after taking the additional debt into account does not exceed 5:1.
Convertible senior notes, net	120,000,000					120,000,000
Interest and other financing expenses related to amortization of debt issuance costs	600,000
Accrued interest related to notes	1,700,000
Convertible Senior Notes [Member] | Over-Allotment Option [Member]
Debt Instrument [Line Items]
Convertible notes issued									15,000,000
Convertible Senior Notes [Member] | Maximum [Member]
Debt Instrument [Line Items]
Convertible notes issued	50,000,000					50,000,000
Consolidated leverage ratio	500.00%
Convertible Senior Notes [Member] | Maximum [Member] | Revolving Debt [Member]
Debt Instrument [Line Items]
Convertible notes issued	50,000,000					50,000,000
Convertible Senior Notes [Member] | Maximum [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Convertible notes issued	150,000,000					150,000,000
Convertible Senior Notes [Member] | Maximum [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Convertible notes issued	$150,000,000					150,000,000

Convertible_Senior_Notes_Line_3

Convertible Senior Notes, Line of Credit and Debt Facility - Reconciliation of Aggregate Convertible Notes Payable Liability (Detail) (USD $)	12 Months Ended
Share data in Thousands, except Per Share data, unless otherwise specified	Jan. 31, 2014	Jan. 31, 2013
Debt Instrument [Line Items]
Beginning balance		$688,000
Issued	5,165,000	8,698,000
Accrued interest	43,000	29,000
Stock converted, value	-5,203,000
Series D Preferred Stock [Member]
Debt Instrument [Line Items]
Stock converted, value		-9,415,000
Shares		1,569
Conversion Price per Share		$6
Common Stock [Member]
Debt Instrument [Line Items]
Stock converted, value	($5,203,000)
Shares	585
Conversion Price per Share	$9