American Superconductor (AMSC) 10-Q 6 Nov 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Sep. 30, 2014	Nov. 03, 2014
Document Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
Entity Registrant Name	'AMERICAN SUPERCONDUCTOR CORP /DE/	'
Entity Central Index Key	'0000880807	'
Current Fiscal Year End Date	'--03-31	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	86,507,099

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Sep. 30, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$34,679	$43,114
Accounts receivable, net	9,673	7,556
Inventory	24,460	20,694
Prepaid expenses and other current assets	10,280	9,004
Restricted cash	3,425	2,913
Total current assets	82,517	83,281
Property, plant and equipment, net	60,388	64,574
Intangibles, net	1,708	1,995
Restricted cash	100	3,394
Deferred tax assets	7,724	7,724
Other assets	3,410	7,541
Total assets	155,847	168,509
Current liabilities:	'	'
Accounts payable and accrued expenses	23,537	21,764
Accrued arbitration liability	10,631	'
Note payable, current portion, net of discount of $361 as of September 30, 2014 and $555 as of March 31, 2014	4,793	6,240
Derivative liabilities	1,841	2,601
Deferred revenue	17,591	9,456
Deferred tax liabilities	7,724	7,761
Total current liabilities	66,117	47,822
Note payable, net of discount of $137 as of September 30, 2014 and $287 as of March 31, 2014	4,529	6,380
Deferred revenue	2,895	990
Other liabilities	965	1,058
Total liabilities	74,506	56,250
Commitments and contingencies (Note 13)	'	'
Stockholders' equity:	'	'
Common stock	860	789
Additional paid-in capital	975,831	966,390
Treasury stock	-771	-370
Accumulated other comprehensive income	749	1,839
Accumulated deficit	-895,328	-856,389
Total stockholders' equity	81,341	112,259
Total liabilities and stockholders' equity	$155,847	$168,509

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified
Other Current Liabilities	'	'
Note payable	$361	$555
Other Noncurrent Liabilities	'	'
Note payable	$137	$287

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]	'	'	'	'
Revenues	$12,455	$24,181	$24,151	$47,267
Cost and operating expenses:	'	'	'	'
Cost of revenues	13,773	22,611	25,860	40,598
Research and development	3,078	3,083	6,198	6,110
Selling, general and administrative	8,046	8,682	15,984	19,508
Arbitration award expense	10,188	'	10,188	'
Restructuring and impairments	3,731	751	4,909	764
Amortization of acquisition related intangibles	39	82	79	164
Total cost and operating expenses	38,855	35,209	63,218	67,144
Operating loss	-26,400	-11,028	-39,067	-19,877
Change in fair value of derivatives and warrants	795	886	760	1,355
Interest expense, net	-496	-3,505	-1,030	-5,617
Other income (expense), net	740	-635	588	-566
Loss before income tax expense	-25,361	-14,282	-38,749	-24,705
Income tax expense	62	341	190	430
Net loss	($25,423)	($14,623)	($38,939)	($25,135)
Net loss per common share	'	'	'	'
Basic	($0.31)	($0.24)	($0.49)	($0.42)
Diluted	($0.31)	($0.24)	($0.49)	($0.42)
Weighted average number of common shares outstanding	'	'	'	'
Basic	81,471	61,116	79,590	59,712
Diluted	81,471	61,116	79,590	59,712

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive (Loss) Income (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement Of Income And Comprehensive Income [Abstract]	'	'	'	'
Net loss	($25,423)	($14,623)	($38,939)	($25,135)
Other comprehensive loss, net of tax:	'	'	'	'
Foreign currency translation income (loss)	-989	691	-1,090	656
Total other comprehensive income (loss), net of tax	-989	691	-1,090	656
Comprehensive loss	($26,412)	($13,932)	($40,029)	($24,479)

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities:	'	'
Net loss	($38,939)	($25,135)
Adjustments to reconcile net loss to net cash used in operations:	'	'
Depreciation and amortization	4,901	5,343
Stock-based compensation expense	3,099	4,287
Impairment of long-lived and intangible assets	3,464	'
Provision for excess and obsolete inventory	1,285	192
Loss on minority interest investments	410	499
Change in fair value of derivatives and warrants	-760	-1,355
Non-cash interest expense	343	4,765
Other non-cash items	-860	892
Changes in operating asset and liability accounts:	'	'
Accounts receivable	-2,264	10,704
Inventory	-5,283	9,315
Prepaid expenses and other current assets	-1,533	3,531
Accounts payable and accrued expenses	4,154	-8,944
Accrued arbitration liability	10,188	'
Deferred revenue	10,426	-18,873
Net cash used in operating activities	-11,369	-14,779
Cash flows from investing activities:	'	'
Purchase of property, plant and equipment	-514	-115
Proceeds from the sale of property, plant and equipment	8	'
Change in restricted cash	2,782	4,053
Change in other assets	-12	-495
Net cash provided by investing activities	2,264	3,443
Cash flows from financing activities:	'	'
Employee taxes paid related to net settlement of equity awards	-400	-57
Repayment of debt	-3,641	-2,308
Proceeds from ATM sales, net	4,825	'
Proceeds from exercise of employee stock options and ESPP	60	99
Net cash provided by (used in) financing activities	844	-2,266
Effect of exchange rate changes on cash and cash equivalents	-174	226
Net decrease in cash and cash equivalents	-8,435	-13,376
Cash and cash equivalents at beginning of year	43,114	39,243
Cash and cash equivalents at end of year	34,679	25,867
Supplemental schedule of cash flow information:	'	'
Cash paid for income taxes, net of refunds	226	'
Issuance of common stock to settle liabilities	1,528	7,831
Cash paid for interest	$684	$400

Nature_of_the_Business_and_Ope

Nature of the Business and Operations and Liquidity	6 Months Ended
	Sep. 30, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]	'
Nature of the Business and Operations and Liquidity	'
	1. Nature of the Business and Operations and Liquidity
	Nature of the Business and Operations
	American Superconductor Corporation (“AMSC” or the “Company”) was founded on April 9, 1987. The Company is a leading provider of megawatt-scale solutions that lower the cost of wind power and enhance the performance of the power grid. In the wind power market, the Company enables manufacturers to field wind turbines through its advanced engineering, support services and power electronics products. In the power grid market, the Company enables electric utilities and renewable energy project developers to connect, transmit and distribute power through its transmission planning services and power electronics and superconductor-based products. The Company’s wind and power grid products and services provide exceptional reliability, security, efficiency and affordability to its customers.
	These unaudited condensed consolidated financial statements of the Company have been prepared on a going concern basis in accordance with United States generally accepted accounting principles (“GAAP”) and the Securities and Exchange Commission’s (“SEC”) instructions to Form 10-Q. The going concern basis of presentation assumes that the Company will continue operations and will be able to realize its assets and discharge its liabilities and commitments in the normal course of business. Certain information and footnote disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those instructions. The year-end condensed balance sheet data was derived from audited financial statements but does not include all disclosures required by GAAP. The unaudited condensed consolidated financial statements, in the opinion of management, reflect all adjustments (consisting of normal recurring adjustments) necessary for a fair statement of the results for the interim periods ended September 30, 2014 and 2013 and the financial position at September 30, 2014.
	Liquidity
	The Company has experienced recurring operating losses and as of September 30, 2014, the Company had an accumulated deficit of $895.3 million. In addition, the Company has experienced recurring negative operating cash flows.  At September 30, 2014, the Company had cash and cash equivalents of $34.7 million. Cash used in operations for the six months ended September 30, 2014 was $11.4 million.  On August 29, 2014, the Arbitration Tribunal for the ICC International Court of Arbitration (the “ICC Court”) found the Company liable for damages in its breach of contract proceeding against Ghodawat Energy Pvt Ltd (“Ghodawat”) and awarded Ghodawat approximately €8.3 million (approximately $10.6 million) plus interest of 5.33%, which accrues from the date of award.  As of the date of this filing, the Company has not paid this award.  See Note 13, “Commitments and Contingencies” for further information.
	From April 1, 2011 through the date of this filing, the Company has reduced its global workforce substantially.  The Company is currently in the process of consolidating certain business operations to reduce facility costs.  As of September 30, 2014, the Company had a global workforce of approximately 291 persons.  The Company plans to closely monitor its expenses and if required, expects to further reduce operating costs and capital spending to enhance liquidity.
	On June 5, 2012, the Company entered into a Loan and Security Agreement (the “Term Loan”) with Hercules Technology Growth Capital, Inc (“Hercules”), under which the Company borrowed $10.0 million.  On November 15, 2013, the Company entered into an amendment of the Term Loan (the “New Term Loan”, and together with the Term Loan, the “Term Loans”), under which the Company borrowed an additional $10.0 million.  The Term Loans contain certain covenants and restrictions including, among others, a requirement to maintain a minimum unrestricted cash balance in the U.S. equal to the lesser of a minimum cash threshold or the remaining principal balance.  (See Note 10, “Debt”, for further information regarding these debt arrangements, including the covenants, restrictions and events of default under the agreements.) The Company believes that it is in compliance with the covenants and restrictions included in the agreements governing these debt arrangements as of the date of this Quarterly Report on Form 10-Q.
	On November 15, 2013, the Company entered into an At Market Sales Arrangement (“ATM”) under which the Company may, at its discretion, sell up to $30.0 million of shares of its common stock (before expenses) through its sales agent, MLV & Co. LLC (“MLV”).  During the three months ended September 30, 2014, the Company received net proceeds of $3.7 million, including sales and commissions and offering expenses, from sales of approximately 2.1 million shares of its common stock at an average sales price of approximately $1.75 per share under the ATM. (See Note 12, “Stockholders’ Equity”, for further information regarding the ATM.)   At September 30, 2014, there was approximately $17.1 million of availability under the Company’s ATM (see further discussion below).  Sales of common stock under the ATM may be made from time to time, at the Company’s discretion, in order to enhance liquidity.
	The Company expects that it will require additional capital, either from sales under the ATM or other sources, to fund its operations, including the Ghodawat arbitration award liability, capital expenditures and scheduled cash payments under its debt obligations through September 30, 2015. The Company’s plans include, and its liquidity is highly dependent on, its ability to increase revenues, its ability to control its operating costs, its ability to utilize the ATM to raise additional capital or raise capital from other sources, and its ability to maintain compliance with the covenants and restrictions on its debt obligations (or obtain waivers from its lender in the event of non-compliance). There can be no assurance that the Company will be able to continue to utilize the ATM or raise capital from other sources.
	In addition, the Company is actively seeking to sell its minority investment in Tres Amigas, LLC, a Delaware limited liability Company (“Tres Amigas”).  The Company no longer believes its investment in Blade Dynamics is recoverable and fully impaired its remaining investment in Blade Dynamics Ltd. (“Blade Dynamics”) during the three months ended September 30, 2014. (See Note 14, “Minority Investments”, for further information about such investments.) There can be no assurance that the Company will be able to sell these investments on commercially reasonable terms or at all.

StockBased_Compensation

Stock-Based Compensation	6 Months Ended
	Sep. 30, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Stock-Based Compensation	'
	2. Stock-Based Compensation
	The Company accounts for its stock-based compensation at fair value. The following table summarizes stock-based compensation expense by financial statement line item for the three and six months ended September 30, 2014 and 2013 (in thousands):
		Three months ended September 30,								Six months ended September 30,
		2014				2013				2014				2013
	Cost of revenues	$	194			$	224			$	346			$	429
	Research and development		521				585				1,000				1,159
	Selling, general and administrative		803				1,343				1,753				2,699
	Total	$	1,518			$	2,152			$	3,099			$	4,287
	During the six months ended September 30, 2014, the Company granted 1,000,000 stock options, and 3,192,502 restricted stock awards. During the six months ended September 30, 2013, the Company granted approximately 831,000 stock options, 400,000 time-based restricted stock awards, 362,000 performance-based restricted stock awards, and issued 212,000 shares of common stock in-lieu of cash bonuses and severance payments issued. The stock options vest generally over 3-5 years, and the time-based restricted stock awards vest generally over three years. For options and awards that vest upon the passage of time, expense is being recorded over the vesting period.  Performance-based restricted stock awards are expensed over the requisite service period based on probability of achievement.
	The estimated fair value of the Company’s stock-based awards, less expected annual forfeitures, is amortized over the awards’ service period. The total unrecognized compensation cost for unvested outstanding stock options was $1.8 million at September 30, 2014. This expense will be recognized over a weighted average expense period of approximately 3.0 years. The total unrecognized compensation cost for unvested outstanding restricted stock was $4.6 million at September 30, 2014. This expense will be recognized over a weighted-average expense period of approximately 1.6 years.
	The weighted-average assumptions used in the Black-Scholes valuation model for stock options granted during the three and six months ended September 30, 2014 and 2013 are as follows:
		Three months ended September 30,						Six months ended September 30,
		2014		2013				2014				2013
	Expected volatility	N/A			75.4	%			85.5	%			75.1	%
	Risk-free interest rate	N/A			1.7	%			1.9	%			1.7	%
	Expected life (years)	N/A			5.8				5.8				5.9
	Dividend yield	N/A		None				None				None
	The expected volatility rate was estimated based on an equal weighting of the historical volatility of the Company’s common stock and the implied volatility of the Company’s traded options. The expected term was estimated based on an analysis of the Company’s historical experience of exercise, cancellation, and expiration patterns. The risk-free interest rate is based on the average of the five and seven year United States Treasury rates.

Computation_of_Net_Loss_per_Co

Computation of Net Loss per Common Share	6 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Computation of Net Loss per Common Share	'
	3. Computation of Net Loss per Common Share
	Basic net loss per share (“EPS”) is computed by dividing net loss by the weighted-average number of common shares outstanding for the period. Where applicable, diluted EPS is computed by dividing the net loss by the weighted-average number of common shares and dilutive common equivalent shares outstanding during the period, calculated using the treasury stock method. Common equivalent shares include the effect of restricted stock, exercise of stock options and warrants and contingently issuable shares. For each of the three and six months ended September 30, 2014, 7.4 million shares were not included in the calculation of diluted EPS as they were considered anti-dilutive, of which 3.9 million relate to unexercised stock options, and 3.5 million relate to the issuance of warrants. For each of the three and six months ended September 30, 2013, 9.7 million shares were not included in the calculation of diluted EPS as they were considered anti-dilutive, of which 3.2 million relate to unvested stock options, 3.2 million relate to the issue of warrants and 3.3 million shares related to the convertible feature of the Company’s unsecured, senior convertible note (the “Exchanged Note”).
	The following table reconciles the numerators and denominators of the earnings per share calculation for the three and six months ended September 30, 2014 and 2013 (in thousands, except per share data):
		Three months ended September 30,						Six months ended September 30,
		2014			2013			2014			2013
	Numerator:
	Net loss	$	(25,423	)	$	(14,623	)	$	(38,939	)	$	(25,135	)
	Denominator:
	Weighted-average shares of common stock outstanding		83,048			62,787			80,876			61,583
	Weighted-average shares subject to repurchase		(1,577	)		(1,671	)		(1,286	)		(1,871	)
	Shares used in per-share calculation ― basic		81,471			61,116			79,590			59,712
	Shares used in per-share calculation ― diluted		81,471			61,116			79,590			59,712
	Net loss per share ― basic	$	(0.31	)	$	(0.24	)	$	(0.49	)	$	(0.42	)
	Net loss per share ― diluted	$	(0.31	)	$	(0.24	)	$	(0.49	)	$	(0.42	)

Fair_Value_Measurements

Fair Value Measurements	6 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	4. Fair Value Measurements
	A valuation hierarchy for disclosure of the inputs to valuation used to measure fair value has been established. This hierarchy prioritizes the inputs into three broad levels as follows:
		Level 1 -	Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.
		Level 2 -	Inputs include quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability, and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs).
		Level 3 -	Unobservable inputs that reflect the Company’s assumptions that market participants would use in pricing the asset or liability. The Company develops these inputs based on the best information available, including its own data.
	The Company provides a gross presentation of activity within Level 3 measurement roll-forward and details of transfers in and out of Level 1 and 2 measurements.  A change in the hierarchy of an investment from its current level is reflected in the period during which the pricing methodology of such investment changes.  Disclosure of the transfer of securities from Level 1 to Level 2 or Level 3 is made in the event that the related security is significant to total cash and investments.  The Company did not have any transfers of assets and liabilities between Level 1 and Level 3 of the fair value measurement hierarchy during the three or six months ended September 30, 2014.
	A financial asset’s or liability’s classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement.
	The following table provides the assets and liabilities carried at fair value, measured as of September 30, 2014 and March 31, 2014 (in thousands):
		Total			Quoted Prices in			Significant Other		Significant
		Carrying			Active Markets			Observable Inputs		Unobservable Inputs
		Value			(Level 1)			(Level 2)		(Level 3)
	September 30, 2014:
	Assets:
	Cash equivalents	$	20,185		$	20,185		$	-	$	-
	Derivative liabilities:
	Warrants	$	1,841		$	-		$	-	$	1,841
		Total			Quoted Prices in			Significant Other		Significant
		Carrying			Active Markets			Observable Inputs		Unobservable Inputs
		Value			(Level 1)			(Level 2)		(Level 3)
	March 31, 2014:
	Assets:
	Cash equivalents	$	17,675		$	17,675		$	-	$	-
	Derivative liabilities:
	Warrants	$	2,601		$	-		$	-	$	2,601
	The table below reflects the activity for the Company’s major classes of liabilities measured at fair value (in thousands):
					Warrants
	April  1, 2014				$	2,601
	Mark to market adjustment					(760	)
	Balance at September 30, 2014				$	1,841
		Derivative
		Liability			Warrants
	April  1, 2013	$	529		$	3,633
	Warrant issuance with Senior Secured Term Loan		-			315
	Mark to market adjustment		(525	)		(1,347	)
	Extinguishment of derivative liability		(4	)		-
	Balance at March 31, 2014	$	-		$	2,601
	The following table provides the assets and liabilities measured at fair value on a non-recurring basis, as of September 30, 2014 and March 31, 2014 (in thousands).  During the three months ended September 30, 2014 the following asset was determined to be no longer recoverable and was fully impaired.  See note 14, “Minority Investments” for further details:
		Total			Quoted Prices in			Significant Other		Significant
		Carrying			Active Markets			Observable Inputs		Unobservable Inputs
		Value			(Level 1)			(Level 2)		(Level 3)
	September 30, 2014:
	Assets:
	Investment in unconsolidated entity – Blade Dynamics	$	-		$	-		$	-	$	-
	March 31, 2014:
	Assets:
	Investment in unconsolidated entity – Blade Dynamics	$	3,690		$	-		$	-	$	3,690
	Valuation Techniques
	Cash Equivalents
	Cash equivalents consist of highly liquid instruments with maturities of three months or less that are regarded as high quality, low risk investments and are measured using such inputs as quoted prices, and are classified within Level 1 of the valuation hierarchy. Cash equivalents consist principally of certificates of deposits and money market accounts.
	Derivative Liability
	In April 2012, the Company entered into a Securities Purchase Agreement (the “Purchase Agreement”) with Capital Ventures International (“CVI”), an affiliate of Heights Capital Management, under which the Company issued a $25.0 million, 7% convertible note (the “Initial Note”).  In December 2012, the Company entered into an agreement with CVI pursuant to which it exchanged the Initial Note for the Exchanged Note.  The Exchanged Note was extinguished as of March 31, 2014.  The Company had identified all of the derivatives (“Derivative Liability”) associated with the extinguished Exchanged Note which include holder change of control redemption rights, issuer optional redemption rights, sale redemption rights and a feature to convert the Exchanged Note into equity at the holder’s option.  The Derivative Liability was subject to revaluation at each balance sheet date, and any change in fair value was recorded as a change in fair value in derivatives and warrants until its expiration.  The Company relied on assumptions in a lattice model to determine the fair value of Derivative Liability.  The Company had valued the Derivative Liability within Level 3 of the valuation hierarchy.  (See Note 10, “Debt,” for further discussion of the Exchanged Note, Derivative Liability and valuation assumptions used.)
	Warrants
	Warrants were issued in conjunction with the Purchase Agreement with CVI, and the Term Loans. (See Note 10, “Debt,” and Note 11 “Warrants and Derivative Liabilities,” for additional information.) These warrants are subject to revaluation at each balance sheet date, and any change in fair value will be recorded as a change in fair value in derivatives and warrants until the earlier of their exercise or expiration.
	The Company relies on various assumptions in a lattice model to determine the fair value of warrants. The Company has valued the warrants within Level 3 of the valuation hierarchy. (See Note 11, “Warrants and Derivative Liabilities,” for a discussion of the warrants and the valuation assumptions used.)
	Minority Investment
	The Company accounts for the minority investment in Blade Dynamics on a cost basis (See Note 14, “Minority Investments”).  During the year ended March 31, 2014, the Company determined that as a result of its efforts to sell its investment in Blade Dynamics, certain indicators of impairment existed which required the Company to perform further analysis. Based on analysis which included potential sale scenarios of the investment, the Company recorded an impairment charge of approximately $1.3 million and reported the investment at its estimated fair value in the fourth quarter ended March 31, 2014.
	During the three months ended September 30, 2014, the Company determined that as a result of a dilutive financing which resulted in the Company losing certain of its shareholder rights, as well as certain operational issues and adverse changes to the potential sale scenarios previously considered, its investment in Blade Dynamics was no longer recoverable and therefore recorded an impairment charge of $3.5 million.

Accounts_Receivable

Accounts Receivable	6 Months Ended
	Sep. 30, 2014
Receivables [Abstract]	'
Accounts Receivable	'
	5. Accounts Receivable
	Accounts receivable at September 30, 2014 and March 31, 2014 consisted of the following (in thousands):
		September 30,			March 31,
		2014			2014
	Accounts receivable (billed)	$	8,410		$	6,113
	Accounts receivable (unbilled)		1,279			1,459
	Less: Allowance for doubtful accounts		(16	)		(16	)
	Accounts receivable, net	$	9,673		$	7,556

Inventory

Inventory	6 Months Ended
	Sep. 30, 2014
Inventory Disclosure [Abstract]	'
Inventory	'
	6. Inventory
	Inventory at September 30, 2014 and March 31, 2014 consisted of the following (in thousands):
		September 30,		March 31,
		2014		2014
	Raw materials	$	6,936	$	3,304
	Work-in-process		6,073		4,047
	Finished goods		8,750		10,275
	Deferred program costs		2,701		3,068
	Net inventory	$	24,460	$	20,694
	The Company recorded inventory write-downs of $0.6 million and less than $0.1 million for the three months ended September 30, 2014 and 2013, respectively.  The Company recorded inventory write-downs of $1.3 million and $0.2 million for the six months ended September 30, 2014 and 2013, respectively.  These write downs were based on evaluating its inventory on hand for excess quantities and obsolescence.
	Deferred program costs as of September 30, 2014 and March 31, 2014 primarily represent costs incurred on programs accounted for under contract accounting where the Company needs to complete development programs before revenue and costs will be recognized.

Accounts_Payable_and_Accrued_E

Accounts Payable and Accrued Expenses	6 Months Ended
	Sep. 30, 2014
Payables And Accruals [Abstract]	'
Accounts Payable and Accrued Expenses	'
	7. Accounts Payable and Accrued Expenses
	Accounts payable and accrued expenses at September 30, 2014 and March 31, 2014 consisted of the following (in thousands):
		September 30,			March 31,
		2014			2014
	Accounts payable	$	7,063		$	1,749
	Accrued inventories in-transit		1,330			212
	Accrued miscellaneous expenses		4,424			6,076
	Accrued outside services		3,026			3,716
	Accrued subcontractor program costs		60			290
	Accrued compensation		4,070			5,939
	Income taxes payable		197			173
	Accrued adverse purchase commitments		-			402
	Accrued warranty		3,367			3,207
	Total	$	23,537		$	21,764
	The Company generally provides a one to three year warranty on its products, commencing upon installation. A provision is recorded upon revenue recognition to cost of revenues for estimated warranty expense based on historical experience.
	Product warranty activity was as follows (in thousands):
		Three months ended September 30,						Six months ended September 30,
		2014			2013			2014			2013
	Balance at beginning of period	$	2,855		$	2,787		$	3,207		$	2,709
	Change in accruals for warranties during the period		974			342			903			493
	Settlements during the period		(462	)		(60	)		(743	)		(133	)
	Balance at end of period	$	3,367		$	3,069		$	3,367		$	3,069

Income_Taxes

Income Taxes	6 Months Ended
	Sep. 30, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	8. Income Taxes
	For the three and six months ended September 30, 2014, the Company recorded income tax expense of $0.1 million and $0.2 million, respectively.  For the three and six months ended September 30, 2013, the Company recorded income tax expense of $0.3 million and $0.4 million, respectively.  Income tax expense was primarily due to income taxes in the Company’s foreign jurisdictions.

Restructuring

Restructuring	6 Months Ended
	Sep. 30, 2014
Restructuring And Related Activities [Abstract]	'
Restructuring	'
	9. Restructuring
	The Company accounts for charges resulting from operational restructuring actions in accordance with ASC Topic 420, Exit or Disposal Cost Obligations (“ASC 420”) and ASC Topic 712, Compensation—Nonretirement Postemployment Benefits (“ASC 712”). In accounting for these obligations, the Company is required to make assumptions related to the amounts of employee severance, benefits, and related costs and the time period over which leased facilities will remain vacant, sublease terms, sublease rates and discount rates. Estimates and assumptions are based on the best information available at the time the obligation arises. These estimates are reviewed and revised as facts and circumstances dictate; changes in these estimates could have a material effect on the amount accrued on the consolidated balance sheet.
	During the years ended March 31, 2014 and March 31, 2013, the Company undertook restructuring activities, approved by the Board of Directors, in order to reorganize its global operations, streamline various functions of the business, and reduce its global workforce to better reflect the demand for its products.  During the year ended March 31, 2014, the Company undertook a plan to consolidate its Grid manufacturing activities in its Devens, Massachusetts facility and close its facility in Middleton, Wisconsin.  In addition, the Company is establishing a new Wind manufacturing facility in Romania and as a result reduced the headcount in its operation in China to a level necessary to support demand from its Chinese customers.  The Company also undertook a workforce reduction in July 2013, reducing its workforce by approximately 7%, impacting primarily selling, engineering and general and administrative functions.  The Company recorded restructuring charges for severance and other costs of approximately $0.3 million and $1.4 million during the three and six months ended September 30, 2014, respectively.  During the six months ended September 30, 2013, the Company incurred restructuring costs of approximately $0.8 million. From April 1, 2011 through September 30, 2014, the Company’s various restructuring activities resulted in a substantial reduction of its global workforce. Remaining unpaid amounts under these restructuring activities are expected to be paid by August 31, 2015.
	The following table presents restructuring charges and cash payments (in thousands):
		Severance pay			Facility Exit and
	Six months ended September 30, 2014:	and benefits			Relocation costs			Total
	Accrued restructuring balance at April 1, 2014	$	844		$	-		$	844
	Charges to operations		632			814			1,445
	Cash payments		(696	)		(814	)		(1,509	)
	Accrued restructuring balance at September 30, 2014	$	780		$	-		$	780
	Six months ended September 30, 2013:
	Accrued restructuring at April 1, 2013	$	145		$	54		$	199
	Charges to operations		751			13			764
	Cash payments		(599	)		(37	)		(636	)
	Non-cash/miscellaneous reductions		(166	)		(30	)		(196	)
	Accrued restructuring balance at September 30, 2013	$	131		$	-		$	131
	All restructuring charges discussed above are included within restructuring and impairments in the Company’s unaudited condensed consolidated statements of operations. The Company includes accrued restructuring within accounts payable and accrued expenses in the unaudited condensed consolidated balance sheets.

Debt

Debt	6 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Debt	'
	10. Debt
	Senior Convertible Note
	On April 4, 2012, the Company entered into the Purchase Agreement with CVI and completed a private placement of the Initial Note. After fees and expenses, the net proceeds of the Initial Note were $23.2 million. The Initial Note had an initial conversion price of $4.85 per share, representing a premium of approximately 20% over AMSC’s closing price on April 3, 2012. The Initial Note was payable in monthly installments beginning four months from issuance and ending on October 4, 2014. Monthly payments were payable in cash or the Company’s common stock at the option of the Company, subject to certain trading volume, stock price and other conditions. CVI could elect to defer receipt of monthly installment payments at its option. Any deferred installment payments would continue to accrue interest. The Company registered 10,262,311 shares of common stock which could be used as payment for principal and interest in lieu of cash for resale under the Securities Act of 1933, as amended (the “Securities Act”) as required under a Registration Rights Agreement with CVI.
	The Company accounted for the Initial Note as an instrument that has the characteristics of a debt host contract containing several embedded derivative features that would require bifurcation and separate accounting as a derivative instrument pursuant to the provisions of ASC Topic 815 – Derivatives and Hedging (ASC 815). The Company elected not to use the fair value option for the aggregate amount of the Initial Note and recorded the liability at its stated value on the date of issuance with no changes in fair value reported in subsequent periods. The Company valued these derivatives at $3.8 million upon issuance of the Initial Note. (See Note 11, “Warrants and Derivative Liabilities,” for additional information regarding derivative liabilities.)
	In conjunction with the Initial Note, CVI received a warrant to purchase approximately 3.1 million additional shares of common stock exercisable at a strike price of $5.45 per share, subject to adjustment, until October 4, 2017. Due to certain adjustment provisions within the warrant, it qualified for liability accounting and had a fair value of $7.0 million upon issuance. The Company recorded the value as a debt discount and a warrant liability. (See Note 11, “Warrants and Derivative Liabilities,” for additional information regarding the warrant.)
	On December 20, 2012, the Company entered into an Amendment and Exchange Agreement, (the “Amendment”) with CVI, which amended the Purchase Agreement. Pursuant to the Amendment, the Company and CVI exchanged the Initial Note for the Exchanged Note. At the time of the exchange, the Exchanged Note had the same principal amount and accrued interest as the Initial Note. The Exchanged Note was convertible into the Company’s common stock and had the same scheduled monthly installment payments as the Initial Note. The Exchanged Note provided the Company with additional flexibility to make monthly installment payments in shares of the Company’s common stock. The Company retained the ability to repay the Exchanged Note in cash.
	The Company assessed the changes in the Exchanged Note and accounted for it as a modification of the Initial Note. Therefore, the Company determined the incremental value of the derivative instruments, as a result of the Exchanged Note, as having a reduced conversion price. As a result of the re-valuation, the Company recorded a $0.5 million increase in the value of the derivative liability and additional debt discount. At the modification date, the value of the derivative liability was $1.5 million. The total debt discount, including the embedded derivatives in the Initial Note, the incremental value of embedded derivatives in the Exchanged Note, warrant and legal and origination costs of $13.1 million was amortized into interest expense over the term of the Exchanged Note using the effective interest method. Under this method, interest expense was recognized each period until the debt instruments reached maturity. Given that the maturity of the Exchanged Note was accelerated due to prepayment, the amortization was accelerated.
	On October 9, 2013, the Company entered into a Second Amendment and Warrant Exchange Agreement (the “Second Amendment”) with CVI. The Second Amendment further amended the Purchase Agreement, as amended by the Amendment (collectively, the “Amended Purchase Agreement”), that the Company previously entered into with CVI.
	Pursuant to the Second Amendment, the Company and/or CVI waived certain provisions of the Amended Purchase Agreement and amended certain provisions of the Exchanged Note and exchanged the warrant (the “Original Warrant”) for a new warrant (the Exchanged Warrant”) with a reduced exercise price of $2.61 per share of common stock.
	The Company assessed the changes to the Exchanged Note included in the Second Amendment and accounted for it as a modification of the Exchanged Note. Therefore, the Company determined the incremental value of the derivative instruments, as a result of the Second Amendment, specifically the Exchanged Warrant. (See Note 11 “Warrants and Derivative Liabilities” for discussion of the valuation of the Exchanged Warrant.)
	During the three and six months ended September 30, 2013, the Company recorded non-cash interest expense for amortization of the debt discount related to the convertible notes of $1.2 million and $2.7 million, respectively.
	Provided certain equity conditions were met, the Company could elect to repay principal and interest in shares of the Company’s common stock. If the Company elected to make a payment in shares of the Company’s common stock, the number of shares issued was determined by dividing the amount of such payment by 85% of the lessor of the average volume-weighted average price (“VWAP”) of the 10 consecutive days immediately preceding the payment date or the VWAP price on the day preceding the payment date (the “Market Price”). The Company recorded the difference between the closing price of its common stock on the day preceding the payment date and the Market Price as a discount on the fair value of its shares. During both the three and six months ended September 30, 2013, the Company recorded $1.8 million of non-cash interest expense related to installment payments made by issuing the Company’s common stock at a discount.
	On March 2, 2014, the Company entered into an Exchange Agreement with CVI, pursuant to which the Company exchanged the Exchanged Note for approximately 6.6 million shares of common stock and extinguished the debt.  As a result of this transaction, the Company recorded a loss on the extinguishment of debt of $5.2 million during the three months ended March 31, 2014.
	Senior Secured Term Loans
	On June 5, 2012, the Company entered into the Term Loan with Hercules, under which the Company borrowed $10.0 million. After the closing fees and expenses, the net proceeds to the Company were $9.7 million. The Term Loan bears an interest rate equal to 11% plus the percentage, if any, by which the prime rate as reported by The Wall Street Journal exceeds 3.75%. The Company made interest-only payments from July 1, 2012 through October 31, 2012, after which the Company began repaying the Term Loan in equal monthly installments ending on December 1, 2014. In addition, Hercules received a warrant (the “First Warrant”) to purchase 139,276 shares of common stock, exercisable at an initial strike price of $3.59 per share, subject to adjustment, until December 5, 2017. Due to certain adjustment provisions within the warrant, it qualified for liability accounting and the fair value of $0.4 million was recorded upon issuance, which the Company recorded as a debt discount and a warrant liability.  The Company will pay an end of term fee of $0.5 million upon the earlier of maturity or prepayment of the loan. The Company has accrued the term fee and recorded a corresponding amount into the debt discount. In addition, the Company incurred $0.3 million of legal and origination costs in the year ended March 31, 2013, which have been recorded as a debt discount. The total debt discount including the First Warrant, end of term fee and legal and origination costs of $1.2 million is being amortized into interest expense over the term of the Term Loan using the effective interest method. Under this method, interest expense is recognized each period until the debt instrument reaches maturity. During the three and six months ended September 30, 2014, the Company recorded non-cash interest expense for amortization of the debt discount related to the Term Loan of less than $0.1 million and $0.1 million, respectively.  During the three and six months ended September 30, 2013, the Company recorded non-cash interest expense for amortization of the debt discount related to the Term Loan of $0.1 million and $0.3 million, respectively.
	On November 15, 2013, the Company amended the Term Loan with Hercules and entered into the New Term Loan, borrowing an additional $10.0 million. After closing fees and expenses, the net proceeds to the Company for the New Term Loan were $9.8 million.  The New Term Loan also bears the same interest rate as the Term Loan.  The Company made interest-only payments from December 1, 2013 to May 31, 2014.  If the Company achieved certain revenue targets for the six-month period ending March 31, 2014, interest only payments would continue through August 31, 2014.  The Company did not meet these revenue targets.  As a result, the Company is repaying the New Term Loan in equal monthly installments ending on November 1, 2016.  Hercules received a warrant (the “Second Warrant”) to purchase 256,410 shares of common stock, exercisable at an initial strike price of $1.95 per share, subject to adjustment, until May 15, 2019.  In addition, the exercise price of the First Warrant was reduced to $1.95 per share.  (See Note 11, “Warrants and Derivative Liabilities,” for a discussion on both warrants and the valuation assumptions used.) The Company will pay an end of term fee of $0.5 million upon the earlier of maturity or prepayment of the New Term Loan. The Company has accrued the end of term fee and recorded a corresponding amount into the debt discount.  The New Term Loan includes a mandatory prepayment feature which allows Hercules the right to use any of the Company’s net proceeds from specified asset dispositions greater than $1.0 million in a calendar year to pay off any outstanding accrued interest and principal balance on the New Term Loan.  The Company determined the fair value to be de-minimis for this feature. In addition, the Company incurred $0.2 million of legal and origination costs in the three months ended December 31, 2013, which have been recorded as a debt discount. The total debt discount including the Second Warrant, end of term fee and legal and origination costs of $1.0 million is being amortized into interest expense over the term of the New Term Loan using the effective interest method. If the maturity of either of the term loans is accelerated because of prepayment, then the amortization will be accelerated. During the three and six months ended September 30, 2014, the Company recorded non-cash interest expense for amortization of the debt discount related to the New Term Loan of $0.1 million and $0.2 million, respectively.
	The Term Loans are secured by substantially all of the Company’s existing and future assets, including a mortgage on real property owned by the Company’s wholly-owned subsidiary, ASC Devens LLC, and located at 64 Jackson Road, Devens, Massachusetts.  The Term Loans contain certain covenants that restrict the Company’s ability to, among other things, incur or assume certain debt, merge or consolidate, materially change the nature of the Company’s business, make certain investments, acquire or dispose of certain assets, make guaranties or grant liens on its assets, make certain loans, advances or investments, declare dividends or make distributions or enter into transactions with affiliates. In addition, there is a covenant that requires the Company to maintain a minimum unrestricted cash balance (the “Minimum Threshold”) in the United States of at least $15.0 million at the inception of the New Term Loan.  The Minimum Threshold will be reduced by $2.5 million for every $5.0 million of net proceeds from the sale of its common stock after November 15, 2013, including those under the ATM, to an amount not lower than $7.5 million or the outstanding combined principal balances of the Term Loans, whichever is lower.  As of September 30, 2014, the Minimum Threshold was $9.8 million.  The events of default under the Term Loans include, but are not limited to, failure to pay amounts due, breaches of covenants, bankruptcy events, cross defaults under other material indebtedness and the occurrence of a material adverse effect and/or change in control. In the case of a continuing event of default, Hercules may, among other remedies, declare due all unpaid principal amounts outstanding and any accrued but unpaid interest and foreclose on all collateral granted to Hercules as security under the Term Loans.
	Although the Company believes that it is in and expects to remain in compliance with the covenants and restrictions under the Term Loans as of the date of this Quarterly Report on Form 10-Q, there can be no assurance that the Company will continue to be in compliance.
	Interest expense on the Term Loans for the three and six months ended September 30, 2014, was $0.5 million and $1.0 million, respectively, which included $0.2 million and $0.3 million, respectively, of non-cash interest expense related to the amortization of the debt discount on the Term Loans.  Interest expense on the Exchanged Note and Term Loans for the three and six months ended September 30, 2013, was $3.5 million and $5.6 million, respectively, which included $3.1 million and $4.8 million, respectively, of non-cash interest expense related to the amortization of the debt discount on the Exchanged Note and Term Loans and payment of the Exchanged Note in Company common stock at a discount.

Warrants_and_Derivative_Liabil

Warrants and Derivative Liabilities	6 Months Ended
	Sep. 30, 2014
Derivative Instruments And Hedging Activities Disclosure [Abstract]	'
Warrants and Derivative Liabilities	'
	11. Warrants and Derivative Liabilities
	Senior Convertible Note Warrant
	On April 4, 2012, the Company entered into the Purchase Agreement with CVI. The Purchase Agreement included the Original Warrant to purchase 3,094,060 shares of the Company’s common stock. The warrant is exercisable at any time on or after the date that is six months after the issuance of the warrant and entitles CVI to purchase shares of the Company’s common stock for a period of five years from the initial date the warrant becomes exercisable at a price equal to $5.45 per share, subject to certain price-based and other anti-dilution adjustments. On October 9, 2013, the Company amended the Purchase Agreement with CVI (the “Amendment”). Pursuant to the Amendment, the Company exchanged the Original Warrant for the Exchanged Warrant, with a reduced exercise price of $2.61 per share of common stock. Other than the reduced exercise price, the Exchanged Warrant has the same terms and conditions as the Original Warrant.  As a result of the sales of common stock under the ATM (See Note 12, “Stockholders’ Equity”, for further discussion of the ATM), and other issuances, during the three months ended September 30, 2014, the exercise price of the Exchanged Warrant was reduced to $2.55 per share.  The Exchanged Warrant may not be exercised if, after giving effect to the conversion, CVI together with its affiliates would beneficially own in excess of 4.99% of the Company’s common stock. This percentage may be raised to any other percentage not in excess of 9.99% at the option of CVI, upon at least 61-days prior notice to the Company, or lowered to any other percentage, at the option of CVI, at any time.
	The Company calculated the fair value of the derivative liabilities, (see Note 4, “Fair Value Measurements”, and Note 10, “Debt” for further discussion), and warrants utilizing an integrated lattice model. The lattice model is an option pricing model that involves the construction of a binomial tree to show the different paths that the underlying asset may take over the option’s life. A lattice model can take into account expected changes in various parameters such as volatility over the life of the options, providing more accurate estimates of option prices than the Black-Scholes model.
	The Company accounts for the warrant as a liability due to certain adjustment provisions within the warrant, which requires that it be recorded at fair value. The warrant is subject to revaluation at each balance sheet date and any change in fair value will be recorded as a change in fair value of derivatives and warrants until the earlier of expiration or its exercise at which time the warrant liability will be reclassified to equity.
	Following is a summary of the key assumptions used to calculate the fair value of the warrant:
		September 30,				June 30,
	Fiscal Year 14	2014				2014
	Risk-free interest rate		1.07	%			0.98	%
	Expected annual dividend yield		—	%			—	%
	Expected volatility		76.2	%			83.5	%
	Term  (years)	3.01				3.26
	Fair value	$1.5 million				$2.3 million
										Post-modification				Pre-modification
		March 31,				December 31,				October 9,				October 9,				September 30,			June 30,			March 31,
	Fiscal Year 13	2014				2013				2013				2013				2013			2013			2013
	Risk-free interest rate		1.11	%			1.17	%			1.05	%			1.05	%			1.02	%		1.13	%		0.67	%
	Expected annual dividend yield		—	%			—	%			—	%			—	%			—	%		—	%		—	%
	Expected volatility		80.99	%			75.6	%			71.45	%			71.45	%			71.98	%		71.9	%		71.74	%
	Term  (years)	3.51				3.76				3.99				3.99					4.01			4.27			4.51
	Fair value	$ 2.2 million				$ 2.2 million				$ 3.2 million				$ 2.2 million				$ 2.5 million			$ 3.0 million			$ 3.4 million
	The Company recorded net gains, resulting from the decrease in the fair value of the Exchanged Warrant, of $0.8 million and $0.5 million to change in fair value of derivatives and warrants in the three months ended September 30, 2014, and 2013, respectively.  The Company recorded net gains, resulting from the decrease in the fair value of the Exchanged Warrant, of $0.7 million and $0.9 million to change in fair value of derivatives and warrants in the six months ended September 30, 2014, and 2013, respectively.
	Convertible Note Derivative Liability
	The Company determined certain embedded derivatives issued with the Initial Note required accounting as a liability, which requires they be accounted for as a standalone liability subject to revaluation at each balance sheet date with changes in fair value recorded as change in fair value of derivatives and warrants until the earlier of exercise or expiration.
	The terms of the December 2012 Amendment with CVI provided for, among other things, the exchange of the Initial Note for the Exchanged Note and reduced the conversion price of the Initial Note from $4.85 per share to $3.19 per share in the Exchanged Note. As a result of the sales of common stock under the ATM (See Note 12, “Stockholders’ Equity”, for further discussion of the ATM) the conversion price of the Exchanged Note was further reduced to $3.10 per share.
	On March 2, 2014, the Company entered into an Exchange Agreement with CVI, pursuant to which the Company exchanged the Exchanged Note for approximately 6.6 million shares of common stock, in full satisfaction of all amounts owed under the Exchanged Note, including any accrued interest.  In addition, the Company extinguished the remaining value for the derivative liability identified with the Exchanged Note and any unamortized debt discount.
	Following is a summary of the key assumptions used to value the convertible notes derivative features:
		March 31,		December 31,				September 30,				June 30,			March 31,
	Fiscal Year 13	2014		2013				2013				2013			2013
	Principal outstanding (000's)	$                  —		$	10,411			$	10,411			$	14,389		$	15,380
	Stock price	N/A		$	1.64			$	2.34			$	2.64		$	2.67
	Percentage volume condition met	— %			87.2	%			80.2	%			87.5	%		80.5	%
	Expected volatility	— %			68.63	%			66.26	%			65.8	%		66.91	%
	Risk free rate	— %			0.12	%			0.1	%			0.21	%		0.2	%
	Bond yield	— %			16.5	%			15.5	%			16.7	%		16.5	%
	Recovery rate	— %			35	%			35	%			37	%		30	%
	Redeemable	N/A		yes				yes				yes			yes
	Total time (years)	—			0.75				1				1.26			1.51
	Dilution effect	N/A		yes				yes				yes			yes
	Fair value	$                  —		$                —				$ 0.2 million				$ 0.5 million			$ 0.5 million
	Fair value as a percent of par	— %			0.02	%			0.7	%			3.3	%		3.4	%
	Based on historical VWAP of the Company’s common stock as well as the historic average dollar trading volume of the Company’s common stock, the percentage volume condition is the probability that the Company will convert monthly installment payments into the Company’s common stock. The expected volatility rate was estimated based on an equal weighting of the historical volatility of the Company’s common stock and the implied volatility of the Company’s traded options. To determine the risk-free interest rate, an interpolated rate was used based on the one, two and three-year United States Treasury rates. The bond yield was estimated using comparable corporate debt and yield information. The recovery rate of the Exchanged Note was estimated by reviewing historical corporate debt that went into default. The bond is redeemable by the Company at any point after the one-year anniversary of the grant date provided certain provisions within the note. The total time is based on the actual 30-month contractual terms. It was determined that there is a dilution effect based on the Company’s ability to make payments in shares of common stock.
	The Company recorded net gains, resulting from the decrease in the fair value of the derivative, of $0.3 million to change in fair value of derivatives and warrants in each of the three and six months ended September 30, 2013.
	Senior Secured Term Loan – First Warrant
	On June 5, 2012, the Company entered into the Loan and Security Agreement with Hercules. (See Note 10, “Debt,” for additional information regarding the Loan and Security Agreement.) In conjunction with this agreement, the Company issued the First Warrant to purchase 139,276 shares of the Company’s common stock. The First Warrant is exercisable at any time after its issuance and expires on December 5, 2017, at a price equal to $3.59 per share subject to certain price-based and other anti-dilution adjustments.  The exercise price was reduced to $1.95 per share in conjunction with entering into the New Term Loan.  An anti-dilution adjustment resulted in a reduction to the exercise price to $1.94 per share as of September 30, 2014.
	The Company accounts for the First Warrant as a liability due to certain provisions within the warrant, which requires that it be recorded at fair value. The First Warrant is subject to revaluation at each balance sheet date and any change in fair value will be recorded as changes in fair value of derivatives and warrants until the earlier of expiration or its exercise at which time the warrant liability will be reclassified to equity.
	Following is a summary of the key assumptions used to calculate the fair value of the First Warrant:
		September 30,				June 30,
	Fiscal Year 14	2014				2014
	Risk-free interest rate		1.13	%			1.04	%
	Expected annual dividend yield		—	%			—	%
	Expected volatility		78.3	%			82.75	%
	Term  (years)		3.18				3.43
	Fair value	$ 0.1 million				$ 0.1 million
										Post-modification				Pre-modification
		March 31,				December 31,				November 15,				November 15,				September 30,			June 30,			March 31,
	Fiscal Year 13	2014				2013				2013				2013				2013			2013			2013
	Risk-free interest rate		1.18	%			1.24	%			1	%			1	%			1.09	%		1.2	%		0.7	%
	Expected annual dividend yield		—	%			—	%			—	%			—	%			—	%		—	%		—	%
	Expected volatility		80.73	%			74.79	%			72.64	%			72.64	%			72.1	%		72.3	%		72.01	%
	Term  (years)		3.68				3.93				4.05				4.05				4.18			4.43			4.68
	Fair value	$ 0.1 million				$ 0.1 million				$ 0.1 million				$ 0.1 million				$ 0.2 million			$ 0.2 million			$ 0.2 million
	The Company recorded no change in fair value of derivatives and warrants during either of the three or six month periods ended September 30, 2014 and 2013 due to nominal fair value fluctuation.
Senior Secured Term Loan – Second Warrant
On November 15, 2013, the Company amended the Loan and Security Agreement with Hercules and entered into the New Term Loan. (See Note 10, “Debt,” for additional information regarding the New Term Loan.) In conjunction with this agreement, the Company issued the Second Warrant to purchase 256,410 shares of the Company’s common stock. The Second Warrant is exercisable at any time after its issuance and expires on May 15, 2019, at a price equal to $1.95 per share subject to certain price-based and other anti-dilution adjustments.  An anti-dilution adjustment resulted in a reduction to the exercise price to $1.94 per share as of September 30, 2014.
The Company accounts for the Second Warrant as a liability due to certain provisions within the warrant, which requires that it be recorded at fair value. The Second Warrant is subject to revaluation at each balance sheet date and any change in fair value will be recorded as changes in fair value of derivatives and warrants until the earlier of expiration or its exercise at which time the warrant liability will be reclassified to equity.
Following is a summary of the key assumptions used to calculate the fair value of the Second Warrant:
	September 30,				June 30,
Fiscal Year 14	2014				2014
Risk-free interest rate		1.65	%			1.57	%
Expected annual dividend yield		—	%			—	%
Expected volatility		78.1	%			80	%
Term  (years)		4.62				4.87
Fair value	$ 0.2 million				$ 0.3 million
									New Issuance
	March 31,				December 31,				November 15,
Fiscal Year 13	2014				2013				2013
Risk-free interest rate		1.76	%			1.89	%			1.55	%
Expected annual dividend yield		—	%			—	%			—	%
Expected volatility		79.73	%			80.37	%			76.97	%
Term  (years)		5.12				5.37				5.49
Fair value	$ 0.3 million				$ 0.3 million				$ 0.3 million
The Company recorded a decrease in the fair value of the Second Warrant resulting in a gain of $0.1 million in each of the three and six months ended September 30, 2014.
The Company prepared its estimates for the assumptions used to determine the fair value of the warrants issued in conjunction with both the Exchanged Note and Term Loans utilizing the respective terms of the warrants with similar inputs, as described above.

Stockholders_Equity

Stockholders' Equity	6 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Stockholders' Equity	'
	12. Stockholders’ Equity
	On November 15, 2013, the Company entered into an ATM arrangement, pursuant to which, the Company may, at its discretion, sell up to $30.0 million of the Company’s common stock through its sales agent, MLV.   Sales of common stock made under the ATM are made on The NASDAQ Global Market under the Company’s previously filed and currently effective Registration Statement on Form S-3 (File No. 333-191153) by means of ordinary brokers’ transactions at market prices. Additionally, under the terms of the ATM, the Company may also sell shares of its common stock through MLV, on The NASDAQ Global Select Market or otherwise, at negotiated prices or at prices related to the prevailing market price. Under the terms of the ATM, MLV may not engage in any proprietary trading or trading as principal for MLV’s own account. MLV uses its commercially reasonable efforts to sell the Company’s common stock from time to time, based upon the Company’s instructions (including any price, time or size limits or other customary parameters or conditions the Company may impose). The Company pays MLV a commission of up to 3% of the gross proceeds from the sale of shares of its common stock under the ATM. The Company has also agreed to provide MLV with customary indemnification rights. The offering of common stock pursuant to the ATM will terminate upon the earlier of the sale of all of the common stock subject to the ATM or the termination of the ATM by the Company or MLV. Either party may terminate the ATM at its sole discretion at any time upon written notice to the other party.
	During the three months ended September 30, 2014, the Company received net proceeds of $3.7 million, including sales commissions and offering expenses, from sales of approximately 2.1 million shares of its common stock at an average sales price of approximately $1.75 per share under the ATM.  As of September 30, 2014, the Company has approximately $17.1 million of remaining availability under the ATM.

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
	Sep. 30, 2014
Commitments And Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	13. Commitments and Contingencies
	Commitments
	Purchase Commitments
	The Company periodically enters into non-cancelable purchase contracts in order to ensure the availability of materials to support production of its products. Purchase commitments represent enforceable and legally binding agreements with suppliers to purchase goods or services. The Company periodically assesses the need to provide for impairment on these purchase contracts and record a loss on purchase commitments when required. As of September 30, 2014, the Company had paid the remaining adverse purchase commitment liability.
	Legal Contingencies
	From time to time, the Company is involved in legal and administrative proceedings and claims of various types. The Company records a liability in its consolidated financial statements for these matters when a loss is known or considered probable and the amount can be reasonably estimated. The Company reviews these estimates each accounting period as additional information is known and adjusts the loss provision when appropriate. If a matter is both probable to result in a liability and the amounts of loss can be reasonably estimated, the Company estimates and discloses the possible loss or range of loss. If the loss is not probable or cannot be reasonably estimated, a liability is not recorded in its consolidated financial statements.
	Ghodawat, a company registered in India carrying on the business of wind power development, lodged a Request for Arbitration with the ICC Court on May 12, 2011 and named AMSC Windtec GmbH (“AMSC Austria”) as the Respondent. Under the Request for Arbitration, Ghodawat alleged that AMSC Austria breached an agreement dated March 19, 2008 pursuant to which AMSC Austria granted a license to Ghodawat to manufacture, use, sell, market, erect, commission and maintain certain wind turbines using its technical information and wind turbine design (the “License Agreement”). Under the Request for Arbitration, Ghodawat’s claims in this arbitration amounted to approximately €18 million ($24 million).  AMSC Austria submitted counterclaims under the License Agreement against Ghodawat in the amount of approximately €6 million ($8 million).  On August 29, 2014, the ICC Court ruled that AMSC Austria was liable for damages and awarded Ghodawat approximately €8.3 million (approximately $10.6 million), which includes reimbursement of legal costs and associated expenses.  Interest on this amount will accrue at a rate of 5.33% from the date of award.  The Company had recorded a loss contingency of $0.5 million based on its assessment of probable losses on this claim in a prior period.  As a result of the arbitration award liability, the Company recorded a charge of $10.2 million during the three months ended September 30, 2014.
	Between April 6, 2011 and May 12, 2011, seven putative securities class action complaints were filed against the Company and two of its officers in the United States District Court for the District of Massachusetts (the “Court”); one complaint additionally asserted claims against the underwriters who participated in its November 12, 2010 securities offering. On June 7, 2011, the Court consolidated these actions under the caption Lenartz v. American Superconductor Corporation, et al., Docket No. 1:11-cv-10582-WGY. On August 31, 2011, Lead Plaintiff, the Plumbers and Pipefitters National Pension Fund, filed a consolidated amended complaint against the Company, its officers and directors, and the underwriters who participated in its November 12, 2010 securities offering, asserting claims under sections 10(b) and 20(a) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) and Rule 10b-5 promulgated under the Exchange Act, as well as under sections 11, 12(a)(2) and 15 of the Securities Act.  On November 19, 2013, the Company entered into a Stipulation and Agreement of Settlement (the “Stipulation”), which resolved the claims asserted against the Company, certain of its current and former officers and directors, and the underwriters. The terms of the Stipulation provided, among other things, a settlement payment by the Company of $10.0 million, $8.2 million of which was to be funded by the Company’s insurers and $1.8 million of which was paid through the issuance of 944,882 shares of its common stock (the “Settlement Shares”). In the event that the value of the Settlement Shares (as calculated under the Stipulation) decreased as of the effective date of the settlement, the Company was required to make a cash payment for the difference in value.  The effective date of the Stipulation was June 5, 2014 (the “Effective Date”).  Pursuant to the terms of the Stipulation, (i) on June 11, 2014, the Company made a cash payment of approximately $0.5 million for the decrease in value of the Settlement Shares (as calculated under the Stipulation) as of the Effective Date, and (ii) on June 18, 2014, the Company issued the Settlement Shares.  The issuance of the Settlement Shares was exempt from registration pursuant to Section 3(a)(10) of the Securities Act.  The aforementioned payments by the Company represented the final amounts to be paid to the plaintiffs under the Stipulation.
	Between May 4, 2011 and June 17, 2011, four putative shareholder derivative complaints were filed against the Company (as a nominal defendant) and certain of its directors in the Court. On July 5, 2011, the Court consolidated three of these actions under the caption In re American Superconductor Corporation Derivative Litigation, Docket No. 1:11-cv-10784-WGY. On June 1, 2011, the plaintiff in the fourth action, Marlborough Family Revocable Trust v. Yurek, et al., moved to voluntarily dismiss its complaint and refiled its complaint in Superior Court for the Commonwealth of Massachusetts, Middlesex County. On September 7, 2011, the Marlborough action and another putative shareholder derivative complaint filed in Superior Court for the Commonwealth of Massachusetts were consolidated. That consolidated matter was captioned In re American Superconductor Corporation Shareholder Derivative Litigation, Docket No. 11-1961. On January 12, 2012, an additional shareholder derivative complaint was filed in the Court of Chancery for the State of Delaware. That matter was captioned Krasnoff v. Budhraja, et al., Docket No. 7171. On February 4, 2014, the Company entered into a Stipulation and Agreement of Settlement (the “Derivative Stipulation”) to settle In re American Superconductor Corporation Derivative Litigation, In re American Superconductor Corporation Shareholder Derivative Litigation, and Krasnoff v. Budhraja, et al., (together, the “Derivative Actions”).  The Derivative Stipulation provided for, among other things, (a) a release of all claims relating to the Derivative Actions for the Company, the individual defendants, who are all current or former officers and directors of the Company, and the plaintiffs; (b) a requirement that the Company pay to plaintiffs’ counsel $475,000 for fees and expenses, which was fully funded by the Company’s insurers; and (c) certain additions to the Company’s corporate governance policies. The terms of the Derivative Stipulation were subject to approval by the Court following notice to stockholders. By order entered May 8, 2014, the Court approved the terms of the Derivative Stipulation and issued a final judgment dismissing In re American Superconductor Corporation Derivative Litigation.  Pursuant to the terms of the Derivative Stipulation, the Company and the plaintiffs subsequently jointly sought and obtained dismissal of In re American Superconductor Corporation Shareholder Derivative Litigation, and Krasnoff v. Budhraja, et al. The effective date of the settlement was June 10, 2014.
	On September 13, 2011, the Company commenced a series of legal actions in China against Sinovel Wind Group Co. Ltd. (“Sinovel”). The Company’s Chinese subsidiary, Suzhou AMSC Superconductor Co. Ltd., filed a claim for arbitration with the Beijing Arbitration Commission in accordance with the terms of the Company’s supply contracts with Sinovel. The case is captioned (2011) Jing Zhong An Zi No. 0963. On March 31, 2011, Sinovel refused to accept contracted shipments of 1.5 megawatt, (“MW”) and 3 MW wind turbine core electrical components and spare parts that the Company was prepared to deliver. The Company alleges that these actions constitute material breaches of its contracts because Sinovel did not give it notice that it intended to delay deliveries as required under the contracts. Moreover, the Company alleges that Sinovel has refused to pay past due amounts for prior shipments of core electrical components and spare parts. The Company is seeking compensation for past product shipments and retention (including interest) in the amount of approximately RMB 485 million ($76 million) due to Sinovel’s breaches of its contracts. The Company is also seeking specific performance of its existing contracts as well as reimbursement of all costs and reasonable expenses with respect to the arbitration. The value of the undelivered components under the existing contracts, including the deliveries refused by Sinovel in March 2011, amounts to approximately RMB 4.6 billion ($720 million).
	On October 8, 2011, Sinovel filed with the Beijing Arbitration Commission an application under the caption (2011) Jing Zhong An Zi No. 0963, for a counterclaim against the Company for breach of the same contracts under which the Company filed its original arbitration claim. Sinovel claimed, among other things, that the goods supplied by the Company do not conform to the standards specified in the contracts and claimed damages in the amount of approximately RMB 370 million ($58 million). On October 17, 2011, Sinovel filed with the Beijing Arbitration Commission a request for change of counterclaim to increase its damage claim to approximately RMB 1 billion ($157 million). On December 22, 2011, Sinovel filed with the Beijing Arbitration Commission an additional request for change of counterclaim to increase its damages claim to approximately RMB 1.2 billion ($190 million). On February 27, 2012, Sinovel filed with the Beijing Arbitration Commission an application under the caption (2012) Jing Zhong An Zi No. 0157, against the Company for breach of the same contracts under which the Company filed its original arbitration claim. Sinovel claimed, among other things, that the goods supplied by the Company do not conform to the standards specified in the contracts and claimed damages in the amount of approximately RMB 105 million ($17 million). The Company believes that Sinovel’s claims are without merit and it intends to defend these actions vigorously. Since the proceedings in this matter are in relatively early stages, the Company cannot reasonably estimate possible losses or range of losses at this time.
	The Company also submitted a civil action application to the Beijing No. 1 Intermediate People’s Court under the caption (2011) Yi Zhong Min Chu Zi No. 15524, against Sinovel for software copyright infringement on September 13, 2011. The application alleges Sinovel’s unauthorized use of portions of the Company’s wind turbine control software source code developed for Sinovel’s 1.5MW wind turbines and the binary code, or upper layer, of the Company’s software for the PM3000 power converters in 1.5MW wind turbines. In July 2011, a former employee of the Company’s Austrian subsidiary was arrested in Austria on charges of economic espionage and fraudulent manipulation of data. In September 2011, the former employee pled guilty to the charges, and was imprisoned. As a result of the Company’s internal investigation and a criminal investigation conducted by Austrian authorities, the Company believes that this former employee was contracted by Sinovel through an intermediary while employed by the Company and improperly obtained and transferred to Sinovel portions of its wind turbine control software source code developed for Sinovel’s 1.5MW wind turbines. Moreover, the Company believes the former employee illegally used source code to develop for Sinovel a software modification to circumvent the encryption and remove technical protection measures on the Company’s PM3000 power converters in 1.5MW wind turbines in the field. The Company is seeking a cease and desist order with respect to the unauthorized copying, installation and use of its software, monetary damages of approximately RMB 38 million ($6 million) for its economic losses and reimbursement of all costs and reasonable expenses. The Beijing No. 1 Intermediate People’s Court accepted the case, which was necessary in order for the case to proceed. In November 2011, Sinovel filed a motion to remove this case from the Beijing No. 1 Intermediate People’s Court and transfer the matter to the Beijing Arbitration Commission. On February 14, 2012, the court denied Sinovel’s motion to remove the case. On February 21, 2012, Sinovel filed an appeal of the Beijing No. 1 Intermediate People’s Court decision to the Beijing Higher People’s Court. On April 25, 2012, the Beijing Higher People’s Court issued a final Civil Ruling which supports the Beijing No.1 Intermediate People’s Court’s civil ruling and rejected Sinovel’s appeal. Sinovel filed an appeal of the Beijing Higher People’s Court’s decision with China’s Supreme People’s Court. A hearing regarding this appeal was held at the Chinese Supreme People’s Court on October 26, 2012. On November 23, 2012, China’s Supreme People’s Court issued a Civil Ruling, holding that (1) it will conduct a re-trial of Sinovel’s appeal, and (2) the lower court’s decision will be stayed pending the re-trial. China’s Supreme People’s Court conducted a re-trial of Sinovel’s appeal on May 29, 2013.  On January 26, 2014, the Supreme People’s Court ruled to uphold the Beijing Higher People’s Court ruling that the dispute shall be heard by the court.  On September 15, 2014, the Beijing No. 1 Intermediate People’s Court held its first substantive hearing in the Beijing case.  At the hearing, the parties presented evidence, reviewed claims, and answered questions from the court.  The Company is awaiting a decision from the Beijing No. 1 Intermediate People’s Court.
	The Company submitted a civil action application to the Beijing Higher People’s Court against Sinovel and certain of its employees for trade secret infringement on September 13, 2011 under the caption (2011) Gao Min Chu Zi No. 4193. The application alleges the defendants’ unauthorized use of portions of the Company’s wind turbine control software source code developed for Sinovel’s 1.5MW wind turbines as described above with respect to the Copyright Action. The Company is seeking monetary damages of RMB 2.9 billion ($453 million) for the trade secret infringement as well as reimbursement of all costs and reasonable expenses. The Beijing Higher People’s Court accepted the case, which was necessary in order for the case to proceed. On December 22, 2011, the Beijing Higher People’s Court transferred this case to the Beijing No. 1 Intermediate People’s Court under the caption (2011) Gao Min Chu Zi No. 4193. On June 7, 2012, the Company received an Acceptance Notice from the Beijing No.1 Intermediate People’s Court under the caption (2012) Yi Zhong Min Chu Zi No.6833. In August 2012, Sinovel filed a motion to remove this case from the Beijing No. 1 Intermediate People’s Court and transfer the matter to the Beijing Arbitration Commission. On February 24, 2014, the Beijing No. 1 Intermediate People’s Court denied Sinovel’s motion to remove and transfer the case.  On March 13, 2014, Sinovel filed an appeal of the Beijing No. 1 Intermediate People’s Court decision to the Beijing Higher People’s Court.  On August 7, 2014, the Beijing Higher People’s Court upheld the Beijing No.1 Intermediate Court’s decision and rejected Sinovel’s appeal regarding the jurisdiction opposition.  The Company is currently awaiting notice from the Beijing No. 1 Intermediate People’s Court regarding the first hearing date.
	On September 16, 2011, the Company filed a civil copyright infringement complaint in the Hainan Province No. 1 Intermediate People’s Court against Dalian Guotong Electric Co. Ltd. (“Guotong”), a supplier of power converter products to Sinovel, and Huaneng Hainan Power, Inc. (“Huaneng”), a wind farm operator that has purchased Sinovel wind turbines containing Guotong power converter products. The case is captioned (2011) Hainan Yi Zhong Min Chu Zi No. 62. The application alleges that the Company’s PM1000 converters in certain Sinovel wind turbines have been replaced by converters produced by Guotong. Because the Guotong converters are being used in wind turbines containing the Company’s wind turbine control software, the Company believes that its copyrighted software is being infringed. The Company is seeking a cease and desist order with respect to the unauthorized use of its software, monetary damages of RMB 1.2 million ($0.2 million) for its economic losses (with respect to Guotong only) and reimbursement of all costs and reasonable expenses. The court has accepted the case, which was necessary in order for the case to proceed. In addition, upon the request of the defendant Huaneng, Sinovel has been added by the court to this case as a defendant and Huaneng has been released from this case. In December 2011, Sinovel filed a jurisdiction opposition motion requesting dismissal by the Hainan Province No. 1 Intermediate People’s Court, saying the case should be governed by the Beijing Arbitration Commission. On February 3, 2012, the Company received the Civil Ruling from the court, which granted Sinovel’s motion, and dismissed the entire case. The Company appealed the court’s ruling to the Hainan Higher Court, which on April 5, 2012 upheld the decision of the Hainan Province No. 1 Intermediate People’s Court. On April 9, 2012, the Company filed an appeal of the Hainan Higher Court’s decision with China’s Supreme People’s Court. China’s Supreme People’s Court accepted the appeal on May 23, 2012. The case is captioned, (2012) Min Shen Zi No. 630. On December 20, 2012, China’s Supreme People’s Court issued a Civil ruling, holding that (1) it will conduct a re-trial of the Company’s appeal and (2) the lower court’s decision will be stayed pending the re-trial. China’s Supreme People’s Court conducted a re-trial of Sinovel’s appeal on May 29, 2013.  On January 26, 2014, the Supreme People’s Court revoked Hainan No. 1 Intermediate People’s Court and Hainan Higher People’s Court rulings and ruled that the case shall be heard by the Hainan No. 1 Intermediate People’s Court.  The Hainan No. 1 Intermediate People’s Court accepted the case under the caption (2014) Hainan Yi Zhong Min San Chu Zi No. 1. On October 21, 2014, the Hainan No. 1 Intermediate People’s Court changed the caption of this case to (2014) Hainan Yi Zhong Zhi Min Chu Zi No. 2, and scheduled the first hearing date to be held on November 18, 2014.
	Other
	The Company enters into long-term construction contracts with customers that require the Company to obtain performance bonds. The Company is required to deposit an amount equivalent to some or all the face amount of the performance bonds into an escrow account until the termination of the bond. When the performance conditions are met, amounts deposited as collateral for the performance bonds are returned to the Company. In addition, the Company has various contractual arrangements in which minimum quantities of goods or services have been committed to be purchased on an annual basis.
	As of September 30, 2014 the Company had $3.4 million of restricted cash included in current assets, and $0.1 million of restricted cash included in long-term assets. These amounts included in restricted cash represent deposits to secure letters of credit for various supply contracts. These deposits are held in interest bearing accounts.
	The Company had an unused, unsecured line of credit consisting of €2.7 million (approximately $3.4 million) in Austria as of September 30, 2014.

Minority_Investments

Minority Investments	6 Months Ended
	Sep. 30, 2014
Equity Method Investments And Joint Ventures [Abstract]	'
Minority Investments	'
	14. Minority Investments
	Investment in Tres Amigas LLC
	The Company made an investment in Tres Amigas, focused on providing the first common interconnection of America’s three power grids to help the country achieve its renewable energy goals and facilitate the smooth, reliable and efficient transfer of green power from region to region.  The Company’s original investment in Tres Amigas was $5.4 million.  As of September 30, 2014, the Company holds a 26% ownership interest in Tres Amigas.
	The Company has determined that Tres Amigas is a variable interest entity (“VIE”) and that the Company is not the primary beneficiary of the VIE.  Therefore, the Company has not consolidated Tres Amigas as of September 30, 2014.  The investment is carried at acquisition cost, plus the Company’s equity in undistributed earnings or losses.  The Company’s maximum exposure to loss is limited to the Company’s recorded investment in this VIE.  The Company’s investment in Tres Amigas is included in other assets on the consolidated balance sheet and the equity in undistributed losses of Tres Amigas is included in other expense, net, on the unaudited condensed consolidated statements of operations.
	The net investment activity for the six months ended September 30, 2014 is as follows (in thousands):
	Balance at April 1, 2014	$	1,845
	Minority interest in net losses		(410	)
	Balance at September 30, 2014	$	1,435
	Investment in Blade Dynamics Ltd.
	The Company has acquired (through its Austrian subsidiary), a minority ownership position in Blade Dynamics, a designer and manufacturer of advanced wind turbine blades based on proprietary materials and structural technologies.  The Company’s original investment was for $8.0 million in cash. As of September 30, 2014, the Company holds a 19% ownership interest in Blade Dynamics.
	The investment is carried at the acquisition cost, plus the Company’s equity in undistributed earnings or losses, through December 1, 2012, the date which the company no longer reports undistributed earnings or losses. The Company’s investment in Blade Dynamics is included in other assets on the unaudited condensed consolidated balance sheet and the equity in undistributed losses of Blade Dynamics is included in other expense, net, on the unaudited condensed consolidated statements of operations.
	During the year ended March 31, 2014, the Company determined that as a result of its efforts to sell its investment in Blade Dynamics, certain indicators of impairment existed which required the Company to perform further analysis.  As a result of this analysis, the Company recorded an impairment charge for approximately $1.3 million.
	During the three months ended September 30, 2014, the Company determined that as a result of dilutive financing which resulted in the Company losing certain of its shareholder rights, as well as certain operational issues and adverse changes to the potential sale scenarios previously considered, its investment in Blade Dynamics was no longer recoverable and therefore recorded an impairment charge of $3.5 million.
	The net investment activity for the six months ended September 30, 2014 is as follows (in thousands):
	Balance at April 1, 2014	$	3,690
	Net foreign exchange rate impact		(226	)
	Impairment		(3,464	)
	Balance at September 30, 2014	$	-

Business_Segments

Business Segments	6 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Business Segments	'
	15. Business Segments
	The Company reports its financial results in two reportable business segments: Wind and Grid.
	Through its Windtec Solutions, the Wind business segment enables manufacturers to field wind turbines with highly competitive power output, reliability and affordability. The Company supplies advanced power electronics and control systems, licenses its highly engineered wind turbine designs, and provides extensive customer support services to wind turbine manufacturers. Its design portfolio includes a broad range of drive trains and power ratings of 2 MWs and higher. It provides a broad range of power electronics and software-based control systems that are highly integrated and designed for optimized performance, efficiency, and grid compatibility.
	Through its Gridtec Solutions, the Grid business segment enables electric utilities and renewable energy project developers to connect, transmit and distribute power with highly competitive efficiency, reliability and affordability. The Company provides transmission planning services that allow it to identify power grid congestion, poor power quality and other risks, which help the Company determine how its solutions can improve network performance. These services often lead to sales of grid interconnection solutions for wind farms and solar power plants, power quality systems and transmission and distribution cable systems.
	The operating results for the two business segments are as follows (in thousands):
		Three months ended September 30,						Six months ended September 30,
		2014			2013			2014			2013
	Revenues:
	Wind	$	7,462		$	14,691		$	15,113		$	29,392
	Grid		4,993			9,490			9,038			17,875
	Total	$	12,455		$	24,181		$	24,151		$	47,267
		Three months ended September 30,						Six months ended September 30,
		2014			2013			2014			2013
	Operating loss:
	Wind	$	(14,611	)	$	(2,449	)	$	(18,091	)	$	(4,274	)
	Grid		(6,559	)		(5,750	)		(12,966	)		(10,618	)
	Unallocated corporate expenses		(5,230	)		(2,829	)		(8,010	)		(4,985	)
	Total	$	(26,400	)	$	(11,028	)	$	(39,067	)	$	(19,877	)
	The accounting policies of the business segments are the same as those for the consolidated Company. The Company’s business segments have been determined in accordance with the Company’s internal management structure, which is organized based on operating activities. The Company evaluates performance based upon several factors, of which the primary financial measures are segment revenues and segment operating loss. The disaggregated financial results of the segments reflect allocation of certain functional expense categories consistent with the basis and manner in which Company management internally disaggregates financial information for the purpose of assisting in making internal operating decisions. In addition, certain corporate expenses which the Company does not believe are specifically attributable or allocable to either of the two business segments have been excluded from the segment operating loss.
	Unallocated corporate expenses primarily consist of stock-based compensation expense of $1.5 million and $3.1 million, and restructuring and impairment charges of $3.7 million and $4.9 million, for the three and six months ended September 30, 2014, respectively. Unallocated corporate expenses primarily consist of stock-based compensation expense of $2.2 million and $4.3 million, respectively, for the three and six months ended September 30, 2013, as well as restructuring and impairment charges of $0.8 million for each of the three and six months ended September 30, 2013, respectively.
	Total assets for the two business segments are as follows (in thousands):
		September 30,			March 31,
		2014			2014
	Wind	$	47,569		$	36,701
	Grid		44,779			54,342
	Corporate assets		63,499			77,466
	Total	$	155,847		$	168,509
	The following table sets forth customers who represented 10% or more of the Company’s total revenues for the three and six months ended September 30, 2014 and 2013:
		Three months ended September 30,						Six months ended September 30,
		2014			2013			2014			2013
	INOX Wind Limited		48	%		27	%		48	%		21	%
	RES American Construction, Inc		16	%		—	%	<10		%		—	%
	Beijing JINGCHENG New Energy Co., Ltd		—	%		28	%	<10		%		31	%

Recent_Accounting_Pronouncemen

Recent Accounting Pronouncements	6 Months Ended
	Sep. 30, 2014
Accounting Changes And Error Corrections [Abstract]	'
Recent Accounting Pronouncements	'
	16. Recent Accounting Pronouncements
	In May 2014, the FASB and the International Accounting Standards Board (IASB) issued ASU 2014-09, ASU Revenue from Contracts with Customers (Topic 606), The guidance substantially converges final standards on revenue recognition between the FASB and IASB providing a framework on addressing revenue recognition issues and, upon its effective date, replaces almost all exiting revenue recognition guidance, including industry-specific guidance, in current U.S. generally accepted accounting principles.  The ASU is effective for annual reporting periods beginning after December 15, 2016.  The Company is currently evaluating the impact of adopting ASU 2014-09 to determine the impact, if any, it may have on its current practices.
	In July 2014, the FASB issued ASU 2014-12, Compensation – Stock Compensation (Topic 718): Accounting for Share Based Payments When the Terms of an Award Provide that a Performance Target could be Achieved after the Requisite Service Period.    To account for such awards, a reporting entity should apply existing guidance in FASB Accounting Standards Codification Topic 718, Compensation – Stock Compensation, as it relates to awards with performance conditions that affect vesting.  As such, the performance target should not be reflected in estimating the grant-date fair value of the award. This ASU is effective for annual reporting periods and interim periods, within those annual periods beginning after December 15, 2015.  The Company is currently evaluating the impact of adopting ASU 2014-12 to determine the impact, if any, it may have on its current practices.
	In August 2014, the FASB issued ASU 2014-13, Consolidation (Topic 810): Measuring the Financial Assets and Financial Liabilities of a Consolidated Collateralized Financing Entity.  The new standard applies to reporting entities that are required to consolidate a collaterized financing entity under the variable interest entities subtopic 810-10. This ASU is effective for annual reporting periods ending after December 15, 2016, and interim periods within annual periods beginning after December 15, 2016.  The Company is currently evaluating the impact of adopting ASU 2014-13 to determine the impact, but currently does not believe there will be an impact on its consolidated results of operations, financial condition, or cash flow.
	In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements – Going Concern (Subtopic 205-40): Disclosure of Uncertainties About an Entity’s Ability to Continue as a Going Concern.  The new standard explicitly requires the assessment at interim and annual periods, and provides management with its own disclosure guidance.  This ASU is effective for annual reporting periods and interim periods, within those annual periods ending after December 15, 2016.  The Company is currently evaluating the impact of adopting ASU 2014-15 to determine the impact, if any; it may have on its current practices.

Subsequent_Events

Subsequent Events	6 Months Ended
	Sep. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	17. Subsequent Events
	The Company has performed an evaluation of subsequent events through the time of filing this Quarterly Report on Form 10-Q with the SEC, and has determined that there are no such events that are required to be disclosed.

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	6 Months Ended
	Sep. 30, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Summary of Stock-Based Compensation Expense	'
	The Company accounts for its stock-based compensation at fair value. The following table summarizes stock-based compensation expense by financial statement line item for the three and six months ended September 30, 2014 and 2013 (in thousands):
		Three months ended September 30,								Six months ended September 30,
		2014				2013				2014				2013
	Cost of revenues	$	194			$	224			$	346			$	429
	Research and development		521				585				1,000				1,159
	Selling, general and administrative		803				1,343				1,753				2,699
	Total	$	1,518			$	2,152			$	3,099			$	4,287
Schedule of Weighted Average Assumptions used in Black-Scholes Valuation Model for Stock Options Granted	'
	The weighted-average assumptions used in the Black-Scholes valuation model for stock options granted during the three and six months ended September 30, 2014 and 2013 are as follows:
		Three months ended September 30,						Six months ended September 30,
		2014		2013				2014				2013
	Expected volatility	N/A			75.4	%			85.5	%			75.1	%
	Risk-free interest rate	N/A			1.7	%			1.9	%			1.7	%
	Expected life (years)	N/A			5.8				5.8				5.9
	Dividend yield	N/A		None				None				None

Computation_of_Net_Loss_per_Co1

Computation of Net Loss per Common Share (Tables)	6 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Reconciliation of Numerators and Denominators of EPS Calculation	'
	The following table reconciles the numerators and denominators of the earnings per share calculation for the three and six months ended September 30, 2014 and 2013 (in thousands, except per share data):
		Three months ended September 30,						Six months ended September 30,
		2014			2013			2014			2013
	Numerator:
	Net loss	$	(25,423	)	$	(14,623	)	$	(38,939	)	$	(25,135	)
	Denominator:
	Weighted-average shares of common stock outstanding		83,048			62,787			80,876			61,583
	Weighted-average shares subject to repurchase		(1,577	)		(1,671	)		(1,286	)		(1,871	)
	Shares used in per-share calculation ― basic		81,471			61,116			79,590			59,712
	Shares used in per-share calculation ― diluted		81,471			61,116			79,590			59,712
	Net loss per share ― basic	$	(0.31	)	$	(0.24	)	$	(0.49	)	$	(0.42	)
	Net loss per share ― diluted	$	(0.31	)	$	(0.24	)	$	(0.49	)	$	(0.42	)

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	6 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Schedule of Assets and Liabilities Carried at Fair Value	'
	The following table provides the assets and liabilities carried at fair value, measured as of September 30, 2014 and March 31, 2014 (in thousands):
		Total			Quoted Prices in			Significant Other		Significant
		Carrying			Active Markets			Observable Inputs		Unobservable Inputs
		Value			(Level 1)			(Level 2)		(Level 3)
	September 30, 2014:
	Assets:
	Cash equivalents	$	20,185		$	20,185		$	-	$	-
	Derivative liabilities:
	Warrants	$	1,841		$	-		$	-	$	1,841
		Total			Quoted Prices in			Significant Other		Significant
		Carrying			Active Markets			Observable Inputs		Unobservable Inputs
		Value			(Level 1)			(Level 2)		(Level 3)
	March 31, 2014:
	Assets:
	Cash equivalents	$	17,675		$	17,675		$	-	$	-
	Derivative liabilities:
	Warrants	$	2,601		$	-		$	-	$	2,601
Schedule of Liabilities Measured at Fair Value	'
	The table below reflects the activity for the Company’s major classes of liabilities measured at fair value (in thousands):
					Warrants
	April  1, 2014				$	2,601
	Mark to market adjustment					(760	)
	Balance at September 30, 2014				$	1,841
		Derivative
		Liability			Warrants
	April  1, 2013	$	529		$	3,633
	Warrant issuance with Senior Secured Term Loan		-			315
	Mark to market adjustment		(525	)		(1,347	)
	Extinguishment of derivative liability		(4	)		-
	Balance at March 31, 2014	$	-		$	2,601
Schedule of Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis	'
	The following table provides the assets and liabilities measured at fair value on a non-recurring basis, as of September 30, 2014 and March 31, 2014 (in thousands).  During the three months ended September 30, 2014 the following asset was determined to be no longer recoverable and was fully impaired.  See note 14, “Minority Investments” for further details:
		Total			Quoted Prices in			Significant Other		Significant
		Carrying			Active Markets			Observable Inputs		Unobservable Inputs
		Value			(Level 1)			(Level 2)		(Level 3)
	September 30, 2014:
	Assets:
	Investment in unconsolidated entity – Blade Dynamics	$	-		$	-		$	-	$	-
	March 31, 2014:
	Assets:
	Investment in unconsolidated entity – Blade Dynamics	$	3,690		$	-		$	-	$	3,690

Accounts_Receivable_Tables

Accounts Receivable (Tables)	6 Months Ended
	Sep. 30, 2014
Receivables [Abstract]	'
Schedule of Accounts Receivable	'
	Accounts receivable at September 30, 2014 and March 31, 2014 consisted of the following (in thousands):
		September 30,			March 31,
		2014			2014
	Accounts receivable (billed)	$	8,410		$	6,113
	Accounts receivable (unbilled)		1,279			1,459
	Less: Allowance for doubtful accounts		(16	)		(16	)
	Accounts receivable, net	$	9,673		$	7,556

Inventory_Tables

Inventory (Tables)	6 Months Ended
	Sep. 30, 2014
Inventory Disclosure [Abstract]	'
Schedule of Inventory	'
	Inventory at September 30, 2014 and March 31, 2014 consisted of the following (in thousands):
		September 30,		March 31,
		2014		2014
	Raw materials	$	6,936	$	3,304
	Work-in-process		6,073		4,047
	Finished goods		8,750		10,275
	Deferred program costs		2,701		3,068
	Net inventory	$	24,460	$	20,694

Accounts_Payable_and_Accrued_E1

Accounts Payable and Accrued Expenses (Tables)	6 Months Ended
	Sep. 30, 2014
Payables And Accruals [Abstract]	'
Schedule of Accounts Payable and Accrued Expenses	'
	Accounts payable and accrued expenses at September 30, 2014 and March 31, 2014 consisted of the following (in thousands):
		September 30,			March 31,
		2014			2014
	Accounts payable	$	7,063		$	1,749
	Accrued inventories in-transit		1,330			212
	Accrued miscellaneous expenses		4,424			6,076
	Accrued outside services		3,026			3,716
	Accrued subcontractor program costs		60			290
	Accrued compensation		4,070			5,939
	Income taxes payable		197			173
	Accrued adverse purchase commitments		-			402
	Accrued warranty		3,367			3,207
	Total	$	23,537		$	21,764
Schedule of Product Warranty Activity	'
	Product warranty activity was as follows (in thousands):
		Three months ended September 30,						Six months ended September 30,
		2014			2013			2014			2013
	Balance at beginning of period	$	2,855		$	2,787		$	3,207		$	2,709
	Change in accruals for warranties during the period		974			342			903			493
	Settlements during the period		(462	)		(60	)		(743	)		(133	)
	Balance at end of period	$	3,367		$	3,069		$	3,367		$	3,069

Restructuring_Tables

Restructuring (Tables)	6 Months Ended
	Sep. 30, 2014
Restructuring And Related Activities [Abstract]	'
Schedule of Restructuring Charges and Cash Payments	'
	The following table presents restructuring charges and cash payments (in thousands):
		Severance pay			Facility Exit and
	Six months ended September 30, 2014:	and benefits			Relocation costs			Total
	Accrued restructuring balance at April 1, 2014	$	844		$	-		$	844
	Charges to operations		632			814			1,445
	Cash payments		(696	)		(814	)		(1,509	)
	Accrued restructuring balance at September 30, 2014	$	780		$	-		$	780
	Six months ended September 30, 2013:
	Accrued restructuring at April 1, 2013	$	145		$	54		$	199
	Charges to operations		751			13			764
	Cash payments		(599	)		(37	)		(636	)
	Non-cash/miscellaneous reductions		(166	)		(30	)		(196	)
	Accrued restructuring balance at September 30, 2013	$	131		$	-		$	131

Warrants_and_Derivative_Liabil1

Warrants and Derivative Liabilities (Tables)	6 Months Ended
	Sep. 30, 2014
Schedule of Fair Value Assumptions Used to Calculate Value of Convertible Note Derivative Feature	'
	Following is a summary of the key assumptions used to value the convertible notes derivative features:
		March 31,		December 31,				September 30,				June 30,			March 31,
	Fiscal Year 13	2014		2013				2013				2013			2013
	Principal outstanding (000's)	$                  —		$	10,411			$	10,411			$	14,389		$	15,380
	Stock price	N/A		$	1.64			$	2.34			$	2.64		$	2.67
	Percentage volume condition met	— %			87.2	%			80.2	%			87.5	%		80.5	%
	Expected volatility	— %			68.63	%			66.26	%			65.8	%		66.91	%
	Risk free rate	— %			0.12	%			0.1	%			0.21	%		0.2	%
	Bond yield	— %			16.5	%			15.5	%			16.7	%		16.5	%
	Recovery rate	— %			35	%			35	%			37	%		30	%
	Redeemable	N/A		yes				yes				yes			yes
	Total time (years)	—			0.75				1				1.26			1.51
	Dilution effect	N/A		yes				yes				yes			yes
	Fair value	$                  —		$                —				$ 0.2 million				$ 0.5 million			$ 0.5 million
	Fair value as a percent of par	— %			0.02	%			0.7	%			3.3	%		3.4	%
Securities Purchase Agreement	'
Schedule of Assumptions Used to Calculate the Fair Value of Warrants	'
	Following is a summary of the key assumptions used to calculate the fair value of the warrant:
		September 30,				June 30,
	Fiscal Year 14	2014				2014
	Risk-free interest rate		1.07	%			0.98	%
	Expected annual dividend yield		—	%			—	%
	Expected volatility		76.2	%			83.5	%
	Term  (years)	3.01				3.26
	Fair value	$1.5 million				$2.3 million
										Post-modification				Pre-modification
		March 31,				December 31,				October 9,				October 9,				September 30,			June 30,			March 31,
	Fiscal Year 13	2014				2013				2013				2013				2013			2013			2013
	Risk-free interest rate		1.11	%			1.17	%			1.05	%			1.05	%			1.02	%		1.13	%		0.67	%
	Expected annual dividend yield		—	%			—	%			—	%			—	%			—	%		—	%		—	%
	Expected volatility		80.99	%			75.6	%			71.45	%			71.45	%			71.98	%		71.9	%		71.74	%
	Term  (years)	3.51				3.76				3.99				3.99					4.01			4.27			4.51
	Fair value	$ 2.2 million				$ 2.2 million				$ 3.2 million				$ 2.2 million				$ 2.5 million			$ 3.0 million			$ 3.4 million
Loan and Security Agreement	'
Schedule of Assumptions Used to Calculate the Fair Value of Warrants	'
	Following is a summary of the key assumptions used to calculate the fair value of the First Warrant:
		September 30,				June 30,
	Fiscal Year 14	2014				2014
	Risk-free interest rate		1.13	%			1.04	%
	Expected annual dividend yield		—	%			—	%
	Expected volatility		78.3	%			82.75	%
	Term  (years)		3.18				3.43
	Fair value	$ 0.1 million				$ 0.1 million
										Post-modification				Pre-modification
		March 31,				December 31,				November 15,				November 15,				September 30,			June 30,			March 31,
	Fiscal Year 13	2014				2013				2013				2013				2013			2013			2013
	Risk-free interest rate		1.18	%			1.24	%			1	%			1	%			1.09	%		1.2	%		0.7	%
	Expected annual dividend yield		—	%			—	%			—	%			—	%			—	%		—	%		—	%
	Expected volatility		80.73	%			74.79	%			72.64	%			72.64	%			72.1	%		72.3	%		72.01	%
	Term  (years)		3.68				3.93				4.05				4.05				4.18			4.43			4.68
	Fair value	$ 0.1 million				$ 0.1 million				$ 0.1 million				$ 0.1 million				$ 0.2 million			$ 0.2 million			$ 0.2 million
Senior Secured Term Loan Second Warrant	'
Schedule of Assumptions Used to Calculate the Fair Value of Warrants	'
	Following is a summary of the key assumptions used to calculate the fair value of the Second Warrant:
		September 30,				June 30,
	Fiscal Year 14	2014				2014
	Risk-free interest rate		1.65	%			1.57	%
	Expected annual dividend yield		—	%			—	%
	Expected volatility		78.1	%			80	%
	Term  (years)		4.62				4.87
	Fair value	$ 0.2 million				$ 0.3 million
										New Issuance
		March 31,				December 31,				November 15,
	Fiscal Year 13	2014				2013				2013
	Risk-free interest rate		1.76	%			1.89	%			1.55	%
	Expected annual dividend yield		—	%			—	%			—	%
	Expected volatility		79.73	%			80.37	%			76.97	%
	Term  (years)		5.12				5.37				5.49
	Fair value	$ 0.3 million				$ 0.3 million				$ 0.3 million

Minority_Investments_Tables

Minority Investments (Tables)	6 Months Ended
	Sep. 30, 2014
Equity Method Investments And Joint Ventures [Abstract]	'
Schedule of Net Investment in Tres Amigas LLC	'
	The net investment activity for the six months ended September 30, 2014 is as follows (in thousands):
	Balance at April 1, 2014	$	1,845
	Minority interest in net losses		(410	)
	Balance at September 30, 2014	$	1,435
Schedule of Net Investment in Blade Dynamics Ltd	'
	The net investment activity for the six months ended September 30, 2014 is as follows (in thousands):
	Balance at April 1, 2014	$	3,690
	Net foreign exchange rate impact		(226	)
	Impairment		(3,464	)
	Balance at September 30, 2014	$	-

Business_Segments_Tables

Business Segments (Tables)	6 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Operating Results for Two Business Segments	'
	The operating results for the two business segments are as follows (in thousands):
		Three months ended September 30,						Six months ended September 30,
		2014			2013			2014			2013
	Revenues:
	Wind	$	7,462		$	14,691		$	15,113		$	29,392
	Grid		4,993			9,490			9,038			17,875
	Total	$	12,455		$	24,181		$	24,151		$	47,267
		Three months ended September 30,						Six months ended September 30,
		2014			2013			2014			2013
	Operating loss:
	Wind	$	(14,611	)	$	(2,449	)	$	(18,091	)	$	(4,274	)
	Grid		(6,559	)		(5,750	)		(12,966	)		(10,618	)
	Unallocated corporate expenses		(5,230	)		(2,829	)		(8,010	)		(4,985	)
	Total	$	(26,400	)	$	(11,028	)	$	(39,067	)	$	(19,877	)
Total Business Segments Assets	'
	Total assets for the two business segments are as follows (in thousands):
		September 30,			March 31,
		2014			2014
	Wind	$	47,569		$	36,701
	Grid		44,779			54,342
	Corporate assets		63,499			77,466
	Total	$	155,847		$	168,509
Schedule of Revenues by Major Customers	'
	The following table sets forth customers who represented 10% or more of the Company’s total revenues for the three and six months ended September 30, 2014 and 2013:
		Three months ended September 30,						Six months ended September 30,
		2014			2013			2014			2013
	INOX Wind Limited		48	%		27	%		48	%		21	%
	RES American Construction, Inc		16	%		—	%	<10		%		—	%
	Beijing JINGCHENG New Energy Co., Ltd		—	%		28	%	<10		%		31	%

Nature_of_the_Business_and_Ope1

Nature of the Business and Operations and Liquidity - Additional Information (Detail)	6 Months Ended					0 Months Ended			3 Months Ended
Share data in Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Mar. 31, 2014	Mar. 31, 2013	Nov. 15, 2013	Aug. 29, 2014	Aug. 29, 2014	Jun. 05, 2012	Sep. 30, 2014	Nov. 15, 2013
	USD ($)	USD ($)	USD ($)	USD ($)	New Term Loan	Ghodawat Energy Pvt Ltd	Ghodawat Energy Pvt Ltd	Hercules	MLV & Co. LLC	MLV & Co. LLC
	Employee				USD ($)	USD ($)	EUR (€)	Senior Secured Loan	Atm Arrangement	Atm Arrangement
								USD ($)	USD ($)	USD ($)
Description Of Business [Line Items]	'	'	'	'	'	'	'	'	'	'
Accumulated deficit	($895,328,000)	'	($856,389,000)	'	'	'	'	'	'	'
Cash and cash equivalents	34,679,000	25,867,000	43,114,000	39,243,000	'	'	'	'	'	'
Net cash used in operating activities	11,369,000	14,779,000	'	'	'	'	'	'	'	'
Liability for damages	'	'	'	'	'	10,600,000	8,300,000	'	'	'
Interest rate accrued on liability for damage	'	'	'	'	'	5.33%	5.33%	'	'	'
Number of workforce persons	291	'	'	'	'	'	'	'	'	'
Debt, face amount	'	'	'	'	10,000,000	'	'	10,000,000	'	'
Common stock	'	'	'	'	'	'	'	'	'	30,000,000
Net proceeds from sale of common stock	'	'	'	'	'	'	'	'	3,700,000	'
Sale of common stock	'	'	'	'	'	'	'	'	2.1	'
Average sale price of share	'	'	'	'	'	'	'	'	$1.75	'
Common Stock, Value, Outstanding	'	'	'	'	'	'	'	'	$17,100,000	'

StockBased_Compensation_Summar

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]	'	'	'	'
Total stock-based compensation expense	$1,518	$2,152	$3,099	$4,287
Cost of Revenues	'	'	'	'
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]	'	'	'	'
Total stock-based compensation expense	194	224	346	429
Research and Development	'	'	'	'
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]	'	'	'	'
Total stock-based compensation expense	521	585	1,000	1,159
Selling, General and Administrative	'	'	'	'
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]	'	'	'	'
Total stock-based compensation expense	$803	$1,343	$1,753	$2,699

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	6 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Stock options granted in period	'	212,000
Stock Options	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Stock options granted in period	1,000,000	831,000
Unrecognized compensation cost for unvested employee stock-based compensation awards outstanding, net of forfeitures	$1.80	'
Weighted-average period over which unrecognized compensation expense is expected to be recognized (years)	'3 years	'
Stock Options | Minimum	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Vesting period, in years	'3 years	'
Stock Options | Maximum	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Vesting period, in years	'5 years	'
Restricted Stock	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Restricted stock granted	3,192,502	'
Vesting period, in years	'3 years	'
Unrecognized compensation cost for unvested employee stock-based compensation awards outstanding, net of forfeitures	$4.60	'
Weighted-average period over which unrecognized compensation expense is expected to be recognized (years)	'1 year 7 months 6 days	'
Time-Based Restricted Stock	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Restricted stock granted	'	400,000
Performance-Based Restricted Stock	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Restricted stock granted	'	362,000

StockBased_Compensation_Schedu

Stock-Based Compensation - Schedule of Weighted Average Assumptions used in Black-Scholes Valuation Model for Stock Options Granted (Detail)	3 Months Ended		6 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'	'	'	'
Expected volatility	'	75.40%	85.50%	75.10%
Risk-free interest rate	'	1.70%	1.90%	1.70%
Expected life (years)	'	'5 years 9 months 18 days	'5 years 9 months 18 days	'5 years 10 months 24 days
Dividend yield	0.00%	0.00%	0.00%	0.00%

Computation_of_Net_Loss_Income

Computation of Net (Loss) Income Per Common Share - Additional Information (Detail)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]	'	'	'	'
Anti-dilutive shares excluded from calculation of diluted EPS	7.4	9.7	7.4	9.7
Unexercised Options	'	'	'	'
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]	'	'	'	'
Anti-dilutive shares excluded from calculation of diluted EPS	3.9	'	3.9	'
Unvested Options	'	'	'	'
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]	'	'	'	'
Anti-dilutive shares excluded from calculation of diluted EPS	'	3.2	'	3.2
Warrants	'	'	'	'
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]	'	'	'	'
Anti-dilutive shares excluded from calculation of diluted EPS	3.5	3.2	3.5	3.2
Convertible Notes	'	'	'	'
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]	'	'	'	'
Anti-dilutive shares excluded from calculation of diluted EPS	'	3.3	'	3.3

Computation_of_Net_Loss_Income1

Computation of Net (Loss) Income Per Common Share - Reconciliation of Numerators and Denominators of EPS Calculation (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share Reconciliation [Abstract]	'	'	'	'
Net loss	($25,423)	($14,623)	($38,939)	($25,135)
Weighted-average shares of common stock outstanding	83,048	62,787	80,876	61,583
Weighted-average shares subject to repurchase	-1,577	-1,671	-1,286	-1,871
Shares used in per-share calculation b basic	81,471	61,116	79,590	59,712
Shares used in per-share calculation b diluted	81,471	61,116	79,590	59,712
Basic	($0.31)	($0.24)	($0.49)	($0.42)
Diluted	($0.31)	($0.24)	($0.49)	($0.42)

Fair_Value_Measurements_Schedu

Fair Value Measurements - Schedule of Assets and Liabilities Carried at Fair Value (Detail) (USD $)	Sep. 30, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Cash equivalents	$20,185	$17,675
Warrants	1,841	2,601
Quoted Prices in Active Markets (Level 1)	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Cash equivalents	20,185	17,675
Warrants	0	0
Significant Other Observable Inputs (Level 2)	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Cash equivalents	0	0
Warrants	0	0
Significant Unobservable Inputs (Level 3)	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Cash equivalents	0	0
Warrants	$1,841	$2,601

Fair_Value_Measurements_Schedu1

Fair Value Measurements - Schedule of Liabilities Measured at Fair Value (Detail) (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Mar. 31, 2014
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Ending balance	$1,841	$2,601
Warrants	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Beginning balance	2,601	3,633
Warrant issuance with Senior Secured Term Loan	'	315
Mark to market adjustment	-760	-1,347
Extinguishment of derivative liability	'	0
Ending balance	1,841	2,601
Derivative Liability	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Beginning balance	'	529
Warrant issuance with Senior Secured Term Loan	'	0
Mark to market adjustment	'	-525
Extinguishment of derivative liability	'	-4
Ending balance	'	$0

Fair_Value_Measurements_Schedu2

Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis (Detail) (Investment in unconsolidated entity b Blade Dynamics, USD $)	Sep. 30, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Assets	$0	$3,690
Quoted Prices in Active Markets (Level 1)	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Assets	0	0
Significant Other Observable Inputs (Level 2)	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Assets	0	0
Significant Unobservable Inputs (Level 3)	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Assets	$0	$3,690

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended	12 Months Ended
	Sep. 30, 2014	Mar. 31, 2014	Sep. 30, 2014	Mar. 31, 2014
Blade Dynamics Ltd.	'	'	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'	'	'
Impairment charge on investment	$3,500,000	$1,300,000	($3,464,000)	$1,300,000
Convertible Notes	'	'	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'	'	'
Debt, face amount	'	$25,000,000	'	$25,000,000
Debt Instrument, Interest Rate, Stated Percentage	'	7.00%	'	7.00%

Accounts_Receivable_Schedule_o

Accounts Receivable - Schedule of Accounts Receivable (Detail) (USD $)	Sep. 30, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified
Receivables [Abstract]	'	'
Accounts receivable (billed)	$8,410	$6,113
Accounts receivable (unbilled)	1,279	1,459
Less: Allowance for doubtful accounts	-16	-16
Accounts receivable, net	$9,673	$7,556

Inventory_Schedule_of_Inventor

Inventory - Schedule of Inventory (Detail) (USD $)	Sep. 30, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]	'	'
Raw materials	$6,936	$3,304
Work-in-process	6,073	4,047
Finished goods	8,750	10,275
Deferred program costs	2,701	3,068
Net inventory	$24,460	$20,694

Inventory_Additional_Informati

Inventory - Additional Information (Detail) (USD $)	3 Months Ended	6 Months Ended		3 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2013
				Maximum
Inventory [Line Items]	'	'	'	'
Inventory write-down	$600	$1,285	$192	$100

Accounts_Payable_and_Accrued_E2

Accounts Payable and Accrued Expenses - Schedule of Accounts Payable and Accrued Expenses (Detail) (USD $)	Sep. 30, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified
Payables And Accruals [Abstract]	'	'
Accounts payable	$7,063	$1,749
Accrued inventories in-transit	1,330	212
Accrued miscellaneous expenses	4,424	6,076
Accrued outside services	3,026	3,716
Accrued subcontractor program costs	60	290
Accrued compensation	4,070	5,939
Income taxes payable	197	173
Accrued adverse purchase commitments	0	402
Accrued warranty	3,367	3,207
Total	$23,537	$21,764

Accounts_Payable_and_Accrued_E3

Accounts Payable and Accrued Expenses - Additional Information (Detail)	6 Months Ended
	Sep. 30, 2014
Minimum	'
Product Warranty Accrual [Line Items]	'
Warranty period	'1 year
Maximum	'
Product Warranty Accrual [Line Items]	'
Warranty period	'3 years

Accounts_Payable_and_Accrued_E4

Accounts Payable and Accrued Expenses - Schedule of Product Warranty Activity (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Payables And Accruals [Abstract]	'	'	'	'
Balance at beginning of period	$2,855	$2,787	$3,207	$2,709
Change in accruals for warranties during the period	974	342	903	493
Settlements during the period	-462	-60	-743	-133
Balance at end of period	$3,367	$3,069	$3,367	$3,069

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'	'	'	'
Income tax expense	$62	$341	$190	$430

Restructuring_Additional_Infor

Restructuring - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended	6 Months Ended
In Millions, unless otherwise specified	Jul. 31, 2013	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2013
				Maximum
Restructuring Cost And Reserve [Line Items]	'	'	'	'
Reduction in global workforce, percentage	7.00%	'	'	'
Severance and other costs	'	$0.30	$1.40	'
Restructuring and impairment charges	'	'	'	$0.80

Restructuring_Schedule_of_Rest

Restructuring - Schedule of Restructuring Charges and Cash Payments (Detail) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Restructuring Cost And Reserve [Line Items]	'	'
Accrued restructuring balance	$844	$199
Charges to operations	1,445	764
Cash payments	-1,509	-636
Non-cash/miscellaneous reductions	'	-196
Accrued restructuring balance	780	131
Severance Pay and Benefits	'	'
Restructuring Cost And Reserve [Line Items]	'	'
Accrued restructuring balance	844	145
Charges to operations	632	751
Cash payments	-696	-599
Non-cash/miscellaneous reductions	'	-166
Accrued restructuring balance	780	131
Facility Exit and Relocation Costs	'	'
Restructuring Cost And Reserve [Line Items]	'	'
Accrued restructuring balance	'	54
Charges to operations	814	13
Cash payments	-814	-37
Non-cash/miscellaneous reductions	'	($30)

Debt_Additional_Information_De

Debt - Additional Information (Detail) (USD $)

3 Months Ended

6 Months Ended

0 Months Ended

3 Months Ended

6 Months Ended

0 Months Ended

6 Months Ended

0 Months Ended

6 Months Ended

0 Months Ended

6 Months Ended

0 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

0 Months Ended

3 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Mar. 31, 2014

Dec. 31, 2013

Jun. 30, 2013

Mar. 31, 2013

Mar. 02, 2014

Mar. 31, 2014

Sep. 30, 2013

Sep. 30, 2013

Oct. 09, 2013

Apr. 04, 2012

Sep. 30, 2014

Mar. 02, 2014

Dec. 31, 2013

Dec. 31, 2012

Apr. 04, 2012

Sep. 30, 2014

Nov. 15, 2013

Sep. 30, 2014

Nov. 15, 2013

Jun. 05, 2012

Dec. 31, 2013

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Mar. 31, 2013

Jun. 30, 2014

Jun. 05, 2012

Sep. 30, 2014

Capital Ventures International

Capital Ventures International

Senior Convertible Debt

Senior Convertible Debt

Senior Convertible Debt

Senior Convertible Debt

Senior Convertible Debt

New Unsecured Senior Convertible Note

New Unsecured Senior Convertible Note

New Unsecured Senior Convertible Note

New Unsecured Senior Convertible Note

New Unsecured Senior Convertible Note

Senior Secured Loan

Senior Secured Loan

Senior Secured Loan

Senior Secured Loan

Senior Secured Loan

Senior Secured Loan

Senior Secured Loan

Senior Secured Loan

Senior Secured Loan

Senior Secured Loan

Senior Secured Loan

Senior Secured Loan

Capital Ventures International

Capital Ventures International

Capital Ventures International

Capital Ventures International

Hercules Technology Growth Capital

Hercules Technology Growth Capital

Hercules Technology Growth Capital

Hercules Technology Growth Capital

Hercules Technology Growth Capital

Hercules Technology Growth Capital

Hercules Technology Growth Capital

Hercules Technology Growth Capital

Hercules Technology Growth Capital

Hercules Technology Growth Capital

Minimum

Maximum

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net proceeds after fees and expenses of purchase agreement

'

'

'

'

'

'

'

'

'

'

'

'

'

$23,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Conversion price

'

'

'

'

'

'

'

'

'

'

'

'

'

$4.85

'

'

$3.10

$3.19

$4.85

'

'

'

'

'

'

'

'

'

'

'

'

'

Premium over closing price, percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

20.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Period before first installment payment

'

'

'

'

'

'

'

'

'

'

'

'

'

'4 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares registered for resale

'

'

'

'

'

'

'

'

'

'

'

'

'

10,262,311

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivative liability of note

1,841,000

'

1,841,000

'

2,601,000

'

'

'

'

'

'

'

'

3,800,000

'

'

'

'

'

500,000

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares received from warrants received to purchase common stock

'

'

'

'

'

'

'

'

'

'

'

'

'

3,094,060

'

'

'

'

'

'

256,410

'

256,410

139,276

'

'

'

'

'

'

'

'

Strike price per share

'

'

'

'

'

'

'

'

'

'

'

'

$2.61

$5.45

$2.55

'

'

'

'

'

$1.95

$1.94

$1.95

$3.59

$1.95

'

$1.94

'

'

'

'

'

Fair value of warrants at issuance

'

'

'

'

'

'

'

'

'

'

'

'

'

7,000,000

'

'

'

'

'

'

'

'

'

400,000

'

'

'

'

'

'

'

'

Increase in derivative liability

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,500,000

'

'

'

'

'

'

'

'

'

'

'

'

Total debt discount being amortized into interest expense

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

13,100,000

'

'

'

'

'

'

200,000

'

'

100,000

'

'

Non-cash interest expense amortization of debt discount

200,000

3,100,000

300,000

4,800,000

'

'

'

'

'

'

1,200,000

2,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

100,000

100,000

300,000

'

'

'

100,000

Percentage of stock discount

'

'

85.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of trading days for valuation of shares

'

'

'10 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Non-cash interest expense issuing stock at discount

1,800,000

'

'

1,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt conversion, shares issued

'

'

'

'

'

'

'

'

6,600,000

'

'

'

'

'

'

6,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loss on extinguishment of debt

'

'

'

'

'

'

'

'

'

-5,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Legal and origination costs

10,188,000

'

10,188,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

200,000

'

'

'

300,000

'

'

'

Debt, face amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

10,000,000

10,000,000

'

'

'

'

'

'

'

'

Net proceeds from debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9,800,000

9,700,000

'

'

'

'

'

'

'

'

Interest rate on loan

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

11.00%

'

'

'

'

'

'

'

'

Prime rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.75%

'

End of term fee

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

500,000

'

500,000

'

'

'

Interest expense

500,000

3,500,000

1,000,000

5,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,000,000

'

1,200,000

'

'

'

Minimum amount of proceeds from specified asset dispositions for mandatory prepayment feature

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,000,000

'

'

'

'

'

Covenant, unrestricted cash balance requirement

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

15,000,000

'

'

'

9,800,000

'

'

'

'

'

Net proceeds from sale of common stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,000,000

'

'

'

'

'

Repayments of term loan

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,500,000

'

'

'

'

'

Combined principal balances of the term loans

'

$10,411,000

'

$10,411,000

'

$10,411,000

$14,389,000

$15,380,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$7,500,000

'

'

'

'

'

Warrants_and_Derivative_Liabil2

Warrants and Derivative Liabilities - Additional Information (Detail) (USD $)

0 Months Ended

3 Months Ended

6 Months Ended

9 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

0 Months Ended

3 Months Ended

6 Months Ended

9 Months Ended

0 Months Ended

6 Months Ended

0 Months Ended

1 Months Ended

0 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

0 Months Ended

3 Months Ended

6 Months Ended

In Thousands, except Share data, unless otherwise specified

Nov. 15, 2013

Jun. 05, 2012

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Mar. 02, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Oct. 09, 2013

Apr. 04, 2012

Sep. 30, 2014

Mar. 02, 2014

Dec. 31, 2013

Dec. 31, 2012

Apr. 04, 2012

Dec. 31, 2012

Dec. 31, 2012

Nov. 15, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Nov. 15, 2013

Jun. 05, 2012

Dec. 31, 2013

Sep. 30, 2014

Convertible Bond

Convertible Bond

Senior Secured Term Loan First Warrant

Senior Secured Term Loan First Warrant

Senior Secured Term Loan First Warrant

Senior Secured Term Loan First Warrant

Capital Ventures International

Capital Ventures International

Capital Ventures International

Capital Ventures International

Capital Ventures International

Capital Ventures International

Senior Convertible Debt

Senior Convertible Debt

Senior Convertible Debt

New Unsecured Senior Convertible Note

New Unsecured Senior Convertible Note

New Unsecured Senior Convertible Note

New Unsecured Senior Convertible Note

New Unsecured Senior Convertible Note

New Unsecured Senior Convertible Note

Senior Secured Loan

Senior Secured Loan

Senior Secured Loan

Senior Secured Loan

Senior Secured Loan

Senior Secured Loan

Senior Secured Loan

Senior Secured Loan

Capital Ventures International

Capital Ventures International

Capital Ventures International

Capital Ventures International

Capital Ventures International

Maximum

Maximum

Hercules Technology Growth Capital

Hercules Technology Growth Capital

Hercules Technology Growth Capital

Hercules Technology Growth Capital

Minimum

Maximum

Derivative [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares received from warrants received to purchase common stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,094,060

'

'

'

'

'

'

'

256,410

'

'

'

256,410

139,276

'

'

Warrant exercise, waiting period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'6 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrant exercise period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'5 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise price

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$2.61

$5.45

$2.55

'

'

'

'

'

'

$1.95

$1.94

'

'

$1.95

$3.59

$1.95

$1.94

Beneficial ownership limitation percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4.99%

9.99%

'

'

'

'

'

'

'

'

Required notification period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'61 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gain (loss) in change of fair value of derivative instruments and warrants

'

'

$795

$886

$760

$1,355

'

$300

$300

$0

$0

$0

$0

'

$800

$500

$700

$900

'

'

'

'

'

'

'

'

'

'

'

'

$100

$100

'

'

'

'

Conversion price

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$4.85

'

'

$3.10

$3.19

$4.85

'

'

'

'

'

'

'

'

'

'

Debt conversion, shares issued

'

'

'

'

'

'

'

'

'

'

'

'

'

6,600,000

'

'

'

'

'

'

'

'

6,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Convertible debt instrument redemption waiting period

'

'

'

'

'

'

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Convertible debt instrument contractual term

'

'

'

'

'

'

'30 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants expiration date

15-May-19

5-Dec-17

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants_and_Derivative_Liabil3

Warrants and Derivative Liabilities - Schedule of Assumptions Used to Calculate the Fair Value of Warrants (Detail) (USD $)	3 Months Ended											0 Months Ended		3 Months Ended							0 Months Ended			3 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Oct. 09, 2013	Oct. 09, 2013	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Nov. 15, 2013	Nov. 15, 2013	Nov. 15, 2013	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013
					Senior Convertible Note Warrant	Senior Convertible Note Warrant	Senior Convertible Note Warrant	Senior Convertible Note Warrant	Senior Convertible Note Warrant	Senior Convertible Note Warrant	Senior Convertible Note Warrant	Senior Convertible Note Warrant	Senior Convertible Note Warrant	Senior Secured Term Loan First Warrant	Senior Secured Term Loan First Warrant	Senior Secured Term Loan First Warrant	Senior Secured Term Loan First Warrant	Senior Secured Term Loan First Warrant	Senior Secured Term Loan First Warrant	Senior Secured Term Loan First Warrant	Senior Secured Term Loan First Warrant	Senior Secured Term Loan First Warrant	Senior Secured Term Loan Second Warrant	Senior Secured Term Loan Second Warrant	Senior Secured Term Loan Second Warrant	Senior Secured Term Loan Second Warrant	Senior Secured Term Loan Second Warrant
												Post Modification	Pre Modification								Post Modification	Pre Modification
Derivative [Line Items]	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'
Risk-free interest rate	0.12%	0.10%	0.21%	0.20%	1.07%	0.98%	1.11%	1.17%	1.02%	1.13%	0.67%	1.05%	1.05%	1.13%	1.04%	1.18%	1.24%	1.09%	1.20%	0.70%	1.00%	1.00%	1.55%	1.65%	1.57%	1.76%	1.89%
Expected annual dividend yield	16.50%	15.50%	16.70%	16.50%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%
Expected volatility	68.63%	66.26%	65.80%	66.91%	76.20%	83.50%	80.99%	75.60%	71.98%	71.90%	71.74%	71.45%	71.45%	78.30%	82.75%	80.73%	74.79%	72.10%	72.30%	72.01%	72.64%	72.64%	76.97%	78.10%	80.00%	79.73%	80.37%
Term (years)	'9 months	'1 year	'1 year 3 months 4 days	'1 year 6 months 4 days	'3 years 4 days	'3 years 3 months 4 days	'3 years 6 months 4 days	'3 years 9 months 4 days	'4 years 4 days	'4 years 3 months 7 days	'4 years 6 months 4 days	'3 years 11 months 27 days	'3 years 11 months 27 days	'3 years 2 months 5 days	'3 years 5 months 5 days	'3 years 8 months 5 days	'3 years 11 months 5 days	'4 years 2 months 5 days	'4 years 5 months 5 days	'4 years 8 months 5 days	'4 years 18 days	'4 years 18 days	'5 years 5 months 27 days	'4 years 7 months 13 days	'4 years 10 months 13 days	'5 years 1 month 13 days	'5 years 4 months 13 days
Fair value	'	'	'	'	$1.50	$2.30	$2.20	$2.20	$2.50	$3	$3.40	$3.20	$2.20	$0.10	$0.10	$0.10	$0.10	$0.20	$0.20	$0.20	$0.10	$0.10	$0.30	$0.20	$0.30	$0.30	$0.30

Warrants_and_Derivative_Liabil4

Warrants and Derivative Liabilities - Schedule of Fair Value Assumptions Used to Calculate Value of Convertible Note Derivative Feature (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013
Combined principal balances of the term loans	'	$10,411,000	$10,411,000	$14,389,000	$15,380,000
Stock price	'	$1.64	$2.34	$2.64	$2.67
Percentage volume condition met	'	87.20%	80.20%	87.50%	80.50%
Expected volatility	'	68.63%	66.26%	65.80%	66.91%
Risk-free interest rate	'	0.12%	0.10%	0.21%	0.20%
Expected annual dividend yield	'	16.50%	15.50%	16.70%	16.50%
Recovery rate	'	35.00%	35.00%	37.00%	30.00%
Redeemable	'N/A	'yes	'yes	'yes	'yes
Term (years)	'	'9 months	'1 year	'1 year 3 months 4 days	'1 year 6 months 4 days
Dilution effect	'N/A	'yes	'yes	'yes	'yes
Fair value	'	'	$200,000	$500,000	$500,000
Fair value as a percent of par	'	0.02%	0.70%	3.30%	3.40%

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Detail) (USD $)	Sep. 30, 2014	Mar. 31, 2014	Sep. 30, 2014	Nov. 15, 2013
			MLV & Co. LLC	MLV & Co. LLC
			Atm Arrangement	Atm Arrangement
Schedule Of Capitalization Equity [Line Items]	'	'	'	'
Common stock	$860,000	$789,000	'	$30,000,000
Commission on sale of common stock under the ATM	'	'	'	3.00%
Net proceeds from sale of common stock	'	'	3,700,000	'
Common stock, shares issued	'	'	2,100,000	'
Sale price of common stock per share	'	'	$1.75	'
Common Stock, Value, Outstanding	'	'	$17,100,000	'

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Detail)

0 Months Ended

0 Months Ended

3 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

Nov. 19, 2013

Jul. 05, 2011

12-May-11

Sep. 30, 2014

Sep. 30, 2014

Jun. 11, 2014

Mar. 31, 2014

Jun. 17, 2011

Aug. 29, 2014

Aug. 29, 2014

12-May-11

12-May-11

Sep. 30, 2014

Feb. 27, 2012

Feb. 27, 2012

Dec. 22, 2011

Dec. 22, 2011

Oct. 17, 2011

Oct. 17, 2011

Oct. 08, 2011

Oct. 08, 2011

Sep. 13, 2011

Sep. 13, 2011

Mar. 31, 2011

Mar. 31, 2011

Sep. 16, 2011

Sep. 16, 2011

USD ($)

Claim

Employee

USD ($)

EUR (€)

USD ($)

USD ($)

Bonds

Ghodawat Energy Pvt Ltd

Ghodawat Energy Pvt Ltd

Ghodawat Energy Pvt Ltd

Ghodawat Energy Pvt Ltd

Ghodawat Energy Pvt Ltd

Sinovel Wind Group Co. Ltd.

Sinovel Wind Group Co. Ltd.

Sinovel Wind Group Co. Ltd.

Sinovel Wind Group Co. Ltd.

Sinovel Wind Group Co. Ltd.

Sinovel Wind Group Co. Ltd.

Sinovel Wind Group Co. Ltd.

Sinovel Wind Group Co. Ltd.

Sinovel Wind Group Co. Ltd.

Sinovel Wind Group Co. Ltd.

Sinovel Wind Group Co. Ltd.

Sinovel Wind Group Co. Ltd.

Dalian Guotong Electric Co. Ltd.

Dalian Guotong Electric Co. Ltd.

Claim

USD ($)

USD ($)

EUR (€)

USD ($)

EUR (€)

USD ($)

USD ($)

CNY

USD ($)

CNY

USD ($)

CNY

USD ($)

CNY

USD ($)

CNY

USD ($)

CNY

USD ($)

CNY

Claim

Commitments And Contingencies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Adverse purchase commitments

'

'

'

$0

'

'

$402,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Sought compensation amount

10,000,000

'

'

'

'

'

'

'

'

'

24,000,000

18,000,000

'

17,000,000

105,000,000

190,000,000

1,200,000,000

157,000,000

1,000,000,000

58,000,000

370,000,000

'

'

76,000,000

485,000,000

'

'

Counterclaims under License Agreement

'

'

'

'

'

'

'

'

'

'

8,000,000

6,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Liability for damages

'

'

'

'

'

'

'

475,000

10,600,000

8,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate accrued on liability for damage

'

'

'

'

'

'

'

'

5.33%

5.33%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loss contingency recorded in prior period

'

'

'

'

'

'

'

'

'

'

'

'

500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loss contingency recorded

'

'

'

'

'

'

'

'

'

'

'

'

10,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of putative securities complaints

'

'

7

'

'

'

'

4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of officers putative securities filed against

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of complaints additionally asserted claims against the underwriters

'

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Settlement amount expected to be funded by insurers

'

'

'

8,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Settlement amount expected to be paid by issuance of common stock

'

'

'

1,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, capital shares reserved for future issuance

'

'

'

944,882

944,882

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shortfall payment

'

'

'

'

'

500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of claims consolidated

'

3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Value of the undelivered components

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

720,000,000

4,600,000,000

'

'

Damages claimed for unauthorized use of software

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6,000,000

38,000,000

'

'

'

'

Monetary damages for trade secret infringement

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

453,000,000

2,900,000,000

'

'

'

'

Monetary losses from copyright infringement

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

200,000

1,200,000

Restricted cash included in current assets

'

'

'

3,425,000

'

'

2,913,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Restricted cash

'

'

'

100,000

'

'

3,394,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of credit outstanding

'

'

'

$3,400,000

€ 2,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Minority_Investments_Additiona

Minority Investments - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended	12 Months Ended
	Sep. 30, 2014	Mar. 31, 2014	Sep. 30, 2014	Mar. 31, 2014
Tres Amigas	'	'	'	'
Schedule Of Equity Method Investments [Line Items]	'	'	'	'
Number of commonly interconnected power grids	3	'	3	'
Equity method investment, aggregate cost	$5,400,000	'	$5,400,000	'
Percentage of ownership interest hold	26.00%	'	26.00%	'
Blade Dynamics Ltd.	'	'	'	'
Schedule Of Equity Method Investments [Line Items]	'	'	'	'
Cost method investment, original cost	8,000,000	'	8,000,000	'
Percentage of ownership interest hold	19.00%	'	19.00%	'
Impairment charge on investment	$3,500,000	$1,300,000	($3,464,000)	$1,300,000

Minority_Investments_Schedule_

Minority Investments - Schedule of Net Investment Activity (Detail) (USD $)	3 Months Ended		6 Months Ended			3 Months Ended		6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2014	Mar. 31, 2014	Sep. 30, 2014	Mar. 31, 2014
					Tres Amigas	Blade Dynamics Ltd.	Blade Dynamics Ltd.	Blade Dynamics Ltd.	Blade Dynamics Ltd.
Schedule Of Results Related To Equity Accounted Investees [Line Items]	'	'	'	'	'	'	'	'	'
Beginning Balance	'	'	'	'	$1,845	'	'	$3,690	'
Minority interest in net losses	'	'	'	'	-410	'	'	'	'
Net foreign exchange rate impact	740	-635	588	-566	'	'	'	-226	'
Impairment	'	'	'	'	'	3,500	1,300	-3,464	1,300
Ending Balance	'	'	'	'	$1,435	$0	$3,690	$0	$3,690

Business_Segments_Additional_I

Business Segments - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
			Segment
			MW
Segment Reporting Disclosure Of Entitys Reportable Segments [Abstract]	'	'	'	'
Number of reportable business segments	'	'	2	'
Megawatts of drive trains and power ratings	'	'	2	'
Stock-based compensation expense	$1,518	$2,152	$3,099	$4,287
Restructuring and impairments	$3,731	$751	$4,909	$764

Business_Segments_Operating_Re

Business Segments - Operating Results for Two Business Segments (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]	'	'	'	'
Revenues	$12,455	$24,181	$24,151	$47,267
Operating loss	-26,400	-11,028	-39,067	-19,877
Operating Segments | Wind	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenues	7,462	14,691	15,113	29,392
Operating loss	-14,611	-2,449	-18,091	-4,274
Operating Segments | Grid	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenues	4,993	9,490	9,038	17,875
Operating loss	-6,559	-5,750	-12,966	-10,618
Unallocated corporate expenses	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Operating loss	($5,230)	($2,829)	($8,010)	($4,985)

Business_Segments_Total_Busine

Business Segments - Total Business Segments Assets (Detail) (USD $)	Sep. 30, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified
Segment Reporting Asset Reconciling Item [Line Items]	'	'
Total assets	$155,847	$168,509
Operating Segments | Wind	'	'
Segment Reporting Asset Reconciling Item [Line Items]	'	'
Total assets	47,569	36,701
Operating Segments | Grid	'	'
Segment Reporting Asset Reconciling Item [Line Items]	'	'
Total assets	44,779	54,342
Corporate assets	'	'
Segment Reporting Asset Reconciling Item [Line Items]	'	'
Total assets	$63,499	$77,466

Business_Segments_Schedule_of_

Business Segments - Schedule of Revenues by Major Customers (Detail) (Sales)	3 Months Ended		6 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Inox Wind Limited	'	'	'	'
Segment Reporting Asset Reconciling Item [Line Items]	'	'	'	'
Revenue percentage	48.00%	27.00%	48.00%	21.00%
RES American Construction, Inc	'	'	'	'
Segment Reporting Asset Reconciling Item [Line Items]	'	'	'	'
Revenue percentage	16.00%	'	'	'
Beijing Jingcheng New Energy Company Limited	'	'	'	'
Segment Reporting Asset Reconciling Item [Line Items]	'	'	'	'
Revenue percentage	'	28.00%	'	31.00%
Maximum | RES American Construction, Inc	'	'	'	'
Segment Reporting Asset Reconciling Item [Line Items]	'	'	'	'
Revenue percentage	'	'	10.00%	'
Maximum | Beijing Jingcheng New Energy Company Limited	'	'	'	'
Segment Reporting Asset Reconciling Item [Line Items]	'	'	'	'
Revenue percentage	'	'	10.00%	'