Vicor (VICR) 10-Q 30 Apr 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2014
Document Information [Line Items]	'
Document Type	'10-Q
Amendment Flag	'false
Document Period End Date	31-Mar-14
Document Fiscal Year Focus	'2014
Document Fiscal Period Focus	'Q1
Entity Registrant Name	'VICOR CORP
Entity Central Index Key	'0000751978
Current Fiscal Year End Date	'--12-31
Entity Filer Category	'Accelerated Filer
Entity Common Stock, Shares Outstanding	26,782,623
Class B Common Stock [Member]	'
Document Information [Line Items]	'
Entity Common Stock, Shares Outstanding	11,758,218

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$50,307	$56,339
Short-term investments	643	463
Accounts receivable, less allowance of $240 in 2014 and $198 in 2013	31,769	27,683
Inventories, net	29,521	29,696
Deferred tax assets	131	131
Other current assets	4,666	4,212
Total current assets	117,037	118,524
Long-term investments, net	5,045	5,188
Property, plant and equipment, net	39,176	40,092
Other assets	1,830	1,836
Total assets	163,088	165,640
Current liabilities:	'	'
Accounts payable	8,148	8,677
Accrued compensation and benefits	9,136	8,104
Accrued expenses	4,890	2,841
Income taxes payable	15	15
Deferred revenue	1,095	1,018
Total current liabilities	23,284	20,655
Long-term deferred revenue	868	974
Long-term income taxes payable	1,337	1,339
Deferred income taxes payable	335	335
Total liabilities	25,824	23,303
Commitments and contingencies (Note 10)	'	'
Vicor Corporation stockholders' equity:	'	'
Common Stock	392	392
Additional paid-in capital	169,713	169,474
Retained earnings	103,267	108,645
Accumulated other comprehensive loss	-417	-526
Treasury stock, at cost	-138,927	-138,927
Total Vicor Corporation stockholders' equity	134,146	139,176
Noncontrolling interest	3,118	3,161
Total equity	137,264	142,337
Total liabilities and equity	163,088	165,640
Class B Common Stock [Member]	'	'
Vicor Corporation stockholders' equity:	'	'
Common Stock	$118	$118

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Statement Of Financial Position [Abstract]	'	'
Accounts receivable, less allowance	$240	$198

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Income Statement [Abstract]	'	'
Net revenues	$53,233	$41,946
Cost of revenues	30,441	25,339
Gross margin	22,792	16,607
Operating expenses:	'	'
Selling, general and administrative	17,980	13,887
Research and development	10,251	9,855
Severance charges	'	1,361
Total operating expenses	28,231	25,103
Loss from operations	-5,439	-8,496
Other income, net:	'	'
Total unrealized gains on available-for-sale securities, net	39	52
Portion of losses recognized in other comprehensive income (loss)	-39	-51
Net credit gains recognized in earnings	'	1
Other income, net	30	14
Total other income, net	30	15
Loss before income taxes	-5,409	-8,481
Provision (benefit) for income taxes	17	-3,495
Consolidated net loss	-5,426	-4,986
Less: Net income attributable to noncontrolling interest	-48	4
Net loss attributable to Vicor Corporation	($5,378)	($4,990)
Net loss per common share attributable to Vicor Corporation:	'	'
Basic	($0.14)	($0.12)
Diluted	($0.14)	($0.12)
Shares used to compute net loss per share attributable to Vicor Corporation:	'	'
Basic	38,541	41,167
Diluted	38,541	41,167

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (Loss) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]	'		'
Consolidated net loss	($5,426)		($4,986)
Foreign currency translation gains (losses), net of tax provision (benefit)	77	[1]	-268	[1]
Unrealized gains on available-for-sale securities, net of tax	37	[2]	51	[2]
Other comprehensive income (loss)	114		-217
Consolidated comprehensive income (loss)	-5,312		-5,203
Less: Comprehensive income (loss) attributable to noncontrolling interest	-43		-24
Comprehensive income (loss) attributable to Vicor Corporation	($5,269)		($5,179)
[1]	Net of tax benefit of $0 and $141 for the three months ended March 31, 2014 and 2013, respectively.
[2]	The deferred tax assets associated with the unrealized gains on available-for-sale securities are completely offset by a tax valuation allowance as of March 31, 2014 and 2013. Therefore, there is no net income tax provision (benefit) recognized for the three months ended March 31, 2014 and 2013.

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]	'	'
Foreign currency translation gains (losses), tax benefit	$0	$141
Recognized income tax provision (benefit)	$0	$0

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Operating activities:	'	'
Consolidated net loss	($5,426)	($4,986)
Adjustments to reconcile consolidated net loss to net cash provided by (used for) operating activities:	'	'
Depreciation and amortization	2,443	2,494
Stock-based compensation expense	234	263
Provision for doubtful accounts	53	'
Decrease in long-term deferred revenue	-34	-35
Deferred income taxes	'	-2,264
Severance charges	'	1,361
Excess tax benefit of stock-based compensation	'	-43
Gain on disposal of equipment	-4	-3
Credit loss (gain) on available-for-sale securities	'	-1
(Decrease) increase in long-term income taxes payable	-2	10
Change in current assets and liabilities, net	-1,744	1,523
Net cash used for operating activities	-4,480	-1,681
Investing activities:	'	'
Additions to property, plant and equipment	-1,554	-1,171
Sales and maturities of investments	'	234
Proceeds from sale of equipment	4	3
Decrease in other assets	-34	47
Net cash used for investing activities	-1,584	-887
Financing activities:	'	'
Purchases of Common Stock	'	-10,392
Proceeds from issuance of Common Stock	5	43
Excess tax benefit of stock-based compensation	'	46
Net cash provided by (used for) financing activities	5	-10,303
Effect of foreign exchange rates on cash	27	-280
Net decrease in cash and cash equivalents	-6,032	-13,151
Cash and cash equivalents at beginning of period	56,339	84,554
Cash and cash equivalents at end of period	$50,307	$71,403

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
Basis of Presentation	'
	1. Basis of Presentation
	The accompanying unaudited condensed consolidated financial statements of Vicor Corporation (the “Company”) have been prepared in accordance with generally accepted accounting principles for interim financial information and pursuant to the rules and regulations of the Securities and Exchange Commission. Accordingly, these interim financial statements do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements.
	In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation have been included. Operating results for the three months ended March 31, 2014 are not necessarily indicative of the results that may be expected for any other interim period or the year ending December 31, 2014. The balance sheet at December 31, 2013 presented herein has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. For further information, refer to the consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013 (File No. 0-18277) filed by the Company with the Securities and Exchange Commission.

ShortTerm_and_LongTerm_Investm

Short-Term and Long-Term Investments	3 Months Ended
	Mar. 31, 2014
Investments Debt And Equity Securities [Abstract]	'
Short-Term and Long-Term Investments	'
	2. Short-Term and Long-Term Investments
	As of March 31, 2014, the Company held auction rate securities that had experienced failed auctions totaling $6,000,000 at par value, all of which had been purchased through and are held by a broker-dealer affiliate of Bank of America, N.A. (the “Failed Auction Securities”). The Failed Auction Securities held by the Company are Aaa/AA+/A3/BBB rated by major credit rating agencies, collateralized by student loans, and guaranteed by the U.S. Department of Education under the Federal Family Education Loan Program. Management is not aware of any reason to believe any of the issuers of the Failed Auction Securities are presently at risk of default. Through March 31, 2014, the Company has continued to receive interest payments on the Failed Auction Securities in accordance with the terms of their respective indentures. Management believes the Company ultimately should be able to liquidate all of the Failed Auction Securities without significant loss primarily due to the overall quality of the issues held and the collateral securing the substantial majority of the underlying obligations. However, current conditions in the auction rate securities market have led management to conclude the recovery period for the Failed Auction Securities exceeds 12 months. As a result, the Company continued to classify the Failed Auction Securities as long-term as of March 31, 2014.
	The following is a summary of available-for-sale securities (in thousands):
				Gross			Gross		Estimated
				Unrealized			Unrealized		Fair
	March 31, 2014	Cost		Gains			Losses		Value
	Failed Auction Securities	$	6,000	$	—		$	1,136	$	4,864
	Brokered certificates of deposit		820		4			—		824
		$	6,820	$	4		$	1,136	$	5,688
				Gross			Gross		Estimated
				Unrealized			Unrealized		Fair
	December 31, 2013	Cost		Gains			Losses		Value
	Failed Auction Securities	$	6,000	$	—		$	1,175	$	4,825
	Brokered certificates of deposit		820		6			—		826
		$	6,820	$	6		$	1,175	$	5,651
	All of the Failed Auction Securities as of March 31, 2014 have been in an unrealized loss position for greater than 12 months.
	The amortized cost and estimated fair value of available-for-sale securities on March 31, 2014, by contractual maturities, are shown below (in thousands):
				Estimated
		Cost		Fair Value
	Due in one year or less	$	640	$	643
	Due in two to ten years		180		181
	Due in ten to twenty years		—		—
	Due in twenty to forty years		6,000		4,864
		$	6,820	$	5,688
	Based on the fair value measurements described in Note 3, the fair value of the Failed Auction Securities on March 31, 2014, with a par value of $6,000,000, was estimated by the Company to be approximately $4,864,000, an increase in fair value of $39,000 from December 31, 2013. The gross unrealized loss of $1,136,000 on the Failed Auction Securities consists of two types of estimated loss: an aggregate credit loss of $395,000 and an aggregate temporary impairment of $741,000. In determining the amount of credit loss, the Company compared the present value of cash flows expected to be collected to the amortized cost basis of the securities, considering credit default risk probabilities and changes in credit ratings as significant inputs, among other factors (See Note 3).
	The following table represents a rollforward of the activity related to the credit loss recognized in earnings on available-for-sale auction rate securities held by the Company for the three months ended March 31 (in thousands):
		2014		2013
	Balance at the beginning of the period	$	395	$	317
	Additions for the amount related to credit loss for which other-than- temporary impairment was not previously recognized		—		(1	)
	Balance at the end of the period	$	395	$	316
	At this time, the Company has no intent to sell any of the impaired Failed Auction Securities and does not believe it is more likely than not the Company will be required to sell any of these securities. If current market conditions deteriorate further, the Company may be required to record additional unrealized losses. If the credit rating of the security deteriorates, the Company may be required to adjust the carrying value of these investments through impairment charges recorded in the Condensed Consolidated Statement of Operations, and any such impairment adjustments may be material.
	Based on the Company’s ability to access cash and cash equivalents and its expected operating cash flows, management does not anticipate the current lack of liquidity associated with the Failed Auction Securities held will affect the Company’s ability to execute its current operating plan.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	3. Fair Value Measurements
	The Company accounts for certain financial assets at fair value, defined as the price that would be received to sell an asset or paid to transfer a liability (i.e., an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions market participants would use in pricing an asset or liability. A three-level hierarchy is used to show the extent and level of judgment used to estimate fair value measurements.
	Assets measured at fair value on a recurring basis include the following as of March 31, 2014 (in thousands):
		Using
		Quoted Prices			Significant			Significant		Total Fair
		in Active			Other			Unobservable		Value as of
		Markets			Observable			Inputs		March 31, 2014
		(Level 1)			Inputs			(Level 3)
					(Level 2)
	Cash Equivalents:
	Money market funds	$	12,176		$	—		$	—	$	12,176
	Short-term investments:
	Brokered certificates of deposit		—			643			—		643
	Long-term investments:
	Failed Auction Securities		—			—			4,864		4,864
	Brokered certificates of deposit		—			181			—		181
	Assets measured at fair value on a recurring basis include the following as of December 31, 2013 (in thousands):
		Using
		Quoted Prices			Significant			Significant		Total Fair
		in Active			Other			Unobservable		Value as of
		Markets			Observable			Inputs		December 31, 2013
		(Level 1)			Inputs			(Level 3)
					(Level 2)
	Cash Equivalents:
	Money market funds	$	12,407		$	—		$	—	$	12,407
	Short-term investments:
	Brokered certificates of deposit		—			463			—		463
	Long-term investments:
	Failed Auction Securities		—			—			4,825		4,825
	Brokered certificates of deposit		—			363			—		363
	The Company has brokered certificates of deposit classified as Level 2 because the fair value for these investments has been determined utilizing observable inputs from non-active markets. The fair values fluctuate with changes in market interest rates obtained from information available in publicly quoted markets. Management tested the reported fair values by comparing them to net present value calculations utilizing a discount rate based on U.S. Treasury bill and bond yields for similar maturities.
	As of March 31, 2014, there was insufficient observable auction rate security market information available to determine the fair value of the Failed Auction Securities using Level 1 or Level 2 inputs. As such, the Company’s investments in Failed Auction Securities were deemed to require valuation using Level 3 inputs. Management, after consulting with advisors, valued the Failed Auction Securities using analyses and pricing models similar to those used by market participants (i.e., buyers, sellers, and the broker-dealers responsible for execution of the Dutch auction pricing mechanism by which each issue’s interest rate was set). Management utilized a probability weighted discounted cash flow (“DCF”) model to determine the estimated fair value of these securities as of March 31, 2014. The major assumptions used in preparing the DCF model included: estimates for the amount and timing of future interest and principal payments based on default probability assumptions used to measure the credit loss of 6.6%; the rate of return required by investors to own these securities in the current environment, which management estimates to be 5.0% above the risk free rate of return; and an estimated timeframe of three to five years for successful auctions for these securities to occur. In making these assumptions, management considered relevant factors including: the formula applicable to each security defining the interest rate paid to investors in the event of a failed auction (the “Penalty Rate”); forward projections of the interest rate benchmarks specified in such formulas; the likely timing of principal repayments; the probability of full repayment considering the guarantees by the U.S. Department of Education of the underlying student loans, guarantees by other third parties, and additional credit enhancements provided through other means; and publicly available pricing data for recently issued student loan asset-backed securities not subject to auctions. In developing its estimate of the rate of return required by investors to own these securities, management compared the Penalty Rates of the Failed Auction Securities with yields of actively traded long-term bonds with similar characteristics and, reflecting the limited liquidity for auction rate securities and the discounts to par value seen in recent tender offers by issuers and arms’ length market transactions between informed buyers and sellers, estimated the implied yield (i.e., the discount to par value) necessary to complete a sale of the Failed Auction Securities. Management has calculated an increase or decrease in the liquidity risk premium of 5.0% referenced above of 1.0% (i.e., 100 basis points) as used in the model, would decrease or increase, respectively, the fair value of the Failed Auction Securities by approximately $400,000.
	For purposes of the valuation process for the Failed Auction Securities, “management” consists of senior members of the Company’s finance department. The fair value measurements for the Failed Auction Securities are reviewed and updated on a quarterly basis. The calculations are prepared by the Company’s Corporate Controller, in conjunction with information provided by its valuation advisors, and include the development and substantiation of the unobservable inputs. The methodology, assumptions, and calculations are reviewed and approved by the Company’s Chief Financial Officer and Chief Accounting Officer.
	The significant unobservable inputs used in the fair value measurement of the Company’s Failed Auction Securities are the cumulative probability of earning the maximum rate until maturity, the cumulative probability of principal return prior to maturity, the cumulative probability of default, the liquidity risk premium, and the recovery rate in default. Significant increases (decreases) in any of those inputs in isolation would result in changes in fair value measurement. Significant increases (decreases) in the cumulative probability of earning the maximum rate until maturity, the cumulative probability of principal return prior to maturity, and the recovery rate in default would result in a higher (lower) fair value measurement, while increases (decreases) in the cumulative probability of default and the liquidity risk premium would result in a lower (higher) fair value measurement.
	Generally, the interrelationships are such that a change in the assumption used for the cumulative probability of principal return prior to maturity is accompanied by a directionally similar change in the assumption used for the cumulative probability of earning the maximum rate until maturity and a directionally opposite change in the assumptions used for the cumulative probability of default and the liquidity risk premium. The recovery rate in default is somewhat independent and based upon the securities’ specific underlying assets and published recovery rate indices.
	Quantitative information about Level 3 fair value measurements as of March 31, 2014 are as follows (dollars in thousands):
		Fair Value		Valuation	Unobservable		Range
				Technique	Input		(Weighted
							Average)
	Failed Auction Securities	$4,864		Discounted	Cumulative probability of earning the maximum rate until maturity		0.01% - 0.07%
				cash flow			-0.04%
					Cumulative probability of principal return prior to maturity		70.66% - 94.49%
							-82.58%
					Cumulative probability of default		5.50% - 29.27%
							-17.39%
					Liquidity risk premium		5.00% - 5.00%
							-5.00%
					Recovery rate in default		40.00% - 40.00%
							-40.00%
	The following table summarizes the change in the estimated fair values calculated for those assets valued on a recurring basis utilizing Level 3 inputs (i.e., the Failed Auction Securities) for the three months ended March 31, 2014 (in thousands):
	Balance at the beginning of the period	$	4,825
	Unrealized gain included in Other comprehensive income (loss)		39
	Balance at the end of the period	$	4,864

StockBased_Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Stock-Based Compensation	'
	4. Stock-Based Compensation
	The Company uses the Black-Scholes option pricing model to calculate the fair value of stock option awards as of their grant date. Stock-based compensation expense for the three months ended March 31 was as follows (in thousands):
		Three Months Ended
		March 31,
		2014		2013
	Cost of revenues	$	36	$	4
	Selling, general and administrative		191		183
	Research and development		7		76
	Total stock-based compensation	$	234	$	263
	On December 31, 2010, the Company granted 2,984,250 non-qualified stock options under the VI Chip 2007 Stock Option and Incentive Plan with performance-based vesting provisions tied to achievement of certain margin targets by the VI Chip subsidiary. As of December 31, 2010, the Company determined it was probable the margin targets could be achieved and, accordingly, began recording stock-based compensation expense relating to these options beginning January 1, 2011. This determination remains the same as of March 31, 2014 and, accordingly, expense has been recorded through that date. The unrecognized compensation expense for these performance-based options was approximately $704,000 as of March 31, 2014.

Net_Income_Loss_per_Share

Net Income (Loss) per Share	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Net Income (Loss) per Share	'
	5. Net Income (Loss) per Share
	The following table sets forth the computation of basic and diluted income (loss) per share for the three months ended March 31 (in thousands, except per share amounts):
			Three Months Ended
			March 31,
			2014			2013
	Numerator:
	Net loss attributable to Vicor Corporation		$	(5,378	)	$	(4,990	)
	Denominator:
	Denominator for basic loss per share-weighted			38,541			41,167
	average shares (1)
	Effect of dilutive securities:
	Employee stock options (2)			—			—
	Denominator for diluted loss per share – adjusted weighted-average shares and assumed conversions			38,541			41,167
	Basic loss per share		$	(0.14	)	$	(0.12	)
	Diluted loss per share		$	(0.14	)	$	(0.12	)
	-1	Denominator represents weighted average number of shares of Common Stock and Class B Common Stock outstanding.
	-2	Options to purchase 1,981,028 and 602,841 shares of Common Stock for the three months ended March 31, 2014 and 2013, respectively, were not included in the calculation of net loss per share as the effect would have been antidilutive.

Inventories

Inventories	3 Months Ended
	Mar. 31, 2014
Inventory Disclosure [Abstract]	'
Inventories	'
	6. Inventories
	Inventories are valued at the lower of cost (determined using the first-in, first-out method) or net realizable value. Fixed production overhead is allocated to the inventory cost per unit based on the normal capacity of the production facilities. Abnormal production costs, including fixed cost variances from normal production capacity, if any, are charged to cost of revenues in the period incurred. All shipping and handling costs incurred in connection with the sale of products are included in cost of revenues.
	The Company provides reserves for inventories estimated to be excess, obsolete or unmarketable. The Company’s estimation process for assessing net realizable value is based upon its known backlog, projected future demand and expected market conditions. If the Company’s estimated demand and/or market expectation were to change or if product sales were to decline, the Company’s estimation process may cause larger inventory reserves to be recorded, resulting in larger charges to cost of revenues.
	Inventories were as follows (in thousands):
		March 31, 2014		December 31, 2013
	Raw materials	$	20,179	$	19,744
	Work-in-process		3,658		3,979
	Finished goods		5,684		5,973
	Net balance	$	29,521	$	29,696

Other_Investments

Other Investments	3 Months Ended
	Mar. 31, 2014
Text Block [Abstract]	'
Other Investments	'
	7. Other Investments
	The Company’s gross investment in non-voting convertible preferred stock of Great Wall Semiconductor Corporation (“GWS”) totaled $5,000,000 as of March 31, 2014 and December 31, 2013, giving the Company an approximately 27% ownership interest in GWS. GWS and its subsidiary design and sell semiconductors, conduct research and development activities, develop and license patents, and litigate against those who infringe upon its patented technologies. A director of the Company is the founder, Chairman of the Board, President and Chief Executive Officer (“CEO”), as well as the majority voting shareholder, of GWS. The Company and GWS are parties to an intellectual property cross-licensing agreement, a license agreement and two supply agreements under which the Company purchases certain components from GWS. Purchases from GWS totaled approximately $942,000 and $396,000 for the three months ended March 31, 2014, and 2013, respectively. The Company owed GWS approximately $56,000 and $152,000 as of March 31, 2014 and December 31, 2013, respectively.
	The Company accounts for its investment in GWS under the equity method of accounting. The Company has determined that, while GWS is a variable interest entity, the Company is not the primary beneficiary. The key factors in the Company’s assessment were that the CEO of GWS has: (i) the power to direct the activities of GWS that most significantly impact its economic performance, and (ii) has an obligation to absorb losses or the right to receive benefits from GWS, respectively, that could potentially be significant to GWS.
	The balance in the Company’s net investment in GWS was zero as of March 31, 2014, and December 31, 2013.

Product_Warranties

Product Warranties	3 Months Ended
	Mar. 31, 2014
Guarantees [Abstract]	'
Product Warranties	'
	8. Product Warranties
	The Company generally offers a two-year warranty for all of its products. The Company provides for the estimated cost of product warranties at the time product revenue is recognized. Factors that affect the Company’s warranty reserves include the number of units sold, historical and anticipated rates of warranty returns, and the cost per return. The Company assesses the adequacy of the warranty reserves and adjusts the amounts as necessary. Warranty obligations are included in “Accrued expenses” in the accompanying Condensed Consolidated Balance Sheets.
	Product warranty activity for the three months ended March 31, was as follows (in thousands):
		Three Months Ended
		March 31,
		2014			2013
	Balance at the beginning of the period	$	283		$	364
	Accruals for warranties for products sold in the period		24			29
	Fulfillment of warranty obligations		(55	)		(47	)
	Revisions of estimated obligations		(3	)		(22	)
	Balance at the end of the period	$	249		$	324

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	9. Income Taxes
	The tax provision is based on the estimated annual effective tax rate for the year, which includes estimated federal, state and foreign income taxes (benefit) on the Company’s projected annual pre-tax income (loss) and estimated federal and state income taxes for certain noncontrolling interest subsidiaries that are not part of the Company’s consolidated income tax returns.
	The provision (benefit) for income taxes and the effective income tax rate for the three months ended March 31, were as follows (in thousands):
		Three Months Ended
		March 31,
		2014			2013
	Provision (benefit) for income taxes	$	17		$	(3,495	)
	Effective income tax rate		0.3	%		(41.2	%)
	For the three months ended March 31, 2014, no tax benefit can be recognized for the majority of the Company’s losses due to a full valuation allowance against all domestic deferred tax assets. The provision for the period is primarily due to state taxes. For the three months ended March 31, 2013, a net income tax benefit was recorded primarily due to an increase in net federal deferred tax assets not covered by a valuation allowance at that time, a potential net operating loss carryback for federal income tax purposes and the recognition of a benefit from the federal research tax credit for 2012 of $549,000, as a discrete item in the first quarter of 2013. The federal research tax credit for 2012 and 2013 was extended on January 2, 2013 pursuant to the American Taxpayer Relief Act of 2012.
	As of March 31, 2014, the Company has a valuation allowance of approximately $20,214,000 primarily against all domestic net deferred tax assets, for which realization cannot be considered more likely than not at this time. Management assesses the need for the valuation allowance on a quarterly basis. In assessing the need for a valuation allowance, the Company considers all positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax planning strategies, and past financial performance. In 2013, the Company recorded an increase to the valuation allowance of approximately $10,241,000 for all remaining domestic net deferred tax assets not previously covered by a valuation allowance due to the following factors: (1) the Company’s forecast of future taxable income, of the appropriate nature, based on its quarterly assessment was not sufficient to support the recoverability of the remaining domestic deferred tax assets; (2) recent cumulative losses and the Company’s projection of continued losses into 2014; (3) while the Company has the ability to carryback federal net operating losses or credits to utilize against federal taxable income, it will generate only $1,600,000 in cash refunds; and (4) the lack of prudent and feasible tax planning strategies. These assessment factors remain unchanged, as does management’s conclusion concerning the need for a full valuation allowance against all domestic net deferred tax assets, as of March 31, 2014. The valuation allowance against these deferred tax assets may require adjustment in the future based on changes in the mix of temporary differences, changes in tax laws, and operating performance. If and when management determines the valuation allowance should be released, the adjustment would result in a tax benefit in the Condensed Consolidated Statements of Operations and may include a portion to be accounted for through “Additional paid-in capital”, a component of Stockholders’ Equity. The amount of the tax benefit to be recorded in a particular quarter could be material.
	In August 2013, the Company received notice from the Internal Revenue Service that its federal corporate tax returns for the tax years 2010 and 2011 had been selected for audit. The audit is in progress. There are no other income tax audits currently in process.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2014
Commitments And Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	10. Commitments and Contingencies
	At March 31, 2014, the Company had approximately $1,538,000 of capital expenditure commitments.
	On January 28, 2011, SynQor, Inc. (“SynQor”) filed a complaint for patent infringement against Ericsson, Inc. (“Ericsson”), Cisco Systems, Inc. (“Cisco”) and the Company in U.S. District Court for the Eastern District of Texas (“the Texas Action”). This immediately followed a complaint filed by the Company on January 26, 2011, in U.S. District Court for the District of Massachusetts, in which the Company sought a declaratory judgment that its bus converter products do not infringe any valid claim of certain of SynQor’s U.S. patents, and that the claims of those patents are invalid. SynQor and Ericsson subsequently entered into a definitive settlement agreement in May 2011 in which they, among other terms and conditions, agreed to mutual releases and a dismissal with prejudice of all claims asserted against each other in the litigation. With respect to the Company, SynQor’s complaint alleges the Company’s products, including, but not limited to, unregulated bus converters used in intermediate bus architecture power supply systems, infringe certain SynQor patents. SynQor seeks, among other items, an injunction against further infringement and an award of unspecified compensatory and enhanced damages, interest, costs and attorney fees. On February 8, 2011, SynQor filed a motion for preliminary injunction seeking an order enjoining the Company from manufacturing, using, selling, and offering for sale in the United States and/or importing into the United States certain identified unregulated bus converters, as well as any other bus converters not significantly different from those products. On February 17, 2011, the Company withdrew its Massachusetts action without prejudice to allow the litigation to proceed in Texas. On May 16, 2011, SynQor announced it was withdrawing its motion for preliminary injunction against the Company. On September 16, 2011, the U.S. District Court for the Eastern District of Texas issued an order setting a trial date of July 7, 2014. On September 20, 2011, SynQor filed an amended complaint in the Texas Action. The amended complaint repeated the allegations of patent infringement against the Company contained in SynQor’s original complaint, and included additional patent infringement allegations with respect to U.S. Patent No. 8,023,290 (“290 patent”), which was issued on that day. As with SynQor’s original complaint, the amended complaint alleged that the Company’s products, including but not limited to the Company’s unregulated bus converters used in intermediate bus architecture power supply systems, infringed the asserted patents. On October 4, 2011, the Company filed an answer and counterclaims to SynQor’s amended complaint, in which the Company alleges the 290 patent is unenforceable because it was procured through inequitable conduct before the U.S. Patent and Trademark Office and seeks damages against SynQor for SynQor’s unfair and deceptive trade practices and tortious interference with prospective economic advantage in connection with SynQor’s allegations of patent infringement against the Company. On January 2, 2014, the court issued its claim construction order following a claim construction hearing held on December 17, 2013. On January 16, 2014, the Company filed a motion seeking reconsideration of certain aspects of the court’s claim construction ruling. On March 31, 2014, the court issued an order severing the case against the Company and Cisco into two separate matters, with separate trials to be held with respect to SynQor’s claims against Cisco and SynQor’s claims against the Company. The court also cancelled the previously scheduled trial date of July 7, 2014, and has indicated that any trial will be held after September 2014. SynQor has filed a motion for reconsideration of this order, which is pending. The Company continues to believe that none of its products, including its unregulated bus converters, infringe any valid claim of the asserted SynQor patents, either alone or when used in an intermediate bus architecture implementation. The Company believes SynQor’s claims lack merit and, therefore, continues to vigorously defend itself against SynQor’s patent infringement allegations. The Company does not believe a loss is probable for this matter. If a loss were to be incurred, though, the Company cannot estimate the amount of possible loss or range of possible loss at this time.
	In addition, the Company is involved in certain other litigation and claims incidental to the conduct of its business. While the outcome of lawsuits and claims against the Company cannot be predicted with certainty, management does not expect any current litigation or claims to have a material adverse impact on the Company’s financial position or results of operations.

Segment_Information

Segment Information	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Segment Information	'
	11. Segment Information
	The Company has organized its business segments according to its key product lines. The Brick Business Unit segment (“BBU”) designs, develops, manufactures and markets the Company’s modular power converters and configurable products, and also includes the operations of the Company’s Westcor division, the six entities comprising Vicor Custom Power, and the BBU operations of Vicor Japan Company, Ltd. (“VJCL”). The VI Chip segment includes VI Chip Corporation, which designs, develops, manufactures and markets the Company’s factorized power architecture (“FPA”) products. The VI Chip segment also includes the VI Chip business conducted through VJCL. The Picor segment includes Picor Corporation, which designs, develops, manufactures and markets integrated circuits and related products for use in a variety of power management and power system applications. Picor develops these products to be sold as part of the Company’s products or to third parties for separate applications.
	The Company’s chief operating decision maker evaluates performance and allocates resources based on segment revenues and segment operating income (loss). The operating income (loss) for each segment includes selling, general and administrative and research and development expenses directly attributable to the segment. Certain of the Company’s indirect overhead costs, which include corporate selling, general and administrative expenses, are allocated among the segments based upon an estimate of costs associated with each segment. Assets allocated to each segment are based upon specific identification of such assets, which include accounts receivable, inventories, fixed assets and certain other assets. The Corporate segment consists of those operations and assets shared by all segments. The costs of certain centralized executive and administrative functions are recorded in this segment, as are certain shared assets, most notably cash and cash equivalents, deferred tax assets, long-term investments, the Company’s facilities in Massachusetts, real estate and other assets. The Company’s accounting policies and method of presentation for segments are consistent with that used throughout the Condensed Consolidated Financial Statements.
	The following table provides significant segment financial data as of and for the three months ended March 31, (in thousands):
			BBU		VI Chip			Picor			Corporate			Eliminations			Total
															(1	)
	2014:00:00
	Net revenues		$	43,689	$	9,341		$	2,950		$	—		$	(2,747	)	$	53,233
	Income (loss) from operations			2,312		(6,847	)		(742	)		(162	)		—			(5,439	)
	Total assets			138,770		20,011			4,514			75,130			(75,337	)		163,088
	Depreciation and amortization			1,193		791			101			358			—			2,443
	2013:00:00
	Net revenues		$	38,202	$	3,407		$	1,782		$	—		$	(1,445	)	$	41,946
	Income (loss) from operations			2,149		(9,238	)		(1,204	)		(203	)		—			(8,496	)
	Total assets			102,264		17,843			5,334			108,551			(46,149	)		187,843
	Depreciation and amortization			1,194		901			108			291			—			2,494
	-1	The elimination for net revenues is principally related to inter-segment revenues of Picor to BBU and VI Chip and for inter-segment revenues of VI Chip to BBU. The elimination for total assets is principally related to inter-segment accounts receivable due to BBU for the funding of VI Chip and Picor operations.

Impact_of_Recently_Issued_Acco

Impact of Recently Issued Accounting Standards	3 Months Ended
	Mar. 31, 2014
Accounting Changes And Error Corrections [Abstract]	'
Impact of Recently Issued Accounting Standards	'
	12. Impact of Recently Issued Accounting Standards
	Effective January 1, 2014, the Company adopted new accounting guidance related to the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. The guidance requires an unrecognized tax benefit to be presented as a decrease in a deferred tax asset where a net operating loss, a similar tax loss, or a tax credit carryforward exists and certain criteria are met. The adoption of this new guidance did not impact the Company’s financial position or results of operations.

ShortTerm_and_LongTerm_Investm1

Short-Term and Long-Term Investments (Tables)	3 Months Ended
	Mar. 31, 2014
Investments Debt And Equity Securities [Abstract]	'
Summary of Available-for-Sale Securities	'
	The following is a summary of available-for-sale securities (in thousands):
				Gross			Gross		Estimated
				Unrealized			Unrealized		Fair
	March 31, 2014	Cost		Gains			Losses		Value
	Failed Auction Securities	$	6,000	$	—		$	1,136	$	4,864
	Brokered certificates of deposit		820		4			—		824
		$	6,820	$	4		$	1,136	$	5,688
				Gross			Gross		Estimated
				Unrealized			Unrealized		Fair
	December 31, 2013	Cost		Gains			Losses		Value
	Failed Auction Securities	$	6,000	$	—		$	1,175	$	4,825
	Brokered certificates of deposit		820		6			—		826
		$	6,820	$	6		$	1,175	$	5,651
Amortized Cost and Estimated Fair Value of Available-for-Sale Securities	'
	The amortized cost and estimated fair value of available-for-sale securities on March 31, 2014, by contractual maturities, are shown below (in thousands):
				Estimated
		Cost		Fair Value
	Due in one year or less	$	640	$	643
	Due in two to ten years		180		181
	Due in ten to twenty years		—		—
	Due in twenty to forty years		6,000		4,864
		$	6,820	$	5,688
Rollforward of Credit Loss Recognized in Earnings on Available-for-Sale Auction Rate Securities	'
	The following table represents a rollforward of the activity related to the credit loss recognized in earnings on available-for-sale auction rate securities held by the Company for the three months ended March 31 (in thousands):
		2014		2013
	Balance at the beginning of the period	$	395	$	317
	Additions for the amount related to credit loss for which other-than- temporary impairment was not previously recognized		—		(1	)
	Balance at the end of the period	$	395	$	316

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Assets Measured at Fair Value on Recurring Basis	'
	Assets measured at fair value on a recurring basis include the following as of March 31, 2014 (in thousands):
		Using
		Quoted Prices			Significant			Significant		Total Fair
		in Active			Other			Unobservable		Value as of
		Markets			Observable			Inputs		March 31, 2014
		(Level 1)			Inputs			(Level 3)
					(Level 2)
	Cash Equivalents:
	Money market funds	$	12,176		$	—		$	—	$	12,176
	Short-term investments:
	Brokered certificates of deposit		—			643			—		643
	Long-term investments:
	Failed Auction Securities		—			—			4,864		4,864
	Brokered certificates of deposit		—			181			—		181
	Assets measured at fair value on a recurring basis include the following as of December 31, 2013 (in thousands):
		Using
		Quoted Prices			Significant			Significant		Total Fair
		in Active			Other			Unobservable		Value as of
		Markets			Observable			Inputs		December 31, 2013
		(Level 1)			Inputs			(Level 3)
					(Level 2)
	Cash Equivalents:
	Money market funds	$	12,407		$	—		$	—	$	12,407
	Short-term investments:
	Brokered certificates of deposit		—			463			—		463
	Long-term investments:
	Failed Auction Securities		—			—			4,825		4,825
	Brokered certificates of deposit		—			363			—		363
Quantitative Information about Level 3 Fair Value Measurements	'
	Quantitative information about Level 3 fair value measurements as of March 31, 2014 are as follows (dollars in thousands):
		Fair Value		Valuation	Unobservable		Range
				Technique	Input		(Weighted
							Average)
	Failed Auction Securities	$4,864		Discounted	Cumulative probability of earning the maximum rate until maturity		0.01% - 0.07%
				cash flow			-0.04%
					Cumulative probability of principal return prior to maturity		70.66% - 94.49%
							-82.58%
					Cumulative probability of default		5.50% - 29.27%
							-17.39%
					Liquidity risk premium		5.00% - 5.00%
							-5.00%
					Recovery rate in default		40.00% - 40.00%
							-40.00%
Change in Estimated Fair Values Calculated for Assets Valued on Recurring Basis Utilizing Level 3 Inputs	'
	The following table summarizes the change in the estimated fair values calculated for those assets valued on a recurring basis utilizing Level 3 inputs (i.e., the Failed Auction Securities) for the three months ended March 31, 2014 (in thousands):
	Balance at the beginning of the period	$	4,825
	Unrealized gain included in Other comprehensive income (loss)		39
	Balance at the end of the period	$	4,864

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Stock-Based Compensation Expense	'
	Stock-based compensation expense for the three months ended March 31 was as follows (in thousands):
		Three Months Ended
		March 31,
		2014		2013
	Cost of revenues	$	36	$	4
	Selling, general and administrative		191		183
	Research and development		7		76
	Total stock-based compensation	$	234	$	263

Net_Income_Loss_per_Share_Tabl

Net Income (Loss) per Share (Tables)	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Computation of Basic and Diluted Income (Loss) Per Share	'
	The following table sets forth the computation of basic and diluted income (loss) per share for the three months ended March 31 (in thousands, except per share amounts):
			Three Months Ended
			March 31,
			2014			2013
	Numerator:
	Net loss attributable to Vicor Corporation		$	(5,378	)	$	(4,990	)
	Denominator:
	Denominator for basic loss per share-weighted			38,541			41,167
	average shares (1)
	Effect of dilutive securities:
	Employee stock options (2)			—			—
	Denominator for diluted loss per share – adjusted weighted-average shares and assumed conversions			38,541			41,167
	Basic loss per share		$	(0.14	)	$	(0.12	)
	Diluted loss per share		$	(0.14	)	$	(0.12	)
	-1	Denominator represents weighted average number of shares of Common Stock and Class B Common Stock outstanding.
	-2	Options to purchase 1,981,028 and 602,841 shares of Common Stock for the three months ended March 31, 2014 and 2013, respectively, were not included in the calculation of net loss per share as the effect would have been antidilutive.

Inventories_Tables

Inventories (Tables)	3 Months Ended
	Mar. 31, 2014
Inventory Disclosure [Abstract]	'
Summary of Inventories	'
	Inventories were as follows (in thousands):
		March 31, 2014		December 31, 2013
	Raw materials	$	20,179	$	19,744
	Work-in-process		3,658		3,979
	Finished goods		5,684		5,973
	Net balance	$	29,521	$	29,696

Product_Warranties_Tables

Product Warranties (Tables)	3 Months Ended
	Mar. 31, 2014
Guarantees [Abstract]	'
Product Warranty Activity	'
	Product warranty activity for the three months ended March 31, was as follows (in thousands):
		Three Months Ended
		March 31,
		2014			2013
	Balance at the beginning of the period	$	283		$	364
	Accruals for warranties for products sold in the period		24			29
	Fulfillment of warranty obligations		(55	)		(47	)
	Revisions of estimated obligations		(3	)		(22	)
	Balance at the end of the period	$	249		$	324

Income_Taxes_Tables

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2014
Income Tax Disclosure [Abstract]	'
Provision (Benefit) for Income Taxes and Effective Income Tax Rate	'
	The provision (benefit) for income taxes and the effective income tax rate for the three months ended March 31, were as follows (in thousands):
		Three Months Ended
		March 31,
		2014			2013
	Provision (benefit) for income taxes	$	17		$	(3,495	)
	Effective income tax rate		0.3	%		(41.2	%)

Segment_Information_Tables

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Significant Segment Financial Data	'
	The following table provides significant segment financial data as of and for the three months ended March 31, (in thousands):
			BBU		VI Chip			Picor			Corporate			Eliminations			Total
															(1	)
	2014:00:00
	Net revenues		$	43,689	$	9,341		$	2,950		$	—		$	(2,747	)	$	53,233
	Income (loss) from operations			2,312		(6,847	)		(742	)		(162	)		—			(5,439	)
	Total assets			138,770		20,011			4,514			75,130			(75,337	)		163,088
	Depreciation and amortization			1,193		791			101			358			—			2,443
	2013:00:00
	Net revenues		$	38,202	$	3,407		$	1,782		$	—		$	(1,445	)	$	41,946
	Income (loss) from operations			2,149		(9,238	)		(1,204	)		(203	)		—			(8,496	)
	Total assets			102,264		17,843			5,334			108,551			(46,149	)		187,843
	Depreciation and amortization			1,194		901			108			291			—			2,494
	-1	The elimination for net revenues is principally related to inter-segment revenues of Picor to BBU and VI Chip and for inter-segment revenues of VI Chip to BBU. The elimination for total assets is principally related to inter-segment accounts receivable due to BBU for the funding of VI Chip and Picor operations.

ShortTerm_and_LongTerm_Investm2

Short-Term and Long-Term Investments - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Unrealized Losses On Short Term And Long Term Investments [Line Items]	'	'	'	'
Fair value of Failed Auction Securities	$5,688,000	$5,651,000	'	'
Minimum period for which failed auction securities been in unrealized loss position	'12 months	'	'	'
Gross Unrealized Losses	1,136,000	1,175,000	'	'
Aggregate credit loss	395,000	395,000	316,000	317,000
Failed Auction Securities [Member]	'	'	'	'
Unrealized Losses On Short Term And Long Term Investments [Line Items]	'	'	'	'
Fair value of Failed Auction Securities	4,864,000	4,825,000	'	'
Period for which failed auction securities been in unrealized loss position	'Exceeds 12 months	'	'	'
Increase in fair value	39,000	'	'	'
Gross Unrealized Losses	1,136,000	1,175,000	'	'
Aggregate credit loss	395,000	'	'	'
Aggregate temporary impairment loss	$741,000	'	'	'

ShortTerm_and_LongTerm_Investm3

Short-Term and Long-Term Investments - Summary of Available-for-Sale Securities (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	$6,820	$6,820
Gross Unrealized Gains	4	6
Gross Unrealized Losses	1,136	1,175
Estimated Fair Value	5,688	5,651
Failed Auction Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	6,000	6,000
Gross Unrealized Gains	'	'
Gross Unrealized Losses	1,136	1,175
Estimated Fair Value	4,864	4,825
Brokered Certificates of Deposit [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	820	820
Gross Unrealized Gains	4	6
Gross Unrealized Losses	'	'
Estimated Fair Value	$824	$826

ShortTerm_and_LongTerm_Investm4

Short-Term and Long-Term Investments - Amortized Cost and Estimated Fair Value of Available-for-Sale Securities (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Amortized Cost And Fair Value Debt Securities [Abstract]	'	'
Due in one year or less, Cost	$640	'
Due in two to ten years, Cost	180	'
Due in ten to twenty years, Cost	'	'
Due in twenty to forty years, Cost	6,000	'
Total Cost	6,820	6,820
Due in one year or less, Estimated Fair Value	643	'
Due in two to ten years, Estimated Fair Value	181	'
Due in ten to twenty years, Estimated Fair Value	'	'
Due in twenty to forty years, Estimated Fair Value	4,864	'
Estimated Fair Value	$5,688	$5,651

ShortTerm_and_LongTerm_Investm5

Short-Term and Long-Term Investments - Rollforward of Credit Loss Recognized in Earnings on Available-for-Sale Auction Rate Securities (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Amortized Cost And Fair Value Debt Securities [Abstract]	'	'
Balance at the beginning of the period	$395	$317
Additions for the amount related to credit loss for which other-than- temporary impairment was not previously recognized	'	-1
Balance at the end of the period	$395	$316

Fair_Value_Measurements_Assets

Fair Value Measurements - Assets Measured at Fair Value on Recurring Basis (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Estimated Fair Value	$5,688	$5,651
Failed Auction Securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Estimated Fair Value	4,864	4,825
Brokered Certificates of Deposit [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Estimated Fair Value	824	826
Recurring [Member] | Short-Term Brokered Certificates of Deposit [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Estimated Fair Value	643	463
Recurring [Member] | Failed Auction Securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Estimated Fair Value	4,864	4,825
Recurring [Member] | Brokered Certificates of Deposit [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Estimated Fair Value	181	363
Recurring [Member] | Money Market Funds [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Cash Equivalents	12,176	12,407
Recurring [Member] | Quoted Prices in Active Markets (Level 1) [Member] | Short-Term Brokered Certificates of Deposit [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Estimated Fair Value	'	'
Recurring [Member] | Quoted Prices in Active Markets (Level 1) [Member] | Failed Auction Securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Estimated Fair Value	'	'
Recurring [Member] | Quoted Prices in Active Markets (Level 1) [Member] | Brokered Certificates of Deposit [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Estimated Fair Value	'	'
Recurring [Member] | Quoted Prices in Active Markets (Level 1) [Member] | Money Market Funds [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Cash Equivalents	12,176	12,407
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Short-Term Brokered Certificates of Deposit [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Estimated Fair Value	643	463
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Failed Auction Securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Estimated Fair Value	'	'
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Brokered Certificates of Deposit [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Estimated Fair Value	181	363
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Money Market Funds [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Cash Equivalents	'	'
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Short-Term Brokered Certificates of Deposit [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Estimated Fair Value	'	'
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Failed Auction Securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Estimated Fair Value	4,864	4,825
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Brokered Certificates of Deposit [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Estimated Fair Value	'	'
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Money Market Funds [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Cash Equivalents	'	'

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Percent of credit loss	6.60%
Rate of return required	5.00%
Estimated timeframe for auctions of securities minimum	'3 years
Estimated timeframe for auctions of securities maximum	'5 years
Percentage of liquidity risk premium	5.00%
Increase or decrease in the liquidity risk premium	1.00%
Increase or decrease, respectively, the fair value of the Failed Auction Securities	$400,000

Fair_Value_Measurements_Quanti

Fair Value Measurements - Quantitative Information about Level 3 Fair Value Measurements (Detail) (USD $)

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

In Thousands, unless otherwise specified

Failed Auction Securities [Member]

Failed Auction Securities [Member]

Failed Auction Securities [Member]

Failed Auction Securities [Member]

Failed Auction Securities [Member]

Failed Auction Securities [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Significant Unobservable Inputs (Level 3) [Member]

Significant Unobservable Inputs (Level 3) [Member]

Significant Unobservable Inputs (Level 3) [Member]

Significant Unobservable Inputs (Level 3) [Member]

Significant Unobservable Inputs (Level 3) [Member]

Significant Unobservable Inputs (Level 3) [Member]

Failed Auction Securities [Member]

Failed Auction Securities [Member]

Failed Auction Securities [Member]

Failed Auction Securities [Member]

Failed Auction Securities [Member]

Failed Auction Securities [Member]

Failed Auction Securities [Member]

Failed Auction Securities [Member]

Failed Auction Securities [Member]

Failed Auction Securities [Member]

Cumulative Probability of Earning Maximum Rate Until Maturity [Member]

Cumulative Probability of Principal Return Prior to Maturity [Member]

Cumulative Probability of Default [Member]

Liquidity Risk Premium [Member]

Recovery Rate in Default [Member]

Significant Unobservable Inputs (Level 3) [Member]

Significant Unobservable Inputs (Level 3) [Member]

Significant Unobservable Inputs (Level 3) [Member]

Significant Unobservable Inputs (Level 3) [Member]

Significant Unobservable Inputs (Level 3) [Member]

Significant Unobservable Inputs (Level 3) [Member]

Significant Unobservable Inputs (Level 3) [Member]

Significant Unobservable Inputs (Level 3) [Member]

Significant Unobservable Inputs (Level 3) [Member]

Significant Unobservable Inputs (Level 3) [Member]

Cumulative Probability of Earning Maximum Rate Until Maturity [Member]

Cumulative Probability of Principal Return Prior to Maturity [Member]

Cumulative Probability of Default [Member]

Liquidity Risk Premium [Member]

Recovery Rate in Default [Member]

Cumulative Probability of Earning Maximum Rate Until Maturity [Member]

Cumulative Probability of Principal Return Prior to Maturity [Member]

Cumulative Probability of Default [Member]

Liquidity Risk Premium [Member]

Recovery Rate in Default [Member]

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

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Estimated Fair Value

$5,688

$5,651

$4,864

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Valuation Technique

'

'

'Discounted cash flow

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unobservable Input

'

'

'

'Cumulative probability of earning the maximum rate until maturity

'Cumulative probability of principal return prior to maturity

'Cumulative probability of default

'Liquidity risk premium

'Recovery rate in default

'

'

'

'

'

'

'

'

'

'

Weighted Average Interest Rate

'

'

'

-0.04%

-82.58%

-17.39%

-5.00%

-40.00%

0.01%

70.66%

5.50%

5.00%

40.00%

0.07%

94.49%

29.27%

5.00%

40.00%

Fair_Value_Measurements_Change

Fair Value Measurements - Change in Estimated Fair Values for Assets Valued on Recurring Basis Utilizing Level 3 Inputs (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Balance at the beginning of the period	$4,825
Unrealized gain included in Other comprehensive income (loss)	39
Balance at the end of the period	$4,864

StockBased_Compensation_StockB

Stock-Based Compensation - Stock-Based Compensation Expense (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'
Total stock-based compensation	$234	$263
Cost of Revenues [Member]	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'
Total stock-based compensation	36	4
Selling, General and Administrative [Member]	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'
Total stock-based compensation	191	183
Research and Development [Member]	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'
Total stock-based compensation	$7	$76

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (2007 VI Chip Plan [Member], USD $)	Mar. 31, 2014	Dec. 31, 2010
2007 VI Chip Plan [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Non-qualified stock options	'	2,984,250
Unrecognized compensation cost related to performance-based stock options	$704,000	'

Net_Income_Loss_per_Share_Comp

Net Income (Loss) per Share - Computation of Basic and Diluted Income (Loss) Per Share (Detail) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Numerator:	'	'
Net loss attributable to Vicor Corporation	($5,378)	($4,990)
Denominator:	'	'
Denominator for basic loss per share-weighted average shares	38,541	41,167
Effect of dilutive securities:	'	'
Employee stock options	'	'
Denominator for diluted loss per share - adjusted weighted-average shares and assumed conversions	38,541	41,167
Basic loss per share	($0.14)	($0.12)
Diluted loss per share	($0.14)	($0.12)

Net_Income_Loss_per_Share_Comp1

Net Income (Loss) per Share - Computation of Basic and Diluted Income (Loss) Per Share (Parenthetical) (Detail)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Earnings Per Share [Abstract]	'	'
Options to purchase shares of Common Stock not included in the computation of diluted income per share	1,981,028	602,841

Inventories_Summary_of_Invento

Inventories - Summary of Inventories (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]	'	'
Raw materials	$20,179	$19,744
Work-in-process	3,658	3,979
Finished goods	5,684	5,973
Net balance	$29,521	$29,696

Other_Investments_Additional_I

Other Investments - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Variable Interest Entity [Line Items]	'	'	'
Ownership interest in investment	27.00%	'	27.00%
Purchase of components under agreement	$942,000	$396,000	'
Company owed GWS	56,000	'	152,000
Great Wall Semiconductor Corporation (GWS) [Member]	'	'	'
Variable Interest Entity [Line Items]	'	'	'
Investment in non-voting convertible preferred stock	0	'	0
Great Wall Semiconductor Corporation (GWS) [Member] | Convertible Preferred Stock [Member]	'	'	'
Variable Interest Entity [Line Items]	'	'	'
Investment in non-voting convertible preferred stock	$5,000,000	'	$5,000,000

Product_Warranties_Additional_

Product Warranties - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2014
Guarantees [Abstract]	'
Warranty period	'2 years

Product_Warranties_Product_War

Product Warranties - Product Warranty Activity (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Guarantees [Abstract]	'	'
Balance at the beginning of the period	$283	$364
Accruals for warranties for products sold in the period	24	29
Fulfillment of warranty obligations	-55	-47
Revisions of estimated obligations	-3	-22
Balance at the end of the period	$249	$324

Income_Taxes_Provision_Benefit

Income Taxes - Provision (Benefit) for Income Taxes and Effective Income Tax Rate (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Income Tax Disclosure [Abstract]	'	'
Provision (benefit) for income taxes	$17	($3,495)
Effective income tax rate	0.30%	-41.20%

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Deferred Tax Assets Liabilities [Line Items]	'	'	'
Tax benefit recognized	$0	'	'
Federal research tax credit	'	'	549,000
Valuation allowance, deferred tax assets	20,214,000	'	'
Deferred tax assets valuation allowance increase	'	10,241,000	'
Forecast [Member]	'	'	'
Deferred Tax Assets Liabilities [Line Items]	'	'	'
Expected cash refunds to be generated	$1,600,000	'	'

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Detail) (USD $)	Mar. 31, 2014
Commitments And Contingencies Disclosure [Abstract]	'
Capital expenditure commitments	$1,538,000

Segment_Information_Additional

Segment Information - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2014
	Entity
Segment Reporting [Abstract]	'
Number of entities comprising operating segment	6

Segment_Information_Significan

Segment Information - Significant Segment Financial Data (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]	'	'	'
Net revenues	$53,233	$41,946	'
Income (loss) from operations	-5,439	-8,496	'
Total assets	163,088	187,843	165,640
Depreciation and amortization	2,443	2,494	'
Operating Segments [Member] | BBU [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Net revenues	43,689	38,202	'
Income (loss) from operations	2,312	2,149	'
Total assets	138,770	102,264	'
Depreciation and amortization	1,193	1,194	'
Operating Segments [Member] | VI Chip [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Net revenues	9,341	3,407	'
Income (loss) from operations	-6,847	-9,238	'
Total assets	20,011	17,843	'
Depreciation and amortization	791	901	'
Operating Segments [Member] | Picor [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Net revenues	2,950	1,782	'
Income (loss) from operations	-742	-1,204	'
Total assets	4,514	5,334	'
Depreciation and amortization	101	108	'
Operating Segments [Member] | Corporate [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Net revenues	'	'	'
Income (loss) from operations	-162	-203	'
Total assets	75,130	108,551	'
Depreciation and amortization	358	291	'
Eliminations [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Net revenues	-2,747	-1,445	'
Income (loss) from operations	'	'	'
Total assets	-75,337	-46,149	'
Depreciation and amortization	'	'	'