Vicor (VICR) 10-Q 29 Apr 16 2016 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2016	Apr. 22, 2016
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q1
Trading Symbol	VICR
Entity Registrant Name	VICOR CORP
Entity Central Index Key	751,978
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		27,037,328
Class B Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		11,758,218

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 59,710	$ 62,980
Accounts receivable, less allowance of $148 in 2016 and $171 in 2015	23,349	25,982
Inventories, net	24,150	23,442
Other current assets	3,048	3,102
Total current assets	110,257	115,506
Long-term investments, net	2,553	2,866
Property, plant and equipment, net	37,177	37,450
Long-term deferred tax assets, net	15	15
Other assets	1,908	1,708
Total assets	151,910	157,545
Current liabilities:
Accounts payable	8,232	7,470
Accrued compensation and benefits	8,145	8,349
Accrued expenses	2,220	2,568
Accrued severance charges	37	195
Income taxes payable	29	31
Deferred revenue	1,933	1,988
Total current liabilities	20,596	20,601
Long-term deferred revenue	433	468
Contingent consideration obligations	352	144
Long-term income taxes payable	193	192
Deferred income taxes payable		55
Total liabilities	$ 21,574	$ 21,460
Commitments and contingencies (Note 11)
Vicor Corporation stockholders' equity:
Common Stock	$ 395	$ 395
Additional paid-in capital	174,605	174,337
Retained earnings	94,334	99,685
Accumulated other comprehensive loss	(394)	(577)
Treasury stock, at cost	(138,927)	(138,927)
Total Vicor Corporation stockholders' equity	130,131	135,031
Noncontrolling interest	205	1,054
Total equity	130,336	136,085
Total liabilities and equity	151,910	157,545
Class B Common Stock [Member]
Vicor Corporation stockholders' equity:
Common Stock	$ 118	$ 118

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Accounts receivable, allowance	$ 148	$ 171

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Net revenues	$ 46,027	$ 64,017
Cost of revenues	26,711	35,126
Gross margin	19,316	28,891
Operating expenses:
Selling, general and administrative	14,016	14,862
Research and development	10,729	10,419
Total operating expenses	24,745	25,281
Income (loss) from operations	(5,429)	3,610
Other income (expense), net:
Total unrealized gains (losses) on available-for-sale securities, net	27	(15)
Portion of gains (losses) recognized in other comprehensive income (loss)	(23)	19
Net credit gains recognized in earnings	4	4
Other income (expense), net	71	(33)
Total other income (expense), net	75	(29)
Income (loss) before income taxes	(5,354)	3,581
Less: Provision for income taxes	22	139
Consolidated net income (loss)	(5,376)	3,442
Less: Net income (loss) attributable to noncontrolling interest	(25)	71
Net income (loss) attributable to Vicor Corporation	$ (5,351)	$ 3,371
Net income (loss) per common share attributable to Vicor Corporation:
Basic	$ (0.14)	$ 0.09
Diluted	$ (0.14)	$ 0.09
Shares used to compute net income (loss) per common share attributable to Vicor Corporation:
Basic	38,794	38,689
Diluted	38,794	39,149

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Consolidated net income (loss)		$ (5,376)	$ 3,442
Foreign currency translation gains (losses), net of tax	[1]	173	(37)
Unrealized gains (losses) on available-for-sale securities, net of tax	[2]	23	(15)
Other comprehensive income (loss)		196	(52)
Consolidated comprehensive income (loss)		(5,180)	3,390
Less: Comprehensive income (loss) attributable to noncontrolling interest		(12)	71
Comprehensive income (loss) attributable to Vicor Corporation		$ (5,168)	$ 3,319
[1]	Net of tax provision (benefit) of $0 for the three months ended March 31, 2016 and 2015, respectively.
[2]	The deferred tax assets associated with cumulative unrealized losses on available-for-sale securities are completely offset by a tax valuation allowance as of March 31, 2016 and 2015. Therefore, there is no net income tax provision (benefit) recognized for the three months ended March 31, 2016 and 2015.

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (Parenthetical) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Foreign currency translation gains (losses), tax provision (benefit)	$ 0	$ 0
Recognized income tax provision (benefit)	$ 0	$ 0

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating activities:
Consolidated net income (loss)	$ (5,376)	$ 3,442
Adjustments to reconcile consolidated net income (loss) to net cash provided by (used for) operating activities:
Depreciation and amortization	2,195	2,403
Stock-based compensation expense	329	563
(Benefit) provision for doubtful accounts	(28)	33
Decrease in long-term deferred revenue	(35)	(34)
Deferred income taxes	(55)
Gain on disposal of equipment	(2)	(35)
Credit gain on available-for-sale securities	(4)	(4)
Increase in long-term income taxes payable	1	6
Change in current assets and liabilities, net	2,141	(1,304)
Net cash (used for) provided by operating activities	(834)	5,070
Investing activities:
Additions to property, plant and equipment	(1,887)	(1,469)
Sales and maturities of investments		270
Proceeds from sale of equipment	2	35
Increase in other assets	(214)	(65)
Net cash used for investing activities	(2,099)	(1,229)
Financing activities:
Proceeds from issuance of Common Stock	19	310
Acquisition of noncontrolling interest	(372)
Net cash provided by financing activities	(353)	310
Effect of foreign exchange rates on cash	16	(16)
Net (decrease) increase in cash and cash equivalents	(3,270)	4,135
Cash and cash equivalents at beginning of period	62,980	55,187
Cash and cash equivalents at end of period	59,710	$ 59,322
Supplemental disclosure of non-cash financing activities:
Acquisition of noncontrolling interest	$ (346)

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	1. Basis of Presentation The accompanying unaudited Condensed Consolidated Financial Statements of Vicor Corporation and its consolidated subsidiaries (collectively, 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, 2016 are not necessarily indicative of the results that may be expected for any other interim period or the year ending December 31, 2016. The balance sheet at December 31, 2015 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, 2015 filed by the Company with the Securities and Exchange Commission on March 8, 2016.

Long-Term Investments

Long-Term Investments	3 Months Ended
	Mar. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Long-Term Investments	2. Long-Term Investments As of March 31, 2016 and December 31, 2015, the Company held one auction rate security that had experienced failed auctions of $3,000,000 at par value, which was purchased through and is held by a broker-dealer affiliate of Bank of America, N.A. (the “Failed Auction Security”). The Failed Auction Security held by the Company is Aaa/AA+ 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 the issuer of the Failed Auction Security is presently at risk of default. Through March 31, 2016, the Company has continued to receive interest payments on the Failed Auction Security in accordance with the terms of its indenture. Management believes the Company ultimately should be able to liquidate the Failed Auction Security without significant loss primarily due to the overall quality of the issue held and the collateral securing the substantial majority of the underlying obligation. However, current conditions in the auction rate securities market have led management to conclude the recovery period for the Failed Auction Security exceeds 12 months. As a result, the Company continued to classify the Failed Auction Security as long-term as of March 31, 2016. The following is a summary of available-for-sale securities (in thousands): Gross Gross Estimated Unrealized Unrealized Fair March 31, 2016 Cost Gains Losses Value Failed Auction Security $ 3,000 $ — $ 447 $ 2,553 Gross Gross Estimated Unrealized Unrealized Fair December 31, 2015 Cost Gains Losses Value Failed Auction Security $ 3,000 $ — $ 474 $ 2,526 Brokered certificates of deposit 340 — — 340 $ 3,340 $ — $ 474 $ 2,866 As of March 31, 2016, the Failed Auction Security had been in an unrealized loss position for greater than 12 months. The amortized cost and estimated fair value of the available-for-sale security on March 31, 2016, by contractual maturity, is shown below (in thousands): Estimated Cost Fair Value Due in twenty to forty years $ 3,000 $ 2,553 Based on the fair value measurements described in Note 3, the fair value of the Failed Auction Security on March 31, 2016, with a par value of $3,000,000, was estimated by the Company to be approximately $2,553,000. The gross unrealized loss of $447,000 on the Failed Auction Security consists of two types of estimated loss: an aggregate credit loss of $68,000 and an aggregate temporary impairment of $379,000. 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 security, 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 the Failed Auction Security for the three months ended March 31 (in thousands): 2016 2015 Balance at the beginning of the period $ 72 $ 84 Reductions in the amount related to credit gain for which other-than-temporary impairment was not previously recognized (4 ) (4 ) Balance at the end of the period $ 68 $ 80 At this time, the Company has no intent to sell the impaired Failed Auction Security and does not believe it is more likely than not the Company will be required to sell this security. 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 the investment through impairment charges recorded in the Condensed Consolidated Statements 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 Security held will affect the Company’s ability to execute its current operating plan.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2016
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 included the following as of March 31, 2016 (in thousands): Using Significant Quoted Prices Other Significant in Active Observable Unobservable Total Fair Markets Inputs Inputs Value as of (Level 1) (Level 2) (Level 3) March 31, 2016 Cash equivalents: Money market funds $ 9,599 $ — $ — $ 9,599 Long-term investments: Failed Auction Security — — 2,553 2,553 Liabilities: Contingent consideration obligations — — (352 ) (352 ) Assets measured at fair value on a recurring basis included the following as of December 31, 2015 (in thousands): Using Significant Quoted Prices Other Significant in Active Observable Unobservable Total Fair Markets Inputs Inputs Value as of (Level 1) (Level 2) (Level 3) December 31, 2015 Cash equivalents: Money market funds $ 10,412 $ — $ — $ 10,412 Long-term investments: Failed Auction Security — — 2,526 2,526 Brokered certificates of deposit — 340 — 340 Liabilities: Contingent consideration obligation — — (144 ) (144 ) The Company has classified its contingent consideration obligations as Level 3 because the fair value for these liabilities was determined using unobservable inputs. The liabilities were based on estimated sales of legacy products over the period of royalty payments at the royalty rate (see Note 7), discounted using the Company’s estimated cost of capital. The Company has classified its brokered certificates of deposit as Level 2 because the fair value for these investments was 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, 2016, there was insufficient observable auction rate security market information available to determine the fair value of the Failed Auction Security using Level 1 or Level 2 inputs. As such, the Company’s investment in the Failed Auction Security was deemed to require valuation using Level 3 inputs. Management, after consulting with advisors, valued the Failed Auction Security 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 this security as of March 31, 2016. 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 2.3%; the rate of return required by investors to own this type of security 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 this type of security to occur. In making these assumptions, management considered relevant factors including: the formula applicable to the 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 the security, management compared the Penalty Rate of the Failed Auction Security 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 arm’s 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 Security. 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 Security by approximately $100,000. For purposes of the valuation process for the Failed Auction Security, “management” consists of senior members of the Company’s finance department. The fair value measurements for the Failed Auction Security 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 Failed Auction Security 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 security’s specific underlying assets and published recovery rate indices. Quantitative information about Level 3 fair value measurements as of March 31, 2016 is as follows (dollars in thousands): Valuation Unobservable Weighted Fair Value Technique Input Average Failed Auction Security $ 2,553 Discounted Cumulative probability of earning the maximum rate until maturity 0.03 % Cumulative probability of principal return prior to maturity 94.06 % Cumulative probability of default 5.91 % Liquidity risk premium 5.00 % Recovery rate in default 40.00 % The change in the estimated fair value calculated for the investment valued on a recurring basis utilizing Level 3 inputs (i.e., the Failed Auction Security) for the three months ended March 31, 2016 was as follows (in thousands): Balance at the beginning of the period $ 2,526 Credit gain on available-for-sale securities included in Other income (expense), net 4 Gain included in Other comprehensive income (loss) 23 Balance at the end of the period $ 2,553 The change in the estimated fair value calculated for the liabilities valued on a recurring basis utilizing Level 3 inputs (i.e., the Contingent consideration obligations) for the three months ended March 31, 2016 was as follows (in thousands): Balance at the beginning of the period $ 144 Obligation incurred upon acquisition of noncontrolling interest (see Note 7) 208 Balance at the end of the period $ 352 There were no transfers between Level 1 and Level 2 of the fair value hierarchy during the three months ended March 31, 2016.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based 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, 2016 2015 Cost of revenues $ 52 $ 61 Selling, general and administrative 238 408 Research and development 39 94 Total stock-based compensation $ 329 $ 563 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 VI Chip Corporation. 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, 2016 and, accordingly, expense has been recorded through that date. The unrecognized compensation expense for these performance-based options was approximately $451,000 as of March 31, 2016.

Net Income (Loss) per Share

Net Income (Loss) per Share	3 Months Ended
	Mar. 31, 2016
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 net income (loss) per share for the three months ended March 31 (in thousands, except per share amounts): Three Months Ended March 31, 2016 2015 Numerator: Net income (loss) attributable to Vicor Corporation $ (5,351 ) $ 3,371 Denominator: Denominator for basic net income (loss) per share-weighted average shares (1) 38,794 38,689 Effect of dilutive securities: Employee stock options (2) — 460 Denominator for diluted net income (loss) per share – adjusted weighted-average shares and assumed conversions 38,794 39,149 Basic net income (loss) per share $ (0.14 ) $ 0.09 Diluted net income (loss) per share $ (0.14 ) $ 0.09 (1) Denominator represents weighted average number of shares of Common Stock and Class B Common Stock outstanding. (2) Options to purchase 731,672 and 112,929 shares of Common Stock for the three months ended March 31, 2016 and 2015, respectively, were not included in the calculation of net income per share as the effect would have been antidilutive.

Inventories

Inventories	3 Months Ended
	Mar. 31, 2016
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, historical consumption 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, 2016 December 31, 2015 Raw materials $ 17,292 $ 16,257 Work-in-process 3,050 2,879 Finished goods 3,808 4,306 Net balance $ 24,150 $ 23,442

Noncontrolling Interest Transac

Noncontrolling Interest Transactions	3 Months Ended
	Mar. 31, 2016
Noncontrolling Interest [Abstract]
Noncontrolling Interest Transactions	7. Noncontrolling Interest Transactions On March 30, 2016, the Company acquired 100% ownership of certain operating assets and cash of its consolidated subsidiary, Converpower Corporation (“Converpower”), in which it held a 49% ownership interest. The operating assets and cash were acquired in exchange for the Company’s common shares representing that 49% interest and the aggregate dollar amount of royalty payments to be made by the Company to Converpower. The transaction was executed through a newly-formed, wholly-owned subsidiary, Granite Power Technologies, Inc. (“GPT”), the business operations of which had formerly existed as a division of Vicor. The shares of Converpower common stock held by the Company were contributed to GPT prior to the transaction. At the same time that it entered into the Asset Purchase Agreement associated with this transaction, the Company and Converpower entered into a license agreement providing the Company the right to continue manufacturing certain Converpower products in exchange for payment of royalties, quarterly through June 30, 2021, equal to a percentage of the revenue generated by the manufacture and sale of these products by GPT. The estimated present value of total future royalties, included in “Contingent consideration obligations” in the accompanying Condensed Consolidated Balance Sheet as of March 31, 2016, is $208,000. Although the Company exchanged its shares representing its 49% equity interest in Converpower, it acquired 100% control of the business operations. Accordingly, this transaction has been accounted for as an acquisition of a noncontrolling interest (i.e., an equity transaction). As such, as presented in the Company’s Condensed Consolidated Balance Sheet as of March 31, 2016, the noncontrolling interest balance in equity associated with Converpower was reduced to zero, and the additional paid-in capital account was reduced by $208,000, the estimated present value of total future royalties. As a result of the transactions associated with the consolidation of the Converpower operation into GPT, the Company’s aggregate balance of cash, short-term interest receivable, and long-term investments on its Condensed Consolidated Balance Sheet as of March 31, 2016, declined by approximately $718,000. No amounts were recorded in the Condensed Consolidated Statement of Operations related to these transactions.

Severance and Other Charges

Severance and Other Charges	3 Months Ended
	Mar. 31, 2016
Restructuring and Related Activities [Abstract]
Severance and Other Charges	8. Severance and Other Charges A summary of the activity related to the accrued severance charges, is as follows (in thousands): Balance as of December 31, 2015 $ 195 Payments (158 ) Balance as of March 31, 2016 $ 37

Product Warranties

Product Warranties	3 Months Ended
	Mar. 31, 2016
Guarantees [Abstract]
Product Warranties	9. Product Warranties The Company generally offers a two-year warranty for all of its products, though it is party to a limited number of supply agreements with certain customers contractually committing the Company to warranty and indemnification requirements exceeding those to which the Company has been exposed in the past. The Company provides for the estimated cost of product warranties at the time product revenue is recognized. Factors influencing 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 periodically assesses the adequacy of 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, 2016 2015 Balance at the beginning of the period $ 584 $ 204 Accruals for warranties for products sold in the period 122 15 Fulfillment of warranty obligations (68 ) (32 ) Revisions of estimated obligations (50 ) — Balance at the end of the period $ 588 $ 187

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	10. 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 on the Company’s projected pre-tax income (loss) and, in 2015, for estimated federal and state income taxes for certain noncontrolling interest subsidiaries that were not part of the Company’s consolidated income tax returns . The provisions for income taxes and the effective income tax rates for the three months ended March 31 were as follows (dollars in thousands): Three Months Ended March 31, 2016 2015 Provision for income taxes $ 22 $ 139 Effective income tax rate 0.4 % 3.9 % The provision for the three months ended March 31, 2016 was primarily due to estimated state taxes in jurisdictions in which the Company does not have net operating loss carryforwards. No tax benefit could be recognized for the majority of the Company’s losses during the period due to a full valuation allowance against all net domestic deferred tax assets. In addition, in connection with the Company’s acquisition of 100% ownership of certain operating assets and cash of Converpower, the related deferred tax liability for unremitted earnings of $55,000 was reversed and recorded as a discrete benefit in the first quarter of 2016 (see Note 7). The provision for the three months ended March 31, 2015 was primarily due to estimated federal and state taxes for one noncontrolling interest subsidiary, and for estimated state taxes in jurisdictions in which the Company does not have net operating loss carryforwards. As of March 31, 2016, the Company continues to maintain a valuation allowance of approximately $25,863,000 against all domestic net deferred tax assets and the majority of foreign net deferred tax assets, for which realization cannot be considered more likely than not at this time.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	11. Commitments and Contingencies At March 31, 2016, the Company had approximately $1,844,000 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 the 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 the 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. 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 that date, SynQor also announced it and Ericsson had entered into a definitive settlement agreement, the terms of which were not disclosed. On September 16, 2011, the U.S. District Court for the Eastern District of Texas (the “Texas Court”) 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 (the “ ‘290 patent”), which was issued on that day. As with SynQor’s original complaint, the amended complaint alleges the Company’s products, including but not limited to the Company’s unregulated bus converters used in intermediate bus architecture power supply systems, infringe 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 Texas 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 Texas Court’s claim construction ruling. On March 31, 2014, the Texas 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. On June 30, 2014, the Company filed a number of motions seeking summary judgment in this matter, including for a finding of no direct, indirect, or willful infringement and for a finding of indefiniteness with respect to U.S. Patent No. 7,272,021 (the “ ‘021 patent”), which is one of four related patents at question in the Texas Action. The Texas Court has yet to rule on these motions. On October 23, 2014, the Texas Court issued an order continuing trial in this matter indefinitely. On January 7, 2015, the Company’s case and that of Cisco were assigned to a new judge within the Texas Court. On February 6, 2015, SynQor filed a motion to consolidate the Company’s and Cisco’s cases for trial, which was subsequently denied. On March 13, 2015, the U.S. Court of Appeals for the Federal Circuit in Washington, D.C. Circuit issued a ruling invalidating certain claims of U.S. Patent No. 7,072,190 (the “ ‘190 patent”) asserted by SynQor against the Company. Challenges to the validity of the remaining claims relating to the ‘190 patent, and to the remaining patents asserted by SynQor against the Company, remain pending before the U.S. Patent and Trademark Office and in the Texas Action. On March 26, 2015, the Texas Court scheduled pre-trial conferences for September 15, 2015, for Cisco’s case and January 13, 2016, for the Company’s case. On April 20, 2015, the Patent Trial and Appeal Board of the United States Patent and Trademark Office (the “PTAB”) issued a decision upholding the validity of all of the claims of SynQor’s U.S. Patent No. 7,564,702 (the “ ‘702 patent”), another of the power converter patents included in the claims asserted against the Company in the Texas Action. On May 20, 2015, the Company filed a request for rehearing concerning that decision. The PTAB has not ruled on that request. On May 5, 2015, the PTAB issued a decision invalidating all of the asserted claims of the ‘021 patent. On June 10, 2015, SynQor filed a request for rehearing concerning that decision. The PTAB has not ruled on that request. The Company has received no notice from the Texas Court regarding the timing of rulings on the Company’s summary judgment motions. On June 19, 2015, the Texas Court issued an order scheduling a jury trial in SynQor’s patent infringement action against Cisco beginning on November 30, 2015. SynQor’s patent infringement allegations against Cisco include allegations that Cisco is using certain parts supplied by the Company in infringing circuits. On October 5, 2015, the Texas Court issued an order denying a motion by Cisco seeking a stay of SynQor’s case against Cisco pending the resolution of matters concerning the asserted SynQor patents before the PTAB. On November 20, 2015, SynQor and Cisco informed the Texas Court they had reached a confidential settlement of SynQor’s case against Cisco. On November 24, 2015, a Magistrate Judge of the Texas Court issued an order staying SynQor’s case against the Company pending the resolution of matters concerning the asserted SynQor patents before the PTAB. SynQor has filed a motion seeking reconsideration of that order, and that request is still pending. The Company continues to believe 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, including such use by Cisco. 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, however, the Company cannot estimate the amount of possible loss or range of possible loss at this time. In addition to the SynQor matter, 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, 2016
Segment Reporting [Abstract]
Segment Information	12. 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 DC-DC converters and configurable products, and also includes the 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 many of the Company’s advanced power component 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. The Picor segment develops these products for use in the Company’s BBU and VI Chip modules, to be sold as complements to the Company’s BBU and VI Chip products, or for sale to third parties for separate (i.e., stand-alone) 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 segment financial data for the three months ended March 31 (in thousands): BBU VI Chip Picor Corporate Eliminations Total 2016: Net revenues $ 36,869 $ 7,747 $ 2,955 $ — $ (1,544 ) $ 46,027 Income (loss) from operations 1,506 (5,708 ) (1,004 ) (223 ) — (5,429 ) Total assets 176,502 17,247 5,724 77,569 (125,132 ) 151,910 Depreciation and amortization 1,119 584 126 366 — 2,195 2015: Net revenues $ 44,878 $ 14,180 $ 7,109 $ — $ (2,150 ) $ 64,017 Income (loss) from operations 5,379 (3,488 ) 2,017 (298 ) — 3,610 Total assets 155,737 17,125 7,489 79,483 (98,561 ) 161,273 Depreciation and amortization 1,153 799 97 354 — 2,403 (1) The elimination for net revenues is principally related to inter-segment sales by Picor to BBU and VI Chip and for inter-segment sales by 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 Accou

Impact of Recently Issued Accounting Standards	3 Months Ended
	Mar. 31, 2016
Accounting Changes and Error Corrections [Abstract]
Impact of Recently Issued Accounting Standards	13. Impact of Recently Issued Accounting Standards In March 2016, the Financial Accounting Board (“FASB”) issued new guidance for employee share-based payment accounting, which makes several modifications to existing guidance related to the accounting for forfeitures, employer tax withholding on share-based compensation and the financial statement presentation of excess tax benefits or deficiencies. This new guidance also clarifies the statement of cash flows presentation for certain components of share-based awards. The standard is effective for interim and annual reporting periods beginning after December 15, 2016, with early adoption permitted. The Company has not yet determined the impact this new guidance will have on its consolidated financial statements and related disclosures. In February 2016, the FASB issued new guidance for lease accounting, which will require lessees to recognize all leases with a duration of greater than twelve months on the balance sheet. For lessors, the guidance modifies the classification criteria and accounting for sales-type and direct financing leases. The new standard is effective for interim and annual periods beginning after December 15, 2018, with early adoption permitted. The Company has not yet determined the impact this new guidance will have on its consolidated financial statements and related disclosures. In July 2015, the FASB issued new guidance for inventory accounting, which will require companies to measure in scope inventory at the lower of cost or net realizable value. Current guidance requires an entity to measure inventory at the lower of cost or market. The new guidance does not apply to inventory that is measured using last-in, first-out (“LIFO”) or retail inventory methods. The guidance applies to all other inventory, which includes inventory that is measured using first-in, first-out (“FIFO”), which the Company employs, or average cost methods. The new guidance will be effective for the Company on January 1, 2017, and is to be applied prospectively with earlier application permitted as of the beginning of an interim or annual reporting period. The Company has not yet determined the impact the new guidance will have on its consolidated financial statements and related disclosures. In May 2014, the FASB issued new guidance for revenue recognition, which will require an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The new guidance will replace most existing revenue recognition guidance in U.S. Generally Accepted Accounting Principles when it becomes effective which, for the Company, will now be on January 1, 2018, as on July 9, 2015, the FASB voted to defer the effective date of the new standard by one year. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect the new guidance will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect the standard will have on its ongoing financial reporting.

Long-Term Investments (Tables)

Long-Term Investments (Tables)	3 Months Ended
	Mar. 31, 2016
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, 2016 Cost Gains Losses Value Failed Auction Security $ 3,000 $ — $ 447 $ 2,553 Gross Gross Estimated Unrealized Unrealized Fair December 31, 2015 Cost Gains Losses Value Failed Auction Security $ 3,000 $ — $ 474 $ 2,526 Brokered certificates of deposit 340 — — 340 $ 3,340 $ — $ 474 $ 2,866
Amortized Cost and Estimated Fair Value of Available-for-Sale Securities by Contractual Maturities	The amortized cost and estimated fair value of the available-for-sale security on March 31, 2016, by contractual maturity, is shown below (in thousands): Estimated Cost Fair Value Due in twenty to forty years $ 3,000 $ 2,553
Rollforward of Credit (Gain) Loss Recognized in Earnings on Failed Auction Security	The following table represents a rollforward of the activity related to the credit loss recognized in earnings on the Failed Auction Security for the three months ended March 31 (in thousands): 2016 2015 Balance at the beginning of the period $ 72 $ 84 Reductions in the amount related to credit gain for which other-than-temporary impairment was not previously recognized (4 ) (4 ) Balance at the end of the period $ 68 $ 80

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	Assets measured at fair value on a recurring basis included the following as of March 31, 2016 (in thousands): Using Significant Quoted Prices Other Significant in Active Observable Unobservable Total Fair Markets Inputs Inputs Value as of (Level 1) (Level 2) (Level 3) March 31, 2016 Cash equivalents: Money market funds $ 9,599 $ — $ — $ 9,599 Long-term investments: Failed Auction Security — — 2,553 2,553 Liabilities: Contingent consideration obligations — — (352 ) (352 ) Assets measured at fair value on a recurring basis included the following as of December 31, 2015 (in thousands): Using Significant Quoted Prices Other Significant in Active Observable Unobservable Total Fair Markets Inputs Inputs Value as of (Level 1) (Level 2) (Level 3) December 31, 2015 Cash equivalents: Money market funds $ 10,412 $ — $ — $ 10,412 Long-term investments: Failed Auction Security — — 2,526 2,526 Brokered certificates of deposit — 340 — 340 Liabilities: Contingent consideration obligation — — (144 ) (144 )
Quantitative Information about Level 3 Fair Value Measurements	Quantitative information about Level 3 fair value measurements as of March 31, 2016 is as follows (dollars in thousands): Valuation Unobservable Weighted Fair Value Technique Input Average Failed Auction Security $ 2,553 Discounted Cumulative probability of earning the maximum rate until maturity 0.03 % Cumulative probability of principal return prior to maturity 94.06 % Cumulative probability of default 5.91 % Liquidity risk premium 5.00 % Recovery rate in default 40.00 %
Change in Estimated Fair Values Calculated for Investment Valued on Recurring Basis Utilizing Level 3 Inputs	The change in the estimated fair value calculated for the investment valued on a recurring basis utilizing Level 3 inputs (i.e., the Failed Auction Security) for the three months ended March 31, 2016 was as follows (in thousands): Balance at the beginning of the period $ 2,526 Credit gain on available-for-sale securities included in Other income (expense), net 4 Gain included in Other comprehensive income (loss) 23 Balance at the end of the period $ 2,553
Change in Estimated Fair Value Calculated for Liabilities Valued on Recurring Basis Utilizing Level 3 Inputs	The change in the estimated fair value calculated for the liabilities valued on a recurring basis utilizing Level 3 inputs (i.e., the Contingent consideration obligations) for the three months ended March 31, 2016 was as follows (in thousands): Balance at the beginning of the period $ 144 Obligation incurred upon acquisition of noncontrolling interest (see Note 7) 208 Balance at the end of the period $ 352

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based 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, 2016 2015 Cost of revenues $ 52 $ 61 Selling, general and administrative 238 408 Research and development 39 94 Total stock-based compensation $ 329 $ 563

Net Income (Loss) per Share (Ta

Net Income (Loss) per Share (Tables)	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
Computation Of Basic And Diluted Net Income (Loss) Per Share	The following table sets forth the computation of basic and diluted net income (loss) per share for the three months ended March 31 (in thousands, except per share amounts): Three Months Ended March 31, 2016 2015 Numerator: Net income (loss) attributable to Vicor Corporation $ (5,351 ) $ 3,371 Denominator: Denominator for basic net income (loss) per share-weighted average shares (1) 38,794 38,689 Effect of dilutive securities: Employee stock options (2) — 460 Denominator for diluted net income (loss) per share – adjusted weighted-average shares and assumed conversions 38,794 39,149 Basic net income (loss) per share $ (0.14 ) $ 0.09 Diluted net income (loss) per share $ (0.14 ) $ 0.09 (1) Denominator represents weighted average number of shares of Common Stock and Class B Common Stock outstanding. (2) Options to purchase 731,672 and 112,929 shares of Common Stock for the three months ended March 31, 2016 and 2015, respectively, were not included in the calculation of net income per share as the effect would have been antidilutive.

Inventories (Tables)

Inventories (Tables)	3 Months Ended
	Mar. 31, 2016
Inventory Disclosure [Abstract]
Summary of Inventories	Inventories were as follows (in thousands): March 31, 2016 December 31, 2015 Raw materials $ 17,292 $ 16,257 Work-in-process 3,050 2,879 Finished goods 3,808 4,306 Net balance $ 24,150 $ 23,442

Severance and Other Charges (Ta

Severance and Other Charges (Tables)	3 Months Ended
	Mar. 31, 2016
Restructuring and Related Activities [Abstract]
Summary of Activity Related to Accrued Severance Charges	A summary of the activity related to the accrued severance charges, is as follows (in thousands): Balance as of December 31, 2015 $ 195 Payments (158 ) Balance as of March 31, 2016 $ 37

Product Warranties (Tables)

Product Warranties (Tables)	3 Months Ended
	Mar. 31, 2016
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, 2016 2015 Balance at the beginning of the period $ 584 $ 204 Accruals for warranties for products sold in the period 122 15 Fulfillment of warranty obligations (68 ) (32 ) Revisions of estimated obligations (50 ) — Balance at the end of the period $ 588 $ 187

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Provisions for Income Taxes and Effective Income Tax Rates	The provisions for income taxes and the effective income tax rates for the three months ended March 31 were as follows (dollars in thousands): Three Months Ended March 31, 2016 2015 Provision for income taxes $ 22 $ 139 Effective income tax rate 0.4 % 3.9 %

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2016
Segment Reporting [Abstract]
Significant Segment Financial Data	The following table provides segment financial data for the three months ended March 31 (in thousands): BBU VI Chip Picor Corporate Eliminations Total 2016: Net revenues $ 36,869 $ 7,747 $ 2,955 $ — $ (1,544 ) $ 46,027 Income (loss) from operations 1,506 (5,708 ) (1,004 ) (223 ) — (5,429 ) Total assets 176,502 17,247 5,724 77,569 (125,132 ) 151,910 Depreciation and amortization 1,119 584 126 366 — 2,195 2015: Net revenues $ 44,878 $ 14,180 $ 7,109 $ — $ (2,150 ) $ 64,017 Income (loss) from operations 5,379 (3,488 ) 2,017 (298 ) — 3,610 Total assets 155,737 17,125 7,489 79,483 (98,561 ) 161,273 Depreciation and amortization 1,153 799 97 354 — 2,403 (1) The elimination for net revenues is principally related to inter-segment sales by Picor to BBU and VI Chip and for inter-segment sales by 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.

Long-Term Investments - Additio

Long-Term Investments - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Unrealized Losses On Short Term And Long Term Investments [Line Items]
Amortized cost of securities		$ 3,340,000
Minimum period for which failed auction securities been in unrealized loss position	12 months
Estimated Fair Value		2,866,000
Gross unrealized losses		474,000
Aggregate credit loss	$ 68,000	72,000	$ 80,000	$ 84,000
Failed Auction Security [Member]
Unrealized Losses On Short Term And Long Term Investments [Line Items]
Amortized cost of securities	$ 3,000,000	3,000,000
Period for which failed auction securities been in unrealized loss position	Exceeds 12 months
Estimated Fair Value	$ 2,553,000	2,526,000
Gross unrealized losses	447,000	$ 474,000
Aggregate credit loss	68,000
Aggregate temporary impairment loss	$ 379,000

Long-Term Investments - Summary

Long-Term Investments - Summary of Available-for-Sale Securities (Detail) - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Cost		$ 3,340,000
Gross Unrealized Gains		0
Gross unrealized losses		474,000
Estimated Fair Value		2,866,000
Failed Auction Security [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	$ 3,000,000	3,000,000
Gross Unrealized Gains	0	0
Gross unrealized losses	447,000	474,000
Estimated Fair Value	$ 2,553,000	2,526,000
Brokered Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost		340,000
Gross Unrealized Gains		0
Estimated Fair Value		$ 340,000

Long-Term Investments - Amortiz

Long-Term Investments - Amortized Cost and Estimated Fair Value of Available-for-Sale Securities by Contractual Maturities (Detail) $ in Thousands	Mar. 31, 2016USD ($)
Available-for-sale Securities, Debt Maturities [Abstract]
Due in twenty to forty years, Cost	$ 3,000
Due in twenty to forty years, Estimated Fair Value	$ 2,553

Long-Term Investments - Rollfor

Long-Term Investments - Rollforward of Credit (Gain) Loss Recognized in Earnings on Failed Auction Security (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Available-for-sale Securities, Debt Maturities [Abstract]
Balance at the beginning of the period	$ 72	$ 84
Reductions in the amount related to credit gain for which other-than-temporary impairment was not previously recognized	(4)	(4)
Balance at the end of the period	$ 68	$ 80

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated Fair Value		$ 2,866,000
Failed Auction Security [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated Fair Value	$ 2,553,000	2,526,000
Recurring [Member] | Contingent Consideration Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities, fair value on recurring basis	(352,000)	(144,000)
Recurring [Member] | Failed Auction Security [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated Fair Value	2,553,000	2,526,000
Recurring [Member] | Long-Term Brokered Certificates of Deposit [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated Fair Value		340,000
Recurring [Member] | Money Market Funds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Cash equivalents	9,599,000	10,412,000
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	9,599,000	10,412,000
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Long-Term Brokered Certificates of Deposit [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated Fair Value		340,000
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Contingent Consideration Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities, fair value on recurring basis	(352,000)	(144,000)
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Failed Auction Security [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated Fair Value	$ 2,553,000	$ 2,526,000

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2016USD ($)
Fair Value Disclosures [Abstract]
Percent of credit loss	2.30%
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	$ 100,000
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	$ 0

Fair Value Measurements - Quant

Fair Value Measurements - Quantitative Information about Level 3 Fair Value Measurements (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value		$ 2,866
Failed Auction Security [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	$ 2,553
Valuation Technique	Discounted cash flow
Failed Auction Security [Member] | Significant Unobservable Inputs (Level 3) [Member] | Cumulative Probability of Earning Maximum Rate Until Maturity [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input	Cumulative probability of earning the maximum rate until maturity
Weighted Average Interest Rate	0.03%
Failed Auction Security [Member] | Significant Unobservable Inputs (Level 3) [Member] | Cumulative Probability of Principal Return Prior to Maturity [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input	Cumulative probability of principal return prior to maturity
Weighted Average Interest Rate	94.06%
Failed Auction Security [Member] | Significant Unobservable Inputs (Level 3) [Member] | Cumulative Probability of Default [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input	Cumulative probability of default
Weighted Average Interest Rate	5.91%
Failed Auction Security [Member] | Significant Unobservable Inputs (Level 3) [Member] | Liquidity Risk Premium [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input	Liquidity risk premium
Weighted Average Interest Rate	5.00%
Failed Auction Security [Member] | Significant Unobservable Inputs (Level 3) [Member] | Recovery Rate in Default [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input	Recovery rate in default
Weighted Average Interest Rate	40.00%

Fair Value Measurements - Chang

Fair Value Measurements - Change in Estimated Fair Values Calculated for Investment Valued on Recurring Basis Utilizing Level 3 Inputs (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2016USD ($)
Fair Value Disclosures [Abstract]
Balance at the beginning of the period	$ 2,526
Credit gain on available-for-sale securities included in Other income (expense), net	4
Gain included in Other comprehensive income (loss)	23
Balance at the end of the period	$ 2,553

Fair Value Measurements - Cha38

Fair Value Measurements - Change in Estimated Fair Value Calculated for Liabilities Valued on Recurring Basis Utilizing Level 3 Inputs (Detail) - Significant Unobservable Inputs (Level 3) [Member] - Contingent Consideration Obligations [Member] $ in Thousands	3 Months Ended
	Mar. 31, 2016USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at the beginning of the period	$ 144
Obligation incurred upon acquisition of noncontrolling interest	208
Balance at the end of the period	$ 352

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock based compensation	$ 329	$ 563
Cost of Revenues [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock based compensation	52	61
Selling, General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock based compensation	238	408
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock based compensation	$ 39	$ 94

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - 2007 VI Chip Plan [Member] - USD ($)	Mar. 31, 2016	Dec. 31, 2010
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	$ 451,000

Net Income (Loss) per Share - C

Net Income (Loss) per Share - Computation Of Basic And Diluted Net Income (Loss) Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Numerator:
Net income (loss) attributable to Vicor Corporation	$ (5,351)	$ 3,371
Denominator:
Denominator for basic net income (loss) per share-weighted average shares	38,794	38,689
Effect of dilutive securities:
Employee stock options		460
Denominator for diluted net income (loss) per share - adjusted weighted-average shares and assumed conversions	38,794	39,149
Basic net income (loss) per share	$ (0.14)	$ 0.09
Diluted net income (loss) per share	$ (0.14)	$ 0.09

Net Income (Loss) per Share -42

Net Income (Loss) per Share - Computation Of Basic And Diluted Net Income (Loss) Per Share (Parenthetical) (Detail) - shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share [Abstract]
Options to purchase shares of Common Stock not included in the computation of diluted income (loss) per share	731,672	112,929

Inventories - Summary of Invent

Inventories - Summary of Inventories (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Inventory Disclosure [Abstract]
Raw materials	$ 17,292	$ 16,257
Work-in-process	3,050	2,879
Finished goods	3,808	4,306
Net balance	$ 24,150	$ 23,442

Noncontrolling Interest Trans44

Noncontrolling Interest Transactions - Additional Information (Detail) - USD ($)	Mar. 30, 2016	Mar. 31, 2016	Dec. 31, 2015
Noncontrolling Interest [Line Items]
Contingent consideration		$ 352,000	$ 144,000
Converpower Corporation [Member]
Noncontrolling Interest [Line Items]
Ownership percentage by parent in certain operating assets and cash	100.00%
Minority interest percentage by non controlling interest	49.00%
Percentage of common shares exchanged	49.00%
Contingent consideration		$ 208,000
Royalty payment description		Through June 30, 2021
Noncontrolling interest		$ 0
Percentage of control of business operations acquired		100.00%
Reduction in cash, short-term interest receivable, and long-term investments		$ 718,000
Deconsolidation effect in statement of operations		0
Converpower Corporation [Member] | Additional Paid-In Capital [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interest		$ (208,000)

Severance and Other Charges - S

Severance and Other Charges - Summary of Activity Related to Accrued Severance Charges by Segment (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2016USD ($)
Restructuring and Related Activities [Abstract]
Restructuring Reserve, Beginning Balance	$ 195
Payments	(158)
Restructuring Reserve, Ending Balance	$ 37

Product Warranties - Additional

Product Warranties - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2016
Guarantees [Abstract]
Product warranty period	2 years

Product Warranties - Product Wa

Product Warranties - Product Warranty Activity (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Guarantees [Abstract]
Balance at the beginning of the period	$ 584	$ 204
Accruals for warranties for products sold in the period	122	15
Fulfillment of warranty obligations	(68)	(32)
Revisions of estimated obligations	(50)
Balance at the end of the period	$ 588	$ 187

Income Taxes - Provisions for I

Income Taxes - Provisions for Income Taxes and Effective Income Tax Rates (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 22	$ 139
Effective income tax rate	0.40%	3.90%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 30, 2016	Mar. 31, 2015
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	$ 0		$ 0
Tax benefit recognized	0
Unremitted earnings reversed	55,000
Valuation allowance, deferred tax assets	$ 25,863,000
Converpower Corporation [Member]
Income Tax Disclosure [Line Items]
Ownership percentage by parent in certain operating assets and cash		100.00%

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	Mar. 31, 2016USD ($)
Commitments and Contingencies Disclosure [Abstract]
Capital expenditure commitments	$ 1,844,000

Segment Information - Significa

Segment Information - Significant Segment Financial Data (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net revenues	$ 46,027	$ 64,017
Income (loss) from operations	(5,429)	3,610
Total assets	151,910	161,273	$ 157,545
Depreciation and amortization	2,195	2,403
Operating Segments [Member] | BBU [Member]
Segment Reporting Information [Line Items]
Net revenues	36,869	44,878
Income (loss) from operations	1,506	5,379
Total assets	176,502	155,737
Depreciation and amortization	1,119	1,153
Operating Segments [Member] | VI Chip [Member]
Segment Reporting Information [Line Items]
Net revenues	7,747	14,180
Income (loss) from operations	(5,708)	(3,488)
Total assets	17,247	17,125
Depreciation and amortization	584	799
Operating Segments [Member] | Picor [Member]
Segment Reporting Information [Line Items]
Net revenues	2,955	7,109
Income (loss) from operations	(1,004)	2,017
Total assets	5,724	7,489
Depreciation and amortization	126	97
Operating Segments [Member] | Corporate [Member]
Segment Reporting Information [Line Items]
Income (loss) from operations	(223)	(298)
Total assets	77,569	79,483
Depreciation and amortization	366	354
Eliminations [Member]
Segment Reporting Information [Line Items]
Net revenues	(1,544)	(2,150)
Total assets	$ (125,132)	$ (98,561)