XML 69 R55.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Long-Term Investments - Rollforward of Credit (Gain) Loss Recognized in Earnings on Available-for-Sale Auction Rate Securities (Detail) - Failed Auction Security [Member] - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items] |  |  |
Balance at the beginning of the period | $ 59,000 | $ 72,000 | $ 84,000
Reductions in the amount related to credit gain for which other-than-temporary impairment was not previously recognized | (11,000) | (13,000) | (12,000)
Balance at the end of the period | $ 48,000 | $ 59,000 | $ 72,000

X
- Definition The cumulative amount of credit losses recognized in earnings related to debt securities held for which a portion of an other than temporary impairment (OTTI) was recognized in other comprehensive income (a component of shareholders' equity). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 8B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82897076&loc=SL6284393-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 8B -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=82897076&loc=SL6284393-111563 + Details
Name: | us-gaap_OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCreditLossesOnDebtSecuritiesHeld
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Other than temporary impairment credit losses recognized in earnings additions and deductions additional credit losses. + References No definition available. + Details
Name: | vicr_OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsAndDeductionsAdditionalCreditLosses
Namespace Prefix: | vicr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_AuctionRateSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |