v2.4.1.9

Income Taxes (Narrative) (Details) (USD $) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2014 | Sep. 30, 2014 | Jun. 30, 2014 | Mar. 31, 2014 | Dec. 31, 2013 | Sep. 30, 2013 | Jun. 30, 2013 | Mar. 31, 2013 | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Income Tax [Line Items] |  |  |  |  |  |  |  |  |  |  |
Valuation allowance increase (decrease) |  |  |  |  |  |  |  |  |  | $ 900,000 us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount |
Valuation allowance | 3,079,000 us-gaap_DeferredTaxAssetsValuationAllowance |  |  |  | 27,181,000 us-gaap_DeferredTaxAssetsValuationAllowance |  |  |  | 3,079,000 us-gaap_DeferredTaxAssetsValuationAllowance | 27,181,000 us-gaap_DeferredTaxAssetsValuationAllowance |
Provision for (benefit from) income taxes | (22,270,000)us-gaap_IncomeTaxExpenseBenefit | 283,000 us-gaap_IncomeTaxExpenseBenefit | 174,000 us-gaap_IncomeTaxExpenseBenefit | 182,000 us-gaap_IncomeTaxExpenseBenefit | 128,000 us-gaap_IncomeTaxExpenseBenefit | 210,000 us-gaap_IncomeTaxExpenseBenefit | 92,000 us-gaap_IncomeTaxExpenseBenefit | 70,000 us-gaap_IncomeTaxExpenseBenefit | (21,631,000)us-gaap_IncomeTaxExpenseBenefit | 500,000 us-gaap_IncomeTaxExpenseBenefit | 358,000 us-gaap_IncomeTaxExpenseBenefit
Undistributed earnings of foreign subsidiaries | 6,800,000 us-gaap_UndistributedEarningsOfForeignSubsidiaries |  |  |  | 8,500,000 us-gaap_UndistributedEarningsOfForeignSubsidiaries |  |  |  | 6,800,000 us-gaap_UndistributedEarningsOfForeignSubsidiaries | 8,500,000 us-gaap_UndistributedEarningsOfForeignSubsidiaries |
Unrecognized tax benefits that would impact effective tax rate | 2,100,000 us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate |  |  |  | 1,000,000 us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate |  |  |  | 2,100,000 us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate | 1,000,000 us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate | 1,000,000 us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate
Internal Revenue Service (IRS) [Member] |  |  |  |  |  |  |  |  |  |  |
Income Tax [Line Items] |  |  |  |  |  |  |  |  |  |  |
Operating loss carryforwards | 56,700,000 us-gaap_OperatingLossCarryforwards / us-gaap_IncomeTaxAuthorityAxis = us-gaap_InternalRevenueServiceIRSMember |  |  |  |  |  |  |  | 56,700,000 us-gaap_OperatingLossCarryforwards / us-gaap_IncomeTaxAuthorityAxis = us-gaap_InternalRevenueServiceIRSMember |  |
Deferred tax asset not recognized, net operating loss carryforwards | 21,400,000 qlys_DeferredTaxAssetNotRecognizedNetOperatingLossCarryforwards / us-gaap_IncomeTaxAuthorityAxis = us-gaap_InternalRevenueServiceIRSMember |  |  |  |  |  |  |  | 21,400,000 qlys_DeferredTaxAssetNotRecognizedNetOperatingLossCarryforwards / us-gaap_IncomeTaxAuthorityAxis = us-gaap_InternalRevenueServiceIRSMember |  |
Internal Revenue Service (IRS) [Member] | Research and Development Credits [Member] |  |  |  |  |  |  |  |  |  |  |
Income Tax [Line Items] |  |  |  |  |  |  |  |  |  |  |
Tax credit carryforward | 5,000,000 us-gaap_TaxCreditCarryforwardAmount / us-gaap_IncomeTaxAuthorityAxis = us-gaap_InternalRevenueServiceIRSMember / us-gaap_TaxCreditCarryforwardAxis = us-gaap_ResearchMember |  |  |  |  |  |  |  | 5,000,000 us-gaap_TaxCreditCarryforwardAmount / us-gaap_IncomeTaxAuthorityAxis = us-gaap_InternalRevenueServiceIRSMember / us-gaap_TaxCreditCarryforwardAxis = us-gaap_ResearchMember |  |
State and Local Jurisdiction [Member] |  |  |  |  |  |  |  |  |  |  |
Income Tax [Line Items] |  |  |  |  |  |  |  |  |  |  |
Valuation allowance | 3,079,000 us-gaap_DeferredTaxAssetsValuationAllowance / us-gaap_IncomeTaxAuthorityAxis = us-gaap_StateAndLocalJurisdictionMember |  |  |  |  |  |  |  | 3,079,000 us-gaap_DeferredTaxAssetsValuationAllowance / us-gaap_IncomeTaxAuthorityAxis = us-gaap_StateAndLocalJurisdictionMember |  |
Operating loss carryforwards | 10,500,000 us-gaap_OperatingLossCarryforwards / us-gaap_IncomeTaxAuthorityAxis = us-gaap_StateAndLocalJurisdictionMember |  |  |  |  |  |  |  | 10,500,000 us-gaap_OperatingLossCarryforwards / us-gaap_IncomeTaxAuthorityAxis = us-gaap_StateAndLocalJurisdictionMember |  |
Deferred tax asset not recognized, net operating loss carryforwards | 1,700,000 qlys_DeferredTaxAssetNotRecognizedNetOperatingLossCarryforwards / us-gaap_IncomeTaxAuthorityAxis = us-gaap_StateAndLocalJurisdictionMember |  |  |  |  |  |  |  | 1,700,000 qlys_DeferredTaxAssetNotRecognizedNetOperatingLossCarryforwards / us-gaap_IncomeTaxAuthorityAxis = us-gaap_StateAndLocalJurisdictionMember |  |
State and Local Jurisdiction [Member] | Research and Development Credits [Member] |  |  |  |  |  |  |  |  |  |  |
Income Tax [Line Items] |  |  |  |  |  |  |  |  |  |  |
Tax credit carryforward | 5,200,000 us-gaap_TaxCreditCarryforwardAmount / us-gaap_IncomeTaxAuthorityAxis = us-gaap_StateAndLocalJurisdictionMember / us-gaap_TaxCreditCarryforwardAxis = us-gaap_ResearchMember |  |  |  |  |  |  |  | 5,200,000 us-gaap_TaxCreditCarryforwardAmount / us-gaap_IncomeTaxAuthorityAxis = us-gaap_StateAndLocalJurisdictionMember / us-gaap_TaxCreditCarryforwardAxis = us-gaap_ResearchMember |  |
Federal and State Jurisdictions [Member] |  |  |  |  |  |  |  |  |  |  |
Income Tax [Line Items] |  |  |  |  |  |  |  |  |  |  |
Provision for (benefit from) income taxes | $ (23,700,000)us-gaap_IncomeTaxExpenseBenefit / us-gaap_IncomeTaxAuthorityAxis = us-gaap_DomesticCountryMember |  |  |  |  |  |  |  |  |  |

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- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319 + Details
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