v2.4.1.9

Stockholders' Equity (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Oct. 03, 2012
Common Stock
Options outstanding under equity incentive plans	7,605,407us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	7,039,093us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	6,513,508us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	6,312,041us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Total shares reserved for future issuance	8,409,037us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
Convertible Preferred Stock and Preferred Stock
Preferred stock, shares authorized	20,000,000us-gaap_PreferredStockSharesAuthorized	20,000,000us-gaap_PreferredStockSharesAuthorized
Preferred stock, par value per share (in dollars per share)	$ 0.001us-gaap_PreferredStockParOrStatedValuePerShare	$ 0.001us-gaap_PreferredStockParOrStatedValuePerShare
2000 Equity Incentive Plan
Common Stock
Options outstanding under equity incentive plans	3,970,662us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber / us-gaap_PlanNameAxis = qlys_A2000EquityIncentivePlanMember
2012 Equity Incentive Plan
Common Stock
Options outstanding under equity incentive plans	3,634,745us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber / us-gaap_PlanNameAxis = qlys_A2012EquityIncentivePlanMember
Shares available for future grants under an equity incentive plan	803,630us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant / us-gaap_PlanNameAxis = qlys_A2012EquityIncentivePlanMember
Preferred Stock
Convertible Preferred Stock and Preferred Stock
Preferred stock, shares authorized					20,000,000us-gaap_PreferredStockSharesAuthorized / us-gaap_StatementClassOfStockAxis = us-gaap_PreferredStockMember
Preferred stock, par value per share (in dollars per share)					$ 0.001us-gaap_PreferredStockParOrStatedValuePerShare / us-gaap_StatementClassOfStockAxis = us-gaap_PreferredStockMember

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