Shareholders' Equity Market Based Restricted Stock (Details) (USD $)
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3 Months Ended |
12 Months Ended |
0 Months Ended |
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Feb. 01, 2014
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Jan. 31, 2015
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Feb. 01, 2014
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Feb. 02, 2013
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Nov. 18, 2014
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Oct. 03, 2012
tranche
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Jun. 18, 2014
tranche
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Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
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Risk Free Interest Rate |
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1.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
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Granted, weighted average grant date fair value |
$ 3.96us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
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$ 3.92us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
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$ 1.03us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
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Expected Term |
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6 years
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6 years
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6 years
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Restricted Stock [Member] |
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Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
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Non-vested shares outstandings |
641,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember
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704,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember
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641,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember
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Number of tranches |
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3evlv_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNumberOfTranches / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember
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7evlv_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNumberOfTranches / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember
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Number of consecutive trading days |
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20 days
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Risk Free Interest Rate |
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1.03%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember
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0.32%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember
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Implied volatility rate |
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60.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember
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78.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember
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Granted, weighted average grant date fair value |
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$ 4.91us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember
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Expected Term |
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2 years 9 months 18 days
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Market Based Stock Restricted Stock Awards [Member] | Restricted Stock [Member] |
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Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
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Non-vested shares outstandings |
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133,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember / us-gaap_PlanNameAxis = evlv_MarketBasedStockRestrictedStockAwardsMember
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Required holding period |
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1 year
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Tranche 1 [Member] |
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Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
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Granted, weighted average grant date fair value |
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0.93us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_PlanNameAxis = evlv_Tranche1Member
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Expected Term |
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15 months
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Tranche 1 [Member] | Restricted Stock [Member] |
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Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
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Exercise price range, minimum |
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6.00evlv_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisePriceRangeLowerRangeLimit / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember / us-gaap_PlanNameAxis = evlv_Tranche1Member
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Award vesting percentage |
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50.00%evlv_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardVestingPercentage / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember / us-gaap_PlanNameAxis = evlv_Tranche1Member
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Granted, weighted average grant date fair value |
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1.48us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember / us-gaap_PlanNameAxis = evlv_Tranche1Member
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Expected Term |
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15 months
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Tranche 2 [Member] |
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Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
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Granted, weighted average grant date fair value |
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0.95us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_PlanNameAxis = evlv_Tranche2Member
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Expected Term |
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20 months
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Tranche 2 [Member] | Restricted Stock [Member] |
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Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
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Exercise price range, minimum |
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8.00evlv_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisePriceRangeLowerRangeLimit / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember / us-gaap_PlanNameAxis = evlv_Tranche2Member
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Award vesting percentage |
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25.00%evlv_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardVestingPercentage / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember / us-gaap_PlanNameAxis = evlv_Tranche2Member
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Granted, weighted average grant date fair value |
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1.39us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember / us-gaap_PlanNameAxis = evlv_Tranche2Member
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Expected Term |
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20 months
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Tranche 3 [Member] |
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Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
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Granted, weighted average grant date fair value |
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0.95us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_PlanNameAxis = evlv_Tranche3Member
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Expected Term |
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24 months
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Tranche 3 [Member] | Restricted Stock [Member] |
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Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
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Exercise price range, minimum |
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10.00evlv_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisePriceRangeLowerRangeLimit / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember / us-gaap_PlanNameAxis = evlv_Tranche3Member
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Award vesting percentage |
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25.00%evlv_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardVestingPercentage / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember / us-gaap_PlanNameAxis = evlv_Tranche3Member
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Granted, weighted average grant date fair value |
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1.31us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember / us-gaap_PlanNameAxis = evlv_Tranche3Member
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Expected Term |
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24 months
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