Quarterly report pursuant to Section 13 or 15(d)

Debt (Details 4)

v2.4.1.9
Debt (Details 4) (USD $)
In Thousands, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Interest expense on convertible debt  
Accretion of debt discount $ 2,356us-gaap_AmortizationOfDebtDiscountPremium
Unsecured debt | Convertible Notes  
Interest expense on convertible debt  
Coupon interest 755us-gaap_InterestExpenseDebtExcludingAmortization
/ us-gaap_DebtInstrumentAxis
= env_ConvertibleUnsecured1.75PercentNotesDueDecember2019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
Amortization of issuance costs 241us-gaap_AmortizationOfFinancingCosts
/ us-gaap_DebtInstrumentAxis
= env_ConvertibleUnsecured1.75PercentNotesDueDecember2019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
Accretion of debt discount 1,210us-gaap_AmortizationOfDebtDiscountPremium
/ us-gaap_DebtInstrumentAxis
= env_ConvertibleUnsecured1.75PercentNotesDueDecember2019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
Interest Expense, Debt, Total $ 2,206us-gaap_InterestExpenseDebt
/ us-gaap_DebtInstrumentAxis
= env_ConvertibleUnsecured1.75PercentNotesDueDecember2019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember