Quarterly report pursuant to Section 13 or 15(d)

Debt (Details 2)

v2.4.1.9
Debt (Details 2) (Unsecured debt, Credit Agreement, USD $)
In Thousands, unless otherwise specified
0 Months Ended
Dec. 08, 2014
Mar. 31, 2015
Jun. 19, 2014
Revolving credit facility
     
Debt      
Credit facility amount     $ 100,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_DebtInstrumentAxis
= env_CreditAgreementMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
Increase credit facility, amount     25,000env_LineOfCreditFacilityMaximumBorrowingCapacityContingentRightToIncreaseMaximumBorrowingCapacityAmount
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_DebtInstrumentAxis
= env_CreditAgreementMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
Commitment fee 0.25%us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_DebtInstrumentAxis
= env_CreditAgreementMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
   
Amount outstanding   0us-gaap_LineOfCredit
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_DebtInstrumentAxis
= env_CreditAgreementMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
 
Revolving credit facility | LIBOR | Minimum
     
Debt      
Spread on variable rate basis 1.50%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_DebtInstrumentAxis
= env_CreditAgreementMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_VariableRateAxis
= us-gaap_LondonInterbankOfferedRateLIBORMember
   
Revolving credit facility | LIBOR | Maximum
     
Debt      
Spread on variable rate basis 3.25%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_DebtInstrumentAxis
= env_CreditAgreementMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_VariableRateAxis
= us-gaap_LondonInterbankOfferedRateLIBORMember
   
Letter of credit
     
Debt      
Credit facility amount     $ 5,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
/ us-gaap_CreditFacilityAxis
= us-gaap_LetterOfCreditMember
/ us-gaap_DebtInstrumentAxis
= env_CreditAgreementMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember