Partners' Capital - Ownership and Shares (Details)	3 Months Ended
Mar. 31, 2018
Partners' Capital
Allocations to partners (as a percent)	100.00%

Represents the percentage of incentive distributions to be allocated to the General Partner.

No definition available.

Name:	eva_DistributionMadeToGeneralPartnerCashDistributionsAllocationsOfNetIncome
Namespace Prefix:	eva_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration