Employee Benefits (Details)	12 Months Ended
Dec. 31, 2015
Employee Benefits.
Minimum age of the employees to participate in defined contribution plan	21 years

This represents the employees eligible age to participate in the defined contribution plan.

No definition available.

Name:	eprs_DefinedContributionPlanEligibleAgeOfEmployeesToBeCovered
Namespace Prefix:	eprs_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration