Commission percentage for selling securities on behalf of the company.

No definition available.

Name:	eprs_BrokerageCommissionsPercentage
Namespace Prefix:	eprs_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of initial batches to be manufactured as per agreement.

+ References

No definition available.

+ Details

Name:	eprs_NumberOfInitialBatchesToBeManufactured
Namespace Prefix:	eprs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of the aggregate number of shares outstanding.

+ References

No definition available.

+ Details

Name:	eprs_PercentageOfAggregateNumberOfSharesOutstanding
Namespace Prefix:	eprs_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The value of the shares authorized by the subsidiary per stock transaction.

+ References

No definition available.

+ Details

Name:	eprs_SaleOfStockValueOfSharesAuthorizedInTransaction
Namespace Prefix:	eprs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the trailing period of common stock issued under stock purchase plan.

+ References

No definition available.

+ Details

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

- Definition

Represents the trailing share price of common stock issued under stock purchase plan.

+ References

No definition available.

+ Details

Name:	eprs_TrailingSharePrice
Namespace Prefix:	eprs_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of new stock issued during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30
-Article 5

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

Name:	us-gaap_SubsequentEventLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=eprs_AtMarketSalesAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=eprs_StockPurchaseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=eprs_SettlementAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Subsequent Events (Details) - Subsequent event $ / shares in Units, $ in Millions			1 Months Ended
	Mar. 09, 2016 $ / shares shares	Feb. 29, 2016 USD ($)	Jan. 31, 2016 item	Mar. 08, 2016
At-the-Market Sales Agreement
Subsequent Events
Aggregate value of shares authorized to be sold \| $		$ 30
Commission from the sale of shares		3.00%
Stock Purchase Agreement
Subsequent Events
Issuance of shares \| shares	1,772,107
Trailing period (in days)	10 days
Trailing share price (in dollars per share) \| $ / shares	$ 2.82
Stock Purchase Agreement \| Minimum
Subsequent Events
Percentage of the aggregate number of shares outstanding				10.00%
Stock Purchase Agreement \| Maximum
Subsequent Events
Percentage of the aggregate number of shares outstanding				19.99%
Settlement Agreement
Subsequent Events
Number of final batches to be manufactured on or before June 30,2016 \| item			15