Refers to the number of years shares will automatically increase.

No definition available.

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Namespace Prefix:	gemp_
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- Definition

Refers to the percentage of annual increase which is equal to the company's fully diluted share.

+ References

No definition available.

+ Details

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Namespace Prefix:	gemp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
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Period Type:	duration

- Definition

Gross number of share options (or share units) granted during the period.

+ References

No definition available.

+ Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=gemp_InducementPlanMember
Namespace Prefix:
Data Type:	na
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Period Type:

- Details

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Namespace Prefix:
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- Details

Name:	us-gaap_PlanNameAxis=gemp_EquityIncentivePlan2015Member
Namespace Prefix:
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Share-Based Compensation - Stock Options (Details) - shares			9 Months Ended
	May 22, 2018	Apr. 09, 2018	Sep. 30, 2018	Jan. 01, 2018	Sep. 30, 2016	Apr. 30, 2016	Apr. 30, 2015
Stock Options, Additional Disclosures
Percentage of company's fully diluted shares			20.00%
A&R 2015 Plan
Stock Options, Additional Disclosures
Number of years common shares automatically increase			10 years
Common stock reserved for issuance (in shares)	3,115,077			415,077
Granted (in shares)	300,000
Inducement Plan
Stock Options, Additional Disclosures
Common stock reserved for issuance (in shares)		450,000			300,000
Granted (in shares)		150,000
Employees, Directors And Consultants \| 2015 Plan
Stock Options, Additional Disclosures
Common stock reserved for issuance (in shares)							320,615
Employees, Directors And Consultants \| A&R 2015 Plan
Stock Options, Additional Disclosures
Common stock reserved for issuance (in shares)						2,400,000