Name:	jspr_ExpectedVolatility
Namespace Prefix:	jspr_
Data Type:	dtr:percentItemType
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Period Type:	duration

The risk-free interest rate assumption that is used in valuing an option on its own shares.

No definition available.

Name:	jspr_RiskfreeInterestRate
Namespace Prefix:	jspr_
Data Type:	dtr:percentItemType
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- References

No definition available.

Name:	jspr_ScheduleOfBusinessCombinationTheEstimatedFairValueAbstract
Namespace Prefix:	jspr_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Series A-1 redeemable convertible preferred stock value.

No definition available.

Name:	jspr_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueSeriesA1RedeemableConvertiblePreferredStockValueinShares
Namespace Prefix:	jspr_
Data Type:	dtr:perShareItemType
Balance Type:	na
Period Type:	duration

Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

No definition available.

Name:	jspr_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm
Namespace Prefix:	jspr_
Data Type:	xbrli:durationItemType
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Period Type:	duration

Face amount per share of no-par value common stock.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Name:	us-gaap_CommonStockNoParValue
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Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

Discount rate from fair value on offering date that participants pay for shares.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901