XML 76 R50.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Share-Based Compensation - Summary of Incentive Unit Activity (Detail) - Incentive Units - USD ($) $ / shares in Units, $ in Thousands | 1 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2017 | Dec. 31, 2017 | Dec. 31, 2016
Number of Units |  |  |
Outstanding Beginning Balance |  | 413,266 |
Granted |  | 9,132 |
Forfeited |  | (19,541) |
Cancelled | (402,857) | (402,857) |
Outstanding Ending Balance |  |  | 413,266
Weighted Average Strike Price |  |  |
Outstanding Beginning Balance |  | $ 2.75 |
Granted |  | 1.28 |
Forfeited |  | 4.99 |
Cancelled |  | $ 2.62 |
Outstanding Ending Balance |  |  | $ 2.75
Weighted Average Contractual Term |  |  |
Outstanding Beginning Balance |  |  | 9 years 1 month 6 days
Aggregate Intrinsic Value |  |  |
Outstanding Beginning Balance |  | $ 779 |
Outstanding Ending Balance |  |  | $ 779

X
- Definition Share based compensation arrangement by share based payment award non option equity instruments aggregate intrinsic value. + References No definition available. + Details
Name: | spro_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsAggregateIntrinsicValueRollforwards
Namespace Prefix: | spro_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share based compensation arrangement by share based payment award non option equity instruments weighted average contractual term. + References No definition available. + Details
Name: | spro_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageContractualTermRollforwards
Namespace Prefix: | spro_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share based compensation arrangement by share based payment award non option equity instruments weighted average strike price. + References No definition available. + Details
Name: | spro_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageStrikePriceRollForward
Namespace Prefix: | spro_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share based compensation arrangement by share based payment award non options outstanding intrinsic value. + References No definition available. + Details
Name: | spro_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionsOutstandingIntrinsicValue
Namespace Prefix: | spro_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Share based compensation arrangement by share based payment award non options outstanding weighted average exercise price. + References No definition available. + Details
Name: | spro_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionsOutstandingWeightedAverageExercisePrice
Namespace Prefix: | spro_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Share based compensation arrangement by share based payment award options outstanding weighted average remaining contractual term. + References No definition available. + Details
Name: | spro_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm
Namespace Prefix: | spro_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share based compensation arrangements by share based payment award non options cancelled in period weighted average exercise price. + References No definition available. + Details
Name: | spro_ShareBasedCompensationArrangementsByShareBasedPaymentAwardNonOptionsCancelledInPeriodWeightedAverageExercisePrice
Namespace Prefix: | spro_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share based compensation arrangements by share based payment award non options forfeitures in period weighted average exercise price. + References No definition available. + Details
Name: | spro_ShareBasedCompensationArrangementsByShareBasedPaymentAwardNonOptionsForfeituresInPeriodWeightedAverageExercisePrice
Namespace Prefix: | spro_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share based compensation arrangements by share based payment award non options grants in period weighted average exercise price. + References No definition available. + Details
Name: | spro_ShareBasedCompensationArrangementsByShareBasedPaymentAwardNonOptionsGrantsInPeriodWeightedAverageExercisePrice
Namespace Prefix: | spro_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of shares under non-option equity instrument agreements for which rights to exercise lapsed. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(4) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExpirations
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of shares under non-option equity instrument agreements that were cancelled as a result of occurrence of a terminating event. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(3) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Net number of non-option equity instruments granted to participants. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of equity instruments other than options outstanding, including both vested and non-vested instruments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(ii) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AwardTypeAxis=spro_IncentiveUnitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |