Name:	olma_PrepaidClinicalTrialCosts
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount of expenses paid in advance for reimbursable research and development costs from a collaboration partner.

No definition available.

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Data Type:	xbrli:monetaryItemType
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Amount of asset related to consideration paid in advance for subscriptions and licenses that provides economic benefits within a future period of one year or the normal operating cycle, if longer.

No definition available.

Name:	olma_PrepaidSubscriptionsAndLicenses
Namespace Prefix:	olma_
Data Type:	xbrli:monetaryItemType
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Carrying amount as of the balance sheet date of current interest earned but not received. Also called accrued interest or accrued interest receivable. For classified balance sheets, represents the current amount receivable, that is amounts expected to be collected within one year or the normal operating cycle, if longer.

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Amount of asset related to consideration paid in advance for other costs that provide economic benefits within a future period of one year or the normal operating cycle, if longer.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 340
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Amount of asset related to consideration paid in advance for costs that provide economic benefits in future periods, and amount of other assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer.

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- References

No definition available.

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Data Type:	xbrli:stringItemType
Balance Type:	na
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Amount of asset related to consideration paid in advance for insurance that provides economic benefits within a future period of one year or the normal operating cycle, if longer.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 210
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 340
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Reference 3: http://www.xbrl.org/2003/role/exampleRef
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