Name:	ovas_AccruedLegalAuditAndTaxServicesCurrent
Namespace Prefix:	ovas_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Represents the carrying value as of the balance sheet date of obligations incurred through that date and payable for professional fees and consultancy fees, such as for legal and accounting services received. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle, if longer).

No definition available.

Name:	ovas_AccruedProfessionalAndConsultantFeesCurrent
Namespace Prefix:	ovas_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Represents the carrying value as of the balance sheet date of obligations incurred through that date and payable for the obligations related to technology access fee. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle, if longer).

No definition available.

Name:	ovas_AccruedTechnologyAccessFeePayableCurrent
Namespace Prefix:	ovas_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Represents the carrying value as of the balance sheet date of obligations incurred through that date and payable for the obligations related to development, site costs and contract manufacturing. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle, if longer).

No definition available.

Name:	ovas_DevelopmentSiteCostsAndContractManufacturing
Namespace Prefix:	ovas_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Name:	us-gaap_AccruedLiabilitiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Name:	us-gaap_EmployeeRelatedLiabilitiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Carrying value as of the balance sheet date of obligations incurred through that date and payable arising from transactions not otherwise specified in the taxonomy. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Current Liabilities

-URI http://asc.fasb.org/extlink&oid=6509677

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6935-107765

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.20)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6911-107765

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 9

-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e7018-107765