Subsequent Events (Details)	Oct. 09, 2020 USD ($) numberOfRenewalOptions	Jun. 30, 2018
Subsequent Events
Leases, term of contract (in years)		5 years
Subsequent events
Subsequent Events
Leases, term of contract (in years)	7 years
Base payments \| $	$ 1,800,000
Number of renewal options \| numberOfRenewalOptions	1
Lease renewal term (in years)	5 years

Lessee, Operating Lease, Number Of Renewal Options

No definition available.

Name:	ocgn_LesseeOperatingLeaseNumberOfRenewalOptions
Namespace Prefix:	ocgn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Operating Lease, Total Base Payments

+ References

No definition available.

+ Details

Name:	ocgn_OperatingLeaseTotalBasePayments
Namespace Prefix:	ocgn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918673-209980

+ Details

Name:	us-gaap_LesseeOperatingLeaseRenewalTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_LesseeOperatingLeaseTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

Name:	us-gaap_SubsequentEventLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: