Operating Leases, Advance Termination Period

No definition available.

Name:	opnt_OperatingLeasesAdvanceTerminationPeriod
Namespace Prefix:	opnt_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represent that amount of monthly rental expenses for operating lease.

+ References

No definition available.

+ Details

Name:	opnt_OperatingLeasesMonthlyRentExpense
Namespace Prefix:	opnt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Security Deposit, Period Of Rent Equivalent

+ References

No definition available.

+ Details

Name:	opnt_SecurityDepositPeriodOfRentEquivalent
Namespace Prefix:	opnt_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

+ References

No definition available.

+ Details

Name:	us-gaap_LeaseAndRentalExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

The amount of an asset, typically cash, provided to a counterparty to provide certain assurance of performance by the entity pursuant to the terms of a written or oral agreement, such as a lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.8,17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_SecurityDeposit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_CounterpartyNameAxis=opnt_RegusManagementGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Commitments - Facility Leases (Details) $ in Thousands		3 Months Ended
Commitments - Facility Leases (Details) $ in Thousands	Apr. 20, 2017 GBP (£)	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)
Other Commitments [Line Items]
Rent expense \| $		$ 104	$ 64
Regus Management Group
Other Commitments [Line Items]
Rent expense	£ 2,473
Rent expense, monthly	7,521
Security deposit	£ 15,042
Security deposit, period of rent equivalent	2 months
Advance termination period	3 months