COMMITMENTS AND CONTINGENCIES - Supply Agreements (Details) - Supply Agreement $ in Millions	6 Months Ended
Jun. 30, 2024 USD ($)
Supply Commitment [Line Items]
Purchase obligation, percentage	75.00%
JHS
Supply Commitment [Line Items]
Annual purchase obligation	$ 1.5
Antares
Supply Commitment [Line Items]
Annual purchase obligation	2.0
Hanmi
Supply Commitment [Line Items]
Purchase obligation in 2024	19.1
Purchase obligation in 2025	3.8
Purchase of inventory	$ 12.6

Purchase Obligation, Annual Obligation

No definition available.

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Namespace Prefix:	asrt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Purchase Obligation, Percentage

+ References

No definition available.

+ Details

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Namespace Prefix:	asrt_
Data Type:	dtr-types1:percentItemType
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Period Type:	instant

- Definition

Payments of cash to suppliers for goods and services during the current period.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-17

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 17
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-17

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of purchase arrangement to be paid in next fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

No definition available.

+ Details

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

- Definition

Amount of purchase arrangement to be paid in second fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

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- Details

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- Details

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- Details

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- Details

Name:	srt_CounterpartyNameAxis=asrt_HanmiMember
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Period Type: