Business Acquisition, Equity Interest Issued Or Issuable, Shares Outstanding, Exercise Price

No definition available.

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Namespace Prefix:	asrt_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Class Of Warrant Or Right, Exercise Cap, Aggregate Ownership Percentage

+ References

No definition available.

+ Details

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Namespace Prefix:	asrt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Sale Of Stock, Consideration Received On Transaction, Gross

+ References

No definition available.

+ Details

Name:	asrt_SaleOfStockConsiderationReceivedOnTransactionGross
Namespace Prefix:	asrt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Warrant, Exercise Period

+ References

No definition available.

+ Details

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Namespace Prefix:	asrt_
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Balance Type:	na
Period Type:	duration

- Definition

Cash received on stock transaction after deduction of issuance costs.

+ References

No definition available.

+ Details

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

- Definition

The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

No definition available.

+ Details

Name:	us-gaap_SaleOfStockPricePerShare
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Data Type:	dtr-types:perShareItemType
Balance Type:	na
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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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of non-option equity instruments exercised by participants.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares issued under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Value of outstanding derivative securities that permit the holder the right to purchase securities (usually equity) from the issuer at a specified price.

+ References

No definition available.

+ Details

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

- Details

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Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
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Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=asrt_WarrantAgreementsMember
Namespace Prefix:
Data Type:	na
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- Details

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Data Type:	na
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- Details

Name:	dei_LegalEntityAxis=asrt_ZylaLifeSciencesMember
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SHAREHOLDERS' EQUITY (Details) - USD ($) $ / shares in Units, $ in Millions				3 Months Ended
	Feb. 12, 2021	Feb. 09, 2021	May 20, 2020	Mar. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, shares sold (in shares)	8,750,000	5,650,000
Stock offering, purchase price (in dollars per share)	$ 3.92	$ 2.48
Stock offering, gross proceeds	$ 34.3	$ 14.0
Stock offering, net proceeds	$ 32.2	$ 13.1
Warrants exercised (in shares)				400,000
Common shares issued (in shares)				400,000
Warrants outstanding				$ 0.0
Zyla Life Sciences \| Iroko \| Warrant Agreements
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise aggregate ownership percentage maximum threshold			49.00%
Exercise aggregate ownership percentage term			18 months
Zyla Life Sciences \| Money market funds \| Zyla Life Sciences
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase price, number of shares outstanding, per share (in dollars per share)			$ 0.0016