Securities litigation insurance receivable.

No definition available.

Name:	achc_SecuritiesLitigationInsuranceReceivable
Namespace Prefix:	achc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Unfavorable adjustment for professional and general liability claims.

+ References

No definition available.

+ Details

Name:	achc_UnfavorableAdjustmentForProfessionalAndGeneralLiabilityClaims
Namespace Prefix:	achc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount receivable from insurance and similar arrangements for reimbursement and payment of malpractice claims and litigation costs.

+ References

No definition available.

+ Details

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

- Definition

The current portion of the amount receivable from insurance and similar arrangements for reimbursement and payment of malpractice claims and litigation costs.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(a)(4))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480657/210-10-S50-2

+ Details

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

- Definition

The noncurrent portion of the receivable from insurance and similar arrangements for reimbursement and payment of malpractice claims and litigation costs.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(17))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480657/210-10-S50-7

+ Details

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

- Definition

Amount awarded to other party in judgment or settlement of litigation.

+ References

+ Details

Name:	us-gaap_LitigationSettlementAmountAwardedToOtherParty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of litigation expense, including but not limited to legal, forensic, accounting, and investigative fees.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(6))
-SubTopic 10
-Topic 220
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

+ Details

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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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
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-Subparagraph (a)
-Publisher FASB
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section S99
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-Subparagraph (SAB Topic 5.W.Q2)
-Publisher FASB
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 275
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-9

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 720
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483359/720-20-50-1

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
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-Publisher FASB
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 450
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-4

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-1

+ Details

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

- Definition

Amount of damages awarded to the plaintiff in the legal matter.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-9

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-4

+ Details

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

- Definition

Amount of damages paid to the plaintiff in the legal matter.

+ References

+ Details

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

- Definition

Annual coverage limit provided by the insurance arrangement for malpractice claims.

+ References

No definition available.

+ Details

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

- Definition

Maximum coverage per malpractice claim provided by the insurance arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 954
-SubTopic 450
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477850/954-450-50-1

+ Details

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

- Definition

Amount of the accrued liability on an undiscounted basis for malpractice claims (including general and professional liability) at the end of the accounting period.

+ References

+ Details

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

- Definition

Amount of the current portion of the accrued liability on an undiscounted basis for malpractice claims (including general and professional liability).

+ References

+ Details

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

- Definition

Amount of the noncurrent portion of the accrued liability on an undiscounted basis for malpractice claims (including general and professional liability).

+ References

+ Details

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

- Definition

Cash received for the settlement of litigation during the current period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 25
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-25

+ Details

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

- Definition

Amount per policy of risk ceded to reinsurer in excess of risk undertaken originally by insurer that is not ceded to reinsurer.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479838/944-20-50-3

+ Details

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

- Details

Name:	srt_LitigationCaseAxis=achc_InmanLitigationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=achc_CompensatoryDamagesMember
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=achc_PunitiveDamagesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_LitigationCaseAxis=achc_SecuritiesLitigationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_LitigationCaseAxis=achc_FashionValleyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_LitigationCaseAxis=achc_SandovalLitigationMember
Namespace Prefix:
Data Type:	na
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Period Type:

- Details

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Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands					1 Months Ended		3 Months Ended	6 Months Ended
	May 12, 2026	Nov. 24, 2025	Jan. 19, 2024	Jul. 07, 2023	Apr. 29, 2026	Aug. 31, 2025	Jun. 30, 2026	Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2025
Loss Contingencies [Line Items]
Aggregate amount on settlement agreements			$ 400,000
Unfavorable adjustment for professional and general liability claims							$ 28,600	$ 28,600
Professional and general liability reserve							224,700	224,700		$ 181,800
Professional and general liability reserve current							50,300	50,300		31,400
Professional and general liability reserve noncurrent							174,300	174,300		150,400
Insurance receivable							33,300	33,300		28,800
Insurance receivable – current portion							8,332	8,332		7,211
Insurance receivable noncurrent							$ 25,000	25,000		21,600
Securities litigation insurance receivable										$ 31,538
Legal settlements expense								13,751	$ 3,504
Inman Litigation [Member] \| Compensatory Damages [Member]
Loss Contingencies [Line Items]
Awarded plaintiff damages amount				$ 80,000
Inman Litigation [Member] \| Punitive Damages [Member]
Loss Contingencies [Line Items]
Awarded plaintiff damages amount				$ 405,000
Securities Litigation [Member]
Loss Contingencies [Line Items]
Defendants paid in exchange for release of liability		$ 179,000
Securities litigation insurance receivable		$ 31,500
Insurance proceeds received								31,500
Fashion Valley [Member] \| Compensatory Damages [Member]
Loss Contingencies [Line Items]
Awarded plaintiff damages amount	$ 35,000
Fashion Valley [Member] \| Punitive Damages [Member]
Loss Contingencies [Line Items]
Awarded plaintiff damages amount	$ 70,000
Sandoval Litigation [Member]
Loss Contingencies [Line Items]
Legal settlements expense					$ 15,000
Maximum [Member]
Loss Contingencies [Line Items]
Maximum coverage limit per claim						$ 10,000
Maximum professional liability for certain other claims thereafter						25,000		25,000
Reinsurance policy aggregate policy limit						80,000
Minimum [Member]
Loss Contingencies [Line Items]
Maximum professional liability for certain other claims thereafter						15,000		15,000
Reinsurance policy aggregate policy limit						$ 75,000		$ 75,000