Additional principal amount divestiture.

No definition available.

Name:	ston_AdditionalPrincipalAmountDivestiture
Namespace Prefix:	ston_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Business combination, consideration to be transferred.

+ References

No definition available.

+ Details

Name:	ston_BusinessCombinationConsiderationToBeTransferred
Namespace Prefix:	ston_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Debt instrument aggregate principal amount redeemed.

+ References

No definition available.

+ Details

Name:	ston_DebtInstrumentAggregatePrincipalAmountRedeemed
Namespace Prefix:	ston_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Land purchase obligations.

+ References

No definition available.

+ Details

Name:	ston_LandPurchaseObligations
Namespace Prefix:	ston_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of cemeteries yet to acquire.

+ References

No definition available.

+ Details

Name:	ston_NumberOfCemeteriesYetToAcquire
Namespace Prefix:	ston_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of cemetery divested.

+ References

No definition available.

+ Details

Name:	ston_NumberOfCemeteryDivested
Namespace Prefix:	ston_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of crematories divested.

+ References

No definition available.

+ Details

Name:	ston_NumberOfCrematoriesDivested
Namespace Prefix:	ston_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of funeral home divested.

+ References

No definition available.

+ Details

Name:	ston_NumberOfFuneralHomeDivested
Namespace Prefix:	ston_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of gain (loss) from sale and disposal of integrated set of activities and assets capable of being conducted and managed for purpose of providing return in form of dividend, lower cost, or other economic benefit to investor, owner, member and participant.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4582445-111684

+ Details

Name:	us-gaap_GainLossOnSaleOfBusiness
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3179-108585

+ Details

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

- Definition

This element represents the cash inflow during the period from the sale of a component of the entity.

+ References

+ Details

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

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=ston_RemainingCaliforniaSaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=ston_ClearstoneSaleMember
Namespace Prefix:
Data Type:	na
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- Details

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- Details

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Name:	us-gaap_TypeOfArrangementAxis=ston_CaliforniaAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
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ACQUISITIONS AND DIVESTITURES - Additional Information (Detail) $ in Thousands							3 Months Ended	6 Months Ended		9 Months Ended
	May 24, 2021 USD ($) Property	Apr. 02, 2021 USD ($) Property	Mar. 23, 2021 USD ($) Property	Nov. 03, 2020 USD ($) Property	Apr. 07, 2020 USD ($)	Jan. 03, 2020 USD ($) Property	Jun. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of cemeteries yet to acquire \| Property			4
Total purchase price			$ 5,400
Aggregate cash purchase price								$ 6,578	$ 48,336
Gain (loss) on sale of business								(1,353)	$ 28,951
Additional principal amount of the 2024 notes redeemed		$ 6,700
Remaining California Sale
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Aggregate cash purchase price				$ 7,100
Aggregate principal amount of debt redeemed from assets dispositions				5,700
Remaining California Sale \| 2024 Notes
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Aggregate principal amount of debt redeemed from assets dispositions				$ 5,600
Clearstone Sale
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Aggregate cash purchase price		$ 6,200
Missouri Sale
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Aggregate cash purchase price	$ 720,000,000
Number of cemetery divested \| Property	3
Gain (loss) on sale of business							$ (1,700)	$ (1,700)
Oakmont Agreement
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of cemetery divested \| Property						1
Number of funeral home divested \| Property						1
Gain (loss) on sale of business										$ 24,400
Oakmont Agreement \| Oakmont Sale
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Aggregate cash purchase price						$ 33,000
Oakmont Agreement \| Oakmont Sale \| 2024 Notes
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Aggregate principal amount of debt redeemed from assets dispositions						$ 30,300
Olivet Agreement
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Aggregate principal amount of debt redeemed from assets dispositions					$ 20,500
Land purchase obligations					17,100
Olivet Agreement \| Olivet Sale
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Gain (loss) on sale of business										$ 7,200
Aggregate purchase price					$ 25,000
California Agreement
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of cemetery divested \| Property				5
Number of funeral home divested \| Property				6
Number of crematories divested \| Property				4
Clearstone Agreement
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of cemetery divested \| Property		9
Number of funeral home divested \| Property		10
Number of crematories divested \| Property		4