COMMITMENTS AND CONTINGENCIES - Additional Information (Detail) $ in Millions	12 Months Ended
Dec. 31, 2021 USD ($)
Commitments And Contingencies [Line Items]
Maximum contribution of eligible employees	75.00%
Employer's matching contribution percentage of first 3% of employee's contribution	25.00%
Defined contribution plan charges to operations	$ 0.5
Second Quarter Twenty Fourteen Acquisition
Commitments And Contingencies [Line Items]
Aggregate fixed rent payment to landlord	36.0
Deferred fixed rent	$ 6.0
Second Quarter Twenty Fourteen Acquisition \| Minimum
Commitments And Contingencies [Line Items]
Fixed rent for lease term deferred	6 years
Second Quarter Twenty Fourteen Acquisition \| Maximum
Commitments And Contingencies [Line Items]
Fixed rent for lease term deferred	11 years

Aggregate amount of fixed rent payments committed.

No definition available.

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- Definition

Commitments and Contingencies [Line Items]

+ References

No definition available.

+ Details

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- Definition

Fixed Rent For Lease Term Deferred

+ References

No definition available.

+ Details

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Namespace Prefix:	ston_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of excess of rental payment required by lease over rental income recognized.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 25
-Paragraph 11
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123408481&loc=SL77919140-209958

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=123415192&loc=d3e39896-112707

+ Details

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

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

+ Details

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Balance Type:	debit
Period Type:	duration

- Definition

Percentage employer matches of the employee's percentage contribution matched.

+ References

No definition available.

+ Details

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- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

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- Details

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- Details

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