XML 99 R74.htm IDEA: XBRL DOCUMENT v3.23.1

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES - Narrative (Details) - USD ($)	Apr. 10, 2019	Dec. 31, 2021	Feb. 28, 2021
Executive Compensation
Other Commitments [Line Items]
Percentage of profit cash settled	5.00%
Participation threshold	$ 300,000,000
Loss contingency, vesting term	4 years
Loss contingency accrual		$ 11,132,000
Separation Agreement
Other Commitments [Line Items]
Percentage of profit cash settled			5.00%
Percentage of profit cash settled, deemed vested			3.75%
Percentage of profit cash settled, forfeited			1.25%
Percentage of profit cash settled, increase			2.50%

X

- Definition

Loss Contingency, Participation Threshold

+ References

No definition available.

+ Details

Name:	sst_LossContingencyParticipationThreshold
Namespace Prefix:	sst_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Loss Contingency, Percentage of Profit Cash Settled

+ References

No definition available.

+ Details

Name:	sst_LossContingencyPercentageOfProfitCashSettled
Namespace Prefix:	sst_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Loss Contingency, Percentage of Profit Cash Settled Deemed Vested

+ References

No definition available.

+ Details

Name:	sst_LossContingencyPercentageOfProfitCashSettledDeemedVested
Namespace Prefix:	sst_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Loss Contingency, Percentage of Profit Cash Settled Forfeited

+ References

No definition available.

+ Details

Name:	sst_LossContingencyPercentageOfProfitCashSettledForfeited
Namespace Prefix:	sst_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Loss Contingency, Percentage of Profit Cash Settled Increase

+ References

No definition available.

+ Details

Name:	sst_LossContingencyPercentageOfProfitCashSettledIncrease
Namespace Prefix:	sst_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Loss Contingency, Vesting Term

+ References

No definition available.

+ Details

Name:	sst_LossContingencyVestingTerm
Namespace Prefix:	sst_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount of loss contingency liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349

Reference 2: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=121557415&loc=d3e14615-108349

+ Details

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

X

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

X

- Details

Name:	us-gaap_OtherCommitmentsAxis=sst_ExecutiveCompensationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_OtherCommitmentsAxis=sst_SeparationAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: