Represents the age of employees to be eligible to participate in the defined contribution plan.

No definition available.

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

- Definition

Represents employee contributions to a defined contribution pension plan as a percentage of eligible compensation.

+ References

No definition available.

+ Details

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Namespace Prefix:	ssb_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of the employee contribution for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

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Namespace Prefix:	ssb_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of first eligible compensation for employer matches of the employee's percentage contribution matched.

+ References

No definition available.

+ Details

Name:	ssb_DefinedContributionPlanEmployerMatchingContributionFirstEligibleCompensationPercent
Namespace Prefix:	ssb_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

Name:	ssb_ScheduleOfDefinedContributionBenefitPlansDisclosuresLineItems
Namespace Prefix:	ssb_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 70
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480794/715-70-50-1

+ Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Retirement Plans - Safe Harbor plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Retirement Plans
Matching contribution by the company (as a percent)	100.00%
Percentage of employees matching contribution for first eligible compensation	4.00%
Employee savings plan	$ 17,178	$ 16,528	$ 15,357
Minimum
Retirement Plans
Age of employees to be eligible to participate in the defined contribution plan	18 years
Percentage of eligible compensation that participants may elect to contribute	1.00%
Maximum
Retirement Plans
Percentage of eligible compensation that participants may elect to contribute	85.00%