Summary of Significant Accounting Policies - Loans (Details) $ in Millions	Sep. 30, 2024 USD ($)
Summary of Significant Accounting Policies
Net book balance	$ 1

Represents the net book balance for non-accrual loan to be individually evaluated for loss.

No definition available.

Name:	ssb_NetBookBalanceForNonAccrualLoanToBeEvaluatedIndividuallyForLoss
Namespace Prefix:	ssb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant