Commitments and Contingent Liabilities (Details) - USD ($) $ in Millions	3 Months Ended	24 Months Ended
Sep. 30, 2023	Dec. 31, 2024	Jun. 30, 2023
Commitments to extend credit and standby letters of credit			$ 11,100.0
Liability recorded for expected credit losses on unfunded commitments			$ 63.4
Forecast
FDIC quarterly special assessment	$ 2.8
Total FDIC special assessment		$ 22.7

The total amount outstanding of the commitments to extend credit and standby letters of credit as of the reporting date.

No definition available.

Name:	ssb_CommitmentsToExtendCreditAndStandbyLettersOfCredit
Namespace Prefix:	ssb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant