XML 67 R56.htm IDEA: XBRL DOCUMENT
v3.24.3

Investment Securities - Securities with gross unrealized losses (Details) - USD ($) $ in Thousands | Sep. 30, 2024 | Dec. 31, 2023
--- | --- | ---
Securities Held to Maturity, Gross Unrealized Losses |  |
Twelve Months or More | $ 337,561 | $ 402,704
Securities Held to Maturity, Fair Value |  |
Twelve Months or More | 1,963,746 | 2,084,737
Securities Available for Sale, Gross Unrealized Losses |  |
Less Than Twelve Months | 1,341 | 536
Twelve Months or More | 641,700 | 777,980
Securities Available for Sale, Fair Value |  |
Less Than Twelve Months | 36,769 | 66,584
Twelve Months or More | 4,375,170 | 4,618,627
U.S. Treasuries |  |
Securities Available for Sale, Gross Unrealized Losses |  |
Twelve Months or More |  | 830
Securities Available for Sale, Fair Value |  |
Less Than Twelve Months | 696 |
Twelve Months or More |  | 73,890
U.S. Treasuries | Maximum |  |
Securities Available for Sale, Gross Unrealized Losses |  |
Less Than Twelve Months | 1 |
U.S. Government agencies |  |
Securities Held to Maturity, Gross Unrealized Losses |  |
Twelve Months or More | 19,271 | 24,607
Securities Held to Maturity, Fair Value |  |
Twelve Months or More | 128,000 | 172,660
Securities Available for Sale, Gross Unrealized Losses |  |
Twelve Months or More | 15,453 | 21,383
Securities Available for Sale, Fair Value |  |
Twelve Months or More | 175,724 | 224,706
Residential mortgage-backed securities issued by U.S. government agencies or sponsored enterprises |  |
Securities Held to Maturity, Gross Unrealized Losses |  |
Twelve Months or More | 188,925 | 227,312
Securities Held to Maturity, Fair Value |  |
Twelve Months or More | 1,144,338 | 1,210,790
Securities Available for Sale, Gross Unrealized Losses |  |
Less Than Twelve Months | 80 | 122
Twelve Months or More | 216,781 | 263,970
Securities Available for Sale, Fair Value |  |
Less Than Twelve Months | 17,925 | 9,358
Twelve Months or More | 1,452,928 | 1,539,208
Residential collateralized mortgage-obligations issued by U.S. government agencies or sponsored enterprises |  |
Securities Held to Maturity, Gross Unrealized Losses |  |
Twelve Months or More | 58,371 | 68,139
Securities Held to Maturity, Fair Value |  |
Twelve Months or More | 361,467 | 376,745
Securities Available for Sale, Gross Unrealized Losses |  |
Twelve Months or More | 82,254 | 99,313
Securities Available for Sale, Fair Value |  |
Twelve Months or More | 487,928 | 527,422
Commercial mortgage-backed securities issued by U.S. government agencies or sponsored enterprises |  |
Securities Held to Maturity, Gross Unrealized Losses |  |
Twelve Months or More | 61,691 | 71,327
Securities Held to Maturity, Fair Value |  |
Twelve Months or More | 288,169 | 282,728
Securities Available for Sale, Gross Unrealized Losses |  |
Less Than Twelve Months |  | 91
Twelve Months or More | 157,131 | 194,380
Securities Available for Sale, Fair Value |  |
Less Than Twelve Months |  | 7,959
Twelve Months or More | 958,412 | 955,059
State and municipal obligations |  |
Securities Available for Sale, Gross Unrealized Losses |  |
Less Than Twelve Months | 1,259 | 177
Twelve Months or More | 133,136 | 152,114
Securities Available for Sale, Fair Value |  |
Less Than Twelve Months | 17,464 | 6,340
Twelve Months or More | 960,941 | 967,305
Small Business Administration loan-backed securities |  |
Securities Held to Maturity, Gross Unrealized Losses |  |
Twelve Months or More | 9,303 | 11,319
Securities Held to Maturity, Fair Value |  |
Twelve Months or More | 41,772 | 41,814
Securities Available for Sale, Gross Unrealized Losses |  |
Less Than Twelve Months | 2 | 128
Twelve Months or More | 34,430 | 42,222
Securities Available for Sale, Fair Value |  |
Less Than Twelve Months | 684 | 42,447
Twelve Months or More | 311,253 | 304,770
Corporate securities |  |
Securities Available for Sale, Gross Unrealized Losses |  |
Less Than Twelve Months |  | 18
Twelve Months or More | 2,515 | 3,768
Securities Available for Sale, Fair Value |  |
Less Than Twelve Months |  | 480
Twelve Months or More | $ 27,984 | $ 26,267

X
- Definition Fair value of investment in debt security measured at amortized cost (held-to-maturity), in continuous unrealized loss position for 12 months or longer. + References No definition available. + Details
Name: | ssb_DebtSecuritiesHeldToMaturityContinuousUnrealizedLossPosition12MonthsOrLongerFairValueDisclosure
Namespace Prefix: | ssb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in continuous loss position for 12 months or longer. + References No definition available. + Details
Name: | ssb_DebtSecuritiesHeldToMaturityContinuousUnrealizedLossPosition12MonthsOrLongerGrossUnrealizedLoss
Namespace Prefix: | ssb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | ssb_DebtSecuritiesHeldToMaturityContinuousUnrealizedLossPositionFairValueDisclosureAbstract
Namespace Prefix: | ssb_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | ssb_DebtSecuritiesHeldToMaturityUnrealizedLossPositionAccumulatedLossesAbstract
Namespace Prefix: | ssb_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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 Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479081/326-30-55-8 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479106/326-30-50-4 + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479081/326-30-55-8 Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-7 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479106/326-30-50-5 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-7 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479106/326-30-50-5 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479081/326-30-55-8 Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-7 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479106/326-30-50-5 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-7 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479106/326-30-50-5 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=ssb_SmallBusinessAdministrationLoanBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |