XML 50 R40.htm IDEA: XBRL DOCUMENT
v3.24.2.u1

Loans and Allowance for Credit Losses - Amortized Cost of Loans to Borrowers, Modified (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2024 | Jun. 30, 2023 | Jun. 30, 2024 | Jun. 30, 2023
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period | $ 24,894 | $ 9,133 | $ 25,724 | $ 23,604
% of Portfolio Segment | 0.32% | 0.12% | 0.33% | 0.32%
Term Extension |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period | $ 12,555 | $ 9,133 | $ 13,385 | $ 23,410
Term Extension and Interest Rate Reduction |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period |  |  | 0 | 194
Payment Delays (Other Than Insignificant) |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period | 12,339 | 0 | 12,339 | 0
Commercial Loans | Commercial real estate |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period | $ 3,358 | $ 1,286 | $ 4,188 | $ 14,932
% of Portfolio Segment | 0.13% | 0.05% | 0.16% | 0.58%
Commercial Loans | Commercial real estate | Term Extension |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period | $ 3,358 | $ 1,286 | $ 4,188 | $ 14,932
Commercial Loans | Commercial real estate | Term Extension and Interest Rate Reduction |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period |  |  | 0 | 0
Commercial Loans | Commercial real estate | Payment Delays (Other Than Insignificant) |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period | 0 | 0 | 0 | 0
Commercial Loans | Commercial and industrial |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period | $ 21,429 | $ 5,193 | $ 21,429 | $ 5,762
% of Portfolio Segment | 1.51% | 0.36% | 1.51% | 0.40%
Commercial Loans | Commercial and industrial | Term Extension |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period | $ 9,090 | $ 5,193 | $ 9,090 | $ 5,762
Commercial Loans | Commercial and industrial | Term Extension and Interest Rate Reduction |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period |  |  | 0 | 0
Commercial Loans | Commercial and industrial | Payment Delays (Other Than Insignificant) |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period | 12,339 | 0 | 12,339 | 0
Commercial Loans | Consumer real estate | Payment Delays (Other Than Insignificant) |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period |  |  |  | 0
Commercial Loans | Commercial construction |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period |  | $ 1,621 |  | $ 1,621
% of Portfolio Segment |  | 0.46% |  | 0.46%
Commercial Loans | Commercial construction | Term Extension |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period |  | $ 1,621 |  | $ 1,621
Commercial Loans | Commercial construction | Term Extension and Interest Rate Reduction |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period |  |  |  | 0
Commercial Loans | Commercial construction | Payment Delays (Other Than Insignificant) |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period |  | 0 |  | 0
Commercial Loans | Business banking |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period |  | $ 1,033 |  |
% of Portfolio Segment |  | 0.08% |  |
Commercial Loans | Business banking | Term Extension |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period |  | $ 1,033 |  |
Commercial Loans | Business banking | Payment Delays (Other Than Insignificant) |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period |  | $ 0 |  | 0
Business Banking |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period |  |  |  | $ 1,033
% of Portfolio Segment |  |  |  | 0.08%
Business Banking | Term Extension |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period |  |  |  | $ 1,033
Business Banking | Term Extension and Interest Rate Reduction |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period |  |  |  | 0
Consumer Loans | Consumer real estate |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period | $ 107 |  | $ 107 | $ 256
% of Portfolio Segment | 0.01% |  | 0.01% | 0.02%
Consumer Loans | Consumer real estate | Term Extension |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period | $ 107 |  | $ 107 | $ 62
Consumer Loans | Consumer real estate | Term Extension and Interest Rate Reduction |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period |  |  | 0 | $ 194
Consumer Loans | Consumer real estate | Payment Delays (Other Than Insignificant) |  |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |
Financing receivable, modified in period | $ 0 |  | $ 0 |

X
- Definition Amortized cost excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-42 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestModifiedPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage, excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty to total financing receivables. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-42 + Details
Name: | us-gaap_FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
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://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 34 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-34 Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 33 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-33 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 12A -Publisher FASB -URI https://asc.fasb.org/1943274/2147481933/310-10-55-12A Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-42 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-42 + Details
Name: | us-gaap_FinancingReceivableModificationsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_LoanRestructuringModificationAxis=us-gaap_ExtendedMaturityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LoanRestructuringModificationAxis=us-gaap_ExtendedMaturityAndInterestRateReductionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LoanRestructuringModificationAxis=us-gaap_PaymentDeferralMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=stba_CommercialAndIndustrialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=stba_ConsumerRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConstructionLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=stba_BusinessBankingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=stba_BusinessBankingPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |