XML 37 R27.htm IDEA: XBRL DOCUMENT
v3.4.0.3

Loans and Loans Held for Sale (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2016
Receivables [Abstract] |
Composition of Loans | The following table indicates the composition of the acquired and originated loans as of the dates presented:
(dollars in thousands) | March 31, 2016 |  | December 31, 2015
Commercial |  |  |
Commercial real estate | $ | 2,260,231 |  |  | $ | 2,166,603 |
Commercial and industrial | 1,334,119 |  |  | 1,256,830 |
Commercial construction | 379,293 |  |  | 413,444 |
Total Commercial Loans | 3,973,643 |  |  | 3,836,877 |
Consumer |  |  |
Residential mortgage | 650,544 |  |  | 639,372 |
Home equity | 467,671 |  |  | 470,845 |
Installment and other consumer | 76,189 |  |  | 73,939 |
Consumer construction | 8,701 |  |  | 6,579 |
Total Consumer Loans | 1,203,105 |  |  | 1,190,735 |
Total Portfolio Loans | 5,176,748 |  |  | 5,027,612 |
Loans held for sale | 11,739 |  |  | 35,321 |
Total Loans | $ | 5,188,487 |  |  | $ | 5,062,933 |
Restructured Loans for Periods Presented | The following table summarizes the restructured loans as of the dates presented:
| March 31, 2016 |  | December 31, 2015
(dollars in thousands) | Performing TDRs | Nonperforming TDRs | Total TDRs |  | Performing TDRs | Nonperforming TDRs | Total TDRs
Commercial real estate | $ | 6,339 |  | $ | 3,747 |  | $ | 10,086 |  |  | $ | 6,822 |  | $ | 3,548 |  | $ | 10,370 |
Commercial and industrial | 6,280 |  | 1,695 |  | 7,975 |  |  | 6,321 |  | 1,570 |  | 7,891 |
Commercial construction | 4,367 |  | 1,742 |  | 6,109 |  |  | 5,013 |  | 1,265 |  | 6,278 |
Residential mortgage | 2,537 |  | 1,193 |  | 3,730 |  |  | 2,590 |  | 665 |  | 3,255 |
Home equity | 3,215 |  | 911 |  | 4,126 |  |  | 3,184 |  | 523 |  | 3,707 |
Installment and other consumer | 23 |  | 3 |  | 26 |  |  | 25 |  | 88 |  | 113 |
Total | $ | 22,761 |  | $ | 9,291 |  | $ | 32,052 |  |  | $ | 23,955 |  | $ | 7,659 |  | $ | 31,614 |
Restructured Loans for Periods Stated | The following tables present the restructured loans during the periods presented:
| Three Months Ended March 31, 2016 |  | Three Months Ended March 31, 2015
(dollars in thousands) | Number of Loans | Pre-Modification Outstanding Recorded Investment(1) | Post-Modification Outstanding Recorded Investment(1) | Total Difference in Recorded Investment |  | Number of Loans | Pre-Modification Outstanding Recorded Investment(1) | Post-Modification Outstanding Recorded Investment(1) | Total Difference in Recorded Investment
Commercial real estate |  |  |  |  |  |  |  |  |
Principal deferral | — |  | $ | — |  | $ | — |  | $ | — |  |  | 2 |  | $ | 2,851 |  | $ | 2,851 |  | $ | — |
Chapter 7 bankruptcy(2) | 1 |  | 709 |  | 702 |  | (7 | ) |  | — |  | — |  | — |  | — |
Commercial and industrial |  |  |  |  |  |  |  |  |  |
Principal deferral | — |  | — |  | — |  | — |  |  | 6 |  | 661 |  | 661 |  | — |
Chapter 7 bankruptcy(2) | — |  | — |  | — |  | — |  |  | 1 |  | 3 |  | 1 |  | (2 | )
Maturity date extension | 2 |  | 625 |  | 605 |  | (20 | ) |  | 1 |  | 780 |  | 765 |  | (15 | )
Commercial Construction |  |  |  |  |  |  |  |  |  |
Principal deferral | — |  | — |  | — |  | — |  |  | 1 |  | 104 |  | 103 |  | (1 | )
Maturity date extension | 1 |  | 33 |  | 33 |  | — |  |  | — |  | — |  | — |  | — |
Residential mortgage |  |  |  |  |  |  |  |  |  |
Chapter 7 bankruptcy(2) | 3 |  | 221 |  | 219 |  | (2 | ) |  | — |  | — |  | — |  | — |
Maturity date extension | 1 |  | 483 |  | 483 |  | — |  |  | — |  | — |  | — |  | — |
Home equity |  |  |  |  |  |  |  |  |  |
Principal deferral | — |  | — |  | — |  | — |  |  | — |  | — |  | — |  | — |
Chapter 7 bankruptcy(2) | 5 |  | 245 |  | 243 |  | (2 | ) |  | 8 |  | 142 |  | 133 |  | (9 | )
Maturity date extension and interest rate reduction | 1 |  | 130 |  | 130 |  | — |  |  | — |  | — |  | — |  | — |
Maturity date extension | 2 |  | 200 |  | 199 |  | (1 | ) |  | 1 |  | 71 |  | 71 |  | — |
Total by Concession Type |  |  |  |  |  |  |  |  |  |  |  |  |
Principal deferral | — |  | $ | — |  | $ | — |  | $ | — |  |  | 9 |  | $ | 3,616 |  | $ | 3,615 |  | $ | (1 | )
Maturity date extension and interest rate reduction | 1 |  | 130 |  | 130 |  | — |  |  | — |  | — |  | — |  | — |
Chapter 7 bankruptcy(2) | 9 |  | 1,175 |  | 1,164 |  | (11 | ) |  | 9 |  | 145 |  | 134 |  | (11 | )
Maturity date extension | 6 |  | 1,341 |  | 1,320 |  | (21 | ) |  | 2 |  | 851 |  | 836 |  | (15 | )
Total | 16 |  | $ | 2,646 |  | $ | 2,614 |  | $ | (32 | ) |  | 20 |  | $ | 4,612 |  | $ | 4,585 |  | $ | (27 | )
(1) Excludes loans that were fully paid off or fully charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end. (2) Chapter 7 bankruptcy loans where the debt has been legally discharged through the bankruptcy court and not reaffirmed.
Summary of Nonperforming Assets of Defaulted TDRs | The following tables present a summary of TDRs which defaulted during the periods presented that had been restructured within the last 12 months prior to defaulting:
| Defaulted TDRs
| March 31, 2016 |  | March 31, 2015
(dollars in thousands) | Number of Defaults | Recorded Investment |  |  | Number of Defaults | Recorded Investment |
Commercial real estate | — | $ | — |  |  | — | $ | — |
Commercial and Industrial | — | — |  |  | — | — |
Commercial construction | 1 | 616 |  |  | — | — |
Residential mortgage | — | — |  |  | 1 | 183 |
Home equity | — | — |  |  | 1 | 5 |
Installment and other consumer | — | — |  |  | — | — |
Consumer construction | — | — |  |  | — | — |
Total | 1 | $ | 616 |  |  | 2 | $ | 188 |
Summary of Nonperforming Assets | The following table is a summary of nonperforming assets as of the dates presented:
| Nonperforming Assets
(dollars in thousands) | March 31, 2016 |  | December 31, 2015
Nonperforming Assets |  |  |
Nonaccrual loans | $ | 42,543 |  |  | $ | 27,723 |
Nonaccrual TDRs | 9,291 |  |  | 7,659 |
Total nonaccrual loans | 51,834 |  |  | 35,382 |
OREO | 297 |  |  | 354 |
Total Nonperforming Assets | $ | 52,131 |  |  | $ | 35,736 |

X
- Definition Defaulted troubled debt restructurings on financing receivables. + References No definition available. + Details
Name: | stba_DefaultedTroubledDebtRestructuringsOnFinancingReceivablesTableTableTextBlock
Namespace Prefix: | stba_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition New restructured loans for the periods stated. + References No definition available. + Details
Name: | stba_NewRestructuredLoansForPeriodStatedTableTableTextBlock
Namespace Prefix: | stba_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule of financing receivables non performing assets. + References No definition available. + Details
Name: | stba_ScheduleOfFinancingReceivablesNonPerformingAssetsTableTableTextBlock
Namespace Prefix: | stba_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition Tabular disclosure of the various types of trade accounts and notes receivable and for each the gross carrying value, allowance, and net carrying value as of the balance sheet date. Presentation is categorized by current, noncurrent and unclassified receivables. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.3,4) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of financing receivables and troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953676-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953682-111524 + Details
Name: | us-gaap_TroubledDebtRestructuringsOnFinancingReceivablesTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration