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v3.21.1

Allowance for Credit Losses - Additional Information (Details) - USD ($) $ in Thousands | 3 Months Ended |  |  |
--- | --- | --- | --- | ---
Mar. 31, 2021 | Mar. 31, 2020 | Dec. 31, 2020 | Jan. 01, 2020 | Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Adjustment to allowance for credit loss | $ 115,101 | $ 96,850 | $ 117,612 |  | $ 62,224
Provision for credit losses on loans | 3,301 | 18,430 |  |  |
Net loan charge-offs | $ 5,812 | $ 11,156 |  |  |
Net loan charge-offs, percent | 0.33% | 0.63% |  |  |
Portfolio loans, net of unearned income | $ 7,183,168 |  | 7,225,860 |  |
Total loans | 7,068,067 |  | 7,108,248 |  |
COVID-19 |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Financing receivable, credit loss, expense (reversal), period increase (decrease) | (16,900) | $ (20,000) |  |  |
Provision for credit losses on loans | 3,100 |  |  |  |
ACL provision, COVID-19 assessment, revised forecast |  | 14,300 |  |  |
Financing receivable, allowance for credit loss, qualitative reserve, period increase (decrease) | $ 2,700 | 3,100 |  |  |
Forecast period | 2 years |  |  |  |
Commercial |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Portfolio loans, net of unearned income | $ 5,676,683 |  | 5,673,707 |  |
Nonperforming |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Portfolio loans, net of unearned income | 132,413 |  | 146,774 |  |
Nonperforming | COVID-19 |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Increase (decrease) in non-performing loans | 61,400 |  |  |  |
Portfolio loans, net of unearned income | 135,200 | 73,800 |  |  |
Commercial and industrial | Commercial |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Adjustment to allowance for credit loss | 14,663 | 19,870 | 16,100 |  | 15,681
Provision for credit losses on loans | 2,728 | 6,196 |  |  |
Net loan charge-offs | 4,165 | 9,860 |  |  |
Portfolio loans, net of unearned income | 1,699,588 |  | 1,559,552 |  |
Commercial and industrial | Nonperforming | Commercial |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Portfolio loans, net of unearned income | 12,416 |  | 16,985 |  |
Commercial real estate | Commercial |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Adjustment to allowance for credit loss | 66,842 | 42,611 | 65,656 |  | 30,577
Provision for credit losses on loans | 1,996 | 7,639 |  |  |
Net loan charge-offs | 810 | $ 415 |  |  |
Portfolio loans, net of unearned income | 2,780,327 |  | 2,791,947 |  |
Commercial real estate | Commercial | Hotel | COVID-19 |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Portfolio loans, net of unearned income | 53,600 |  |  |  |
Commercial real estate | Nonperforming | Commercial |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Portfolio loans, net of unearned income | 95,074 |  | $ 101,070 |  |
CARES Act, Paycheck Protection Program Loans | Commercial |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Total loans | $ 499,100 |  |  |  |
Impact of new accounting standard |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Adjustment to allowance for credit loss |  |  |  | $ 27,400 | 27,352
Impact of new accounting standard | S&T Legacy Loans |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Adjustment to allowance for credit loss |  |  |  | 8,200 |
Impact of new accounting standard | Commercial and industrial | Commercial |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Adjustment to allowance for credit loss |  |  |  | 9,900 | 7,853
Impact of new accounting standard | Commercial real estate | Commercial |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Adjustment to allowance for credit loss |  |  |  |  | $ 4,810
Impact of new accounting standard | DNB |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Adjustment to allowance for credit loss |  |  |  | $ 9,300 |

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