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Allowance for Credit Losses - Age Analysis of Past Due Loans Segregated by Class of Loans (Details) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2022 USD ($) loan | Dec. 31, 2021 USD ($) loan | Dec. 31, 2020 USD ($)
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | $ 7,183,969 | $ 6,999,990 |
Nonaccrual | $ 19,052 | $ 66,291 | $ 146,774
Number of modified loans | loan | 0 | 8 |
CARES Act, Paycheck Protection Program Loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Number of modified loans | loan |  | 8 |
Modified loans |  | $ 28,800 |
Current |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | $ 7,144,576 | 6,927,943 |
30-59 Days Past Due |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 18,093 | 3,085 |
60-89 Days Past Due |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 2,248 | 2,672 |
Total Past Due Loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 39,393 | 72,048 |
Commercial | CARES Act, Paycheck Protection Program Loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Modified loans |  | 28,800 |
Commercial | Commercial real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 2,538,839 | 2,690,528 |
Nonaccrual | 7,100 | 31,488 | 101,070
Commercial | Commercial and industrial |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 1,510,392 | 1,513,523 |
Nonaccrual | 283 | 15,239 | 16,985
Commercial | Commercial construction |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 381,963 | 424,755 |
Nonaccrual | 384 | 2,471 | 384
Commercial | Business banking |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 1,205,944 | 1,135,693 |
Nonaccrual | 4,490 | 9,641 | 17,122
Commercial | Current | Commercial real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 2,523,315 | 2,659,040 |
Commercial | Current | Commercial and industrial |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 1,505,805 | 1,497,755 |
Commercial | Current | Commercial construction |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 381,579 | 421,834 |
Commercial | Current | Business banking |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 1,199,586 | 1,124,748 |
Commercial | 30-59 Days Past Due | Commercial real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 8,424 | 0 |
Commercial | 30-59 Days Past Due | Commercial and industrial |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 4,304 | 529 |
Commercial | 30-59 Days Past Due | Commercial construction |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 0 | 450 |
Commercial | 30-59 Days Past Due | Business banking |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 1,583 | 813 |
Commercial | 60-89 Days Past Due | Commercial real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 0 | 0 |
Commercial | 60-89 Days Past Due | Commercial and industrial |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 0 | 0 |
Commercial | 60-89 Days Past Due | Commercial construction |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 0 | 0 |
Commercial | 60-89 Days Past Due | Business banking |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 285 | 491 |
Commercial | Total Past Due Loans | Commercial real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 15,524 | 31,488 |
Commercial | Total Past Due Loans | Commercial and industrial |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 4,587 | 15,768 |
Commercial | Total Past Due Loans | Commercial construction |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 384 | 2,921 |
Commercial | Total Past Due Loans | Business banking |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 6,358 | 10,945 |
Consumer | Consumer real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 1,421,953 | 1,127,585 |
Nonaccrual | 6,526 | 7,294 | 11,117
Consumer | Other consumer |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 124,878 | 107,906 |
Nonaccrual | 269 | 158 | $ 96
Consumer | Current | Consumer real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 1,409,907 | 1,117,073 |
Consumer | Current | Other consumer |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 124,384 | 107,492 |
Consumer | 30-59 Days Past Due | Consumer real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 3,617 | 1,087 |
Consumer | 30-59 Days Past Due | Other consumer |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 165 | 206 |
Consumer | 60-89 Days Past Due | Consumer real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 1,903 | 2,130 |
Consumer | 60-89 Days Past Due | Other consumer |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 60 | 50 |
Consumer | Total Past Due Loans | Consumer real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | 12,046 | 10,512 |
Consumer | Total Past Due Loans | Other consumer |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Portfolio loans, net of unearned income | $ 494 | $ 414 |

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