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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, 2020 USD ($) loan | Dec. 31, 2019 USD ($) | Jan. 01, 2020 USD ($)
Financing Receivable, Past Due [Line Items] |  |  |
Current | $ 7,069,730 | $ 7,055,361 |
Past Due | 156,130 | 81,791 |
Non- performing | 146,774 | 54,057 |
Total | 7,225,860 | 7,137,152 |
Restructured loans | $ 22,650 | 32,206 |
CARES Act, Paycheck Protection Program Loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Number of modified loans | loan | 52 |  |
CARES Act, Paycheck Protection Program Loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Restructured loans | $ 195,600 |  |
30-59 Days Past Due |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 2,888 | 17,992 |
60-89 Days Past Due |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 5,965 | 5,985 |
90 Days Past Due |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 503 | 3,757 |
Commercial |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Total | 5,977,643 | 5,756,971 |
Commercial | Commercial real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Current | 2,690,877 | 3,025,505 |
Past Due | 101,070 | 34,087 |
Non- performing | 101,070 | 25,356 |
Total | 2,791,947 | 3,059,592 | $ 3,416,518
Restructured loans | 4,791 | 25,159 |
Commercial | Commercial and industrial |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Current | 1,542,567 | 1,466,460 |
Past Due | 16,985 | 14,069 |
Non- performing | 16,985 | 10,911 |
Total | 1,559,552 | 1,480,529 | 1,720,833
Restructured loans | 13,716 | 5,661 |
Commercial | Other Consumer |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Current | 462,094 | 367,204 |
Past Due | 3,983 | 2,856 |
Non- performing | 384 | 737 |
Total | 466,077 | 370,060 | 375,445
Restructured loans | 2,329 |  |
Commercial | Business banking |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Current | 1,140,581 | 830,735 |
Past Due | 19,486 | 16,055 |
Non- performing | 17,122 | 9,863 |
Total | 1,160,067 | 846,790 | 0
Restructured loans | 165 |  |
Commercial | 30-59 Days Past Due | Commercial real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 0 | 7,749 |
Commercial | 30-59 Days Past Due | Commercial and industrial |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 0 | 126 |
Commercial | 30-59 Days Past Due | Other Consumer |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 19 | 956 |
Commercial | 30-59 Days Past Due | Business banking |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 1,614 | 5,093 |
Commercial | 60-89 Days Past Due | Commercial real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 0 | 71 |
Commercial | 60-89 Days Past Due | Commercial and industrial |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 0 | 1,589 |
Commercial | 60-89 Days Past Due | Other Consumer |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 3,580 | 1,163 |
Commercial | 60-89 Days Past Due | Business banking |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 379 | 1,099 |
Commercial | 90 Days Past Due | Commercial real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 0 | 911 |
Commercial | 90 Days Past Due | Commercial and industrial |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 0 | 1,443 |
Commercial | 90 Days Past Due | Other Consumer |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 0 | 0 |
Commercial | 90 Days Past Due | Business banking |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 371 | 0 |
Consumer |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Total | 1,248,217 | 1,380,181 |
Consumer | Other Consumer |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Total |  | 8,390 |
Consumer | Consumer real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Current | 1,153,028 | 1,283,591 |
Past Due | 14,304 | 11,616 |
Non- performing | 11,117 | 6,063 |
Total | 1,167,332 | 1,295,207 | 1,545,323
Restructured loans | 1,645 |  |
Consumer | Other consumer |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Current | 80,583 | 81,866 |
Past Due | 302 | 3,108 |
Non- performing | 96 | 1,127 |
Total | 80,885 | 84,974 | $ 79,033
Restructured loans | 4 |  |
Consumer | 30-59 Days Past Due | Consumer real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 1,087 | 2,620 |
Consumer | 30-59 Days Past Due | Other consumer |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 168 | 1,448 |
Consumer | 60-89 Days Past Due | Consumer real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 1,968 | 1,758 |
Consumer | 60-89 Days Past Due | Other consumer |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 37 | 305 |
Consumer | 90 Days Past Due | Consumer real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | 132 | 1,175 |
Consumer | 90 Days Past Due | Other consumer |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Past Due | $ 0 | $ 228 |

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